kinetic studies of phagocytosis

107

KINETIC STUDIES OF PHAGOCYTOSIS

I. THE SERUM INDEPENDENT PARTICLE UPTAKE BY PMN FROM PATIENTS WITH RHEUMATOID ARTHRITIS AND

SYSTEMIC LUPUS ERYTHEMATOSUS

R. HALLGREN, L. HAKANSSON, and P. VENGE

The initial phagocytic rate of IgG coated polyvinyl toluene latex particles was assayed for isolated PMN cells. The kinetic studies of phagocytosis were performed in serum-free medium using an electronic particle counter. The mean phagocytic rate for the reference group of apparently healthy individuals was 0.60 min-'. PMN cells from 5 of 26 patients with rheumatoid arthritis ( R A ) had subnormal values of particle ingestion rate, although the mean of the group was not significantly reduced compared to the controls. Correlation coefficient between the log of rheumatoid factor titer and phagocytic rate was 0.58 (P < 0.001 ). During penicillamine treatment an increased rate of phagocytosis was observed in patients with RA. Gran- ulocytes isolated from I7 patients with systemic lupus erythematosus (SLE) had a significantly increased (P < 0.001) mean initial rate of phagocytosis (0.91 min-I). Two patients in this group had an acute exacerbation of disease activity and were treated with large doses of pred- nisone. An appreciable decline in phagocytic rate was observed during the intensive corticosteroid therapy.

Circulating immune complexes have been de- tected in chronic inflammatory connective tissue dis-

From the Departments of Internal Medicine and Clinical Chemistry University Hospital, Uppsala, Sweden.

R. Hallgren, M.D.: Department of Internal Medicine; L. Hakansson, M.Sc.: Department of Clinical Chemistry; P. Venge, M.D.: Department of Clinical Chemistry.

Address reprint requests to Dr. Roger HPllgren, Department of Internal Medicine, University Hospital, S-750 14 Uppsala. Sweden.

Submitted for publication May 18. 1977; accepted in revised form August 26. 1972.

orders by several investigators using different techniques (1-4). The presence of deposited IgG complexes at the site of the inflammatory process ( 5 ) has implicated a central pathophysiological role of antigen-antibody complexes in inflammation. Tissue-bound IgG aggregates attract granulocytes, which during their phagocytic performance release proteins extracellularly from their granules (6). Some of these proteins are proteolytic enzymes (7) and are partly responsible for the degenera- tive tissue changes observed during inflammation. The reactivity of PMN cells is supposed to vary in different clinical conditions. Frustrated response of granulocytes to IgG complexes may lead to increased release of proteolytic enzymes. On the other hand, defect and slow reactivity of granulocytes may hamper the elimination of immune complexes and increase the sensitivity for infectious diseases. In view of these considerations of the inflammatory reaction, the handling of immune complexes by PMN cells in patients with chronic inflammatory diseases is probably of great importance.

In the present report, we have used a new technique to measure phagocytosis of IgG complexes (8). This method enables kinetic studies of the initial rate of the phagocytic uptake in a serum-free milieu. The phagocytic rate of isolated granulocytes from patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) has been studied. The data obtained are discussed with respect to different serological variables such as rheumatoid factor titer, immunoglobulins, and complement levels. The effect of treatment with corticosteroids and penicillamine on the phagocytic function in a few patients is also reported.

Arthritis and Rheumatism, Vol. 21. No. 1 (January-February 1978)

108 HALLGREN ET A L

MATERIALS AND METHODS All patients studied were hospitalized at the Depart-

ment of Internal Medicine, University Hospital, Uppsala. There were 26 patients with definite RA, according to the diagnostic criteria of the American Rheumatism Association, and 17 patients with SLE, according to the criteria proposed by Cohen er a/. (9). The age of the patients ranged from 22 to 62 years. The activity of the disease was assessed on a 0 to +3 scale on the basis of arthritis and systemic activity.

Donors of normal serum and blood leukocytes were either apparently healthy laboratory workers or blood donors at the Blood Centre, University Hospital, Uppsala.

Isolation of peripheral blood granulocytes from hepar- inized blood was performed by an initial sedimentation of the blood in I % of dextran T 500 (Pharmacia, Uppsala, Sweden). The preparation procedures are described in detail in a pre- vious work (10). The purity of PMN in the final suspension was about 90%.

The method for studies of the initial phagocytic rate of PMN, which has been described previously (8), utilized an electronic particle counter. The modified routine assay was performed in Ringerdex solution (Pharmacia, Sweden) with glucose added (6.94 mmole/liter) using siliconized glass tubes, at 37" C during continuous magnetic stirring (1,600 rpm). Five-hundred microliters of granulocyte suspension were added to an equal volume of suspended equally sized latex particles with a diameter of 2.03 pm and a volume of 4.38 X lo-" liter obtained from Coulter Electronics Ltd., Dunstable. Bedfordshire, England. Protein coating of the particles was

loo 1

l o l l 1.b * ' 510 '

INCUBATION TIME (MINUTES) Figure 1A. Uptake of IgG coated latex particles as a function of time. The final concentration of polymorphonuclear leukocytes was 2 X lom/ liter and of latex particles 20 X lOs/liter.

performed by incubating 50 mg of human IgG (AB Kabi, Sweden) with 200 X 100 particles per liter in 10 ml of 0.1 mole/liter borate buffer, pH 8, 2 for 2 days at 4" C during constant mixing. About 35% of added IgG was particle bound. Before the use in the phagocytic assay the particle suspension was washed in Ringerdex medium.

During standard incubation the final concentration of PMN was 2 X IO*/liter and of latex particles 20 X IV/liter. Aliquots of 100 pl were taken from the incubation mixture immediately after initial mixing and then at intervals of 30 seconds during the first 3 minutes of incubation and at intervals of 1 minute during the rest of the incubation period. The aliquots were immediately diluted 'to 10 ml with isotonic diluent using an automatic dispenser (Dilumatic, B. Braun, Melsungen AG, W. Germany). By use of the volume-discrimi- nating ability of a particle counter (Trombocounter", Coulter Electronics Ltd., England), with a 70-pm orifice and with the pulse height threshold control set for 3 to 30 X lO-", the small latex particles not cell-associated could be selectively counted whereas cells and internalized particles were not counted. A typical time related particle uptake curve is illustrated in Fig- ure IA. By making reciprocal plots of the uptake curves obtained, one can calculate the slope of the initial linear part of the uptake curve (Figure IB). The phagocytic rate is expressed as the reciprocal value of the slope in min-'.

In all cases blood was drawn for estimation of the erythrocyte sedimentation rate and serum haptoglobin values at the Department of Clinical Chemistry, University Hospital, Uppsala. Serum levels of IgG, IgA, and IgM and the complement components C3 and C4 were measured at the Blood Centre, Uppsala, by a nephelometric technique according to the principles outlined by Lizana and Hellsing ( l l ) , and by radial immunodiffusion (12), respectively. Total hemolytic complement activity (CH,,) was determined by Dr. K. E. Fjellstr8m. Department of Internal Medicine, Uppsala, ac-

I I " " I

0.5 MINUTE3

Figure 1B. Reciprocal plots of the particle uptake curve obtained in Fig- ure I A . On the abscissa, the incubation time values are given in min-'. On the ordinate, the uptake percent values are expressed as decimal fractions. The phagocytic rate was calculated as the reciprocal value of the slope of' the line (min-').

KINETIC STUDIES OF PHAGOCYTOSIS 109

W t U IY 0.6- E 2 0.L-

>

I a

"1

0.21

. 0 . . .. .. 0 0

. . . ! 0. . 0

N . . .

1 I I

CONTR. RA SL E Figure 2. The phagocytic rate of P M N cells isolated from apparently healthy individuals ( n = 39)# patients with R A ( n = 26). and patients with SLE (n = 17). The arithmetic mean of the phagocytic rate of each group is indicated.

cording to Kabat and Mayer (13). Serum antinuclear anti- bodies (ANA) were assayed by indirect immunofluorescence at SBL, Stockholm. Rheumatoid factor (RF) titer was determined by latex agglutination at the Department of Bacte- riology, Uppsala.

The significance of differences applied on groups and on paired values, respectively, was tested by Student's t test.

RESULTS Initial Phagocytic Rate of PMN Isolated from

Healthy Individuals and from Patients with RA and SLE. Figure 2 shows the phagocytic rates of PMN isolated from normal controls and patients with RA and SLE. The mean phagocytic rate for the control group was 0.60 f 0.12 (SD) min-'. The modest difference in phagocytic rate between 15 healthy females (0.63 f 0.15 min-') and 24 healthy males (0.59 f 0.09 min-') was not signifi- cant. Patients with SLE as a group had a significantly increased ( P < 0.001) particle uptake with a mean 0.91 f 0.2 (SD) min-'. There was a strong clinical impres- sion of a positive correlation between the inflammatory activity and the phagocytic rate value in patients with SLE.

At the time of- the investigation of the gran-

ulocyte phagocytic function, the SLE patients were, with a few exceptions, on treatment with steroids and azathioprine. The patients with RA were treated mainly with salicylates. However, 1 week before admission to the hospital the therapy of RA patients was withdrawn to minimize its eventual influence on the granulocyte function. Moreover, no effect was observed on the phagocytic performance during 5 days after administration of 2.5 grams acetylsalicylate to 2 healthy volunteers. PMN from 5 of 26 patients with RA had subnormal values of particle ingestion rate, although the mean of the group [0.54 f 0.19 (SD) min-'1 was not significantly reduced compared to the controls (Figure 2). There was no ap- parent correlation between the disease activity and the phagocytic rate among the patients with RA. The phagocytic rate of granulocytes of 5 healthy individuals was measured on several occasions during a period of 4-7 weeks. The intraindividual day-to-day variations were small and within the reproducibility of the method (coefficient of variation & 11%). However, at times of upper respiratory infections such as common colds, a consistent increase in phagocytic rates was noticed.

Serological Studies on Patients with RA and SLE : Relation to Phagocytic Rate. There was no correlation between the phagocytic rate in patients with RA and SLE, respectively, and the erythrocyte sedimentation rate or serum haptoglobin values. There was a signifi- cant correlation between the log of the R F titer in the RA sera and the phagocytic rate of RA neutrophils (Figure 3), indicating an impaired phagocytosis in pa-

0 0 0

0

0 0 0 .

0. 0

0

0.1 0.3 0.5 0:7 69 PHAGOCYTIC RATE (MINUTES- ' )

Figure 3. Correlation between the log of the RF titer and phagocytic rate in 26 patients with R A . The solid line is the regression line (y = 2.39 x - 3.85). The correlation coeflcient is 0.58 ( P < 0.001).

110 HALLGREN ET AL

1.2- h

-i z Y

0.8- IY u I-

8 0.4- 9 n 0 1.0 PENICILLAMINE

0.5 g/DAY

8 28 30 WEEKS

0 1 2

Figure 4. The clinical course and the phagocytic rote volue (a) in a patient during long-term treatment with D-penicillamine. The RF titers (0) are also given in the Jigure.

tients with high serum R F levels. There was no correlation between the serum immunoglobulins (IgG, IgA, IgM), the serum hemolytic activity (CH,,), the serum complement components C3/C4 or the ANA titer, and the phagocytic rate of PMN from SLE patients. How- ever, the highest values of the phagocytic rate were noticed in patients with pronounced hypocomplemen- temia and intensive disease activity.

Influence on Phagocytic Rate of Corticosteroid and Penicillamine Treatment. Five patients with RA were treated with penicillamine. The phagocytic rate was determined throughout the course of treatment. In 4 patients an increased rate of phagocytosis (mean in- crement of 38%) was noticed after 7 days of treatment with penicillamine at a dose of 0.25 gram daily. In one patient, a dramatic reduction of phagocytic uptake was observed after administration of penicillamine. The reduction of the phagocytic uptake rate was obtained at the same time as the patient developed eosinophilia and a severe skin reaction. When the drug had been withdrawn, and the skin and eosinophilic reaction had decreased the phagocytic rate reverted to that before the adverse reaction. Only 2 patients tolerated the penicillamine treatment for more than 2 months; at the time of this study, they had been on treatment for about 8 months. Both patients have improved in their arthritis and the R F titer has been reduced. The clinical course and the stimulated phagocytic uptake of granulocytes are illustrated in 1 patient in Figure 4.

Two patients were admitted to the hospital with an acute exacerbation of SLE. The patients had reduced serum levels of CH,, and complement factors C3 and C4 and clinical signs of disease activity. The patients were treated with large oral doses of corticosteroids (70-80 mg prednisolonc daily). Both patients had supernor- mal phagocytic uptake values (1.2, 1.15 min-') at the time of admission. During the course of treatment such serological variables of disease activity as serum complement and erythrocyte sedimentation rates improved,

c I 1 I Y

1 I I I I I

0 10 20 30 40 DAYS AFTER ADMITTANCE

Figure 5. Serial values of the phagocytic rate (0) in a patient with SLE treated with prednisolone.

KINETIC STUDIES OF PHAGOCYTOSIS 1 1 1

as did the clinical manifestations. In both patients a reduction of PMN phagocytic rate to the normal range was observed during the hospital period of about 6 weeks. In Figure 5 , the clinical course and the phagocytic rate in one of the patients is illustrated. The other patient, a 33-year-old woman, had fever and severe vas- culitis with threatening gangrene in her toes as the dominating signs of her disease. This patient was treated initially with a modified corticosteroid regime with three single injections of 0.5-1 gram of methylprednisolone every other day. The effect on the phagocytic rate is illustrated in Figure 6. As can be seen, the phagocyte rate was markedly reduced 1 and 2 hours after a steroid injection.

DISCUSSION Results reported previously from studies of

phagocytosis by peripheral blood granulocytes of RA patients varied, probably because of the different techniques used. Brandt and Hedberg (14) found a normal phagocytic uptake of yeast particles in the presence of serum. Bodel and Hollingsworth (15) demonstrated decreased phagocytosis by both peripheral blood and sy- novial fluid neutrophils in RA with a staphylococcal system.

In several studies patients with RA have been shown to have an increased susceptibility for severe bacterial infections and the presence of R F has been related to the number of infections (16-18). The present investigation provides presumptive support for the the- ory that R F interferes with the phagocytic performance. There are several ways in which RF may disturb the phagocytic process. Because a positive correlation between the amount of circulating immune complexes and the R F titer has previously been reported (19), it is possible that granulocytes of strongly sero-positive patients are already loaded with previously ingested immune aggregates. In support of this idea is the observation that PMN cells of patients with Felty’s syndrome and RA contain inclusions of aggregates of IgG, IgM, and C3 (20, 21). An alternative explanation is that the Fc receptor on the cell surface is blocked by the R F or the RF-lgG complexes. These and other aspects of the role of RF in phagocytosis remain to be tested in experimental studies.

Granulocytes from patients with SLE had in this study an increased phagocytic rate compared to the reference range. These findings do not agree with those of Brandt et al. (14), who studied 7 patients with SLE and reported defect ingestion of yeast particles. It

should be pointed out, however, that their studies on phagocytosis were performed in the presence of plasma. We have found a pronounced reduction of the phagocytic uptake by granulocytes obtained from both healthy individuals and patients with SLE in the presence of fresh SLE sera (to be published). Zurier (22) has also recently observed an inhibitor of phagocytosis in SLE sera. The possible relation of these in vitro observa- tions to the inflammatory process in SLE in patients in vivo is uncertain. However, at present we interpret the above data to mean that a reduced elimination rate of circulating immune complexes is possible because of humoral factors in SLE sera which interfere with the phagocytic uptake by unknown reasons. As isolated PMN cells from SLE patients have an increased reactivity for immune complexes, extravascularly deposited complexes might force these cells to an enhanced release of their lysosomal proteolytic enzymes.

The stimulated serum-independent phagocytic rate of SLE granulocytes seems specific. However, an overall problem in the evaluation of phagocytic uptake is the distinction between truly internalized particles and particles attached to the cell surface only. The phagocytic assay used in this study is an indirect method and therefore the particle uptake was controlled by light microscopy according to principles outlined in a pre- vious paper (8). The results obtained by the different methods agreed in an excellent way.

Another methodological problem is whether

METHY LPREDNISOLON E

It 6 i i i4 TIME AFTER INJECTION (HOURS)

Figure 6. The eflect of a single injection of 0.5 gram methylprednisolone on the initial rate of phagocytosis (@) in a patient with active SLE. The iv injection of methylprednisolone is indicated by an arrow.

112

observed results in this paper have all to do with IgG coating of particles, as even uncoated latex particles are ingested by PMNs. During the short incubation periods used, however, uncoated particles are not taken up to any appreciable degree by normal human neutrophils (8). Control experiments with PMNs from SLE patients did not indicate that the interaction of these cells with non-IgG-coated particles was different from cells obtained from apparently healthy individuals.

The use of D-penicillamine, a reducing and chelating agent, in the treatment of RA is based upon the observation that this drug acts by dissociating the disulfide bonds of RF (23). Several studies report the beneficial effects of penicillamine in RA (24,25). The way in which this drug reduces inflammatory joint activity is not known. Serological features during therapy are reduction of RF titers and decreased serum immuno- globulin level (26). In vitro studies have shown that D- penicillamine inhibits lymphocyte transformation (27) and at high concentrations also decreases chemotaxis (28). The effect of D-penicillamine in vivo on the function of PMN cells has not been reported before. Our studies indicate a stimulatory effect on the initial rate of phagocytosis of granulocytes isolated from patients on treatment with D-penicillamine. This effect was seen during an early course of treatment before any clinical improvement was evident or before the R F titer was reduced. The reported reduction in RF titers and serum immune complex levels (29-3 1) during penicillamine treatment might be explained by an enhanced elimination.

In 1 patient a profound impairment of the phagocytic response of granulocytes coincided with an allergic reaction to penicillamine. The phagocytic function improved concomitantly with clinical recovery. A transient defect in the chemotaxis of peripheral blood PMN has also been described recently in I patient during a drug induced allergic reaction (32). Defects in phagocytic and chemotactic function might in these cases be caused by a common, but until now unrecognized, mechanism.

Anti-inflammatory drugs such as corticosteroids reduce phagocytosis and bacterial killing in vitro (33,34). The in vivo results vary and the high doses of corticosteroids required to influence granulocyte function in vitro have also been puzzling. In any case, there is a widespread clinical experience that corticosteroid treatment increases the incidence of bacterial infections. In this study we observed pronounced reduction of the initial rate of phagocytosis after a single injection of 0.5 gram methylprednisolone. This steroid-induced depres- sion has also been observed on healthy volunteers (un-

HALLGREN ET AL

published data). Granulocytes of patients with active SLE normalized their overstimulated initial phagocytic uptake during the course of a more moderate steroid treatment.

The identification of abnormalities of granulocyte function is essential for our understanding of the inflammatory response in a variety of clinical settings. Kinetic measurements of phagocytosis seems to be a sensitive and a potentially useful method for clinical studies. The influence of therapeutic agents on host re- sistance is an essential problem for clinicians. Further studies on SLE patients may reveal whether the initial phagocytic rate is a suitable variable to follow granulocyte function during immunosuppressive treatment.

ACKNOWLEDGMENTS The authors wish to thank Dr. K.-E. Fjellstrom, De-

partment of Internal Medicine, Uppsala, for his help in the clinical evaluation of the patients. This study was supported by the Svenska Livforsakringsbolags namnd for medicinsk forskning, Gustav V:s 80-Brs fond, and the Faculty of Medi- cine, University of Uppsala.

I .

2.

3 .

4.

5 .

REFERENCES Kunkel HG, Miiller-Eberhard HJ, Fudenberg HH, To- masi TB: Gamma-globulin complexes in rheumatoid arthritis and certain other conditions. J Clin Invest

Agnello V, Koffler D, Eisenberg JW, Winchester R, Kun- kel HG: Clq precipitins in the sera of patients with systemic lupus erythematosus and other hypocomplementic states: characterization of high and low molecular weight types. J Exp Med 134:228-241, 1971 (suppl) Nydegger UE, Lambert PH, Gerber H, Miescher PA: Circulating immune complexes in the serum in systemic lupus erythematosus and in carriers of hepatitis B antigen. J Clin Invest 54:297-309, 1974 Hallgren R , Wide L: Detection of circulating IgG aggregates and immune complexes using lZsI protein from Staphylococcus aureus. Ann Rheum Dis 35:306-313, 1976 Cochrane CG, Koffler D: Immune complex disease in experimental animals and man. Adv Immunol

40:117-129, 1961

16:185-264, 1973 6. Henson PM: Mediators of Inflammation. New York, Ple-

num Press, 1974, chap 1 7. Venge P, Hallgren R, Stilenheim G, Olsson I: Extra-

cellular release of lysosomal protein from human granulocytes during phagocytosis of Staphylococcus protein A-lgG complexes. I . Effects of serum and cations of the selective release from different granula populations. In preparation

8. Hiillgren R, Jansson L, Venge P Kinetic studies of phago-

KINETIC STUDIES OF PHAGOCYTOSIS 113

cytosis of IgG coated latex particles using a thrombocyte counter. J Lab Clin Med. Accepted for publication

9. Cohen AS, Reynolds WE, Frankling EC, Kulka JP, Ropes MW, Schulman LE, and Wallace SL: Preliminary criteria for the classification of systemic lupus erythematosus. Bull Rheum Dis 21:643-648, 1971

10. Hallgren R, Stilenheim G: Quantification of phagocytosis by human neutrophils. The use of radiolabelled staphylococcal protein A- lgG complexes. Immunology

1 1 . Lizana J , Hellsing K: Polymer enhancement of automated immunological nephelometric analysis as illustrated by determination of urinary albumin. Clin Chem 2041 5-420, 1974

12. Mancini G, Carbonara AO, Heremans JF: Immuno- chemical quantitation of antigens by single radial immunodiffusion. lmmunochemistry 2:235-254, 1965

13. Kabat EA, Mayer MM: Experimental Immunochemistry. Springfield, Illinois, Charles C Thomas Publisher, 1961, chap 4

14. Brandt L, Hedberg H: Impaired phagocytosis by peripheral blood granulocytes in systemic lupus erythematosus. Scand J Haematol 6:348-353, 1969

15. Bodel PT, Hollingsworth JW: Comparative morphology, respiration and phagocytic function of leukocytes from blood and joint fluid in rheumatoid arthritis. J Clin Invest

16. Kellgren JH, Ball JF , Fairbrother RW, Barnes KL: Sup- purative arthritis complicating rheumatoid arthritis. Br Med J I:1193-1199, 1958

17. Uddin J , Kraus AS, Kelly HG: Survivorship and death in rheumatoid arthritis. Arthritis Rheum 13: 125-130, 1970

18. Huskinson EC, Dudley HF: Severe, unusual and recurrent infections in rheumatoid arthritis. Ann Rheum Dis

19. Zubler RH, Nydegger U, Perrin LH, Fehr JK, McCorm- ick J, Lambert PH, Miescher RA: Circulating and intra- articular immune complexes in patients with rheumatoid arthritis. Correlation of lzsl-Clq binding activity with clinical and biological features of the disease. J Clin Invest

20. Gupta RC, LaForce FM, Mills DM: Polymorphonuclear leukocyte inclusions and impaired bacterial killing in patients with Felty’s syndrome. J Lab Clin Med 88:183-193, 1976

30755-762, 1976

45~580-589, 1966

31:118-121, 1972

57: 1308-13 19, 1976

21. Vaughan JH, Barnett EV, Sobel MV, Jacox RF: Intra- cytoplasmatic inclusions of immunoglobulins in rheumatoid arthritis and other diseases. Arthritis Rheum

22. Zurier RB: Reduction of phagocytosis and lysosomal en- zyme release from human leukocytes by serum from patients with systemic lupus erythematosus. Arthritis Rheum 19:73-78, 1976

23. Jaffe IA: Intra-articular dissociation of rheumatoid factor. J Lab Clin Med 60:409-421, 1962

24. Day AT, Golding J R , Lee PN, Butterworth AD: Penicilla- mine in rheumatoid arthritis: a long term study. Br Med J

25. Maldykowa H, Chwalinska-Sadowska H, Luft S, Glinska- Urban M, Odrzywolska A, Jaworska H: Results of cupr- enil (D-penicillamine) treatment in patients with rheumatoid arthritis. Rheumatologica 10:9-21, 1972

26. Bluestone R, Goldberg LS: Effect of D-penicillamine on serum immunoglobulins and rheumatoid factor. Ann Rheum Dis 32:50-52, 1973

27. Roath S, Wills R: The effect of penicillamine on lympho- cytes in culture. Postgrad Med J 5056-59, 1974 (suppl)

28. Chwalinska-Sadowska H, Baum J: The effect of D-penicillamine on polymorphonuclear leukocyte function. J Clin Invest 58:871-879, 1976

29. Mohammed I. Barraclough D, Holborow EJ, Ansell BM: Effect of penicillamine therapy on circulating immune complexes in rheumatoid arthritis. Ann Rheum Dis

30. Bresnihan FP, Ansell BM: Effect of penicillamine treatment on immune complexes in two cases of seropositive juveni le rheumatoid ar thr i t is . Ann Rheum Dis 35:463-465, 1976

31. Norberg R, Gedda PO: Effects of Circulating IgG Com- plexes i n Rheumatoid Arthritis by Treatment with Peni- cillamine. Oslo, Fabritius & SGner, 1977, pp 146-151

32. Bowers TK, Craddock PR, Jacob HS: Acquired granulocyte abnormality during drug allergic reactions: Pos- sible role of complement activation. Blood 49:3-8, 1977

33. Ward PA: Leukotactic factors in health and disease. Am J Pathol 64:521-530, 1971

34. Bishop CR, Athens JW, Boggs DR, Warner HR, Cart- Wright G E , Wintrobe MM: XIII. A non-steady-state kinetic evaluation of the mechanism of cortisone-induced granulocytosis. J Clin Invest 47:249-260, 1968

I 1: 125-1 33, 1968

1:180-183, 1974

35~458-461, 1976

kinetic studies of phagocytosis

Documents