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Hemolysis in the newborn infant resulting from deficiencies of red blood cell enzymes: Diagnosis and management
T H E J O U R N A L OF
PEDIATRIC S MAY
MEDICAL
1974
V o l u m e 84
N~:mber 5
PROGRESS
Hemolysis in the newborn infant resulting from deficiencies of red blood cell enzymes: Diagnosis and management Inherited deficiencies o f red cell enzymes are recognized causes o f hemolysis Ot newborn infants. Neonatal manifestations include erythroblastosis fetalis, anemia, hyperbilirubinemia, or a combination o f these. Some infants with enzyme deficiencies demonstrate no neonatal manifestations; in others death may result from hydrops fetalis or kernicterus. In cases o f suspected hemolysis, simple diagnostic measures will identify the most common causes o f the anemia and~or the hyperbilirubinemia; these are not inherited deficiencies of enzymes but are red cell sensitization and congenital and acquired infections. Persistent hemolysis and abnormalities in the G-6-PD screening test, in the Heinz body preparation, or in an autohemolysis test support a tentative diagnosis of enzyme deficiency. The diagnosis is confirmed by specific enzyme assay. Appropriate therapy depends on the severity o f anemia and~orhyperbilirubinemia and may include transfusion of packedred cells or an exchange transfusion. Careful follow-up is essential to determine the chronicity and severity o f hemolysis.
Priscilla Ann Gilman, M.D., Baltimore, Md.
HYDROPS FETALIS, anemia, hyperbilirubinemia, or kernicterus may occur in a newborn infant with hemolysis resulting from an inherited red cell enzyme deficiency, which must be considered in the differential diagnosis when any of these features are manifest. More than twenty different red cell enzyme deficiencies have been describedl-4; acute or chronic hemolysis is associated with at least 18 of them. 1-26 The severity of hemolysis in the neonate varies with the specific enzymatic defect (qualitative and quantitative defects), with the gestational age of the infant, with exposure to certain From the Department o f Pediatrics, University of Maryland School o f Medicine. Supported in part by the Frank G. Bressler Reserve Fund and the Thomas 1f. Wilson Sanitarium for Children. Reprint address:Department of Pediatrics, Universityof Maryland Hospital, 22 S. Greene St., Baltimore, Md. 21201.
drugs or chemicals, and with intercurrent infections. On the other hand, some infants with red cell enzyme deficiencies do not exhibit neonatal manifestations. Identification of the exact etiology of hemolysis is necessary in order to institute appropriate therapy and avoid unnecessary and p o t e n t i a l l y h a r m f u l diagnostic and therapeutic measures both in the patient and in subsequent siblings. In this commentary an attempt is made to summarize the differentiating features and the nature and frequency of neonatal manifestations of the inherited red cell enzyme deficiencies. Methods for distinguishing these d i s o r d e r s f r o m the c o m m o n h e m o l y t i c and nonh e m o l y t i c causes o f n e o n a t a l a n e m i a and hyperbilirubinemia a r e discussed, and appropriate therapy is suggested. The mature red ceil derives energy necessary for its Vol. 84, No. 5, pp. 6.25-634
626
Gilman
The Journal of Pediatrics May 1974
Abbreviations used ATP: HMP: NADPH: CNSHA:
adenosine triphospbate hexose monophosphate reduced triphosphopyridine nucleotide
congenital nonspherocytic hemolytic anemia DPNH: reduced diphosphopyridine nucleotide G-6-PD: glucose-6-phosphate dehydrogenase 6-P-GD: 6-phosphogluconic dehydrogenase GR: glutathione reductase GSH Px: glutathione peroxidase GSH synthetase: glutatbione synthetase T-GC synthetase: y-glutamyl-eysteine synthetase HK: hexokinase GPI: glucosephosphate isomerase PFK: phosphofructokinase TPI: triosephosphate isomerase G-3-PD: glyceraldehyde-3-phosphate dehydrogenase PGK: phosphoglycerate kinase 2,3-DPGM: 2,3-diphosp hoglycerom!atase 2,3-diphosphoglycerate phosphatase 2,3-DPG phosphatase: pyruvate kinase PK: RPK: ribosephosphate pyrophosphokinase AK: adenylate kinase ATPase: adenosine triphosphatase
survival from glycolysis, Approximately 93 per cent of the energy comes from ATP generated via the EmbdenMeyerhof pathway; the remainder is derived from the hexose monophosphate shunt. 9 The HMP shunt and steps in glutathione metabolism provide N A D P H and reduced glutathione, which protect hemoglobin and certain e n z y m e s f r o m o x i d a t i v e d e n a t u r a t i o n . The biochemical steps in these pathways are outlined in Fig. 1. Congenital nonspherocytic hemolytic anemia, the characteristic form of anemia resulting from some of the persistent enzyme deficiencies, is characterized by chronic lifelong hemolysis, gallstone formation, varying degrees of splenomegaly, and partial improvement in hemolysis following splenectomy. The red cell osmotic fragility is normal and there is neither an abnormal type o f h e m o g l o b i n n o r an a p p r e c i a b l e n u m b e r o f spherocytes. One third of persons with CNSHA have glucose-6-phosphate dehydrogenase deficiency and many of the other persons have one of the other inherited enzyme deficiencies.The most common red cell enzyme deficiencies occur in the HMP shunt. Since this pathway does not supply a major portion of red cells' energy, these deficiencies are not consistently associated with CNSHA, but are associated with episodic hemolysis secondary to oxidative damage. A few HMP enzyme deficiencies are a s s o c i a t e d with both acute episodic
hemolysis and CNSHA. Enzyme defects in the EmbdenM e y e r h o f pathway are relatively rare. Since this pathway supplies most of the energy (ATP) of the red cell, these deficiencies are usually associated with severe manifestations, both in the neonate and in older persons.
SPECIFIC
ENZYME
DEFICIENCIES
In Table I are summarized the differentiating features of the presently recognized red cell enzyme deficiencies associated with hemolysis. Glucose-6-phosphate dehydrogenase and pyruvate kinase deficiency, the two m o s t f r e q u e n t l y occurring e n z y m a t i c defects, are described in the text. Deaths are due to hydrops fetalis or kernicterus. In some of the enzyme deficiencies, a deficiency of the enzyme in white cells and in other tissues m a y cause associated n o n h e m a t o l o g i c signs and symptoms. G l u c o s e - 6 - p h o s p h a t e d e h y d r o g e n a s e deficiency, found in more than 100 million persons of all races t h r o u g h o u t the world, is t r a n s m i t t e d on the Xc h r o m o s o m e . 5 M o r e than 70 v a r i a n t s h a v e b e e n described and more than 20 of these are associated with C N S H A J ~ All persons with G-6-PD deficiency (hemizygous males, homozygous females, and some heterozygous females) are susceptible to acute, episodic hemolysis following exposure to certain "oxidant" drugs and chemicals. The severity of hemolysis is related to the enzyme variant, severity of deficiency, and specific inciting agent. Table II contains a partial list of commonly available substances which may precipitate hemolysis. A more complete list is available. 1 G-6-PD deficiency with the normal (B+) enzyme occurs more frequently in persons originating from the Mediterranean area (Sephardic Jews, Sardinians, Greeks, and Iranians) and in Mongolian persons (Chinese, Malayans, Filipinos, and Indonesians). 9 B + deficiency (signified as B - ) is frequently associated with CNSHA. There is a relatively high incidence of anemia, hyperbilirubinemia, and kernicterus in neonates of any gestational age who have deficiency of the B + enzyme or of any variant causing CNSHA. l~ Doxiadis and co-workers 27 reported G-6PD deficiency in one third of the infants who required exchange transfusions for hyperbilirubinemia in Greece. Similar results have been found in China, Israel, and Thailand. Doxiadis and Valaes 7 noted that 90 per cent of 112 G-6-PD-deficient infants developed jaundice after the first 24 hours of age. Maximal jaundice occurred on the third to fifth day of life. Thirty per cent of the infants developed kernicterus. Anemia was often not seen initially, but was present in.all infants by the second week. Jaundice beginning at the end of the first week was usually associated with more severe anemia and with a
Volume 84 Number 5
Hemolysis from deficiencies o f red blood cell enzymes
Glucose
.................
~r-Glut-Cyst + Gly
ADP
MgW"
PHOSPHATE
G-6-P , "D'~Y'9"R"O"G'g'N'~S'E'", 6 - P G
.............................................. I .9.L.~C.?~.E~.H.?~~ ~..A,T..E..,!,S,9,u R.A.Sg,
NAOP
F-6-P% ~
"~'~ . . . . . . DH'()FRs :~O1('i~iA'S'E" .......
NAOPH
SYNTHETASE
AoP
NAOP
................... GSH
............................ ~
ATP /1 M O +y ~
PHOSPHOGL.UCONATE
F-I.6-P
GLUTATHIONE
DEHYDROGENASE .................... 9. . . . . . . . . . . . . . . . R. . E. . O . . .U. .C. .T A S E
~
~
P"O"OSO'P"O"HATEA=A \ DHAP--
627
~
COe *-""l "x''* NAOPH~
!
~
GLUTATI~IONE PEROXIDASE
GSSG 4"i ~
HzO
R-5-P
1~- . . . .
-.,~G_~3_p
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
P~NA NAD
GLYCERALDEHYDE - 3 - PHOSPHATE DEHYDROGENASE
OH
......................................
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ADP .
PHOSPHOGLYCERATE KINASE
2,3-DPG
Mg 4~
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ATP
Pi
3-PG ,
~
~)
DIPHOSPHOGLYCERATE PHOSPHOGLYCEROMUTASE
-OPG
PHOSPHATASE
2-PG PHOSPHOPYRUVATE
I Mg~w"
HYDRATASE
PEP ............................ PYRUVATE KINASE
............................
ADP ~
Mg~-
AT,~
K§
q
Pyruvate LACTATE
DEHYDROGENASE
[" ~
NADH NAD
Lactate
Fig. 1. Giycolysis and related pathways of g|utathione metabolism available to the mature erythrocyte. Enzymes which have been associatedwith hemolysis arc indicated by the double hatched fines. Similar markers should be added for the enzymes gtyceraldehyde-3-phosphate dehydrogenas@8 y-glutamyl-cysteine synthetase,~ probably glutathione reductase,n and possibly diphosphoglycerate pliosphatase.2 (By permission of William N. Valentine: Introduction to hereditary enzymatic deficiencies of erythrocytes, published in Semin. HematoL 8: 307-310, 1971, by Grune & Stratton, Inc.)
history of exposure to offending agents. 7 Clinically significant jaundice was seen in only 5 per cent of G-6PD-deficient newborn infants in Greece, suggesting that factors other than just the enzyme deficiency may be necessary for hemolysis. 6 The major G-6-PD variant, the A-t- enzyme, differs from the B + enzyme by one amino acid substitution. It is found predominantly in the black population. Deficiencies occur in approximately 10 per cent of male and 3 per cent of female black Americans. 9 Deficiency of A-Ienzyme (referred to as A - ) is usually associated with acute episodic hemolysis but not usually with CNSHA. A-t- deficiency results in an increased incidence of hyperbilirubinemia in the premature infant but not in the fullterm infant. 8 Persistent mild hemolysis beyond 2 to 3 months of age is unusual in A - infants. Although G-6-PD deficiency occurs more frequently in certain populations, it may occur in any infant; thus, any male infant with unexplained neonatal jaundice or any female infant with a history of siblings with neonatal jaundice should be examined for this defect.
Evidence for obvious hemolysis may be missing. Hepatosplenomegaly is usually not present, unless there has been exposure to inciting drugs. The blood smear is helpful, even in the absence of frank hemolysis, since fragmented red cells and pyknocytes may be seen. Acute hemolysis in any G-6-PD-deficient neonate may follow drug exposure (Table I1) in the mother prior to delivery or drug e x p o s u r e or i n f e c t i o n in t h e i n f a n t . Microspherocytes and anisocytosis may then be prominent in blood smears from both the mother and the infant. Heinz bodies and elevated levels of hemoglobin in the plasma and urine are then demonstrable. Pyruvate kinase deficiency has been reported in more than 135 cases. 23 It is inherited in an autosomal recessive manner; consanguinity has been frequent, particularly in isolated communities. Neonatal manifestations are frequent and severe, including death in utero from hydrops fetalis. CNSHA is usually severe, but drug-induced h e m o l y s i s does not occur. C o n s i d e r a b l e genetic polymorphism exists, and enzyme variants may account for s o m e o f the m i l d e r cases. D e n s e spiculated
628
Gilman
The Journal of Pediatrics May 1974
Table I. Differentiating features of red cell enzyme deficiencies which may result in hemolysis in the neonate
Neonatal manifestationst Enzyme deficiency (reference)
Epidemiologic features *
Genetic transmission
Frequency
DEFECTSINHEXOSEMONOPHOSPHATESHUNTPATHWAYANDRELATEDGLUTATHIONEMETABOLISM Glucose-6-p hosp hate Millions of cases, worldwide Sex - linked ) 5% dehydrogenase ( G - 6 - P D ) distribution B+ enzyme (1,5,6,7,27) Common in Mediterranean and Mongolian persons A+ enzyme (5,8,9) Millions, USA: 10% black Sex - linked 50% Amales, 3% black females premature males Other variants (10) b-phosphogluconic dehydrogenase (6-P-GD) (1,11) Glutathione reductase (GR) (11)
Millions, same distribution as B3
Need for exchange transfusion
Risk of death
Frequent
Yes
Yes
Sex - linked
Frequent
Yes
Autosomal recessive and unknown Autosornal dominant and unknown
1/3w
Yes
61
None
Glutathione peroxidase (GSH Px) (1,12)
6
Autosomal recessive
4/6
Glutathione synthetase (GSH synthetase) (1,3,13) y-glutamyl-cysteine synthetase (y-GC synthetase) (3)
7(?8)
Autosomal recessive
None
2
Autosomal recessive
1/2
Autosomal recessive
3/8
DEFECTSINEMBDEN-MEYERHOFGLYCOLYTICPATHWAY Hexokinase (HK) (2,14,15) 8
Yes
Yes
*The number represents the number of reported cases. "~'Manifestationsincludeanemia, hyperbilirubinemia,erylhroblastosis fetalis and hydrops fetalis. Deaths includestillbirths and deaths from hydrops felalisor kernicterus. spherocytes are demonstrable in the peripheral blood smear in some patients, and these changes may be more prominent in wet preparations of blood or fo!lowing splenectomy. Differentiating features of the other red cell enzyme deficiencies are summarized in Table I. Severe deficiencies in red cell N A D P H d i a p h o r a s e , l l a c t a t e dehydrogenase, 2 glyoxalase I1,2 catalase, 2 and D P N Hmethemoglobin reductase 2 have been described but are not associated with hemolysis. The role of the deficiency of red cell galactose-l-phosphate uridyl transferase in hemolysis in some newborn infants with galactosemia is unclear. 9 DIAGNOSIS Hemolysis caused by an intrinsic red cell enzyme deficiency needs to be considered in the differential diagno-
sis of a newborn infant with hydrops fetalis, anemia, or hyperbilirubinemia. With the possible exception of G-6PD deficiency in certain populations, the most c o m m o n causes for hemolysis in the newborn infant, however, are red cell sensitization and congenital and acquired infections. Red cell sensitization from R h incompatibility occurs in one in 250 neonates; sensitization from ABO incompatibility occurs in one in 180 newborn infants. Neonatal sepsis occurs in one in 500 to 1,600 infants. 28 Th e next most frequently occurring causes for anemia and hyperbilirubinemia are respiratory distress synd r o m e , s e v e r e anoxia, f e t o m a t e r n a l t r a n s f u s i o n , enclosed hemorrhage, and hemolysis associated with inherited morphologic variations of the red cell. These entities are usually identifiable from information obtained from a detailed medical and obstetrical history, complete physical examination of the newborn infant, and a few
Volume 84 Number 5
Hemolysis from deficiencies o f red blood cell enzymes
History and clinical manifestations of affected persons*
Laboratory data
Drug-induced hemolysis May have mild CNSHA Affected male siblings[drug-induced or CNSHA]
Pyknocytes
In black Americans: episodic hemolysis after drug, exposure or infection, usually no CNSHA lincidence of jaundice in premature, not term A- males Maternal or infant drug exposure Frequent CNSHA Affected male sibs May have CNSHA or drug-induced hemolysis
Pyknocytes THeinz body formation Abnormal RBC morphology and hemolysis in mother, if she bad drug exposure Pyknocytes I'Heinz body formation May have T Heinz body formation
Late onset of clinical signs: hepatosplenomegaly, spastic neurologic changes May have thrombocytopenia and drug- or thalliuminduced pancytopenia 25% have no hematologic abnormalities Heterozygous neonates may have transient hemolysis without drug, but are well in 3 months Homozygotes may have CNSHA Heterozygotes may be drug sensitive Mild CNSHA in some May have hemolysis from drug or lava beans Mild CNSHA May have late onset neurologic changes
T Heinz body formation Some have decrease in white cells and platelets associated with I GR in white ceils and platelets Rule out acquired dietary riboflavin deficiency
CNSHA 3 patients with Fanconi's anemia
THeinz body formation
I Heinz body formation Abnormal autohemolysis
l" Heinz body formation Abnormal autohemolysis Aniso- and poikilocytosis
Spiculated spherocytes Abnormal autohemolysis I in WBC and platelet number and HK in patients with Fanconi's anemia
~:TableII lists drugs which produce hemolysis. w fraction representsthe numberof reported cases noted to have neonatalmanifestations.
simple laboratory procedures performed on the mother's and infant's blood9 The initial laboratory studies on the infant's blood should include blood type and rhesus factor, direct and indirect Coombs' test, direct- and indirect-reacting serum bilirubin concentration, hemoglobin concentration, hematocrit, reticulocyte count, and examination of the peripheral blood smear. Studies on the mother's blood should include blood type and rhesus factor, serologic test for syphilis, hemoglobin concentration, and examination of the peripheral blood smear. Anemia is frequently overlooked in the newborn inf a n t because of lack of familiarity with n o r m a l hematologic values for the neonatal period. Table III lists these normal values. 9 Small-for-gestational age infants tend to have values appropriate for their gestational age. During the first week of life, capillary
629
Continued.
hemoglobin and hematocrit values are significantly greater than venous values; the m e a n capillary hemoglobin concentration for full-term infants on Day 1 is 19.8 Gin. per 100 ml. with a range of 16.6 to 23.4 Gin. per 100 ml. 9 In the author's laboratory, a cord or venous blood hemoglobin of 14 Gin. per 100 ml. or less or a capillary hemoglobin of 15.5 Gin. per 100 ml. or less is considered evidence of anemia in a full-term infant. Unusual or persistent elevations of the nucleated red cell and reticulocyte counts reflect hemolysis or response to blood loss even without obvious anemia. The rate of rise of the concentration of serum bilirubin is significant. A n increase more rapid than 5 mg9 per 100 9ml. per day in a neonate reflects accelerated hemolysis or enclosed hemorrhage. 29 Pure hemolysis and physiologic jaundice cause elevations of indirect-reacting bilirubin Concentrations of direct-reacting serum bilirubin greater
630
Gilman
The Journal of Pediatrics May 1974
Table I. Cont'd. Neonatal manifestations? Enzyme deficiency (reference)
Epidemiologic features *
Genetic transmission
DEFECTS IN EMBDEN-MEYERHOFGLYCOLYTICPATHWAY Glucosephosphate isomerase 12 (GPI) (2)
Frequency
4/12
Phosphofructokinase (PFK) (2, 16, 17)
5
Sex - linked
None
Triosephosphate isomerase (TPI) (2)
11
Autosomal recessive (?located on chromosome 5)
8/11
?Autosomal recessive
None
10 males 5 females
Sex - linked
2/10
5
1/5
2
Autosomal recessive (?dominant) Unclear
) 135
Autosomal recessive
35/59
Glyceraldehyde-3phosphate dehydrogenase (G-3-PD) (18) Phosphoglycerate kinase (PGK) (19,20) 2,3-dip hosphoglyceromutase (2,3-DPGM) (21) 2,3-diphosp hoglycerate phosphatase (2,3-DPG phosphatase) (2) Pyruvate kinase (PK) (21,22,23,24)
1
Need for exchange transfusion
Risk of death
Yes
Yes
Yes
Very frequent
Yes
OTHER DEFECTS
Ribosephosphate pyrophosphokinase (RPK) (4,25) Adenylate kinase (AK) (9) Adenosine triphosphatase (ATPase) (26)
4
Unknown
3 7(?12)
Autosomal recessive Autosomal dominant
than 1.5 mg. per 100 ml. suggest hepatic obstruction or damage associated with severe red cell sensitization, bacterial sepsis, or other congenital infections. Alterations in the peripheral blood smear frequently suggest the etiology of hemolysis (Fig. 2). Examination of the infant's blood smear for spherocytes, elliptocytes, and stomatocytes will quickly identify an inherited morphologic red cell change. In addition, the blood smear is useful in identifying the spherocytes of ABO incompatibility (Fig. 2, A) and transmitted autoimmune hemolytic anemia, as well as the leukopenia, thrombocytopenia, and fragmented, bizarre red cells associated with congenital rubella, toxoplasmosis, cytomegalic inclusion disease, herpes simplex, syphilis, and acquired bacterial infections. The presence of these alterations suggests the need for confirmatory studies. The presence of target cells and aniso- and poikilocytosis suggest an alpha-chain defect in hemoglobin synthesis which oc-
2/4 2/3 None
curs in 2 to 7 per cent of Oriental and Negro newborn infants. 3~ Changes in red cell morphology in glyc01ytic enzyme deficiencies are quite nonspecific: macrocytosis, polychromatophilia, and occasionally dense spiculated spherocytes (Fig. 2, B). Pyknocytes may be prominent in G-6-PD deficiency (Fig. 2, C). Microspherocytes occur in G-6-PD deficiency following drug exposure or in GPI deficiency. 2 Prominent basophilic stippling is seen in R P K deficiency.a. 25 Persistence of hemolysis beyond the newborn period is often the best indication to suggest an underlying inherited enzymatic defect. Important historical data include a family history of chronic hemolysis or recurrent jaundice; neonatal jaundice; consanguinity; jaundice, anemia, or brown urine following infections or exposure to certain drugs; chronic or recurrent severe infections, neurologic or muscle disease, and sudden death in infant siblings or cousins. Two useful screening laboratory pro-
Volume 84 Number 5
Hemolysis from deficiencies o f red blood cell enzymes
History and clinical manifestations of affected persons~ CNSHA
Males: Type VII glycogen storage disease [episodic muscle weakness], very mild CNSHA Mothers: mild CNSHA, no muscle disease Severe CNSHA. Recurrent infection, onset neurologic problems (speech, motor) after 6 months age, early deaths from infection, cardiac arrhythmia "Cat cry" syndrome in 2 patients Sibs or cousins with neurologic dysfunction, early death Mild CNSHA, worse with infection and drug
Males: mental retardation, neurologic problems, recurrent infections, CNSHA and early death Females: mild CNSHA Infant death from seizures or infection in male sibs or cousins CNSHA CNSHA may be mild Cerebral dysgenesis, retarded development, muscular hypotony, achromotrichy Severe CNSHA History of consanguinity, affected sibs
Laboratory data Prominent aniso- and poikilocytosis; spiculated spherocytes Abnormal incubated osmotic fragility and autohemolysis GPI may be deficient in leukocytes and platelets Muscle PFK |; may have [ leukocyte PFK
[ TPI in myocardium, brain, leukocyte Partial deletion of chromosome 5 in "cat cry'syndrome
I Leukocyte G-3-PD
Abnormal autohemolysis May have ~ leukocyte PGK
Abnormal autohemolysis
Spiculated spherocytes; may have pykfiocytes Abnormal autohemolysis
CNSHA
Prominent basophilic stippling of red cells Abnormal autohemolysis
CNSHA CNSHA
Abnormal autohemolysis
cedures include a Heinz body preparation 12 and an autohemolysis test. 31, 32 Heinz bodies are increased in defects in the HMP shunt and in glutathione metabolism. Increased autohemolysis in vitro is found in defects in either of the glycolytic pathways; correction by glucose or ATP will help establish in which glycolytic pathway the defect occurs. 32 The specific enzyme deficiency is determined by quantitative assay of an appropriately obtained and treated blood sample. 33 Simple qualitative screening tests are available for some of the enzymes (G-6-PD, 1GR, 1 GSH Px, 1TPI, 33and PK2). Screening tests for G-6-PD deficiency based on dye reduction, methemoglobin reduction, or fluorescence will detect the homozygous deficient female or the hemizygous deficient male. Female carriers are not always identified, nor are those patients who are deficient but who have an elevated reticulocyte count following a hemolytic reaction. 1If the baby's blood sam-
631
pie contains transfused red cells, the screening test and quantitative assay will not demonstrate the enzyme deficiency. The demonstration of alterations in enzyme activity in family members may suggest a pattern of inheritance and hence assist in making a presumptive diagnosis.
THERAPY If the obstetrical history of a woman reveals that previous pregancies have terminated in delivery of hydropic infants who did not have evidence of red cell sensitization, the possibility of an inherited enzyme deficiency should be considered. If possible, appropriate enzyme assays should then be obtained on the parents. If both parents are shown to be heterozygous for PK, TPI, or HK deficiency, then premature induction of labor may be indicated to save a severely affected infant. Delivery should be undertaken only after preparations have been
632
Gilman
The Journal of Pediatrics May 1974
Table II. Commonly available agents which may produce hemolysis in G-6-PD-deficient persons Headache and cold remedies containing Acetophenetidin (phenacetin), acetanilid, or quinine: 666, APC tablets, Super Anahist, Anacin, Empirin, Bromo Seltzer, Stanback Sulfonamides Nitrofurans Antimalarials Others: Acetylsalicylicacid (large doses) Vitamin K water soluble analogues (doses greater than 2.5 rag. in infant, 100 rag. in adul0 Black Draught and other senna compounds Nalidixic acid (NegGram) p-Aminosalicylicacid Naphthalene mothballs (inhaled or ingested) Nitrobenzene derivatives Aniline derivatives
Fig. 2. A, Spherocytes and a nucleated red cell in B-O incompatibility. B, Dense spiculated spherocytes in CNSHA from PK deficiency. C, Pyknocytes in neonate with G-6-PD deficiency. D, Elliptocytes in congenital ovalocytosis. completed for an immediate packed cell or a regular exchange transfusion in the delivery room. The severity of clinical manifestations of hemolysis will determine which therapeutic measures are necessary. A s e v e r e l y affected infant, p r e s e n t i n g with erythroblastosis fetalis or hydrops fetalis at delivery, should have an immediate exchange transfusion. The use of fresh whole blood is preferable. A partial exchange transfusion with packed red cells may be life saving by stabilizing a moribund infant until he can tolerate a regular exchange transfusion. More than one exchange transfusion may be necessary. Heparinized blood from the infant should be obtained before transfusion and refrigerated for subsequent enzyme assays. A n i n f a n t with severe h y p e r b i l i r u b i n e m i a or symptoms of kernicterus, regardless of the serum bilirubin level, should be treated with one or more exchange transfusions, using freshly drawn whole blood. Severe hyperbilirubinemia is defined as a rate of rise in serum bilirubin concentration of 1 mg. per 100 ml. per hour or greater during the first 24 hours of life; a serum bilirubin concentration greater than 20 mg. per 100 ml. at any age, or a serum bilirubin concentration approaching 20 mg. per 100 ml. with an elevated saturation index.34A sick or premature infant should have an exchange transfusion performed at a lower serum bilirubin concentration than the well full-term infant. The intravenous administration of 1 Gm. of albumin per kilogram of body weight one hour before the exchange
transfusion will result in more efficient removal of bilirubin. 35 However, this priming dose of albumin is contraindicated in the presence of hydrops fetalis, severe anemia (hemoglobin less than 10.5 Gm. per 100 ml. blood, hematocrit less than 32 per cent), congestive heart failure, shock, or cardiac arrhythmias. The need for subsequent transfusions to correct late anemia may be avoided by the administration of the packed red cells which have been allowed to sediment during the exchange transfusion. Another benefit of exchange. transfusion is the temporary reduction of progressive hemolysis, as a result of the removal of most of the enzyme deficient red cells and, in the case of drug-induced hemolysis, removal of any circulating drug (Table II). In the latter instance, a G-6-PD normal donor should be used to provide blood for an exchange transfusion. Infants with mild to moderate degree of hyperbilirubinemia should be observed for progression of hyperbilirubinemia or anemia or appearance of symptoms relating to either. The use of phototherapy to treat hyperbilirubinemia secondary to red cell enzyme deficiencies has not been evaluated, although general guidelines for its use are available. 36 It should not become a s u b s t i t u t e for i d e n t i f y i n g t h e c a u s e o f h y p e r bilirubinemia. An indicated exchange transfusion should not be delayed in order to administer phototherapy. The e f f e c t i v e n e s s o f p h o t o t h e r a p y in reducing hyperbilirubinemia is impaired in the presence of hemolysis. The bilirubin level may not decrease, even when visible jaundice improves with phototherapy. 37 In addition, alterations in erythrocyte membrane metabolism may b e induced by photo-oxidation in the presence of bilirubin, which acts as a photosensitizing agent. 38 Thus, there is the possibility of aggravating hemolysis by using photo-
Volume 84 Number 5
Hemolysis from deficiencies of red blood cell enzymes
633
Table III. Normal hematologic values of the newborn infant (venous blood)
Premature (gestational age)
Full-term
Cord blood
Hemoglobin (Gm./100 ml.) Range Hematocrit
(0/0) Reticulocyte count (%) Nucleated RBC per cu. mm. (% per 100 WBC) Per 100 RBC RBC Morphology
16.8 13.7-20.1 (14.0")
Day 7
Day 2
Day 1
17.8
17.0
14.5
15.0
(14.5)
(14.0)
(14.0)
(12.5)
(13.0)
45 (40)
47 (42)
53
58
55
54
(48)
(45)
(45)
500 (10%) 0.1
34 weeks Day 1
18.4
(44) 3-7
28 weeks Day l
3-7
1-3
0-1
200 (7%) 0.05
0-5
0
0 Macrocytes 5% pyknocytes
5-10
3-10
1,000
1,500 (21%)
0
0.5
0.2 Macrocytes 10% pyknocytes
*The hemoglobinand hematocritvalues listed in the parentheses are consideredindicativeof anemia by this author.
therapy in the presence o f a pre-existing metabolic defect. Therefore, the routine use of phototherapy is not advised when a red cell enzyme deficiency is considered in the differential diagnosis. If used in patients with mild hyperbilirubinemia without anemia, the bilirubin and hemoglobin levels should be monitored closely during and following phototherapy. Theoretically, there could be immediate or delayed anemia, if the primary h e m o l y t i c process is exacerbated by phototherapy. If progressive anemia occurs without hyperbilirubinemia and is accompanied by poor sucking and feeding, lethargy, rapid pulse, and enlarging liver, transfusion with packed red blood cells is indicated (15 to 20 cc. per kilogram). Administration of iron will not correct this anemia, although it may prevent delayed anemia when an unusual amount of blood has been drawn for diagnostic purposes, or an exchange transfusion has been given. Folic acid is recommended for the infant with severe chronic hemolysis who is feeding poorly or who has recurrent diarrhea or infections. Infants with mild alterations in hemoglobin and bilirubin levels should be managed by expectant observation while in the nursery. The severity and chronicity of hemolysis should be determined by subsequent follow-up. Parents of infants with red cell enzyme deficiencies associated with drug-induced hemolysis (G-6PD, 6-P-GD, GR, GSH Px, GSH synthetase deficiencies) should be given instructions to avoid the agents listed in Table II.
In families with a history of drug-induced hemolysis, communication between the pediatrician and obstetrician concerning maternal drug ingestion during the third trimester may prevent problems in subsequent newborn infants. Careful planning by this team may allow premature delivery and appropriate emergency measures necessary to salvage a severely affected infant with PK, TPI, or H K deficiency in families who have had a previous severely affected infant. SUMMARY A newborn infant with an inherited deficiency of a red cell enzyme may present with signs of severe or p r o g r e s s i v e h e m o l y s i s . Initial diagnostic m e a s u r e s should exclude the more common causes of hemolysis and then establish evidence for abnormal erythrocyte metabolism. The exact diagnosis is made by an enzyme assay of the infant's red cells. The severity of anemia and hyperbilirubinemia will determine whether a packed red cell or exchange transfusion is necessary. Follow-up is essential to determine the chronicity and severity of hemolysis.
REFERENCES 1. Beutler, E.: Abnormalities of the hexosemonophosphate shunt, Semin. Hematol. 8: 311, 1971. 2. Valentine, W. N.: Deficiencies associated with EmbdenMeyerhof pathway and other metabolic pathways, Semin. Hematol. 8: 348, 1971. 3. Konrad, P. N., Richards, F., II, Valentine, W. N., and
634
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17. 18.
19.
Gilman
Paglia, D. E,: 3' -Glutamyl-cysteine synthetase deficiency, N. Engl. J. Med. 286: 557, 1972. Valentine, W. N., Anderson, H. M., Paglia, D. E., et al.: Studies on human erythrocyte nucleotide metabolism. 1I. Nonspherocytic hemolytic anemia, high red cell ATP, and ribosephosphate pyrophosphokinase (RPK, E.C. 2,7,6,1) deficiency, Blood 39: 674, 1972. Carson, P. E., and Frischer, H.: Glucose-6-phosphate dehydrogenase deficiency and related disorders of the pentose phosphate pathway, Am, J. Med. 41: 744, 1966. Fessas, P. H., Doxiadis, S. A., and Valaes, T.: Neonatal jaundice in glucose-6-phosphate dehydrogenase deficient infants, Br. Med. J. 2: 1359, 1962. Doxiadis, S. A., and Valaes, T.: The clinical picture of glucose-6-phosphate deficiency in early infancy, Arch. Dis. Child. 39: 545, 1964. Eshaghpour, E., Oski, F. A., and Williams, M.: The relationship of erythrocyte glucose-6-phosphate dehydrogenase deficiency to hyperbilirubinemia in Negro premature infants, J. PEDIATR.70: 595, t967. Oski, F. A., and Naiman, J. L.: Hematologic problems in the newborn, ed. 2, Philadelphia, 1972, W. B. Saunders Company. Rattazzi, M. C., Corash, L. M., van Zaness, G. E., Jaffe, E. R., and Piomelli, S.: G6PD deficiency and chronic hemolysis: Four new mutants--relationships between clinical syndrome and enzyme kinetics, Blood 38: 205, 1971. Wailer, H. D.: Glutathione reductase deficiency in Beutler, E., editor: Hereditary disorders of erythrocyte metabolism, New York, 1968, Grune & Stratton, Inc. Necheles, T. F., Boles, T. A., and Allen, D. M.: Erythrocyte glutathione-peroxidase deficiency and hemolytic disease of the newborn infant, J. PEDIATR.72: 3t9, 1968. Mohler, D. bl., Majerus, P. W., Minnich, V., Hess, C. E., and Garrick, M. D.: Glutathione synthetase deficiency as a cause of hereditary hemolytic disease, N. Engl. J. Med. 283: 1253, 1970. Valentine, W. N., Oski, F, A., Pagtia, D. E., Baughan, M. A., Schneider, A. S, and Naiman, J. L.: Hereditary hemolytic anemia with hexokinase deficiency. Role of hexokinase in erythrocyte aging, N. Engl. J. Med. 276: 1, 1967. Necheles, T. F., Rai, U. S., and Cameron, D,: Congenital nonspherocytic hemolytic anemia associated with an unusual erythrocyte hexokinase abnormality, J. Lab. Clin. Med. 76: 593, 1970. Tarui, S., Kono, N., Nasu, T., and Nishikawa, M.: Enzymatic basis for the co-existence of myopathy and hemolytic disease in inherited muscle phosphofructose kinase deficiency, Biochem. Biophys. Res. Commun. 34: 77, 1969. Waterbury, L., and Frenkel, E. P.: Phosphofructokinase deficiency in congenital nonspherocytic hemolytic anemia, Clin. Res. 17: 347, 1969. Oski, F., and Whaun, J.: Hemolytic anemia and red cell glyceraldehyde-3-phosphate dehydrogenase deficiency, Clin. Res. 17: 601, 1969. Konrad, p. N., McCarthy, D. J., Mauer, A. M., Valentine, W. N., and Paglia, D. E.: Erythrocyte and leukocyte phosphoglycerate kinase deficiency with neurologic disease, J. PEDIATR,82: 456, 1973.
The Journal of Pediatrics May 1974
20. Valentine, W. N., Hsieh, H. S., Paglia, D. E., Anderson, H. M., Baughan, M. A., Jaffa, E. R., and Garson, O. M.: H e r e d i t a r y h e m o l y t i c a n e m i a a s s o c i a t e d with phosphoglycerate kinase deficiency in erythrocytes and leukocytes, N. Engl. J. Med. 280: 528, 1969. 21. Keitt, A. S.: Pyruvate kinase deficiency and related disorders of red cell glycolysis, Am. J. Med. 41: 762, 1966. 22. Valentine, W. N., Tanaka, K. R., and Miwa, S.: Specific erythrocyte glycolytic enzyme defect (pyruvate kinase) in three subjects with congenital non-spherocytic hemolytic anemia, Trans. Assoc. Am. Physicians 74: 100, 1961. 23. Tanaka, K. R., and Paglia, D. E.: Pyruvate kinase deficiency, Semin. Hematol. 8: 367, 1971. 24. Oski, F. A., and Diamond, L. K.: Erythrocyte pyruvate kinase deficiency resuiting in congenital nonspherocytic hemolytic anemia, N. Engl. J. Med. 269: 763, 1963. 25. Valentine, W. N., Bennett, J. M., Krivit, W., Konrad, P. N., Lowman, J. T., Paglia, D. E., and Wakem, C. J.: Nonspherocytic, haemolytic anaemia with increased red cell adenine nucleotides, glutathione and basophific stippling and ribosephosphate pyrophosphokinase (RPK) deficiency: studies on two new kindreds, Br. J. Haematol. 24: 157, 1973. 26. Harvald, B., Hanel, K. H., Squires, R., and Trap-Jensen, J.: Adenosine-triphosphatase deficiency in patients with nonspherocytic haemolytic anaemia, Lancet 2: 18, 1964. 27. Doxiadis, S. A., Fessas, P., Valaes, T., and Mastrokalos, N.: Glucose-6-phosphate dehydrogenase deficiency: A new aetiological factor of severe neonatal jaundice, Lancet 1: 297, 1961. 28. Gotoff, S. P., and Behrman, R. E.: Neonatal septicemia, J. PEDIATR.76: 14~2,1970. 29. Rausen, A. R., and Diamond, L. K.: "Enclosed" hemorrhage and neonatal jaundice, Am. J. Dis. Child. 101: 164, 1961. 30. Weatherall, D. J.: Abnormal haemoglobins in the neonatal period and their relationship to thalassemia, Br. J. Haematol. 9: 265, 1963. 31. Rudolph, N., and Gross, R. T.: Studies of in-vitro autohaemolysis in blood from newborn infants, Br. J. Haematol. 12: 351, 1966. 32. Smith, C. H.: Blood diseases of infancy and childhood, ed. 3, St. Louis, 1972, The C. V. Mosby Company. 33. Beutler, E.: Red cell metabolism. A manual of biochemical methods, New York, 1971, Grune & Stratton, Inc. 34. Odell, G. B., Cohen, S. N., and Kelly, P. C.: Studies in kernicterus II. The determination of the saturation of serum albumin with bilirubin, J. PEDIATR.74: 214, 1969. 35. OdeLI,G. B., Cohen, S. N., and Gordes, E. H.: Administration of albumin in the management of hyperbilirubinemia by exchange transfusion , Pediatrics 30: 613, 1962. 36. Behrman, R. E., and Hsia, D. Y. Y.: Summary of a symposium on phototherapy for hyperbiliruhinemia, J. PEDIATR.75: 718, 1969. 37. Patel, D. A., Pildes, R. S., and Behrman, R. E.: Failure of phototherapy to reduce serum bilirubin in newborn infants, J. PEDIATR,77: 1048, 1970. 38. Odell, G. B., Brown, R. S., and Kopelman, A. E.: The photodynamic action of bilirubin on erythrocytes, J. PEDIATR.81: 473, 1972.
PEDIATRIC S MAY
MEDICAL
1974
V o l u m e 84
N~:mber 5
PROGRESS
Hemolysis in the newborn infant resulting from deficiencies of red blood cell enzymes: Diagnosis and management Inherited deficiencies o f red cell enzymes are recognized causes o f hemolysis Ot newborn infants. Neonatal manifestations include erythroblastosis fetalis, anemia, hyperbilirubinemia, or a combination o f these. Some infants with enzyme deficiencies demonstrate no neonatal manifestations; in others death may result from hydrops fetalis or kernicterus. In cases o f suspected hemolysis, simple diagnostic measures will identify the most common causes o f the anemia and~or the hyperbilirubinemia; these are not inherited deficiencies of enzymes but are red cell sensitization and congenital and acquired infections. Persistent hemolysis and abnormalities in the G-6-PD screening test, in the Heinz body preparation, or in an autohemolysis test support a tentative diagnosis of enzyme deficiency. The diagnosis is confirmed by specific enzyme assay. Appropriate therapy depends on the severity o f anemia and~orhyperbilirubinemia and may include transfusion of packedred cells or an exchange transfusion. Careful follow-up is essential to determine the chronicity and severity o f hemolysis.
Priscilla Ann Gilman, M.D., Baltimore, Md.
HYDROPS FETALIS, anemia, hyperbilirubinemia, or kernicterus may occur in a newborn infant with hemolysis resulting from an inherited red cell enzyme deficiency, which must be considered in the differential diagnosis when any of these features are manifest. More than twenty different red cell enzyme deficiencies have been describedl-4; acute or chronic hemolysis is associated with at least 18 of them. 1-26 The severity of hemolysis in the neonate varies with the specific enzymatic defect (qualitative and quantitative defects), with the gestational age of the infant, with exposure to certain From the Department o f Pediatrics, University of Maryland School o f Medicine. Supported in part by the Frank G. Bressler Reserve Fund and the Thomas 1f. Wilson Sanitarium for Children. Reprint address:Department of Pediatrics, Universityof Maryland Hospital, 22 S. Greene St., Baltimore, Md. 21201.
drugs or chemicals, and with intercurrent infections. On the other hand, some infants with red cell enzyme deficiencies do not exhibit neonatal manifestations. Identification of the exact etiology of hemolysis is necessary in order to institute appropriate therapy and avoid unnecessary and p o t e n t i a l l y h a r m f u l diagnostic and therapeutic measures both in the patient and in subsequent siblings. In this commentary an attempt is made to summarize the differentiating features and the nature and frequency of neonatal manifestations of the inherited red cell enzyme deficiencies. Methods for distinguishing these d i s o r d e r s f r o m the c o m m o n h e m o l y t i c and nonh e m o l y t i c causes o f n e o n a t a l a n e m i a and hyperbilirubinemia a r e discussed, and appropriate therapy is suggested. The mature red ceil derives energy necessary for its Vol. 84, No. 5, pp. 6.25-634
626
Gilman
The Journal of Pediatrics May 1974
Abbreviations used ATP: HMP: NADPH: CNSHA:
adenosine triphospbate hexose monophosphate reduced triphosphopyridine nucleotide
congenital nonspherocytic hemolytic anemia DPNH: reduced diphosphopyridine nucleotide G-6-PD: glucose-6-phosphate dehydrogenase 6-P-GD: 6-phosphogluconic dehydrogenase GR: glutathione reductase GSH Px: glutathione peroxidase GSH synthetase: glutatbione synthetase T-GC synthetase: y-glutamyl-eysteine synthetase HK: hexokinase GPI: glucosephosphate isomerase PFK: phosphofructokinase TPI: triosephosphate isomerase G-3-PD: glyceraldehyde-3-phosphate dehydrogenase PGK: phosphoglycerate kinase 2,3-DPGM: 2,3-diphosp hoglycerom!atase 2,3-diphosphoglycerate phosphatase 2,3-DPG phosphatase: pyruvate kinase PK: RPK: ribosephosphate pyrophosphokinase AK: adenylate kinase ATPase: adenosine triphosphatase
survival from glycolysis, Approximately 93 per cent of the energy comes from ATP generated via the EmbdenMeyerhof pathway; the remainder is derived from the hexose monophosphate shunt. 9 The HMP shunt and steps in glutathione metabolism provide N A D P H and reduced glutathione, which protect hemoglobin and certain e n z y m e s f r o m o x i d a t i v e d e n a t u r a t i o n . The biochemical steps in these pathways are outlined in Fig. 1. Congenital nonspherocytic hemolytic anemia, the characteristic form of anemia resulting from some of the persistent enzyme deficiencies, is characterized by chronic lifelong hemolysis, gallstone formation, varying degrees of splenomegaly, and partial improvement in hemolysis following splenectomy. The red cell osmotic fragility is normal and there is neither an abnormal type o f h e m o g l o b i n n o r an a p p r e c i a b l e n u m b e r o f spherocytes. One third of persons with CNSHA have glucose-6-phosphate dehydrogenase deficiency and many of the other persons have one of the other inherited enzyme deficiencies.The most common red cell enzyme deficiencies occur in the HMP shunt. Since this pathway does not supply a major portion of red cells' energy, these deficiencies are not consistently associated with CNSHA, but are associated with episodic hemolysis secondary to oxidative damage. A few HMP enzyme deficiencies are a s s o c i a t e d with both acute episodic
hemolysis and CNSHA. Enzyme defects in the EmbdenM e y e r h o f pathway are relatively rare. Since this pathway supplies most of the energy (ATP) of the red cell, these deficiencies are usually associated with severe manifestations, both in the neonate and in older persons.
SPECIFIC
ENZYME
DEFICIENCIES
In Table I are summarized the differentiating features of the presently recognized red cell enzyme deficiencies associated with hemolysis. Glucose-6-phosphate dehydrogenase and pyruvate kinase deficiency, the two m o s t f r e q u e n t l y occurring e n z y m a t i c defects, are described in the text. Deaths are due to hydrops fetalis or kernicterus. In some of the enzyme deficiencies, a deficiency of the enzyme in white cells and in other tissues m a y cause associated n o n h e m a t o l o g i c signs and symptoms. G l u c o s e - 6 - p h o s p h a t e d e h y d r o g e n a s e deficiency, found in more than 100 million persons of all races t h r o u g h o u t the world, is t r a n s m i t t e d on the Xc h r o m o s o m e . 5 M o r e than 70 v a r i a n t s h a v e b e e n described and more than 20 of these are associated with C N S H A J ~ All persons with G-6-PD deficiency (hemizygous males, homozygous females, and some heterozygous females) are susceptible to acute, episodic hemolysis following exposure to certain "oxidant" drugs and chemicals. The severity of hemolysis is related to the enzyme variant, severity of deficiency, and specific inciting agent. Table II contains a partial list of commonly available substances which may precipitate hemolysis. A more complete list is available. 1 G-6-PD deficiency with the normal (B+) enzyme occurs more frequently in persons originating from the Mediterranean area (Sephardic Jews, Sardinians, Greeks, and Iranians) and in Mongolian persons (Chinese, Malayans, Filipinos, and Indonesians). 9 B + deficiency (signified as B - ) is frequently associated with CNSHA. There is a relatively high incidence of anemia, hyperbilirubinemia, and kernicterus in neonates of any gestational age who have deficiency of the B + enzyme or of any variant causing CNSHA. l~ Doxiadis and co-workers 27 reported G-6PD deficiency in one third of the infants who required exchange transfusions for hyperbilirubinemia in Greece. Similar results have been found in China, Israel, and Thailand. Doxiadis and Valaes 7 noted that 90 per cent of 112 G-6-PD-deficient infants developed jaundice after the first 24 hours of age. Maximal jaundice occurred on the third to fifth day of life. Thirty per cent of the infants developed kernicterus. Anemia was often not seen initially, but was present in.all infants by the second week. Jaundice beginning at the end of the first week was usually associated with more severe anemia and with a
Volume 84 Number 5
Hemolysis from deficiencies o f red blood cell enzymes
Glucose
.................
~r-Glut-Cyst + Gly
ADP
MgW"
PHOSPHATE
G-6-P , "D'~Y'9"R"O"G'g'N'~S'E'", 6 - P G
.............................................. I .9.L.~C.?~.E~.H.?~~ ~..A,T..E..,!,S,9,u R.A.Sg,
NAOP
F-6-P% ~
"~'~ . . . . . . DH'()FRs :~O1('i~iA'S'E" .......
NAOPH
SYNTHETASE
AoP
NAOP
................... GSH
............................ ~
ATP /1 M O +y ~
PHOSPHOGL.UCONATE
F-I.6-P
GLUTATHIONE
DEHYDROGENASE .................... 9. . . . . . . . . . . . . . . . R. . E. . O . . .U. .C. .T A S E
~
~
P"O"OSO'P"O"HATEA=A \ DHAP--
627
~
COe *-""l "x''* NAOPH~
!
~
GLUTATI~IONE PEROXIDASE
GSSG 4"i ~
HzO
R-5-P
1~- . . . .
-.,~G_~3_p
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
P~NA NAD
GLYCERALDEHYDE - 3 - PHOSPHATE DEHYDROGENASE
OH
......................................
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ADP .
PHOSPHOGLYCERATE KINASE
2,3-DPG
Mg 4~
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ATP
Pi
3-PG ,
~
~)
DIPHOSPHOGLYCERATE PHOSPHOGLYCEROMUTASE
-OPG
PHOSPHATASE
2-PG PHOSPHOPYRUVATE
I Mg~w"
HYDRATASE
PEP ............................ PYRUVATE KINASE
............................
ADP ~
Mg~-
AT,~
K§
q
Pyruvate LACTATE
DEHYDROGENASE
[" ~
NADH NAD
Lactate
Fig. 1. Giycolysis and related pathways of g|utathione metabolism available to the mature erythrocyte. Enzymes which have been associatedwith hemolysis arc indicated by the double hatched fines. Similar markers should be added for the enzymes gtyceraldehyde-3-phosphate dehydrogenas@8 y-glutamyl-cysteine synthetase,~ probably glutathione reductase,n and possibly diphosphoglycerate pliosphatase.2 (By permission of William N. Valentine: Introduction to hereditary enzymatic deficiencies of erythrocytes, published in Semin. HematoL 8: 307-310, 1971, by Grune & Stratton, Inc.)
history of exposure to offending agents. 7 Clinically significant jaundice was seen in only 5 per cent of G-6PD-deficient newborn infants in Greece, suggesting that factors other than just the enzyme deficiency may be necessary for hemolysis. 6 The major G-6-PD variant, the A-t- enzyme, differs from the B + enzyme by one amino acid substitution. It is found predominantly in the black population. Deficiencies occur in approximately 10 per cent of male and 3 per cent of female black Americans. 9 Deficiency of A-Ienzyme (referred to as A - ) is usually associated with acute episodic hemolysis but not usually with CNSHA. A-t- deficiency results in an increased incidence of hyperbilirubinemia in the premature infant but not in the fullterm infant. 8 Persistent mild hemolysis beyond 2 to 3 months of age is unusual in A - infants. Although G-6-PD deficiency occurs more frequently in certain populations, it may occur in any infant; thus, any male infant with unexplained neonatal jaundice or any female infant with a history of siblings with neonatal jaundice should be examined for this defect.
Evidence for obvious hemolysis may be missing. Hepatosplenomegaly is usually not present, unless there has been exposure to inciting drugs. The blood smear is helpful, even in the absence of frank hemolysis, since fragmented red cells and pyknocytes may be seen. Acute hemolysis in any G-6-PD-deficient neonate may follow drug exposure (Table I1) in the mother prior to delivery or drug e x p o s u r e or i n f e c t i o n in t h e i n f a n t . Microspherocytes and anisocytosis may then be prominent in blood smears from both the mother and the infant. Heinz bodies and elevated levels of hemoglobin in the plasma and urine are then demonstrable. Pyruvate kinase deficiency has been reported in more than 135 cases. 23 It is inherited in an autosomal recessive manner; consanguinity has been frequent, particularly in isolated communities. Neonatal manifestations are frequent and severe, including death in utero from hydrops fetalis. CNSHA is usually severe, but drug-induced h e m o l y s i s does not occur. C o n s i d e r a b l e genetic polymorphism exists, and enzyme variants may account for s o m e o f the m i l d e r cases. D e n s e spiculated
628
Gilman
The Journal of Pediatrics May 1974
Table I. Differentiating features of red cell enzyme deficiencies which may result in hemolysis in the neonate
Neonatal manifestationst Enzyme deficiency (reference)
Epidemiologic features *
Genetic transmission
Frequency
DEFECTSINHEXOSEMONOPHOSPHATESHUNTPATHWAYANDRELATEDGLUTATHIONEMETABOLISM Glucose-6-p hosp hate Millions of cases, worldwide Sex - linked ) 5% dehydrogenase ( G - 6 - P D ) distribution B+ enzyme (1,5,6,7,27) Common in Mediterranean and Mongolian persons A+ enzyme (5,8,9) Millions, USA: 10% black Sex - linked 50% Amales, 3% black females premature males Other variants (10) b-phosphogluconic dehydrogenase (6-P-GD) (1,11) Glutathione reductase (GR) (11)
Millions, same distribution as B3
Need for exchange transfusion
Risk of death
Frequent
Yes
Yes
Sex - linked
Frequent
Yes
Autosomal recessive and unknown Autosornal dominant and unknown
1/3w
Yes
61
None
Glutathione peroxidase (GSH Px) (1,12)
6
Autosomal recessive
4/6
Glutathione synthetase (GSH synthetase) (1,3,13) y-glutamyl-cysteine synthetase (y-GC synthetase) (3)
7(?8)
Autosomal recessive
None
2
Autosomal recessive
1/2
Autosomal recessive
3/8
DEFECTSINEMBDEN-MEYERHOFGLYCOLYTICPATHWAY Hexokinase (HK) (2,14,15) 8
Yes
Yes
*The number represents the number of reported cases. "~'Manifestationsincludeanemia, hyperbilirubinemia,erylhroblastosis fetalis and hydrops fetalis. Deaths includestillbirths and deaths from hydrops felalisor kernicterus. spherocytes are demonstrable in the peripheral blood smear in some patients, and these changes may be more prominent in wet preparations of blood or fo!lowing splenectomy. Differentiating features of the other red cell enzyme deficiencies are summarized in Table I. Severe deficiencies in red cell N A D P H d i a p h o r a s e , l l a c t a t e dehydrogenase, 2 glyoxalase I1,2 catalase, 2 and D P N Hmethemoglobin reductase 2 have been described but are not associated with hemolysis. The role of the deficiency of red cell galactose-l-phosphate uridyl transferase in hemolysis in some newborn infants with galactosemia is unclear. 9 DIAGNOSIS Hemolysis caused by an intrinsic red cell enzyme deficiency needs to be considered in the differential diagno-
sis of a newborn infant with hydrops fetalis, anemia, or hyperbilirubinemia. With the possible exception of G-6PD deficiency in certain populations, the most c o m m o n causes for hemolysis in the newborn infant, however, are red cell sensitization and congenital and acquired infections. Red cell sensitization from R h incompatibility occurs in one in 250 neonates; sensitization from ABO incompatibility occurs in one in 180 newborn infants. Neonatal sepsis occurs in one in 500 to 1,600 infants. 28 Th e next most frequently occurring causes for anemia and hyperbilirubinemia are respiratory distress synd r o m e , s e v e r e anoxia, f e t o m a t e r n a l t r a n s f u s i o n , enclosed hemorrhage, and hemolysis associated with inherited morphologic variations of the red cell. These entities are usually identifiable from information obtained from a detailed medical and obstetrical history, complete physical examination of the newborn infant, and a few
Volume 84 Number 5
Hemolysis from deficiencies o f red blood cell enzymes
History and clinical manifestations of affected persons*
Laboratory data
Drug-induced hemolysis May have mild CNSHA Affected male siblings[drug-induced or CNSHA]
Pyknocytes
In black Americans: episodic hemolysis after drug, exposure or infection, usually no CNSHA lincidence of jaundice in premature, not term A- males Maternal or infant drug exposure Frequent CNSHA Affected male sibs May have CNSHA or drug-induced hemolysis
Pyknocytes THeinz body formation Abnormal RBC morphology and hemolysis in mother, if she bad drug exposure Pyknocytes I'Heinz body formation May have T Heinz body formation
Late onset of clinical signs: hepatosplenomegaly, spastic neurologic changes May have thrombocytopenia and drug- or thalliuminduced pancytopenia 25% have no hematologic abnormalities Heterozygous neonates may have transient hemolysis without drug, but are well in 3 months Homozygotes may have CNSHA Heterozygotes may be drug sensitive Mild CNSHA in some May have hemolysis from drug or lava beans Mild CNSHA May have late onset neurologic changes
T Heinz body formation Some have decrease in white cells and platelets associated with I GR in white ceils and platelets Rule out acquired dietary riboflavin deficiency
CNSHA 3 patients with Fanconi's anemia
THeinz body formation
I Heinz body formation Abnormal autohemolysis
l" Heinz body formation Abnormal autohemolysis Aniso- and poikilocytosis
Spiculated spherocytes Abnormal autohemolysis I in WBC and platelet number and HK in patients with Fanconi's anemia
~:TableII lists drugs which produce hemolysis. w fraction representsthe numberof reported cases noted to have neonatalmanifestations.
simple laboratory procedures performed on the mother's and infant's blood9 The initial laboratory studies on the infant's blood should include blood type and rhesus factor, direct and indirect Coombs' test, direct- and indirect-reacting serum bilirubin concentration, hemoglobin concentration, hematocrit, reticulocyte count, and examination of the peripheral blood smear. Studies on the mother's blood should include blood type and rhesus factor, serologic test for syphilis, hemoglobin concentration, and examination of the peripheral blood smear. Anemia is frequently overlooked in the newborn inf a n t because of lack of familiarity with n o r m a l hematologic values for the neonatal period. Table III lists these normal values. 9 Small-for-gestational age infants tend to have values appropriate for their gestational age. During the first week of life, capillary
629
Continued.
hemoglobin and hematocrit values are significantly greater than venous values; the m e a n capillary hemoglobin concentration for full-term infants on Day 1 is 19.8 Gin. per 100 ml. with a range of 16.6 to 23.4 Gin. per 100 ml. 9 In the author's laboratory, a cord or venous blood hemoglobin of 14 Gin. per 100 ml. or less or a capillary hemoglobin of 15.5 Gin. per 100 ml. or less is considered evidence of anemia in a full-term infant. Unusual or persistent elevations of the nucleated red cell and reticulocyte counts reflect hemolysis or response to blood loss even without obvious anemia. The rate of rise of the concentration of serum bilirubin is significant. A n increase more rapid than 5 mg9 per 100 9ml. per day in a neonate reflects accelerated hemolysis or enclosed hemorrhage. 29 Pure hemolysis and physiologic jaundice cause elevations of indirect-reacting bilirubin Concentrations of direct-reacting serum bilirubin greater
630
Gilman
The Journal of Pediatrics May 1974
Table I. Cont'd. Neonatal manifestations? Enzyme deficiency (reference)
Epidemiologic features *
Genetic transmission
DEFECTS IN EMBDEN-MEYERHOFGLYCOLYTICPATHWAY Glucosephosphate isomerase 12 (GPI) (2)
Frequency
4/12
Phosphofructokinase (PFK) (2, 16, 17)
5
Sex - linked
None
Triosephosphate isomerase (TPI) (2)
11
Autosomal recessive (?located on chromosome 5)
8/11
?Autosomal recessive
None
10 males 5 females
Sex - linked
2/10
5
1/5
2
Autosomal recessive (?dominant) Unclear
) 135
Autosomal recessive
35/59
Glyceraldehyde-3phosphate dehydrogenase (G-3-PD) (18) Phosphoglycerate kinase (PGK) (19,20) 2,3-dip hosphoglyceromutase (2,3-DPGM) (21) 2,3-diphosp hoglycerate phosphatase (2,3-DPG phosphatase) (2) Pyruvate kinase (PK) (21,22,23,24)
1
Need for exchange transfusion
Risk of death
Yes
Yes
Yes
Very frequent
Yes
OTHER DEFECTS
Ribosephosphate pyrophosphokinase (RPK) (4,25) Adenylate kinase (AK) (9) Adenosine triphosphatase (ATPase) (26)
4
Unknown
3 7(?12)
Autosomal recessive Autosomal dominant
than 1.5 mg. per 100 ml. suggest hepatic obstruction or damage associated with severe red cell sensitization, bacterial sepsis, or other congenital infections. Alterations in the peripheral blood smear frequently suggest the etiology of hemolysis (Fig. 2). Examination of the infant's blood smear for spherocytes, elliptocytes, and stomatocytes will quickly identify an inherited morphologic red cell change. In addition, the blood smear is useful in identifying the spherocytes of ABO incompatibility (Fig. 2, A) and transmitted autoimmune hemolytic anemia, as well as the leukopenia, thrombocytopenia, and fragmented, bizarre red cells associated with congenital rubella, toxoplasmosis, cytomegalic inclusion disease, herpes simplex, syphilis, and acquired bacterial infections. The presence of these alterations suggests the need for confirmatory studies. The presence of target cells and aniso- and poikilocytosis suggest an alpha-chain defect in hemoglobin synthesis which oc-
2/4 2/3 None
curs in 2 to 7 per cent of Oriental and Negro newborn infants. 3~ Changes in red cell morphology in glyc01ytic enzyme deficiencies are quite nonspecific: macrocytosis, polychromatophilia, and occasionally dense spiculated spherocytes (Fig. 2, B). Pyknocytes may be prominent in G-6-PD deficiency (Fig. 2, C). Microspherocytes occur in G-6-PD deficiency following drug exposure or in GPI deficiency. 2 Prominent basophilic stippling is seen in R P K deficiency.a. 25 Persistence of hemolysis beyond the newborn period is often the best indication to suggest an underlying inherited enzymatic defect. Important historical data include a family history of chronic hemolysis or recurrent jaundice; neonatal jaundice; consanguinity; jaundice, anemia, or brown urine following infections or exposure to certain drugs; chronic or recurrent severe infections, neurologic or muscle disease, and sudden death in infant siblings or cousins. Two useful screening laboratory pro-
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Hemolysis from deficiencies o f red blood cell enzymes
History and clinical manifestations of affected persons~ CNSHA
Males: Type VII glycogen storage disease [episodic muscle weakness], very mild CNSHA Mothers: mild CNSHA, no muscle disease Severe CNSHA. Recurrent infection, onset neurologic problems (speech, motor) after 6 months age, early deaths from infection, cardiac arrhythmia "Cat cry" syndrome in 2 patients Sibs or cousins with neurologic dysfunction, early death Mild CNSHA, worse with infection and drug
Males: mental retardation, neurologic problems, recurrent infections, CNSHA and early death Females: mild CNSHA Infant death from seizures or infection in male sibs or cousins CNSHA CNSHA may be mild Cerebral dysgenesis, retarded development, muscular hypotony, achromotrichy Severe CNSHA History of consanguinity, affected sibs
Laboratory data Prominent aniso- and poikilocytosis; spiculated spherocytes Abnormal incubated osmotic fragility and autohemolysis GPI may be deficient in leukocytes and platelets Muscle PFK |; may have [ leukocyte PFK
[ TPI in myocardium, brain, leukocyte Partial deletion of chromosome 5 in "cat cry'syndrome
I Leukocyte G-3-PD
Abnormal autohemolysis May have ~ leukocyte PGK
Abnormal autohemolysis
Spiculated spherocytes; may have pykfiocytes Abnormal autohemolysis
CNSHA
Prominent basophilic stippling of red cells Abnormal autohemolysis
CNSHA CNSHA
Abnormal autohemolysis
cedures include a Heinz body preparation 12 and an autohemolysis test. 31, 32 Heinz bodies are increased in defects in the HMP shunt and in glutathione metabolism. Increased autohemolysis in vitro is found in defects in either of the glycolytic pathways; correction by glucose or ATP will help establish in which glycolytic pathway the defect occurs. 32 The specific enzyme deficiency is determined by quantitative assay of an appropriately obtained and treated blood sample. 33 Simple qualitative screening tests are available for some of the enzymes (G-6-PD, 1GR, 1 GSH Px, 1TPI, 33and PK2). Screening tests for G-6-PD deficiency based on dye reduction, methemoglobin reduction, or fluorescence will detect the homozygous deficient female or the hemizygous deficient male. Female carriers are not always identified, nor are those patients who are deficient but who have an elevated reticulocyte count following a hemolytic reaction. 1If the baby's blood sam-
631
pie contains transfused red cells, the screening test and quantitative assay will not demonstrate the enzyme deficiency. The demonstration of alterations in enzyme activity in family members may suggest a pattern of inheritance and hence assist in making a presumptive diagnosis.
THERAPY If the obstetrical history of a woman reveals that previous pregancies have terminated in delivery of hydropic infants who did not have evidence of red cell sensitization, the possibility of an inherited enzyme deficiency should be considered. If possible, appropriate enzyme assays should then be obtained on the parents. If both parents are shown to be heterozygous for PK, TPI, or HK deficiency, then premature induction of labor may be indicated to save a severely affected infant. Delivery should be undertaken only after preparations have been
632
Gilman
The Journal of Pediatrics May 1974
Table II. Commonly available agents which may produce hemolysis in G-6-PD-deficient persons Headache and cold remedies containing Acetophenetidin (phenacetin), acetanilid, or quinine: 666, APC tablets, Super Anahist, Anacin, Empirin, Bromo Seltzer, Stanback Sulfonamides Nitrofurans Antimalarials Others: Acetylsalicylicacid (large doses) Vitamin K water soluble analogues (doses greater than 2.5 rag. in infant, 100 rag. in adul0 Black Draught and other senna compounds Nalidixic acid (NegGram) p-Aminosalicylicacid Naphthalene mothballs (inhaled or ingested) Nitrobenzene derivatives Aniline derivatives
Fig. 2. A, Spherocytes and a nucleated red cell in B-O incompatibility. B, Dense spiculated spherocytes in CNSHA from PK deficiency. C, Pyknocytes in neonate with G-6-PD deficiency. D, Elliptocytes in congenital ovalocytosis. completed for an immediate packed cell or a regular exchange transfusion in the delivery room. The severity of clinical manifestations of hemolysis will determine which therapeutic measures are necessary. A s e v e r e l y affected infant, p r e s e n t i n g with erythroblastosis fetalis or hydrops fetalis at delivery, should have an immediate exchange transfusion. The use of fresh whole blood is preferable. A partial exchange transfusion with packed red cells may be life saving by stabilizing a moribund infant until he can tolerate a regular exchange transfusion. More than one exchange transfusion may be necessary. Heparinized blood from the infant should be obtained before transfusion and refrigerated for subsequent enzyme assays. A n i n f a n t with severe h y p e r b i l i r u b i n e m i a or symptoms of kernicterus, regardless of the serum bilirubin level, should be treated with one or more exchange transfusions, using freshly drawn whole blood. Severe hyperbilirubinemia is defined as a rate of rise in serum bilirubin concentration of 1 mg. per 100 ml. per hour or greater during the first 24 hours of life; a serum bilirubin concentration greater than 20 mg. per 100 ml. at any age, or a serum bilirubin concentration approaching 20 mg. per 100 ml. with an elevated saturation index.34A sick or premature infant should have an exchange transfusion performed at a lower serum bilirubin concentration than the well full-term infant. The intravenous administration of 1 Gm. of albumin per kilogram of body weight one hour before the exchange
transfusion will result in more efficient removal of bilirubin. 35 However, this priming dose of albumin is contraindicated in the presence of hydrops fetalis, severe anemia (hemoglobin less than 10.5 Gm. per 100 ml. blood, hematocrit less than 32 per cent), congestive heart failure, shock, or cardiac arrhythmias. The need for subsequent transfusions to correct late anemia may be avoided by the administration of the packed red cells which have been allowed to sediment during the exchange transfusion. Another benefit of exchange. transfusion is the temporary reduction of progressive hemolysis, as a result of the removal of most of the enzyme deficient red cells and, in the case of drug-induced hemolysis, removal of any circulating drug (Table II). In the latter instance, a G-6-PD normal donor should be used to provide blood for an exchange transfusion. Infants with mild to moderate degree of hyperbilirubinemia should be observed for progression of hyperbilirubinemia or anemia or appearance of symptoms relating to either. The use of phototherapy to treat hyperbilirubinemia secondary to red cell enzyme deficiencies has not been evaluated, although general guidelines for its use are available. 36 It should not become a s u b s t i t u t e for i d e n t i f y i n g t h e c a u s e o f h y p e r bilirubinemia. An indicated exchange transfusion should not be delayed in order to administer phototherapy. The e f f e c t i v e n e s s o f p h o t o t h e r a p y in reducing hyperbilirubinemia is impaired in the presence of hemolysis. The bilirubin level may not decrease, even when visible jaundice improves with phototherapy. 37 In addition, alterations in erythrocyte membrane metabolism may b e induced by photo-oxidation in the presence of bilirubin, which acts as a photosensitizing agent. 38 Thus, there is the possibility of aggravating hemolysis by using photo-
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Hemolysis from deficiencies of red blood cell enzymes
633
Table III. Normal hematologic values of the newborn infant (venous blood)
Premature (gestational age)
Full-term
Cord blood
Hemoglobin (Gm./100 ml.) Range Hematocrit
(0/0) Reticulocyte count (%) Nucleated RBC per cu. mm. (% per 100 WBC) Per 100 RBC RBC Morphology
16.8 13.7-20.1 (14.0")
Day 7
Day 2
Day 1
17.8
17.0
14.5
15.0
(14.5)
(14.0)
(14.0)
(12.5)
(13.0)
45 (40)
47 (42)
53
58
55
54
(48)
(45)
(45)
500 (10%) 0.1
34 weeks Day 1
18.4
(44) 3-7
28 weeks Day l
3-7
1-3
0-1
200 (7%) 0.05
0-5
0
0 Macrocytes 5% pyknocytes
5-10
3-10
1,000
1,500 (21%)
0
0.5
0.2 Macrocytes 10% pyknocytes
*The hemoglobinand hematocritvalues listed in the parentheses are consideredindicativeof anemia by this author.
therapy in the presence o f a pre-existing metabolic defect. Therefore, the routine use of phototherapy is not advised when a red cell enzyme deficiency is considered in the differential diagnosis. If used in patients with mild hyperbilirubinemia without anemia, the bilirubin and hemoglobin levels should be monitored closely during and following phototherapy. Theoretically, there could be immediate or delayed anemia, if the primary h e m o l y t i c process is exacerbated by phototherapy. If progressive anemia occurs without hyperbilirubinemia and is accompanied by poor sucking and feeding, lethargy, rapid pulse, and enlarging liver, transfusion with packed red blood cells is indicated (15 to 20 cc. per kilogram). Administration of iron will not correct this anemia, although it may prevent delayed anemia when an unusual amount of blood has been drawn for diagnostic purposes, or an exchange transfusion has been given. Folic acid is recommended for the infant with severe chronic hemolysis who is feeding poorly or who has recurrent diarrhea or infections. Infants with mild alterations in hemoglobin and bilirubin levels should be managed by expectant observation while in the nursery. The severity and chronicity of hemolysis should be determined by subsequent follow-up. Parents of infants with red cell enzyme deficiencies associated with drug-induced hemolysis (G-6PD, 6-P-GD, GR, GSH Px, GSH synthetase deficiencies) should be given instructions to avoid the agents listed in Table II.
In families with a history of drug-induced hemolysis, communication between the pediatrician and obstetrician concerning maternal drug ingestion during the third trimester may prevent problems in subsequent newborn infants. Careful planning by this team may allow premature delivery and appropriate emergency measures necessary to salvage a severely affected infant with PK, TPI, or H K deficiency in families who have had a previous severely affected infant. SUMMARY A newborn infant with an inherited deficiency of a red cell enzyme may present with signs of severe or p r o g r e s s i v e h e m o l y s i s . Initial diagnostic m e a s u r e s should exclude the more common causes of hemolysis and then establish evidence for abnormal erythrocyte metabolism. The exact diagnosis is made by an enzyme assay of the infant's red cells. The severity of anemia and hyperbilirubinemia will determine whether a packed red cell or exchange transfusion is necessary. Follow-up is essential to determine the chronicity and severity of hemolysis.
REFERENCES 1. Beutler, E.: Abnormalities of the hexosemonophosphate shunt, Semin. Hematol. 8: 311, 1971. 2. Valentine, W. N.: Deficiencies associated with EmbdenMeyerhof pathway and other metabolic pathways, Semin. Hematol. 8: 348, 1971. 3. Konrad, P. N., Richards, F., II, Valentine, W. N., and
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Paglia, D. E,: 3' -Glutamyl-cysteine synthetase deficiency, N. Engl. J. Med. 286: 557, 1972. Valentine, W. N., Anderson, H. M., Paglia, D. E., et al.: Studies on human erythrocyte nucleotide metabolism. 1I. Nonspherocytic hemolytic anemia, high red cell ATP, and ribosephosphate pyrophosphokinase (RPK, E.C. 2,7,6,1) deficiency, Blood 39: 674, 1972. Carson, P. E., and Frischer, H.: Glucose-6-phosphate dehydrogenase deficiency and related disorders of the pentose phosphate pathway, Am, J. Med. 41: 744, 1966. Fessas, P. H., Doxiadis, S. A., and Valaes, T.: Neonatal jaundice in glucose-6-phosphate dehydrogenase deficient infants, Br. Med. J. 2: 1359, 1962. Doxiadis, S. A., and Valaes, T.: The clinical picture of glucose-6-phosphate deficiency in early infancy, Arch. Dis. Child. 39: 545, 1964. Eshaghpour, E., Oski, F. A., and Williams, M.: The relationship of erythrocyte glucose-6-phosphate dehydrogenase deficiency to hyperbilirubinemia in Negro premature infants, J. PEDIATR.70: 595, t967. Oski, F. A., and Naiman, J. L.: Hematologic problems in the newborn, ed. 2, Philadelphia, 1972, W. B. Saunders Company. Rattazzi, M. C., Corash, L. M., van Zaness, G. E., Jaffe, E. R., and Piomelli, S.: G6PD deficiency and chronic hemolysis: Four new mutants--relationships between clinical syndrome and enzyme kinetics, Blood 38: 205, 1971. Wailer, H. D.: Glutathione reductase deficiency in Beutler, E., editor: Hereditary disorders of erythrocyte metabolism, New York, 1968, Grune & Stratton, Inc. Necheles, T. F., Boles, T. A., and Allen, D. M.: Erythrocyte glutathione-peroxidase deficiency and hemolytic disease of the newborn infant, J. PEDIATR.72: 3t9, 1968. Mohler, D. bl., Majerus, P. W., Minnich, V., Hess, C. E., and Garrick, M. D.: Glutathione synthetase deficiency as a cause of hereditary hemolytic disease, N. Engl. J. Med. 283: 1253, 1970. Valentine, W. N., Oski, F, A., Pagtia, D. E., Baughan, M. A., Schneider, A. S, and Naiman, J. L.: Hereditary hemolytic anemia with hexokinase deficiency. Role of hexokinase in erythrocyte aging, N. Engl. J. Med. 276: 1, 1967. Necheles, T. F., Rai, U. S., and Cameron, D,: Congenital nonspherocytic hemolytic anemia associated with an unusual erythrocyte hexokinase abnormality, J. Lab. Clin. Med. 76: 593, 1970. Tarui, S., Kono, N., Nasu, T., and Nishikawa, M.: Enzymatic basis for the co-existence of myopathy and hemolytic disease in inherited muscle phosphofructose kinase deficiency, Biochem. Biophys. Res. Commun. 34: 77, 1969. Waterbury, L., and Frenkel, E. P.: Phosphofructokinase deficiency in congenital nonspherocytic hemolytic anemia, Clin. Res. 17: 347, 1969. Oski, F., and Whaun, J.: Hemolytic anemia and red cell glyceraldehyde-3-phosphate dehydrogenase deficiency, Clin. Res. 17: 601, 1969. Konrad, p. N., McCarthy, D. J., Mauer, A. M., Valentine, W. N., and Paglia, D. E.: Erythrocyte and leukocyte phosphoglycerate kinase deficiency with neurologic disease, J. PEDIATR,82: 456, 1973.
The Journal of Pediatrics May 1974
20. Valentine, W. N., Hsieh, H. S., Paglia, D. E., Anderson, H. M., Baughan, M. A., Jaffa, E. R., and Garson, O. M.: H e r e d i t a r y h e m o l y t i c a n e m i a a s s o c i a t e d with phosphoglycerate kinase deficiency in erythrocytes and leukocytes, N. Engl. J. Med. 280: 528, 1969. 21. Keitt, A. S.: Pyruvate kinase deficiency and related disorders of red cell glycolysis, Am. J. Med. 41: 762, 1966. 22. Valentine, W. N., Tanaka, K. R., and Miwa, S.: Specific erythrocyte glycolytic enzyme defect (pyruvate kinase) in three subjects with congenital non-spherocytic hemolytic anemia, Trans. Assoc. Am. Physicians 74: 100, 1961. 23. Tanaka, K. R., and Paglia, D. E.: Pyruvate kinase deficiency, Semin. Hematol. 8: 367, 1971. 24. Oski, F. A., and Diamond, L. K.: Erythrocyte pyruvate kinase deficiency resuiting in congenital nonspherocytic hemolytic anemia, N. Engl. J. Med. 269: 763, 1963. 25. Valentine, W. N., Bennett, J. M., Krivit, W., Konrad, P. N., Lowman, J. T., Paglia, D. E., and Wakem, C. J.: Nonspherocytic, haemolytic anaemia with increased red cell adenine nucleotides, glutathione and basophific stippling and ribosephosphate pyrophosphokinase (RPK) deficiency: studies on two new kindreds, Br. J. Haematol. 24: 157, 1973. 26. Harvald, B., Hanel, K. H., Squires, R., and Trap-Jensen, J.: Adenosine-triphosphatase deficiency in patients with nonspherocytic haemolytic anaemia, Lancet 2: 18, 1964. 27. Doxiadis, S. A., Fessas, P., Valaes, T., and Mastrokalos, N.: Glucose-6-phosphate dehydrogenase deficiency: A new aetiological factor of severe neonatal jaundice, Lancet 1: 297, 1961. 28. Gotoff, S. P., and Behrman, R. E.: Neonatal septicemia, J. PEDIATR.76: 14~2,1970. 29. Rausen, A. R., and Diamond, L. K.: "Enclosed" hemorrhage and neonatal jaundice, Am. J. Dis. Child. 101: 164, 1961. 30. Weatherall, D. J.: Abnormal haemoglobins in the neonatal period and their relationship to thalassemia, Br. J. Haematol. 9: 265, 1963. 31. Rudolph, N., and Gross, R. T.: Studies of in-vitro autohaemolysis in blood from newborn infants, Br. J. Haematol. 12: 351, 1966. 32. Smith, C. H.: Blood diseases of infancy and childhood, ed. 3, St. Louis, 1972, The C. V. Mosby Company. 33. Beutler, E.: Red cell metabolism. A manual of biochemical methods, New York, 1971, Grune & Stratton, Inc. 34. Odell, G. B., Cohen, S. N., and Kelly, P. C.: Studies in kernicterus II. The determination of the saturation of serum albumin with bilirubin, J. PEDIATR.74: 214, 1969. 35. OdeLI,G. B., Cohen, S. N., and Gordes, E. H.: Administration of albumin in the management of hyperbilirubinemia by exchange transfusion , Pediatrics 30: 613, 1962. 36. Behrman, R. E., and Hsia, D. Y. Y.: Summary of a symposium on phototherapy for hyperbiliruhinemia, J. PEDIATR.75: 718, 1969. 37. Patel, D. A., Pildes, R. S., and Behrman, R. E.: Failure of phototherapy to reduce serum bilirubin in newborn infants, J. PEDIATR,77: 1048, 1970. 38. Odell, G. B., Brown, R. S., and Kopelman, A. E.: The photodynamic action of bilirubin on erythrocytes, J. PEDIATR.81: 473, 1972.