Acquired C1 inhibitor deficiency in lymphosarcoma

CLINICAL

IMMUNOLOGY

Acquired

AND

IMMUNOPATHOLOGY

CT Inhibitor

1, 39-52

Deficiency

(1972)

in Lymphosarcoma

J. R. CALDWELL,

S. RUDDY, P. H. AND K. F. AUSTEN

Dqmrtment

Robert

of Medicine, B. Brigham

Hospital,

Received

SCHUR,

Hurourd Medial School, Boston, Mussuchusetts

Febnrarg

18.1972

Two patients with lymphosarcoma and circulating 7S IgM were found to have an unusual complement component profile in which the first, fourth and second components and the inhibitor of the activated first component were diminished in the presence of a normal third component and an elevated ninth component. One of these patients experienced attacks of angioedema which can be distinguished from hereditary angioedema by the absence of any complement system defects in other family members and by the reduced level of Cl in the patient’s serum. The Ci inhibitor deficiency in these patients is acquired, most likely as a result of its interaction with activated first component.

INTRODUCTION Depression of one or more serum components of complement has been observed in a variety of human diseases including systemic lupus erythematosus (l), acute and subacute glomerulonephritis (2), subacute bacterial endocarditis with nephritis (3), and allograft rejection (4). Absence of the inhibitor of the activated first component of complement (CTINH) together with decreased function of the fourth (C4) and second (C2) components but normal levels of the first component (Cl) and all terminal components is characteristic of hereditary angioedema (5). This paper reports studies conducted on two patients with lymphosarcoma and circulating 7s IgM, whose sera exhibited an unusual complement pattern: The early reacting components, Cl, C4 and C2, were markedly reduced whereas the third component (C3) was normal and the ninth component (C9) was elevated. Both patients had reduced serum levels of CiINH. One of these, in whom the CiINH was severely depleted, to a degree previously observed only in patients with hereditary angioedema, experienced episodes of angioedema clinically indistinguishable from those seen in patients with the hereditary disease. Evidence will be presented that the depletion of CiINH with associated angioedema in this patient is an acquired rather than an inherited disorder. MATERIALS

AND

METHODS

Blood was drawn into plastic syringes, clotted in glass tubes for 60-90 at room temperature and centrifuged at 25°C; the serum was removed stored in aliquots at -70°C. For cryoglobulin analysis, blood was drawn

39 Copyright All rights

@ 1972 by Academic Press, Inc. of reproduction in any form reserved.

min and and

40

CALI~WELL

ET

41..

processed in a 37°C room; aliquots of 10 ml of serurn were stored at 4°C for 72-96 hr at which time they were examined for a cryoprecipitate. Plasma was obtained from blood collected in 7-ml vacutainers containing 9 mg disodium ethylenediaminetetraacetic acid (EDTA).

The preparation of isotonic dextrose-gelatin-Verona1 buffer (DGVBz+) and gelatin-Verona1 buffer with EDTA (EDTA-GVB2-) (6), hemolytic titrations of CH50 (7), Cl (8), C4 (9), C2 (lo), C3 (ll), C9 (12) and CTINH (13) were performed according to described methods. C4 (14), C3 (15), CTINH (13) and Clq (16) were also measured by radial immunodiffusion. Dr. B. Stroud kindly performed measurements of Cls (17). Immunoelectrophoretic conversion of serum C3 was assessed as follows: zymosan (reagent grade, lot #U2206, Mann Laboratories) was boiled for 1 hr in 0.15 M NaCl and after washing was resuspended at a concentration of 4 mg/ml. Equal volumes (0.1 ml) ofzymosan suspension and serum were incubated together at 37°C for 45 min. After removal of the zymosan particles by centrifugation, the supematant fluid was subjected to immunoelectrophoretic analysis using the Weime apparatus (18).

Material in the patients’ serum which precipitated with isolated Clq OI isolated rheumatoid factor was sought by the techniques described by Ag(20). The pattern of sedinello, Winchester, and Kunkel (19) or Hannestad mentation of the patients’ serum proteins was examined in a Spinco Model E centrifuge. For sucrose density-gradient analyses O.l-ml samples of sera were centrifuged for 16-18 hr on a linear gradient of 10-40s sucrose at 39,090 rpm in a Beckman Model L-2-65B with an SW-50L rotor. The gradients were divided into 30 portions, each of which was assayed for p and y chain antigenic determinants by radial immunodiffusion (21). Sera were screened for low molecular weight (7s) IgM by double diffusion against goat antihuman IgM in 4% polyacrylamide gel (22). The polyacrylamide gel was prepared using a 20: 1 ratio of monomeric to bisacrylamide, to which was added 10 drops of 2%) ammonium persulfate and one drop of N,N,N’,N’ tetramethylethylene diamine per 10 ml of gel solution. The gel was poured to a depth of 3 mm in glass petri dishes, allowed to harden for 30 min and 5-mm wells were cut. Serum samples were placed in the wells and incubated at 37°C for 5 days and 4°C for 2 days to allow a maximum degree of precipitation. Total IgM, IgA and IgG in serum was measured by the radial immunodiffusion technique using monospecific antisera (23). Patierlts R. H. (RBBH #24939), a 55-year-old Caucasian female, was seen for the first time in October 1965, with a S-month history of painful, red swollen hands, shoulders, knees, and feet. There was no previous history of joint disease. She had had a right nephrectomy for hydronephrosis at the age of 28 and recurrent bouts of urinary tract infections treated with multiple courses of sulfonamides

ACQUIRED

C 1 INHIBITOR

DEFICIENCY

41

from the time of operation to her admission. There was no personal or family history of angioedema. Significant laboratory data revealed normal white blood count (WBC), differential, and hematocrit (HCT). Urinalysis showed persistent hematuria in which lo-70 red blood cells/high power field were observed. There was no proteinuria. Blood sedimentation index was 0.85 mm/min (normal less than 0.44 mmlmin). The latex fixation titer was 40,960. In December, 1965, she developed a 4+ proteinuria, still had persistent hematuria with occasional hyaline but no red blood cell casts. Blood urea nitrogen (BUN) was 38 mg/lOO ml. Creatinine clearance was 33 ml/min. Congo red test was negative. Intravenous pyelogram showed an enlarged left kidney with poorly visualized calyces and poor dye excretion. Hemotocrit was 32.5%; serum iron 90 pg/lOO ml; iron binding capacity 330 PgllOO ml. Stool guaiac was 1-2-t positive. In May of 1966,24-hr urine protein was 1.95 g and the BUN 57 mg/lOO ml. After initiation of prednisone therapy the BUN returned to 28 mg/lOO ml and 24-hr urine protein diminished to 400 mg though the hematuria persisted. In November 1967, a CH50 was 31 units/ml (normal range 150-250 units/ml). In January 1968, the antinuclear antibody test (ANF) was negative and the latex fixation titer was 1024. In February, 1968, splenomegaly was noted for the first time. Four months later, the CH50 was 38 units/ml and the levels of Clq and C4 were markedly reduced while C3 was normal. X-ray films of hands and feet demonstrated periarticular demineralization and soft-tissue swelling. In January 1969, the splenomegaly had increased to 8 cm below the left costal margin, a small spike was visible in the p region on serum-protein electrophoresis, WBC was 9700 with 72% lymphocytes, and bone-marrow biopsy revealed infiltration with immature lymphocytes consistent with lymphosarcoma. The patient was treated with Vincristine, cyclophosphamide and splenic irradiation, The development of leukopenia after 4 months necessitated the discontinuation of this therapy. Her subsequent course was complicated by persistence of the active arthritis, thrombophlebitis of the right calf, recurrent urinary tract infections, progression of splenomegaly and an episode of erythema multifonne. Latex fixation test remained positive in titers of approximately 1024. ANF titer was negative or l+ positive at a 1: 10 dilution of serum. Further analyses of complement components revealed not only diminished Cl, C4, and C2 in the presence of normal C3 but also a marked reduction in the CiINH. She subsequently developed purpuric lesions over her extremities; hematologic studies revealed a WBC of lOOO-2000/mm3, Hct of 30%, and a platelet count of 100,000/mm3 with a normal differential. Direct and indirect Coombs tests were repeatedly negative, clotting studies revealed normal levels of Factors V, VIII, IX and prothrombin, and there was no excessive fibrinolytic activity or fibrin split products. After splenectomy in January 1971 her WBC, platelet count and Hct returned to normal. Histologic examination of the spleen revealed atypical reticulum cells with occasional binucleate forms. In February 1971, agarose electrophoresis of serum showed an atypical, broad band migrating slightly to the cathode. Serum IgM level was in excess of 1000 mg/lOO ml by radial immunodiffusion (normal 50-200 mg/lOO ml). Serum IgG

42

CALDWELL

ET

AL.

and IgA levels were normal, In March, 1971 she died at home suddenly following a grand ma1 convulsion. Permission for post mortem examination was not obtained. M. V. (CNH #J4089), a 49-year-old female of Italian descent was referred because, of a l&month history of episodic angioedema which began in the summer of 1969. These attacks involved either part of an extremity, or the face, lips or tongue, or presented as crampy, nonradiating, periumbilical abdominal pain associated with vomiting. The cutaneous or abdominal symptoms occurred either alone or together and usually subsided spontaneously within 2-3 days. No other family member had a history of similar attacks. In August, 1970 she was hospitalized for an episode of angioedema which involved the face, lips and tongue. A serum sample obtained at that time revealed a markedly reduced CTINH when measured by both function and protein; her history together with this finding was thought to be consistent with hereditary angioedema. In July 1970, during a routine insurance examination, she was noted to have splenomegaly. Histological studies of a bone-marrow biopsy and examination of the peripheral blood in November revealed abnormal lymphocytes consistent with the diagnosis of lymphosarcoma. In December she was hospitalized because of increasing splenomegaly and fatigue. Laboratory studies showed a HCT of 34%, a WBC count of 5000/mm”, with 36% polymorphonuclear leukocytes and 62% lymphocytes, a platelet count of 50,00O/mm” and a normal urinalysis. Routine blood chemistries and electrophoresis of serum proteins were normal. Serum IgM level was >lOOO mg/lOO ml. Splenectomy and liver biopsy were performed and tissue pathology showed Iymphosarcoma cells in both the spleen and liver. Following splenectomy, her peripheral blood values all returned to normal without additional therapy, although a bone-marrow biopsy in March of 1971 contained numerous lymphosarcoma cells. Her symptoms of abdominal pain and angioedema have continued. RESULTS

Tables 1 and 2 show that R. H. and M. V. had marked reductions in serum levels of Cl, C4, C2 and CiINH, with normal concentrations of C3 and elevaTARLE C~~~PLE~~ENT-C~~~~PO~E~T SERA

Specimen Control 1 Control 2 R. H. (10/23/70) M. V. (l/18/71) Normal range

Cl 141,000 200,000 6150 15,200 96,ooo200.000

FROM

PATIENTS

c4 43,000 90,000 170 14 23,00057,000

1 ACTWITIES

AND

NORMAL.

c2 3700 3000 280 320 2ooo3900

(U/ml)

IN

~~IVIIXJAL.S

C3 78.000 69,000 60,000 78,000 48,00087.000

c9 72,700 64,000 105.000 173BOO 28,00076.000

CiINH 23.500 25,000 9600 < .5O 20,00050,000

ACQUIRED

Ci

INHIBITOR TABLE

43

DEFICIENCY 2

LEVELS OF COMPLEMENT-COMPONENTS, Cl SUBUNITS, AND CiINH IN SERA FROM PATIENTS AND NORMAL INDIVIDUALS Component Specimen

Clq (aN/ml)

R. H. (10/23/70) M. V. (l/18/71) Normal range

10.2 8.2 18-25

protein

Cls (b%lml)

c4 h/ml)

c3 b-&4

12 11 27-37

<50 <50 208-636

1180 1320 1000-1550

CiINH (mg/lOO

ml)

0.35 10.2 1.26-3.0

tions of C9. Total Cl hemolytic activity, as assessed by an effective molecule titration, was reduced to less than 11% of the mean control value (Table 1); and values for Clq and Cls subunits, assessed by immunodiffusion, were both less than 50% of normal (Table 2). Measurements performed on serial specimens obtained from patient R. H. over a 3-year period demonstrated persistent depressions of Clq and C4, with a transient fall in the level of CiINH during late 1970 (Fig. 1). Serial studies of

C//NH (mg/lOOmll

; , 0

c/q (ugN/ml)

c3 (,w/mll

2000 , ooo

01

I 1968

R.H.

FIG. 1. Radial immunodiffusion measurements specimens from patient R. H. The normal range the shaded area.

I 1969

1970

YEAR of Clq, C4, C3 and Cl inhibitor in serial serum (mean k 2 SD) for each measurement is shown as

44

CALDWELL

ET

AL.

YEAR

MV

FIG. 2. Radial immunodifkion measurements specimens from patient M. V. The normal range as the shaded area.

of Clq, C4, C3 and CT inhibitor in serial serum (mean -+ 2 SD) for each measurement is shown

patient M. V. over a 14-month period indicated continued depressions of CiINH, Clq, and C4, with C3 levels below the lower limit of normal on two occasions (Fig. 2). Studies

of CiINH

und C4 in Family

V

As shown in Tables 1 and 2 and in Fig. 2, patient M. V. had a striking and consistent reduction of CiINH to a level previously observed only in patients with hereditary angioedema (13). CiINH and C4 protein were measured by radial immunodiffusion in the patient’s mother, her four siblings, four children, four nephews and four nieces. As shown in Fig. 3, CTINH was normal in all family members other than the patient; C4 protein was also normal. Serum complement (CH50) measurements were normal as well in three children and one sibling of patient R. H. Studies

of‘C3

The reason for a normal level of C3 in the presence of profound reductions in Cl, C4, and C2 was sought by several different approaches. Initial studies

ACQUIRED

19

22

FIG. 3. Pedigree immunodiifusion

20

C 1 INHIBITOR

2.0

1.6

45

DEFICIENCY

21

20

1.8

19

of Family V. Patient M. V. is shown as the shaded circle. determinations of Ci inhibitor (mg/lOO ml) are shown

17

15

21

The results of radial below each symbol.

were concerned with the possibility that the patients’ sera contained an inhibitor of the C3 convertase enzyme formed by the action of activated Ci on C4 and C2. Sheep erythrocytes in the state EAC14, prepared with excesses of rabbit antibody, guinea pig Ci and human C4 (10) were incubated at a concentration of 1 x 108/ml with oxidized human C2 (24) for 15 min at 30°C to generate about 2.0 sites (S) in the state SAC14°“Y2 per cell. These cells were then incubated at a concentration of 1 X 108/ml in DGVB’+ in microtiter plates for 60 min at 37°C with equal volumes of serial dilutions of patient or control serum in EDTA-GVB*-. The plates were centrifuged and the 50% hemolytic endpoints estimated visually. As seen in Table 3, serum from both patients and two controls lysed these cells equally well. In a second experiment the same EAC140xY2 cells were incubated at 37°C with serum from patient R. H. or a normal serum diluted 1: 50 in EDTA-GVB*-. At varying intervals during the incubation period, aliquots of the mixtures were removed and centrifuged. The cells were washed once, resuspended in DGVB*+, mixed with guinea pig serum diluted 1: 15 with EDTA-GVBZand incubated for 1 hr at 37°C. The decay rate of EAC140xY2 cells in the presence of serum R. H. was not significantly different from the rate in control serum. Thus there was no evidence for a factor which interfered with the action of Ca either by inhibition of its function or by acceleration of its decay. The capacity of the C3 molecule in the patients’ sera to interact with C3 convertase on an EAC140xY2 intermediate was evident from the normal C3 titers (Table 1). The ability of C3 contained in the patients’ sera to participate in the alternate pathway for C3 activation was evaluated by treatment with cobra-venom factor or zymosan. Cobra-venom factor prepared from lyophilized venom of the cobra Naja naja by DEAE-cellulose chromatography, TABLE

3

ABILITY OF PATIENTS' AND CONTROL SERATO LYME EAC140xY2 CELLS Serum producing

Sample R. H. M. V. Control Control

1 2

dilution 50% lysis 48 32 48 32

46

CALDWELL

ET

C3 Titer Sample M. v. R. H. Control Control

Control

1 2

9600 6400 9600 12,800

AL.

iU/ml) After

cobru

vt‘r,om

32 16 24 16

quantitated as described by Ballow and Cochrane (25), diluted to a final concentration of 3 units/ml and incubated with serum from patients and controls for 45 min at 37°C depressed C3 levels to the same degree in sera from patients and controls (Table 4). The incubation of serum with zymosan or aging at 37°C for 24 hr resulted in conversion of C3 to its electrophoretically more anodal form.

Ejfect

c$Putierlts

Sew oil Cl

In an attempt to demonstrate anticomplementary activity in the patients’ sera, equal volumes of patient R. H.‘s and control serum, and mixtures of equal volumes of two control sera were incubated at 37°C. At varying times samples were removed, diluted in DGVB”+ and assayed for total hemolytic C 1

250,000

7

200,000

Ii

I50,000

r

I00,000

t

50,000

0

CONTROL CONTROL PREDICTED OBSERVED CONTROLI

PATIENT RH

CONTROL2

FIG. 4. Titers of Cl in sera and mixtures of sem from controls and patient R. H. For each ture, the Cl titer predicted on the basis of a mixture of equal volumes is also showu.

nrix-

ACQUIRED

C 1 INHIBITOR

47

DEFICIENCY

activity. Figure 4 depicts the absolute Cl titers in the individual sera and in the mixtures at the end of 50 min. The mixture of two control sera had a Cl titer which was halfway between the values obtained for the individual sera. The mixture of control and patient serum was 65% of that which was predicted on the basis of equal volumes. Figure 5 shows the rate of disappearance at 37°C of Cl activity from a mixture of two control sera, R. H. serum, and a mixture of the R. H. and control serum. Patient R. H.‘s serum had a Cl titer of 2000 units at zero time, and the titer fell to 940 units by 50 min. The control mixture had a titer of 200,000 units which remained unchanged, while the titer of the combination fell from 60,000 to 46,500. A steady decline is apparent from the patient’s serum alone and for the control serum mixed with patient’s serum. Similar results were obtained with serum from patient M. V.

7S 1gM The findings of markedly elevated IgM levels in both patients’ sera prompted further investigation of the nature of this immunoglobulin. The results of an Ouchterlony analysis in 4% polyacrylamide gel are shown in Fig. 6. The presence of 7s IgM in significant quantity was confirmed by ultracentrifugation of serum samples from both patients on sucrose density gradients. Proteins with p chain immunologic determinants were found in two bands-one corresponding to the 19s region and another corresponding to the 7s region (Fig.7). The 7s IgM was found in three successive analyses of different bleedings from each of the two patients. Immunodiffusion failed to reveal precipitation between Clq or rheumatoid factor and the patients’ sera. Analytical ultracentrifugation of the patients’ sera

30 I 20 IO

t

. Control

Mixture

l

+

Control

RH

0 RH

MINUTES

FIG. 5. Kinetics of disappearance (a),

R. H. serum

(01, and a mixture

of hemolytic Cl activity from a mixture of R. H. and control serum (0).

of two

control

sera

FIG. 6. Ouchterlony M. V.) and control

rera

analysis. in 4% polyacrybmide (J. C. and S. R.) with rabbit

gel, ofreactio~r anti-IgM.

of patients’

sera (R. II. UKI

faiIed to reveai material sedimenting ahead of the 19s proteins or intemmediate between the 19s and 7s peaks. Fractionation of sera by ultracentrifugation in sucrose density gradients did not reveal IgG determinants in any region other than that corresponding to 7s proteins. No cryoprecipitates were detected in whole serum,

Hemolytic assays of Cl and C4, radial immunodifhzion measurement ot CTINH and a polyacrylamide screening test for the presence of 7S IgM were conducted on sera from 17 patients with lymphosarcoma and in 16 patients with systemic lupus erythematosus. No complement component depressions were noted in the sera of these patients with lymphosarcoma, and the unique profile described for patients R. H. and M. V. was not observed in the patients with systemic lupus erythematosus. No complement component depressions from a patient with systemic lupus erythematosus and the other from a patient with lymphosarcoma, contained trace amounts of 7S IgM. DISCUSSION Two patients with persistently abnormal complement component profiles in which Cl, C4, C2, and CiINH were diminished in the presence of normal C3 and elevated C9 levels (Tables 1 and 2, Figs. 1 and 2) were found to have

ACQUIRED

Cl

INHIBITOR

49

DEFICIENCY

6 4 2

18 16 14 12 10 8 6 4 2 0 t 12 0 8 E

&

2

BOTTOM FIG.

tions

4

6

8

10 12 (4 16 18 20 22 24 26 28 30

Ft?RCJ/Oh’ NUlfBER

7. Radial immunodiffusion measurements from sucrose density gradient analyses

TOP

of material reacting with rabbit anti-IgM in fracof control serum, R. H. serum, and M. V. serum,

lymphosarcoma and circulating 7s IgM (Figs. 6 and 7). The depletion of CiINH, a protein interacting stoichiometrically with Ci and of C4 and C2, the natural substrates of Ci, is strong presumptive evidence for Cl activation in these two patients. The profound reduction of Cl as measured hemolytically in an effective molecule titration, which does not distinguish the precursor form from the active enzyme, is most compatible with an immunologic fixation leading to activation. A nonimmunologic activation of CT and subsequent depletion due to interaction with CiINH cannot be excluded. The finding that the subunit concentration of Cl in terms of Clq and Cls is diminished less than the total Cl hemolytic titer is consistent with the analysis of these parameters in the joint fluids (26) of patients with rheumatoid arthritis wherein an intraarticular immunologic activation of Cl seems likely. The capacity of the patients’ sera to diminish Cl when mixed with normal serum suggests the presence of material in the patients’ sera which fixes and activates this complement protein (Figs. 4 and 5). In seeking an immunologic mechanism for Cl fixation and activation in these patients we failed to detect

50

CALDWELL

ET

AL.

circulating immune complexes by Clq or rheumatoid factor precipitation, by analytical ultracentrifugation or by immunodiffusion analysis of fractions from sucrose density gradients. The presence of an appreciable concentration of 7S IgM (Figs. 6 and 7) in the patients’ sera introduces the possibility that this abnormal immunoglobulin is responsible, but at present there is no information as to the mechanism of its participation. 7s IgM has been found previously in the sera of patients with lymphoproliferative disorders (22), rheumatoid arthritis (27), systemic lupus erythematosus (2622) ataxia telangiectasia, Waldenstrom’s macroglobulinemia (22), immunologic deficiency diseases (29), and in certain chronic infectious states (30). Direct observations concerning the ability of7S IgM to activate the complement system have not been reported. A 7S IgM possessing antibody activity against blood group substances and against cell nuclei has been found (28), but studies of its biologic activity are not available. The hemolytic potency of a purified 19s cold agglutinin was reported to be markedly reduced, but not abolished by reduction into 7s subunits and alkylation (31). Since one molecule of 19s IgM suffices to establish a complement-activating site, while two adjacent molecules of IgG are required (32), diminution in the complementactivating potency of 19s IgM following reduction into subunits might be expected if the subunits acted in a fashion analogous to native IgG. The failure of C3 to be depleted suggests that the C3 convertase formed by the action of CT on C4 and C2 in the patients’ serum was inhibited or rendered unstable. No evidence supporting either of these hypotheses was found by in vitro studies of the patients’ sera (Table 3). C3 itself was functionally intact as indicated by the normal titer when assessedwith the usual EAC14”““2 intermediate (Table 1) and by its susceptibility to conversion and inactivation by interaction of the patients’ sera with zymosan or the cobra-venom factor (Table 4). The depletion of C4 and C2 without C3 is a characteristic of hereditary angioedema, in which Cl is activated episodically by nonimmunologic means and operates in the absence of its natural inhibitor. Although the C3 level is normal under these circumstances, studies with radiolabeled C3 (33) have revealed an increased catabolic rate which is apparently not sufficient to reduce the serum level. These findings have been interpreted to indicate that the activation of Cl and its action on C4 and C2 in a purely fluid-phase phenomenon is less effective in generating C3 convertase than when activation occurs on the surface of an appropriately altered immunoglobulin. Although depletion of C4 and C2 without C3, together with the reduction in CiINH, observed in these patients suggests a predominantly fluid-phase activation, the findings of a markedly reduced hemolytic Cl titer exclude angioedema of the hereditary type. In angioedema of the hereditary type the titer of Cl is normal since there is no immunologic fixation or reduction through interaction with its inhibitor. A family history of angioedema is not a requisite for the diagnosis of hereditary angioedema, since apparent instances in which this disease arises & UO~;O,presumabIy as a result of spontaneous mutation, have been described (34). In such cases, however, transmission of the disease to progeny has occurred. Family studies in patient M. \‘.. who

ACQUIRED

C 1 INHIBITOR

51

DEFICIENCY

experienced attacks of angioedema, failed to reveal angioedema by history or an inhibitor deficiency in her only living parent, her four offspring or living siblings, nephews or nieces (Fig. 3). In the case of M. V., a syndrome clinically indistinguishable from hereditary angioedema is associated with acquired C 1 inhibitor deficiency. Acquired depletion of the Ci inhibitor from serum, presumably through its interaction with activated Ci, has been observed on rare occasions in systemic lupus erythematosus (35), and in a patient with a kappa-type monoclonal IgG cyroglobulin (36). In the latter patient, diminution of C3 in addition to C4 and Cl was demonstrable following cold exposure, and the clinical signs were those of cold urticaria. In contrast, in patient M. V. both the cutaneous and gastrointestinal symptoms and signs and the sparing of serum C3 are indistinguishable from the findings of hereditary angioedema, in which a kinin-like peptide is apparently elaborated by the unopposed action of Ci on C4 and/or C2 (37). ACKNOWLEDGMENTS This research was supported by grants AI-07722, AM-11414, and AM-05577 from the National Institutes of Health and a grant from the Massachusetts Chapter of The Arthritis Foundation. Dr. Caldwell was a postdoctoral trainee supported by Training Grant AI-00366 from the National Institutes of Health. Dr. Ruddy is an investigator of the Howard Hughes Medical Institute. The excellent technical assistance of Mrs. Ann McRryan is gratefully acknowledged. Dr. Franz Rodriguez-Erdmann performed the measurements of the coagulation factors, fibrinolytic activity and fibrin split products. We thank Dr. William F. Moloney for providing the specimens of serum from other patients with lymphomas. REFERENCES 1. MORSE,J. H.,AND MULLER-EBERHARD,H.J., BulJ.N.Y.Acud.Med.38,641,1962. 2. GEW~RZ,H.,PICKERING,R.J.,MERGENHAGEN,S.E.,ANDGOOD,R.A., 556, 3.

4. 5. 6. 7. 8. 9. 10.

11. 12. 13.

14.

Int. Arch.Allergy

34,

1968.

WILLIAMS, R. C. JR., AND KUNKEL, H. G.,J. Clin. Iwest. 41,666, 1962. AUSTEN, K. F., AND RUSSELL, P. S., Ann. N. Y. Acud. Sci. 129,657, 1967. RUDDY, S., AND AUSTEN,K. F., Progr.Med. Genet. 7,69, 1970. NELSON, R. A., JENSEN, J., GIGLI, I., AND TAMURA, R., Immunochemistry 3, 111, 1966. KENT, J. F., AND FIFE, E. H., Amer. J. Trap. Med. 12, 103, 1963. BORSOS, T., AND RAPP, H. J.,]. Immunol. 91, 851, 1963. RUDDY. S., AND AUSTEN, K. F.,J. Immunol.99,1162,1967. Bo~sos, T., AND RAPP, H. J., J. Immunol. 99,263, 1967. RUDDY, S., AND AUSTEN, K. F.,J. Immzlnol. 102,533, 1969. RuDDY,S.,EVERSON,L.K.,SCHUR,P.H., ANDAUSTEN,K. F.,/. Exp. Med. 134,2598,1971. CIGLI, I., RUDDY, S., AND AUSTEN, K. F.,J. Immztnol. 100, 1154, 1968. RUDDY, S., CARPENTER,~. B.,M~~LLER-EBERHARD, H.J., AND AUSTEN,K. F., in “Mechanisms

of Inflammation

Induced

by Immune

Reactions,

Vth

International

Symposium”

(P. A. Miescher and P. Graber, Eds.), pp. 231-251, Schwabe and Co., Basel, 1968. 15. CARPENTER, C. B., GILL, T. J., III., MERRILL, J. P., AND DAMMIN, G. S., Amer.]. Med. 854,

1967.

16. HANAUER, L. B., AND CHRISTIAN, C. L., An1er.J. Med. 17. NAGAKI, K., AND STROUD, R. M., J. In~munol. 102,421,

42,882, 1969.

1967.

43,

52 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37.

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ET

AL.

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