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Neonatal IgM response to acute infection
December, 1969 T h e J o u r n a l of P E D I A T R I C S
1261
Neonatal IgM response to acute infection Prospective observations were made on 567 newborn in[ants to evaluate the association between elevations o[ I g M levels and occurrence o[ acute injections. Five clinical syndromes o[ acute injection were studied. Abnormal elevations occurred in most injected in[ants sez,eral days after appearance o[ clinical signs. Results o[ this study suggest that an I g M screening program for acute injections among high risk infants would [urnish only confirmatory diagnostic in[ormation in most instances. Neonatal I g M determination is, however, an excellent tool/or clinical research.
Sheldon B. Korones, M.D., "x"Jourdan A. Roane, M.D., Mary R. Gilkeson, B.S., Walter Lafferty, B.S., and John L. Sever, M.D., Ph.D. MEMPHIS,
TENN.,
AND BETHESDA~
MD.
C L I N I C A L signs of infection in the newborn infant usually lack specificity, if they are at all present. Except for eventual identification of etiologic agents, laboratory procedures which are routinely utilized as diagnostic aids are of limited value. Measurements of neonatal imlnunoglobulin responses to infection may well have important clinical applications. The potential values and limitations of these procedures have been aptly recognized by sponsorship of this symposium. Several published reports have indicated that elevations of neonatal I g M levels occur in chronic congenital infections such as rubella, ~, '-' cytomegalovirus infection, a toxoplas-
From the Department o[ Pediatrics, University o[ Tennessee, College o[ Medicine and the Section on In[ectious Disease, Perinatal Research Branch, National Institute o[ Neurological Diseases and Stroke. ~Reprint address: GaiIor Memorial Hospital, 42 N. Dunlap, 5th floor, Memphis, Tennessee 38103.
mosis,4.5 and syphilis? The same phenomenon has been observed in herpes simplex infectionfi Stiehm and associates 7 and Alford and associates 1 reported a n m n b e r of infants whose I g M levels were elevated in association with acute infections. O u r study was undertaken to assess the usefulness of serially determined I g M concentrations as aids in the recognition of acute neonatal infections. We were particularly interested in the regularity with which one m a y expect I g M elevations in various infections, the magnitude of these elevations, and the temporal relationship between them and onset of clinical signs. Data in this report are from an ongoing prospective study of I g M response to infection in newborn infants who were admitted to the nurseries of the City of Memphis Hospitals.
METHODS Clinical observations were made prospectively on neonates admitted to the sick Vol. 75, No. 6, part 2, pp. 1261-1270
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Korones et aI.
infant and premature nurseries and on twins who may have been admitted to the fullterm nursery as well. Observations presented in this report were made over an 8 month period between June, 1968, and March, 1969. Infants were examined and their descriptions were recorded by a senior house officer specifically assigned to this study or by one of the authors (S. B. K.). Observations and diagnostic impressions were recorded without knowledge of IgM outcome. Each infant's hospital chart was reviewed by two of the authors and notations were transposed to a summary code sheet. Blood was collected from the umbilical cord at time of delivery and capillary blood was taken by heel prick approximately twice weekly on designated days of the week for the duration of each infant's nursery stay. Serum was separated soon after collection and stored frozen, pending shipment once weekly to the Infectious Disease Laboratory, Perinatal Research Branch, National Institute of Neurological Disease and Stroke (Dr. Sever). IgM assays were performed by a radial diffusion plate method, which has been described elsewhere, s utilizing commercially prepared plates (Hyland Laboratories, Los Angeles, Calif.). Concentrations below 6.0 mg. per cent were reported as "nonreactive" and those over 190 mg. per cent were reported as greater than that value.
The Journal o[ Pediatrics December 1969
TaMe I. Birth weights of 567 study infants Birth weight (Gin.)
No. patients
%
501-1,000 1,001-1,500 1,501-2,000 2,001-2,500 > 2,500 Unknown
19 44 122 188 191 3
3.4 7.7 21.5 33.2 33.7 0.5
Table II. Gestational ages of 567 study infants Gest. age (wk.) < 27 28-30 31-33 34-36 _> 37 Unknown
No. patients 24 40 63 117 232 91
% 4.3 7.1 11.1 20.6 41.0 16.0
Table III. General diagnostic categories of 567 study infants No.
Diagnostic category No disease Definite infection Definite infection with noninfectious disorder Suspected infection Noninfectious disorder
patients 337 63
% 59.6 11.1
15 28 124
2.6 4.9 21.9
RESULTS General characteristics of study population. These data are based upon 2,890 I g M determinations from 567 Negro infants. There were 286 (50.4 per cent) males and 28.1 (49.6 per cent) females. The study cohort includes 33 pairs os twins, 2 sets of triplets, and 11 unmatched twins. Birth weight and gestational age distributions are given in Tables I and II. Distribution of infants by general diagnostic categories is presented in Table III. Serologic test for syphilis. Maternal sera were routinely tested against Venereal Disease Research Laboratory (VDRL) antigen and 6 positive results were observed.
These tests were negative in 5 infants. The sixth infant, who died on the first day of life, weighed 830 grams. Necropsy revealed only extensive atelectasis. Cord IgM was less than 6.0 mg. per cent. IgM levels in healthy infants. Percentile curves for 337 healthy infants according to IgM concentrations for each of the first 28 days of life are presented in Fig. 1. All birth weights were included and events of pregnancy, labor, and delivery were disregarded. Table IV lists data from which these curves were drawn, as well as the range of IgM concentrations and number of infants studied each day. Birth weight over 2,000
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Neonatal I g M response to acute injection
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50
3o "
f
o C 0 R
i-t-w 2
4
T'-I-I\ .\li
/11
] 6
8
IO
/
-r I 12
14 [6 AGE IN DAYS
\ 95% 9~
I--.
; 18
20
22
24
-.5~ 26
28
D
Fig. 1. IgM in 337 healthy Negro neonates (1,324 sera) of all birth weights.
Table IV. Percentiles for IgM n e o n a t e s (all b i r t h w e i g h t s )
Age (days)
50
Cord 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
7.3 8.2 7.4 8.4 8.3 10.6 11.9 15.0 15.0 15.6 15.6 16.8 17.4 19.3 18.6 16.4 16.5 14.1 16.1 I9.4 14.7 16.3 18.5 18.2 14.9 16.2 20.2 16.1 14.3
grams was infants and per cent). unknown. only one
(mg.%)
b y d a y of life f o r 337 h e a l t h y N e g r o
Percentiles [or IgM (rag.%) t 75 I 90 I 95 10.1 11.3 10.2 11.6 11.4 14.6 16.5 20.7 20.8 21.6 21.5 23.2 24.0 26.7 25.7 22.7 22.8 19.5 22.3 26.8 20.3 22.5 25.6 25.2 20.5 22.4 27.9 22.3 19.7
13.5 15.1 13.7 15.6 15.3 19.6 22.1 27.7 27.8 28.9 28.9 31.0 32.2 35.8 34.4 30.4 30.5 26.1 29.8 35.9 27.2 30.1 34.2 33.7
27.5 30.0 37.4 29.9 26.4
r e c o r d e d f o r 268 ( 7 9 . 9 p e r c e n t ) 2,000 g r a m s o r less f o r 68 (20.1 Weight of o n e i n f a n t w a s When twins were encountered, infant from each pair was
16.0 18.0 16.3 18.6 18.2 23.3 26.3 33.0 33.1 34.4 34.3 37.0 38.3 42.6 40.9 36.2 36.3 31.0 35.5 42.7 32.3 35.9 40.8 40.1 32.7 35.7 44.5 35.6 31.4
1
99 22.3 25.0 22.6 25.7 25.3 32.4 36.4 45.8 45.9 47.8 47.6 51.3 53.1 59.0 56.8 50.2 50.4 43.0 49.3 59.2 44.9 49.7 56.6 55.7 45.4 49.5 61.8 49.3 43.6
Range lgM __ High l Low 24 21 20 26 19 22 57 45 38 39 50 35 37 39 44 40 36 39 35 47 35 39 54 38 26 32 27 34 23
5 3 5 5 5 5 5 5 5 5 5 5 5 7 8 5 5 5 5 I0 5 7 5 10 5 5 13 5 5
No. 244 102 102 84 81 59 51 68 60 48 55 37 30 28 32 38 32 28 13 I9 15 17 18 20 12 11 5 7 8
i n c l u d e d . A v a l u e of 5.0 m g . p e r c e n t w a s a s s i g n e d t o d e t e r m i n a t i o n s r e p o r t e d as " n o n reactive." I g M levels i n c o r d b l o o d . I g M d e t e r m i n a t i o n s w e r e p e r f o r m e d o n c o r d s e r a f r o m 335
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The ]ournal o[ Pediatrics December 1969
Table V. Summary of percentile placement of 57 infected infants by I g M level Injection Conjunctivitis: Nonbacterial Bacterial Pneumonia Septicemia Diarrhea Moniliasis (oral)
No. patients
99
9 12 11 7 10 8
7 0 7 2 2 0
No. patients by percentile I 95 I 90 t < 90
1 0 1 1 2 0
irffants. Concentrations from 20 to 120 mg. per cent were demonstrated in 26 specimens (7.8 per cent). Twenty-two (6.6 per cent) of the specimens were thought to contain maternal blood. IgA levels in 19 of them were 1.3 to 8.0 times greater than I g M values. Another serum contained 82.8 mg. per cent I g M and 52.0 mg. per cent IgA, while a day later the I g M was 6.0 mg. per cent. One other sample contained 88.5 mg. per cent I g M and 88.0 mg. per cent IgA. Later determinations were not performed. Eighteen I g M values were obtained from capillary blood within 5 days after cord samples were collected (most were obtained within 48 hours) and 13 of them were below 10 mg. per cent, while 5 others were between 10 and 20 mg. per cent. Cord sera from 4 infants were thought to contain true elevations of I g M which were between 21.8 and 23.0 mg. per cent. IgA was undetectable in all these specimens. These infants were normal in the nursery. Follow-up examination was obtained in but one of them (at 4 months of age) and resulted in normal findings. IgM levels in infected infants. Five different syndromes os infection were studied, i.e., conjunctivitis, pneumonia, septicemia, diarrhea, and oral moniliasis. I g M levels for each entity are given in percentiles according to data for healthy neonates shown in Table I V and Fig. 1. Percentile placements by day of life were analyzed in relation to the day on which signs of disease were first observed. These results are summarized in Table V.
0 3 1 I 2 0
1 9 2 3 4 8
First day > 90 percentile related to onset o[ injection
2 d. before to 12 d. after 3 d. before to 6 d. after Day onset to 10 d. after 2 to I0 d. after 5 d. before to 5 d. after None in 90 percentile
Conjunctivitis. Exudative conjunctivitis occurred in 21 infants which, on clinical bases, could be categorized as probable nonbacterial infections (9 infants) or bacterial infections (12 infants). Bacterial cultures of exudate from infants with nonbacterial conjunctivitis were negative in 4 instances and yielded organisms which were not considered to be the etiologic agents in 5. Cultures from eyes of the bacterial group yielded Gonococcus in 5 infants, Staphylococcus aureus in 2 infants, group B streptococcus and E. coli in one infant each, and H. aegyptus plus E. coli in one infant. Direct smear of exudate from one other infant showed numerous gram-positive cocci and gram-negative rods (a report of culture was not available). Virus cultures were not obtained from any of the 21 infants. Days of onset differed between the 2 groups. In nonbacterial infections, exudate was first noted between 5 and 14 days of life, while in the bacterial infections the day of onset ranged from the first to the twentieth day. There was also difference between the 2 groups in the persistence of exudation despite treatment of all infants with an ophthalmic preparation which contained neosporin, polymyxin, and bacitracin (penicillin was administered for gonococcal infection). Mean duration of exudate in the infants with nonbacterial conjunctivitis was 13.6 days (3 to 24 days) and for those with bacterial disease it was 4.4 days (2 to 11 days). Both groups were observed for a sufficient length of time after onset of disease to permit analysis of I g M responses. Mean day of
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T a b l e V I . Conjunctivitis, n o n b a c t e r i a l a n d b a c t e r i a l : D a y of onset a n d I g M levels (21 infants) Case No. Bacterial culture Nonbacterial (9 cases) 4 Strep. [aecalis 43 Staph. epidemicus 51 Strep. viridans 107 Negative 122 Negative 136 Staph. epidemieus 173 Negative 229 Negative 405 Staph. epidemieus Bacterial (12 cases) 1 Gonococcus 13 Gr. B strep. 121 E. eoli 156 Staph. aureus 253 Gonococcus 397 Gonococcus 420 Gonococcus 429 E. coli 445 Gram + cocci gram-neg, rods 490 H. aegyptus E. coli 1,006 Staph. aureus 1,013 Gonococcus
Duration exudate (days)
Day of onset
First day > 90 percentile
Highest percentile
9 9 14 10 6 6 8 5 10
19 7 21 16 13 -13 17 14
95 99 99 99 99 75 99 99 99
13 15 14 6 20 24+ 3 16 11
2 2 1 14 9 9 6 24 20
-5 -------17
~ 50 90 .( 50 50 75 ~ 50 ~ 50 75 90
3 2 4 i1 Unk. 3 Unk. 5 3
16
--
50
5
3 10
-16
~ 50 90
4 4
observation after a p p e a r a n c e of e x u d a t e was 14.4 for n o n b a c t e r i a l infection a n d 11.8 for bacterial infection. T h e two groups of infants differed in their I g M response. Eight of the 9 cases of n o n b a c t e r i a l conjunctivitis were associated with elevations of I g M levels beyond the ninety-fifth percentile, while I g M in only 3 of the 12 cases of bacterial infection attained the ninetieth percentile. Details of these d a t a are presented in T a b l e V I a n d curves of I g M levels by day of infection for the two groups of infants are presented in Fig. 2. F o l l o w - u p e x a m i n a t i o n has so far been p e r f o r m e d on 6 of the 9 infants with nonbacterial infection a n d 3 of these were abnormal. Baby L. (Case 4) was seen by us at 9 m o n t h s of age at which time spastic diplegia was noted. H e a d circumference a n d skull films were normal. A t 6 m o n t h s of age he was a d m i t t e d to the hospital following
occurrence of a generalized seizure. T r a n sient t e m p e r a t u r e elevation of 101 ~ F. was first observed on the fourth hospital day. Spinal fluid was n o r m a l on 2 occasions. I n the nursery, conjunctivitis a p p e a r e d on the ninth d a y a n d I g M surpassed the ninetyfifth percentile (46.5 rag. p e r cent) on the nineteenth day. Baby M. (Case 229) was evaluated by us at 5 m o n t h s of age a t which time h e a d control was p o o r a n d he was extremely hyperactive. H e was hospitalized at 3 months of age for p n e u m o n i a w h i c h persisted radiologically for 13 days. I n the n u r sery, eye exudate a p p e a r e d on t h e fifth day a n d persisted for 16 days. Highest I g M levels rose beyond the n i n e t y - n i n t h percentile on the seventeenth d a y of life a n d ultimately reached 184.0 mg. p e r cent on the thirtyfirst day when he was discharged. Baby P. (Case 405) was e x a m i n e d at 3 m o n t h s of age at which time his weight was 3,045 grams (birth weight 2,000 g r a m s ) . H e was
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Korones et al.
The Journal of Pediatrics December 1969
200
/
180
160 9- - . o----o
140
NON-BACTERIAL-9 INFANTS BACTERIAL-INFANT WITH HIGHEST LEVELS. FROM 12 CASES
120
:E
I00
~n
80
60
40
.j
20
- 3 -2 - I 0 DAYS DAY BEFORE ONSET
2
4
6
8
I0 12 DAYS AFTER
14
16
18
20
Fig, 2. IgM levels in bacterial and nonbacterial conjunctivitis.
obviously undergrown but other abnormalities were not evident. During the nursery course, eye exudate appeared on the tenth day and persisted for 11 days. IgM level rose beyond the ninety-ninth percentile (58.0 mg. per cent) by the eighteenth day of life. Pneumonia. Pneumonia was diagnosed in 11 infants. A pediatric radiologist, who was unaware of results of IgM determinations, evaluated the chest films of each infant. Radiographic appearance of the lungs was compatible with the diagnosis of pneumonia in 10 infants and was suggestive in one. IgM levels in 7 subjects placed them in the ninety-ninth percentile, while 2 infants were in the ninety-fifth and ninetieth percentiles, respectively. The remainirrg 2 in-
fants were below the fiftieth percentile. One of these babies died on the fourth day of life after severe perinataI distress and persistent respiratory difficulty throughout life. His mother's temperature at the time of delivery was 101.6 ~ F. and the amniotic fluid was purulent. Radiographic appearance of pneumonia was evident on the day of birth. Necropsy revealed extensive bronchopneumonia. Only one IgM determination was performed and this was on the second day of life. It was reported to be nonreactive (below 6.0 mg. per cent). The second infant, a breech delivery, experienced 4 severe apneic episodes during the first 24 hours of life. Two chest films on this day revealed dense areas throughout both lungs, but a moderate degree of improvement was noted on the the second film. Eight IgM determi-
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Neonatal I g M response to acute injection
126 7
T a b l e V I I . Septicemia: Etiologic agent, d a y of onset, and I g M levels (7 infants) Case No. 9 20 108 170 341 1002 1012
Organism E. coli E. coli A. aerogenes Gr. B. strep. M. polymorpha L. monocytogenes P. morgagni
Day of onset
First day Highest percentile >_ 90 percentile
23 5 1 1 1 I0 1
24 -9 10 -14 --
95 <50 99 90 75 99 50
Table VIII. D i a r r h e a Case No. 177 210 227 228 357 402 466 470 522 552
Organism E. eoli, 0111 :B4 Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown
nations were p e r f o r m e d between the second and twenty-sixth days of life a n d none exceeded the fiftieth percentile. Septicemia. Bacterial organisms were cultured from the blood of 7 infants. Agents recovered, day of onset of infection, a n d percentile levels of I g M concentrations are given in T a b l e V I I . I g M levels in 4 infants placed t h e m in the ninetieth percentile or above, while 3 others were below the ninetieth percentile. Diarrhea. F r e q u e n t watery or loose stools were observed from 10 babies. E. coli, 0111:B4, was recovered from one infant. Bacterial p a t h o g e n s were not present in stools of the r e m a i n i n g 9 infants. V i r a l cultures were not obtained. I g M levels were above the ninetieth percentile in 6 infants and below the ninetieth percentile in 4. Details of these observations are presented in Table VIII. Oral moniliasis. O r a l lesions characteristic of m o n i l i a infection were observed in 8 subjects. I g M concentrations did n o t reach the ninetieth percentile in any of these infants.
Day of onset 9 3 4 5 5 3 3 3 15 2
First day > 90 percentile Highest percentile 4 99 -50 9 95 2 95 -<50 4 90 4 90 -75 10 99 -<50
DISCUSSION Data on healthy infants. T h e 337 h e a l t h y neonates who were categorized b y percentiles (Fig. 1 a n d T a b l e I V ) e x h i b i t e d no evidence of infectious or noninfectious disorders d u r i n g their nursery stay. T h e multiple factors w h i c h s t i m u l a t e p r o d u c t i o n of immunoglobulins in a p p a r e n t l y h e a l t h y neonates are not well defined. W e h a v e not, for instance, a t t e m p t e d to e v a l u a t e t h e effects of antibiotic a d m i n i s t r a t i o n in the 73 (21.6 p e r cent) h e a l t h y infants who received them p r o p h y l a c t i c a l l y ; nor have we a t t e m p t e d to define the roles os feeding a n d b a c t e r i a l colonization. C a t e g o r i z a t i o n of I g M levels in healthy neonates by birth weight or gestational age would be i m p o r t a n t b u t our study sample is as yet not sufficiently large to acc o m m o d a t e such as analysis. IgM in cord sera. D e t e r m i n a t i o n s in 335 cord sera yielded 22 specimens (6.6 p e r cent) w h i c h c o n t a i n e d spuriously high levels of I g M p r e s u m a b l y due to c o n t a m i n a t i o n by m a t e r n a l blood. This p h e n o m e n o n imposes a serious l i m i t a t i o n on any screening pro-
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Korones et al.
cedure restricted to I g M in cord samples. If IgM screening is to be performed, capillary samples taken soon after birth and periodically thereafter are clearly preferable to cord samples. Congenital infections are not regularly associated with abnormal increases in IgM levels. McCracken and associates 2 showed concentrations in excess of 20 mg. per cent in only 18 per cent of infants in whom congenital rubella was diagnosed. Ackerman 9 reported an infant who died 6 hours after birth in whom severe congenital syphilis was demonstrated serologically and at necropsy. Using a method similar to the one we have employed, he could not detect IgM in the infant's serum (less than 6.0 rag. per cent). An opportunity to further pursue this point was provided us by data from a previous study of neonatal pneumonia from the Collaborative Perinatal Project? ~ IgM levels were determined on stored cord sera from 30 infants in whom onset of pneumonia occurred within 48 hours after birth. IgM was not detectable (less than 6.0 rag. per cent) in 24 of the 30 specimens. T h e highest concentration in any of the sera was 14.0 mg. per cent. Fourteen infants died within 4 days after birth and in 13 of them IgM was not detected. Sera from 11 of the 16 survivors also did not contain detectable IgM. There was a high incidence of "nonreactivity" in sera of infants who died shortly after birth. A study of immunoglobulin responses in such infants would be of interest. Conjunctivitis. T h e 9 infants in whom nonbacterial conjunctivitis was diagnosed constituted a surprising facet of this study. T h e term "nonbacterial" was applied for want of a better one. This group of infants is characterized as follows: (1) Onset of infection occurred between the fifth and fourteenth days of life; (2) exudate persisted in spite of apparently appropriate treatment; (3) bacterial cultures were negative or yielded organisms of dubious etiologic significance which should have responded to the treatment administered; (4) IgM levels were unusually high in all but one infant; (5) abnormalities were demonstrable in 3 of
The Journal o[ Pediatrics December 1969
the 6 infants thus far followed during the postneonatal period. Our attention was drawn to these infants because of the persistence of conjuncrival exudate and the time of onset, both of which are compatible with inclusion conjunctivitis ( T R I C [trachoma inclusion conjunctivitis] agent). Conjunctival scrapings from 3 infants were negative for inclusions. Only routine bacterial cultures were performed. We were unaware of the high I g M levels these infants had in common. Identification of the causative agent or agents is obviously essential. These clinically classified infections could be an indication of generalized disease which in some instances is associated with subsequent abnormality of growth and development, or they may be uncomplicated conjunctivites caused by one or more organisms capable of elicting an unusually vigorous IgM response. Pneumonia. I g M levels exceeded the ninetieth percentile in 9 of the 11 infants in whom pneumonia occurred. Seven of them were in the ninety-ninth percentile. One of the infants in whom an elevated level did not occur died on the second day of life. Extensive bronchopneumonia was evident at necropsy. One I g M determination, performed on the second day, was nonreactive (less than 6.0 mg. per cent). These findings are similar to those for babies from the Collaborative Perinatal Project who were described in the discussion on cord sera. Low I g M levels seem to be common in infants with fatal pneumonia which begins in utero or within 48 hours after birth. The second infant whose I g M concentrations were not abnormally high m a y not have been infected. This is suggested by the moderate improvement which was noted on the second of 2 chest films taken the same day. Five I g M determinations were performed over the 16 day period of her stay in the nursery. Elevations of I g M levels occurred as early as the day of onset and as late as 10 days after onset of pneumonia. Study design provided for sampling twice weekly and most specimens were therefore taken at 2, 3, and
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Neonatal I g M response to acute infection
4 day intervals. Precise estimation of the day on which elevated levels occurred is not feasible. The infant whose first abnormal rise occurred on the tenth day of disease had 2 previous determinations on the third and sixth days. These data indicate that I g M elevations beyond the ninetieth percentile m a y be expected to occur in association with neonatal pneumonia. An important exception to this statement is the fatally ill infant in whom onset os pneumonia occurs in utero or within 48 hours after birth. Septicemia. Results from 7 infants with apparent septicemia were disappointing. Few neonatal diagnoses are so often made on clinical grounds and so infrequently documented. I g M levels to the ninetieth percentile or above were noted in 4 of 7 infants. T h e organisms which were recovered from the blood were unlikely to be coincidental contaminants (Table V I I ) . Several explanations for the observed array of I g M responses are suggested: (1) Bacteremia rather than septicemia was present in infants whose I g M levels were not elevated; (2) early treatment with effective antibiotics precluded an abnormal rise of I g M ; (3) the immunogenic capacity of different bacterial organisms varies considerably. The management of sick infants would be aided immeasurably if a consistent relationship between I g M elevation, clinical signs, and results of bacterial culture were demonstrated in a large series of septicemic infants. Diarrhea. I g M concentrations rose to the ninetieth percentile or above in 6 of 10 infants whose stools were abnormal. The most interesting aspect of these results is the appearance of increased I g M levels 3 to 5 days before onset of diarrhea in 3 of 6 infants in whom elevations occurred. CONCLUSIONS
Would a screening program for increased levels of I g M be worthwhile for earlier identification of acute infections in a high risk newborn population? In this study, I g M elevations occurred several days
1 2 69
after onset of physical signs with but few exceptions. Assiduous clinical surveillance detected most infections before I g M elevations would have become known to us. One can envision a program in which blood samples are taken once or twice weekly for all high risk infants, but such routine procedures tend to relax alertness of nurse attendants and physicians as well. Information generated by such a screening activity would undoubtedly be valuable confirmatory evidence of clinical impressions which have been long since acted upon. This is not to deprecate the obvious value of neonatal I g M quantitation for clinical research purposes. T h e suggestions furnished by data in this study from infants with conjunctivitis exemplify the type of clinical information which can evolve from application of immunoglobulin determinations to cribside problems. Radiologic interpretations were made by Barry E. Gerald, M.D., Associate Professor of Radiology, Director of Diagnostic Section, Department of Radiology, University of Tennessee College of Medicine. Mrs. Mary W. Gann, Head Nurse, and the entire nursing staff of the delivery suite and house officers of the Department of Obstetrics and Gynecology cooperated fully in collection of cord samples. Dr. Donald A. Thomas performed evaluations of infants in the nursery. Studies of this type are impossible without the interest of those listed above and many more who are not mentioned. REFERENCES
1. Alford, C. A., Schaefer, J., Blankenship, W. J., Straumfjord, J. V., and Cassady, G.: A correlative immunologic, microbiologic and clinical approach to the diagnosis of acute and chronic infections in newborn infants, New England J. Med. 277: 437, 1967. 2. McCracken, G. H., Jr., Hardy, J. B., Chen, T. C., Hoffman, L. S., Gilkeson, M. R., and Sever, J. L.: Serum immunoglobulin levels in newborn infants. II. Survey of cord and follow-up sera from 123 infants with congenital rubella, J. PEDIAT. 74: 383, 1969. 3. McCracken, G. H., Jr., and Shinefield, H. R.: Immunoglobulin concentrations in newborn infants with congenital cytomegalic inclusion disease, Pediatrics 36" 933, 1965. 4. McCraeken, G. It., Jr., and Sever, J. L.: Unpublished data.
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5. Eichenwald, H. F., and Shinefield, H. R.: Antibody production by the human fetus, J. PEDIAT. 63: 870, 1963. (Abst.) 6. Sieber, O. F., Jr., Fulginiti, V. A., Brazie, J., and Umlauf, H. J.: In utero infection of the fetus by herpes simplex virus, J. PEmAT. 69: 30, 1966. 7. Stiehm, E. R., Ammann, A. J., and Cherry, J. D.: Elevated cord macroglobulins in the diagnosis of intrauterine infections, New England J. Med. 275: 971, 1966. 8. McCracken, G. H., Jr., Chen, T. C., Hardy, J. B., and Tzan, N.: Serum immunoglobulin levels in newborn infants. I. Evaluation of a radial diffusion plate method, J. PEDIAT. 74: 378, 1969. 9. Ackerman, B. D.: Congenital syphilis: observations on laboratory diagnosis of intrauterine infection, J. PEDIAT. 74: 459, 1969. 10. Korones, S. B., Abramson, H., and Fujikura, T.: Neonatal pneumonia in liveborn infants, Paper presented at the Meeting of the Collaborative Study on Cerebral Palsy, Mental Retardation and other Neurological and Sensow Disorders of Infancy and Childhood, Washington, D. C., March 24, 1966. DISCUSSION DR. BLANKENSHIP. May I ask Dr. Korones how he made the diagnosis of pneumonia and how can you exclude the possibility that this was noninfectious? By that I would like to suggest that we often see meconium aspiration pneumonia which is in no way associated with infection. If you made your diagnosis of pneumonia on the basis of bacteria and recovery, how did you obtain your specimen? DR. KORONES. No, we were confronted with the same difficulty one is always confronted with. We had to satisfy ourselves with radiologic appearances. In most instances the densities persisted for several days. In one of the two infants in whom IgM elevations did not occur, severe respiratory distress occurred on the second day of life. There was moderate improvement in the second of two films taken that day. This infant
The Journal o[ Pediatrics December 1969
was probably not infected. We have nothing more definitive than the x-ray for the diagnosis of pneumonia. DR. BERENDES. Have you arranged IgM levels by birth weight of child? DR. KORONES. No. DR. BERENDES. I raise this question because it seems obvious from some of the presentations made today that in judging the significance of the IgM level one has to take birth weight into consideration. I say this specifically in view of the lack of an association with pneumonia which occurred during the first two days of li[e, a condition which I believe is almost exclusively found in premature children. DR. KORONES. Your first question was whether I had these IgM values categorized by birth weight and the answer is no. We do not yet have enough data. In our cohort of "healthy" neonates, a number of them were below 2,000 grams at birth. Your second allusion was to infants with pneumonia. I said of 14 infants from the Collaborative Project who died, IgM in 13 of them was less than 6.0 mg. per cent. Of those 13, 5 were over 2,500 grams at birth. DR. ALFORD. One thing that has to be taken into consideration is the time of acquisition of the infection. It takes time to develop an immunoglobulin response. I n many acute infections it is extremely difficult to ascertain the point of acquisition. Conjunctivitis may well be acquired at the time of delivery. Hence, serial determinations may be required to show an IgM rise especially in infections acquired at or right before delivery. DR. KORONES. These were, of course, serial determinations. Mean length of observation was 14.4 and 11.8 days for nonbacterial and bacterial conjunctivitis, respectively. We observed virtually no abnormal IgM elevations in the bacterial infections.
1261
Neonatal IgM response to acute infection Prospective observations were made on 567 newborn in[ants to evaluate the association between elevations o[ I g M levels and occurrence o[ acute injections. Five clinical syndromes o[ acute injection were studied. Abnormal elevations occurred in most injected in[ants sez,eral days after appearance o[ clinical signs. Results o[ this study suggest that an I g M screening program for acute injections among high risk infants would [urnish only confirmatory diagnostic in[ormation in most instances. Neonatal I g M determination is, however, an excellent tool/or clinical research.
Sheldon B. Korones, M.D., "x"Jourdan A. Roane, M.D., Mary R. Gilkeson, B.S., Walter Lafferty, B.S., and John L. Sever, M.D., Ph.D. MEMPHIS,
TENN.,
AND BETHESDA~
MD.
C L I N I C A L signs of infection in the newborn infant usually lack specificity, if they are at all present. Except for eventual identification of etiologic agents, laboratory procedures which are routinely utilized as diagnostic aids are of limited value. Measurements of neonatal imlnunoglobulin responses to infection may well have important clinical applications. The potential values and limitations of these procedures have been aptly recognized by sponsorship of this symposium. Several published reports have indicated that elevations of neonatal I g M levels occur in chronic congenital infections such as rubella, ~, '-' cytomegalovirus infection, a toxoplas-
From the Department o[ Pediatrics, University o[ Tennessee, College o[ Medicine and the Section on In[ectious Disease, Perinatal Research Branch, National Institute o[ Neurological Diseases and Stroke. ~Reprint address: GaiIor Memorial Hospital, 42 N. Dunlap, 5th floor, Memphis, Tennessee 38103.
mosis,4.5 and syphilis? The same phenomenon has been observed in herpes simplex infectionfi Stiehm and associates 7 and Alford and associates 1 reported a n m n b e r of infants whose I g M levels were elevated in association with acute infections. O u r study was undertaken to assess the usefulness of serially determined I g M concentrations as aids in the recognition of acute neonatal infections. We were particularly interested in the regularity with which one m a y expect I g M elevations in various infections, the magnitude of these elevations, and the temporal relationship between them and onset of clinical signs. Data in this report are from an ongoing prospective study of I g M response to infection in newborn infants who were admitted to the nurseries of the City of Memphis Hospitals.
METHODS Clinical observations were made prospectively on neonates admitted to the sick Vol. 75, No. 6, part 2, pp. 1261-1270
1262
Korones et aI.
infant and premature nurseries and on twins who may have been admitted to the fullterm nursery as well. Observations presented in this report were made over an 8 month period between June, 1968, and March, 1969. Infants were examined and their descriptions were recorded by a senior house officer specifically assigned to this study or by one of the authors (S. B. K.). Observations and diagnostic impressions were recorded without knowledge of IgM outcome. Each infant's hospital chart was reviewed by two of the authors and notations were transposed to a summary code sheet. Blood was collected from the umbilical cord at time of delivery and capillary blood was taken by heel prick approximately twice weekly on designated days of the week for the duration of each infant's nursery stay. Serum was separated soon after collection and stored frozen, pending shipment once weekly to the Infectious Disease Laboratory, Perinatal Research Branch, National Institute of Neurological Disease and Stroke (Dr. Sever). IgM assays were performed by a radial diffusion plate method, which has been described elsewhere, s utilizing commercially prepared plates (Hyland Laboratories, Los Angeles, Calif.). Concentrations below 6.0 mg. per cent were reported as "nonreactive" and those over 190 mg. per cent were reported as greater than that value.
The Journal o[ Pediatrics December 1969
TaMe I. Birth weights of 567 study infants Birth weight (Gin.)
No. patients
%
501-1,000 1,001-1,500 1,501-2,000 2,001-2,500 > 2,500 Unknown
19 44 122 188 191 3
3.4 7.7 21.5 33.2 33.7 0.5
Table II. Gestational ages of 567 study infants Gest. age (wk.) < 27 28-30 31-33 34-36 _> 37 Unknown
No. patients 24 40 63 117 232 91
% 4.3 7.1 11.1 20.6 41.0 16.0
Table III. General diagnostic categories of 567 study infants No.
Diagnostic category No disease Definite infection Definite infection with noninfectious disorder Suspected infection Noninfectious disorder
patients 337 63
% 59.6 11.1
15 28 124
2.6 4.9 21.9
RESULTS General characteristics of study population. These data are based upon 2,890 I g M determinations from 567 Negro infants. There were 286 (50.4 per cent) males and 28.1 (49.6 per cent) females. The study cohort includes 33 pairs os twins, 2 sets of triplets, and 11 unmatched twins. Birth weight and gestational age distributions are given in Tables I and II. Distribution of infants by general diagnostic categories is presented in Table III. Serologic test for syphilis. Maternal sera were routinely tested against Venereal Disease Research Laboratory (VDRL) antigen and 6 positive results were observed.
These tests were negative in 5 infants. The sixth infant, who died on the first day of life, weighed 830 grams. Necropsy revealed only extensive atelectasis. Cord IgM was less than 6.0 mg. per cent. IgM levels in healthy infants. Percentile curves for 337 healthy infants according to IgM concentrations for each of the first 28 days of life are presented in Fig. 1. All birth weights were included and events of pregnancy, labor, and delivery were disregarded. Table IV lists data from which these curves were drawn, as well as the range of IgM concentrations and number of infants studied each day. Birth weight over 2,000
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Neonatal I g M response to acute injection
1 2 63
50
3o "
f
o C 0 R
i-t-w 2
4
T'-I-I\ .\li
/11
] 6
8
IO
/
-r I 12
14 [6 AGE IN DAYS
\ 95% 9~
I--.
; 18
20
22
24
-.5~ 26
28
D
Fig. 1. IgM in 337 healthy Negro neonates (1,324 sera) of all birth weights.
Table IV. Percentiles for IgM n e o n a t e s (all b i r t h w e i g h t s )
Age (days)
50
Cord 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
7.3 8.2 7.4 8.4 8.3 10.6 11.9 15.0 15.0 15.6 15.6 16.8 17.4 19.3 18.6 16.4 16.5 14.1 16.1 I9.4 14.7 16.3 18.5 18.2 14.9 16.2 20.2 16.1 14.3
grams was infants and per cent). unknown. only one
(mg.%)
b y d a y of life f o r 337 h e a l t h y N e g r o
Percentiles [or IgM (rag.%) t 75 I 90 I 95 10.1 11.3 10.2 11.6 11.4 14.6 16.5 20.7 20.8 21.6 21.5 23.2 24.0 26.7 25.7 22.7 22.8 19.5 22.3 26.8 20.3 22.5 25.6 25.2 20.5 22.4 27.9 22.3 19.7
13.5 15.1 13.7 15.6 15.3 19.6 22.1 27.7 27.8 28.9 28.9 31.0 32.2 35.8 34.4 30.4 30.5 26.1 29.8 35.9 27.2 30.1 34.2 33.7
27.5 30.0 37.4 29.9 26.4
r e c o r d e d f o r 268 ( 7 9 . 9 p e r c e n t ) 2,000 g r a m s o r less f o r 68 (20.1 Weight of o n e i n f a n t w a s When twins were encountered, infant from each pair was
16.0 18.0 16.3 18.6 18.2 23.3 26.3 33.0 33.1 34.4 34.3 37.0 38.3 42.6 40.9 36.2 36.3 31.0 35.5 42.7 32.3 35.9 40.8 40.1 32.7 35.7 44.5 35.6 31.4
1
99 22.3 25.0 22.6 25.7 25.3 32.4 36.4 45.8 45.9 47.8 47.6 51.3 53.1 59.0 56.8 50.2 50.4 43.0 49.3 59.2 44.9 49.7 56.6 55.7 45.4 49.5 61.8 49.3 43.6
Range lgM __ High l Low 24 21 20 26 19 22 57 45 38 39 50 35 37 39 44 40 36 39 35 47 35 39 54 38 26 32 27 34 23
5 3 5 5 5 5 5 5 5 5 5 5 5 7 8 5 5 5 5 I0 5 7 5 10 5 5 13 5 5
No. 244 102 102 84 81 59 51 68 60 48 55 37 30 28 32 38 32 28 13 I9 15 17 18 20 12 11 5 7 8
i n c l u d e d . A v a l u e of 5.0 m g . p e r c e n t w a s a s s i g n e d t o d e t e r m i n a t i o n s r e p o r t e d as " n o n reactive." I g M levels i n c o r d b l o o d . I g M d e t e r m i n a t i o n s w e r e p e r f o r m e d o n c o r d s e r a f r o m 335
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Korones et al.
The ]ournal o[ Pediatrics December 1969
Table V. Summary of percentile placement of 57 infected infants by I g M level Injection Conjunctivitis: Nonbacterial Bacterial Pneumonia Septicemia Diarrhea Moniliasis (oral)
No. patients
99
9 12 11 7 10 8
7 0 7 2 2 0
No. patients by percentile I 95 I 90 t < 90
1 0 1 1 2 0
irffants. Concentrations from 20 to 120 mg. per cent were demonstrated in 26 specimens (7.8 per cent). Twenty-two (6.6 per cent) of the specimens were thought to contain maternal blood. IgA levels in 19 of them were 1.3 to 8.0 times greater than I g M values. Another serum contained 82.8 mg. per cent I g M and 52.0 mg. per cent IgA, while a day later the I g M was 6.0 mg. per cent. One other sample contained 88.5 mg. per cent I g M and 88.0 mg. per cent IgA. Later determinations were not performed. Eighteen I g M values were obtained from capillary blood within 5 days after cord samples were collected (most were obtained within 48 hours) and 13 of them were below 10 mg. per cent, while 5 others were between 10 and 20 mg. per cent. Cord sera from 4 infants were thought to contain true elevations of I g M which were between 21.8 and 23.0 mg. per cent. IgA was undetectable in all these specimens. These infants were normal in the nursery. Follow-up examination was obtained in but one of them (at 4 months of age) and resulted in normal findings. IgM levels in infected infants. Five different syndromes os infection were studied, i.e., conjunctivitis, pneumonia, septicemia, diarrhea, and oral moniliasis. I g M levels for each entity are given in percentiles according to data for healthy neonates shown in Table I V and Fig. 1. Percentile placements by day of life were analyzed in relation to the day on which signs of disease were first observed. These results are summarized in Table V.
0 3 1 I 2 0
1 9 2 3 4 8
First day > 90 percentile related to onset o[ injection
2 d. before to 12 d. after 3 d. before to 6 d. after Day onset to 10 d. after 2 to I0 d. after 5 d. before to 5 d. after None in 90 percentile
Conjunctivitis. Exudative conjunctivitis occurred in 21 infants which, on clinical bases, could be categorized as probable nonbacterial infections (9 infants) or bacterial infections (12 infants). Bacterial cultures of exudate from infants with nonbacterial conjunctivitis were negative in 4 instances and yielded organisms which were not considered to be the etiologic agents in 5. Cultures from eyes of the bacterial group yielded Gonococcus in 5 infants, Staphylococcus aureus in 2 infants, group B streptococcus and E. coli in one infant each, and H. aegyptus plus E. coli in one infant. Direct smear of exudate from one other infant showed numerous gram-positive cocci and gram-negative rods (a report of culture was not available). Virus cultures were not obtained from any of the 21 infants. Days of onset differed between the 2 groups. In nonbacterial infections, exudate was first noted between 5 and 14 days of life, while in the bacterial infections the day of onset ranged from the first to the twentieth day. There was also difference between the 2 groups in the persistence of exudation despite treatment of all infants with an ophthalmic preparation which contained neosporin, polymyxin, and bacitracin (penicillin was administered for gonococcal infection). Mean duration of exudate in the infants with nonbacterial conjunctivitis was 13.6 days (3 to 24 days) and for those with bacterial disease it was 4.4 days (2 to 11 days). Both groups were observed for a sufficient length of time after onset of disease to permit analysis of I g M responses. Mean day of
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Neonatal I g M response to acute infection
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T a b l e V I . Conjunctivitis, n o n b a c t e r i a l a n d b a c t e r i a l : D a y of onset a n d I g M levels (21 infants) Case No. Bacterial culture Nonbacterial (9 cases) 4 Strep. [aecalis 43 Staph. epidemicus 51 Strep. viridans 107 Negative 122 Negative 136 Staph. epidemieus 173 Negative 229 Negative 405 Staph. epidemieus Bacterial (12 cases) 1 Gonococcus 13 Gr. B strep. 121 E. eoli 156 Staph. aureus 253 Gonococcus 397 Gonococcus 420 Gonococcus 429 E. coli 445 Gram + cocci gram-neg, rods 490 H. aegyptus E. coli 1,006 Staph. aureus 1,013 Gonococcus
Duration exudate (days)
Day of onset
First day > 90 percentile
Highest percentile
9 9 14 10 6 6 8 5 10
19 7 21 16 13 -13 17 14
95 99 99 99 99 75 99 99 99
13 15 14 6 20 24+ 3 16 11
2 2 1 14 9 9 6 24 20
-5 -------17
~ 50 90 .( 50 50 75 ~ 50 ~ 50 75 90
3 2 4 i1 Unk. 3 Unk. 5 3
16
--
50
5
3 10
-16
~ 50 90
4 4
observation after a p p e a r a n c e of e x u d a t e was 14.4 for n o n b a c t e r i a l infection a n d 11.8 for bacterial infection. T h e two groups of infants differed in their I g M response. Eight of the 9 cases of n o n b a c t e r i a l conjunctivitis were associated with elevations of I g M levels beyond the ninety-fifth percentile, while I g M in only 3 of the 12 cases of bacterial infection attained the ninetieth percentile. Details of these d a t a are presented in T a b l e V I a n d curves of I g M levels by day of infection for the two groups of infants are presented in Fig. 2. F o l l o w - u p e x a m i n a t i o n has so far been p e r f o r m e d on 6 of the 9 infants with nonbacterial infection a n d 3 of these were abnormal. Baby L. (Case 4) was seen by us at 9 m o n t h s of age at which time spastic diplegia was noted. H e a d circumference a n d skull films were normal. A t 6 m o n t h s of age he was a d m i t t e d to the hospital following
occurrence of a generalized seizure. T r a n sient t e m p e r a t u r e elevation of 101 ~ F. was first observed on the fourth hospital day. Spinal fluid was n o r m a l on 2 occasions. I n the nursery, conjunctivitis a p p e a r e d on the ninth d a y a n d I g M surpassed the ninetyfifth percentile (46.5 rag. p e r cent) on the nineteenth day. Baby M. (Case 229) was evaluated by us at 5 m o n t h s of age a t which time h e a d control was p o o r a n d he was extremely hyperactive. H e was hospitalized at 3 months of age for p n e u m o n i a w h i c h persisted radiologically for 13 days. I n the n u r sery, eye exudate a p p e a r e d on t h e fifth day a n d persisted for 16 days. Highest I g M levels rose beyond the n i n e t y - n i n t h percentile on the seventeenth d a y of life a n d ultimately reached 184.0 mg. p e r cent on the thirtyfirst day when he was discharged. Baby P. (Case 405) was e x a m i n e d at 3 m o n t h s of age at which time his weight was 3,045 grams (birth weight 2,000 g r a m s ) . H e was
1266
Korones et al.
The Journal of Pediatrics December 1969
200
/
180
160 9- - . o----o
140
NON-BACTERIAL-9 INFANTS BACTERIAL-INFANT WITH HIGHEST LEVELS. FROM 12 CASES
120
:E
I00
~n
80
60
40
.j
20
- 3 -2 - I 0 DAYS DAY BEFORE ONSET
2
4
6
8
I0 12 DAYS AFTER
14
16
18
20
Fig, 2. IgM levels in bacterial and nonbacterial conjunctivitis.
obviously undergrown but other abnormalities were not evident. During the nursery course, eye exudate appeared on the tenth day and persisted for 11 days. IgM level rose beyond the ninety-ninth percentile (58.0 mg. per cent) by the eighteenth day of life. Pneumonia. Pneumonia was diagnosed in 11 infants. A pediatric radiologist, who was unaware of results of IgM determinations, evaluated the chest films of each infant. Radiographic appearance of the lungs was compatible with the diagnosis of pneumonia in 10 infants and was suggestive in one. IgM levels in 7 subjects placed them in the ninety-ninth percentile, while 2 infants were in the ninety-fifth and ninetieth percentiles, respectively. The remainirrg 2 in-
fants were below the fiftieth percentile. One of these babies died on the fourth day of life after severe perinataI distress and persistent respiratory difficulty throughout life. His mother's temperature at the time of delivery was 101.6 ~ F. and the amniotic fluid was purulent. Radiographic appearance of pneumonia was evident on the day of birth. Necropsy revealed extensive bronchopneumonia. Only one IgM determination was performed and this was on the second day of life. It was reported to be nonreactive (below 6.0 mg. per cent). The second infant, a breech delivery, experienced 4 severe apneic episodes during the first 24 hours of life. Two chest films on this day revealed dense areas throughout both lungs, but a moderate degree of improvement was noted on the the second film. Eight IgM determi-
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Neonatal I g M response to acute injection
126 7
T a b l e V I I . Septicemia: Etiologic agent, d a y of onset, and I g M levels (7 infants) Case No. 9 20 108 170 341 1002 1012
Organism E. coli E. coli A. aerogenes Gr. B. strep. M. polymorpha L. monocytogenes P. morgagni
Day of onset
First day Highest percentile >_ 90 percentile
23 5 1 1 1 I0 1
24 -9 10 -14 --
95 <50 99 90 75 99 50
Table VIII. D i a r r h e a Case No. 177 210 227 228 357 402 466 470 522 552
Organism E. eoli, 0111 :B4 Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown
nations were p e r f o r m e d between the second and twenty-sixth days of life a n d none exceeded the fiftieth percentile. Septicemia. Bacterial organisms were cultured from the blood of 7 infants. Agents recovered, day of onset of infection, a n d percentile levels of I g M concentrations are given in T a b l e V I I . I g M levels in 4 infants placed t h e m in the ninetieth percentile or above, while 3 others were below the ninetieth percentile. Diarrhea. F r e q u e n t watery or loose stools were observed from 10 babies. E. coli, 0111:B4, was recovered from one infant. Bacterial p a t h o g e n s were not present in stools of the r e m a i n i n g 9 infants. V i r a l cultures were not obtained. I g M levels were above the ninetieth percentile in 6 infants and below the ninetieth percentile in 4. Details of these observations are presented in Table VIII. Oral moniliasis. O r a l lesions characteristic of m o n i l i a infection were observed in 8 subjects. I g M concentrations did n o t reach the ninetieth percentile in any of these infants.
Day of onset 9 3 4 5 5 3 3 3 15 2
First day > 90 percentile Highest percentile 4 99 -50 9 95 2 95 -<50 4 90 4 90 -75 10 99 -<50
DISCUSSION Data on healthy infants. T h e 337 h e a l t h y neonates who were categorized b y percentiles (Fig. 1 a n d T a b l e I V ) e x h i b i t e d no evidence of infectious or noninfectious disorders d u r i n g their nursery stay. T h e multiple factors w h i c h s t i m u l a t e p r o d u c t i o n of immunoglobulins in a p p a r e n t l y h e a l t h y neonates are not well defined. W e h a v e not, for instance, a t t e m p t e d to e v a l u a t e t h e effects of antibiotic a d m i n i s t r a t i o n in the 73 (21.6 p e r cent) h e a l t h y infants who received them p r o p h y l a c t i c a l l y ; nor have we a t t e m p t e d to define the roles os feeding a n d b a c t e r i a l colonization. C a t e g o r i z a t i o n of I g M levels in healthy neonates by birth weight or gestational age would be i m p o r t a n t b u t our study sample is as yet not sufficiently large to acc o m m o d a t e such as analysis. IgM in cord sera. D e t e r m i n a t i o n s in 335 cord sera yielded 22 specimens (6.6 p e r cent) w h i c h c o n t a i n e d spuriously high levels of I g M p r e s u m a b l y due to c o n t a m i n a t i o n by m a t e r n a l blood. This p h e n o m e n o n imposes a serious l i m i t a t i o n on any screening pro-
1 2 68
Korones et al.
cedure restricted to I g M in cord samples. If IgM screening is to be performed, capillary samples taken soon after birth and periodically thereafter are clearly preferable to cord samples. Congenital infections are not regularly associated with abnormal increases in IgM levels. McCracken and associates 2 showed concentrations in excess of 20 mg. per cent in only 18 per cent of infants in whom congenital rubella was diagnosed. Ackerman 9 reported an infant who died 6 hours after birth in whom severe congenital syphilis was demonstrated serologically and at necropsy. Using a method similar to the one we have employed, he could not detect IgM in the infant's serum (less than 6.0 rag. per cent). An opportunity to further pursue this point was provided us by data from a previous study of neonatal pneumonia from the Collaborative Perinatal Project? ~ IgM levels were determined on stored cord sera from 30 infants in whom onset of pneumonia occurred within 48 hours after birth. IgM was not detectable (less than 6.0 rag. per cent) in 24 of the 30 specimens. T h e highest concentration in any of the sera was 14.0 mg. per cent. Fourteen infants died within 4 days after birth and in 13 of them IgM was not detected. Sera from 11 of the 16 survivors also did not contain detectable IgM. There was a high incidence of "nonreactivity" in sera of infants who died shortly after birth. A study of immunoglobulin responses in such infants would be of interest. Conjunctivitis. T h e 9 infants in whom nonbacterial conjunctivitis was diagnosed constituted a surprising facet of this study. T h e term "nonbacterial" was applied for want of a better one. This group of infants is characterized as follows: (1) Onset of infection occurred between the fifth and fourteenth days of life; (2) exudate persisted in spite of apparently appropriate treatment; (3) bacterial cultures were negative or yielded organisms of dubious etiologic significance which should have responded to the treatment administered; (4) IgM levels were unusually high in all but one infant; (5) abnormalities were demonstrable in 3 of
The Journal o[ Pediatrics December 1969
the 6 infants thus far followed during the postneonatal period. Our attention was drawn to these infants because of the persistence of conjuncrival exudate and the time of onset, both of which are compatible with inclusion conjunctivitis ( T R I C [trachoma inclusion conjunctivitis] agent). Conjunctival scrapings from 3 infants were negative for inclusions. Only routine bacterial cultures were performed. We were unaware of the high I g M levels these infants had in common. Identification of the causative agent or agents is obviously essential. These clinically classified infections could be an indication of generalized disease which in some instances is associated with subsequent abnormality of growth and development, or they may be uncomplicated conjunctivites caused by one or more organisms capable of elicting an unusually vigorous IgM response. Pneumonia. I g M levels exceeded the ninetieth percentile in 9 of the 11 infants in whom pneumonia occurred. Seven of them were in the ninety-ninth percentile. One of the infants in whom an elevated level did not occur died on the second day of life. Extensive bronchopneumonia was evident at necropsy. One I g M determination, performed on the second day, was nonreactive (less than 6.0 mg. per cent). These findings are similar to those for babies from the Collaborative Perinatal Project who were described in the discussion on cord sera. Low I g M levels seem to be common in infants with fatal pneumonia which begins in utero or within 48 hours after birth. The second infant whose I g M concentrations were not abnormally high m a y not have been infected. This is suggested by the moderate improvement which was noted on the second of 2 chest films taken the same day. Five I g M determinations were performed over the 16 day period of her stay in the nursery. Elevations of I g M levels occurred as early as the day of onset and as late as 10 days after onset of pneumonia. Study design provided for sampling twice weekly and most specimens were therefore taken at 2, 3, and
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Neonatal I g M response to acute infection
4 day intervals. Precise estimation of the day on which elevated levels occurred is not feasible. The infant whose first abnormal rise occurred on the tenth day of disease had 2 previous determinations on the third and sixth days. These data indicate that I g M elevations beyond the ninetieth percentile m a y be expected to occur in association with neonatal pneumonia. An important exception to this statement is the fatally ill infant in whom onset os pneumonia occurs in utero or within 48 hours after birth. Septicemia. Results from 7 infants with apparent septicemia were disappointing. Few neonatal diagnoses are so often made on clinical grounds and so infrequently documented. I g M levels to the ninetieth percentile or above were noted in 4 of 7 infants. T h e organisms which were recovered from the blood were unlikely to be coincidental contaminants (Table V I I ) . Several explanations for the observed array of I g M responses are suggested: (1) Bacteremia rather than septicemia was present in infants whose I g M levels were not elevated; (2) early treatment with effective antibiotics precluded an abnormal rise of I g M ; (3) the immunogenic capacity of different bacterial organisms varies considerably. The management of sick infants would be aided immeasurably if a consistent relationship between I g M elevation, clinical signs, and results of bacterial culture were demonstrated in a large series of septicemic infants. Diarrhea. I g M concentrations rose to the ninetieth percentile or above in 6 of 10 infants whose stools were abnormal. The most interesting aspect of these results is the appearance of increased I g M levels 3 to 5 days before onset of diarrhea in 3 of 6 infants in whom elevations occurred. CONCLUSIONS
Would a screening program for increased levels of I g M be worthwhile for earlier identification of acute infections in a high risk newborn population? In this study, I g M elevations occurred several days
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after onset of physical signs with but few exceptions. Assiduous clinical surveillance detected most infections before I g M elevations would have become known to us. One can envision a program in which blood samples are taken once or twice weekly for all high risk infants, but such routine procedures tend to relax alertness of nurse attendants and physicians as well. Information generated by such a screening activity would undoubtedly be valuable confirmatory evidence of clinical impressions which have been long since acted upon. This is not to deprecate the obvious value of neonatal I g M quantitation for clinical research purposes. T h e suggestions furnished by data in this study from infants with conjunctivitis exemplify the type of clinical information which can evolve from application of immunoglobulin determinations to cribside problems. Radiologic interpretations were made by Barry E. Gerald, M.D., Associate Professor of Radiology, Director of Diagnostic Section, Department of Radiology, University of Tennessee College of Medicine. Mrs. Mary W. Gann, Head Nurse, and the entire nursing staff of the delivery suite and house officers of the Department of Obstetrics and Gynecology cooperated fully in collection of cord samples. Dr. Donald A. Thomas performed evaluations of infants in the nursery. Studies of this type are impossible without the interest of those listed above and many more who are not mentioned. REFERENCES
1. Alford, C. A., Schaefer, J., Blankenship, W. J., Straumfjord, J. V., and Cassady, G.: A correlative immunologic, microbiologic and clinical approach to the diagnosis of acute and chronic infections in newborn infants, New England J. Med. 277: 437, 1967. 2. McCracken, G. H., Jr., Hardy, J. B., Chen, T. C., Hoffman, L. S., Gilkeson, M. R., and Sever, J. L.: Serum immunoglobulin levels in newborn infants. II. Survey of cord and follow-up sera from 123 infants with congenital rubella, J. PEDIAT. 74: 383, 1969. 3. McCracken, G. H., Jr., and Shinefield, H. R.: Immunoglobulin concentrations in newborn infants with congenital cytomegalic inclusion disease, Pediatrics 36" 933, 1965. 4. McCraeken, G. It., Jr., and Sever, J. L.: Unpublished data.
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5. Eichenwald, H. F., and Shinefield, H. R.: Antibody production by the human fetus, J. PEDIAT. 63: 870, 1963. (Abst.) 6. Sieber, O. F., Jr., Fulginiti, V. A., Brazie, J., and Umlauf, H. J.: In utero infection of the fetus by herpes simplex virus, J. PEmAT. 69: 30, 1966. 7. Stiehm, E. R., Ammann, A. J., and Cherry, J. D.: Elevated cord macroglobulins in the diagnosis of intrauterine infections, New England J. Med. 275: 971, 1966. 8. McCracken, G. H., Jr., Chen, T. C., Hardy, J. B., and Tzan, N.: Serum immunoglobulin levels in newborn infants. I. Evaluation of a radial diffusion plate method, J. PEDIAT. 74: 378, 1969. 9. Ackerman, B. D.: Congenital syphilis: observations on laboratory diagnosis of intrauterine infection, J. PEDIAT. 74: 459, 1969. 10. Korones, S. B., Abramson, H., and Fujikura, T.: Neonatal pneumonia in liveborn infants, Paper presented at the Meeting of the Collaborative Study on Cerebral Palsy, Mental Retardation and other Neurological and Sensow Disorders of Infancy and Childhood, Washington, D. C., March 24, 1966. DISCUSSION DR. BLANKENSHIP. May I ask Dr. Korones how he made the diagnosis of pneumonia and how can you exclude the possibility that this was noninfectious? By that I would like to suggest that we often see meconium aspiration pneumonia which is in no way associated with infection. If you made your diagnosis of pneumonia on the basis of bacteria and recovery, how did you obtain your specimen? DR. KORONES. No, we were confronted with the same difficulty one is always confronted with. We had to satisfy ourselves with radiologic appearances. In most instances the densities persisted for several days. In one of the two infants in whom IgM elevations did not occur, severe respiratory distress occurred on the second day of life. There was moderate improvement in the second of two films taken that day. This infant
The Journal o[ Pediatrics December 1969
was probably not infected. We have nothing more definitive than the x-ray for the diagnosis of pneumonia. DR. BERENDES. Have you arranged IgM levels by birth weight of child? DR. KORONES. No. DR. BERENDES. I raise this question because it seems obvious from some of the presentations made today that in judging the significance of the IgM level one has to take birth weight into consideration. I say this specifically in view of the lack of an association with pneumonia which occurred during the first two days of li[e, a condition which I believe is almost exclusively found in premature children. DR. KORONES. Your first question was whether I had these IgM values categorized by birth weight and the answer is no. We do not yet have enough data. In our cohort of "healthy" neonates, a number of them were below 2,000 grams at birth. Your second allusion was to infants with pneumonia. I said of 14 infants from the Collaborative Project who died, IgM in 13 of them was less than 6.0 mg. per cent. Of those 13, 5 were over 2,500 grams at birth. DR. ALFORD. One thing that has to be taken into consideration is the time of acquisition of the infection. It takes time to develop an immunoglobulin response. I n many acute infections it is extremely difficult to ascertain the point of acquisition. Conjunctivitis may well be acquired at the time of delivery. Hence, serial determinations may be required to show an IgM rise especially in infections acquired at or right before delivery. DR. KORONES. These were, of course, serial determinations. Mean length of observation was 14.4 and 11.8 days for nonbacterial and bacterial conjunctivitis, respectively. We observed virtually no abnormal IgM elevations in the bacterial infections.