Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Receptors, Complement 3b”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51Linked to original sources
PubMed1986

Interaction of complement-solubilized immune complexes with CR1 receptors on human erythrocytes. The binding reaction.

The binding of complement (C)-solubilized 125I bovine serum albumin (BSA) anti-BSA immune complexes (IC) to CR1 receptors on human red blood cells (RBC-CR1) was studied. The binding of IC to CR1 was strongly dependent on the molar antigen to antibody ratio, and IC formed in moderate antigen excess showed no binding. IC solubilized in 50% human serum in the presence of autologous RBC bound rapidly to RBC-CR1, with maximal binding within less than 1 min at 37 degrees C. Release of CR1-bound IC under these conditions occurred slowly, requiring more than 30 min. Only binding of 'partially' solubilized, e.g., anti C3c (C4c), and conglutinin-reactive IC occurred, whereas fully solubilized complexes (IC-C3dg, C4d) showed virtually no binding. Solubilization of IC in the presence of Mg-EGTA or in C2-deficient serum resulted in a markedly delayed binding of IC to RBC, indicating the importance of an intact classical pathway in preparing the IC for binding to RBC-CR1. C-solubilized IC could be absorbed to solid-phase conglutinin or antibody to C3c and C4c, and these ligands were able to inhibit the binding of solubilized IC to RBC. Heparin also exerted a marked, dose-dependent inhibitory effect on the binding of presolubilized IC to RBC-CR1, whereas the binding was unaffected by the addition of monosaccharides or by the concentration of Ca2+ or Mg2+ ions.

Animals↗
PubMed1986

Phagocytosis of agarose beads by receptors for C3b (CR1) and iC3b (CR3) on human alveolar macrophages cultured on fibronectin in vitro. A scanning electron microscopic study.

We studied the phagocytosis of agarose beads by human alveolar macrophages in terms of the morphology, the receptors involved, and the cellular substrates (plastic or fibronectin) used. Beads coated with C3b (58%) and iC3b (42%) by treatment with serum, were ingested during 45 min by CR1 and CR3 on the macrophages. This ingestion was inhibited 80-90% by the presence of polyclonal F(ab')2 anti-C3 fragments. Since the phagocytosis of both C3b- and iC3b-coated beads was about threefold stronger than for C3b-coated beads (trypsinized serum-treated beads), the results indicate that the CR3 is more phagocytic than the CR1. The phagocytosis of initially complement uncoated beads, which are slowly opsonized with macrophage-produced C3b and iC3b in vitro, was also strongly inhibited (70-80%) by the presence of anti-human C3 F(ab')2 fragments. There was an increased phagocytosis (10-17%) of complement precoated beads by macrophages cultured on the fibronectin substrate versus the plastic substrate. The morphology and rapid phagocytosis of the complement precoated beads was demonstrated by SEM. The general impression was that membranous protrusions stretched towards the beads, which became increasingly enclosed by plasma membrane.

Adult↗
PubMed1987

Characteristics of human rheumatoid synovial and normal blood dendritic cells. Retention of class II major histocompatibility complex antigens and accessory function after short-term culture.

Dendritic cells (DC) were isolated from synovial tissue and synovial fluids of patients with rheumatoid arthritis and from peripheral blood of healthy donors. The cells were analysed for various surface antigens in indirect immunofluorescence by means of monoclonal antibodies. Surface antigen expression and accessory activity of the DC during short-term cultures were also investigated. Both the rheumatoid synovial and the normal blood DC were strongly positive for panleucocyte antigen and class II major histocompatibility complex (MHC) antigens (HLA-DP, HLA-DQ, and HLA-DR). The DC suspensions (purity approximately 80-85%) showed very low percentage of cells staining for various other cell membrane markers, including B cell, T cell, natural killer (NK) cell, and various monocyte/macrophage markers as well as markers specific for dendritic reticulum cells and Reed Sternberg cells. Moreover, neither rheumatoid nor normal DC reacted with the RFD1 monoclonal antibody, which is specific for interdigitating cells of human thymus. In contrast to Langerhans' cells, the DC lacked the thymocyte (T6) marker. The various DC expressed neither complement receptors (CR1, CR3), transferrin receptors, nor Fc receptors. They also lacked enzyme markers like peroxidase and nonspecific esterase. The DC formed clusters with autologous T cells. Cluster formation was readily inhibited by anti-HLA-DR and anti-CD2 (T11) monoclonal antibodies. After 3 to 5 days in culture the DC still expressed class II MHC antigens and were potent stimulators in allogeneic mixed lymphocyte reactions (MLR). Only a small number of cells in the DC suspensions from synovial tissue expressed fibroblast antigens before and after culture.

Antigen-Presenting Cells↗
PubMed1988

The expression of CR1 and CR3 on non-modulated and modulated granulocytes of healthy blood donors as measured by flow cytofluorometry.

Complement receptors, CR1 and CR3, on neutrophils increase their cellular spontaneously at 37 degrees C or after mechanical stress during the cell preparation. We have established a cell preparation procedure and a cytofluorometric immunoassay method to evaluate the receptor expression in vivo in this study. The expression of CR1 and CR3 was studied after haemolysis in NH4Cl at different temperatures and incubation intervals. It was shown that cell preparation and receptor analysis must be performed at 15 degrees C or lower to avoid up-regulation of the receptor structures. Two minutes' incubation at 20 degrees C was sufficient to modulate the cells in this regard. Granulocytes from healthy blood donors were analysed and the mean fluorescence intensity (MFI), which reflects the number of receptors on the cell surface, showed a normal distribution for the CR1 (n = 158) and CR3 (n = 76) expression in the healthy population. The MFI of the two receptors showed a correlation (r = 0.71). Granulocytes from all donors could be modulated at 37 degrees C to a similar degree for both receptors (r = 0.76), despite the fact that they are supposed to be mobilized from different intracellular pools. A group of patients with localized inflammatory processes, such as sinusitis, differed from the healthy controls. In this group, the CR1 expression was not normally distributed, but 15 out of 26 patients (58%) had granulocytes with a CR1 expression exceeding the mean +/- SD of the normal population.

Adolescent↗
PubMed1988

Inefficient binding of IgM immune complexes to erythrocyte C3b-C4b receptors (CR1) and weak incorporation of C3b-iC3b into the complexes.

The binding of soluble complement-reacted IgM immune complexes (IC) to erythrocyte (E) C3b-C4b receptors (CR1) and the incorporation of C3b-iC3b into solid phase IgM-IC was investigated. The optimal binding of liquid phase IgM-IC to E-CR1 was obtained with IC formed at moderate antibody excess, but the binding was low (2-3%) when compared to the binding of the corresponding IgG-IC (50-60%). Solid phase IC were prepared by coating microwells with heat-aggregated bovine serum albumin (BSA) followed by incubation with rabbit IgM anti-BSA antibody. The IC were reacted with human serum at 37 degrees C. The binding of C3b-iC3b was determined by use of biotinylated F(ab')2 antibodies to C3b-C3c and avidin-coupled alkaline phosphatase. The incorporation of C3b-iC3b into solid-phase IgM-IC increased when increasing amounts of IgM antibody were reacted with the antigen. The binding reaction was slow, reaching a maximum after about 2 h at 37 degrees C. The binding of C3b-iC3b to the IgM-IC was remarkably inefficient when compared to the incorporation into IgG-IC reacted with the same amounts of BSA-precipitating antibody.

Animals↗
PubMed1989

Reduced erythrocyte CR1 (CD 35) receptor function and complement opsonization in factor I-deficient patients is restored by plasma infusion.

Erythrocytes (E) from three factor I-deficient patients were investigated for surface-bound complement factors and CR1 (CD 35) expression and function. The E were coated with C4b, C3b, and factor H. Following plasma infusion or in vitro incubation of the patients' E with normal human serum (NHS) or purified factor I, cell-bound C4b and C3b could no longer be detected. The E now expressed C3d, and factor H was unaffected, indicating that factor H was bound to the C3d part of the C3b molecules, providing the co-factor for effective cleavage of E-bound C3b when purified factor I was added. The binding of monoclonal anti-CR1 antibodies (M710) to the patients' E was markedly reduced compared with control E, and was not normalized by treatment with NHS, probably because covalently bound C3d/factor H interfered with the binding of M710. By contrast, the reduced ability of the patients' E-CR1 to bind complement-opsonized immune complexes (IC) was normalized after plasma infusion. This shows that the impaired CR1 function was acquired and emphasizes the importance of performing functional CR1 assays. Complement opsonization of IC for binding to normal E was severely compromised in the patients' sera due to consumption of factor B and C3. After plasma infusion the opsonization capacity of the patients' sera was restored. Thus, two mechanisms of importance for normal clearance of IC were compromised in factor I-deficient patients: (1) the opsonization of IC for binding to E-CR1, and (2) the capacity of E-CR1 to bind opsonized complexes. Both dysfunctions were temporarily corrected by plasma infusion.

Adult↗
PubMed1990

Zinc ions inhibit factor I-mediated release of CR1-bound immune complexes and degradation of cell-bound complement factors C3b and C4b.

ZnCl2 exerted a dose-dependent inhibition of citrate-phosphate-dextrose (CPD) plasma-induced release of 125I-labelled BSA-anti-BSA immune complexes (IC) bound to complement receptor type 1 (CR1, CD35) in human whole blood. Maximal inhibition was observed at 10 mM of ZnCl2. Furthermore, the release of IC bound to erythrocyte (E)-CR1 by purified factor I, factor I-deficient serum plus purified factor I, or normal human serum was reduced by approximately 90%, 64%, and 52%, respectively, in the presence of 10 mM ZnCl2. The effect of ZnCl2 on factor I-mediated degradation of cell-bound C3b/C4b was also investigated employing CPD blood or E from a factor I-deficient donor. These cells expressed covalently bound C3b and C4b as demonstrated by a simple agglutination technique. Upon incubation of CPD whole blood with purified factor I, or of E with purified factor I or normal CPD plasma, the C-fragments were cleaved and the cells were no longer agglutinated by antibodies to C3c and C4c. The presence of ZnCl2 prevented this factor I-mediated degradation of C3b and C4b, as evidenced by the unaffected agglutination of the cells by the antibodies. We conclude that ZnCl2 inhibited factor I activity since: (1) release of complement-preopsonized IC from E-CR1 by purified factor I was markedly inhibited (90%) in the presence of ZnCl2, (2) preincubation of the cells with ZnCl2 caused only a moderate inhibition (32-38%) of the IC release, and (3) degradation by purified factor I of covalently cell-bound C3b and C4b was abrogated in the presence of 10 mM ZnCl2.

Animals↗
PubMed1990

Phagocytosis of agarose beads by receptors for C3b (CR1) and iC3b (CR3) on alveolar macrophages from patients with sarcoidosis.

Alveolar macrophages (AM) from sarcoidosis patients exhibit no detectable defect in their potential to synthesize the functional alternative and terminal pathway of complement. They also synthesize more C9 than AM from healthy controls. Various authors have suggested that sarcoid AM have decreased phagocytic ability. In the present work we studied whether there was any difference in C3 receptor-mediated phagocytosis of serum-treated and native agarose beads by AM recovered from patients with active sarcoidosis compared with controls. AM from seven patients with active sarcoidosis and seven healthy controls were cultured under serum-free conditions for 2, 12, 24, and 48 h. We found a significantly increased CR1 and CR3 receptor-mediated phagocytosis of native agarose beads by AM from the seven patients. CR1 and CR3 were also detected on AM directly recovered from bronchoalveolar lavage fluid using fluorescein-conjugated monoclonal anti-receptor antibodies. The percentage of AM expressing CR appeared to be increased in sarcoidosis. The reason for the enhanced phagocytosis of agarose beads by the sarcoid AM is probably the result of both increased synthesis and receptors of complement. Altered complement production and complement receptors may be important for the pathogenesis of this granulomatous disorder.

Adult↗
PubMed1991

Granulocyte-dependent extracellular cytotoxicity is enhanced by complement C3bi and independent of phagocytosis.

We have evaluated phagocytosis, C3-binding and cytotoxicity of human leukocytes simultaneously, using IgM-sensitized C3-fragment-bearing sheep erythrocytes (EAC3b, EAC3bi) as targets. In this method, 51Cr-labelled EAC3b or EAC3bi were added to human peripheral granulocytes anchored by fibronectin onto microtitre plate wells. The degrees of haemolysis, binding and ingestion of the target cells were estimated from the radioactivity released. We found that the granulocytes predominantly lysed EAC3bi but not EAC3b or EAC4b. EAC3bi lysis elicited from granulocytes was as effective as that from lymphocytes under the same assay conditions. However, one difference in the cytolysis of the two effector cells was that EAC3bi bound efficiently to all of the granulocytes similarly to EAC3b, whereas it bound to only 4% of the lymphocytes. The bound cells did not appear to be efficiently phagocytosed by the granulocytes. Blocking studies using antibodies suggested that C3bi receptors, CR3 and CR4, but not other C3-binding proteins, C3b/C4b receptor (CR1), membrane cofactor protein (MCP) or decay-accelerating factor (DAF), are involved in granulocyte-mediated haemolysis. We speculate that simultaneous stimulation of the C3bi receptors and the fibronectin receptor results in elicitation of cytotoxicity by granulocytes.

Carrier Proteins↗
PubMed1992

Over-estimation of the number of complement receptor type 1 (CR1) on erythrocytes.

The number of CR1 on erythrocytes, as measured by monoclonal antibodies, remains undefined because of the repetitive structure of CR1 and the presence of different types of structural CR1 alleles. We studied the number of CR1 per erythrocyte using two monoclonal antibodies, E11 and 3D9, which recognize different sites on CR1. The number of binding sites was higher for E11 than for 3D9 (ratio E11/3D9: 1.9 +/- 0.4, n = 17); however, this ratio was not affected by CR1 numbers or alleles. Partial digestion with papain of CR1 on erythrocytes abolished the binding of 3D9. It reduced the binding of E11 to one-third of its initial value (0.35 +/- 0.03; n = 13) using cells with different CR1 numbers or alleles. By immunoblotting, a unique 75-kDa stump of CR1 remained attached to the erythrocytes for every allele studied. Taken together, these results suggest that the number of CR1 has been over-estimated in the past using E11 by a factor of 2, or more probably 3. However, the over-estimation of CR1 number has been identical for erythrocytes bearing different CR1 numbers or alleles.

Antibodies, Monoclonal↗
PubMed1992

Membrane expression and function of complement receptors CR1 and CR3 on neutrophils from HIV-infected subjects: modulation by rTNF-alpha and rGM-CSF.

We evaluated membrane expression and function of complement receptors CR1 and CR3 on neutrophils from 27 HIV-positive (HIV+) subjects (14 in the CDC class III and 13 class IV) as well as their modulation in vitro by recombinant tumour necrosis factor-alpha (rTNF-alpha) and granulocyte-macrophage colony stimulating factor (rGM-CSF). While CR1 was expressed at similar levels on neutrophils from controls and HIV+ subjects, CR3 expression was significantly higher in CDC class IV subjects than in healthy controls. CR1 and CR3 expression was significantly increased after treatment of neutrophils with both cytokines, without differences between controls and HIV+ subjects. Similarly, the superoxide anion (O2-) production in response to C3-coated zymosan (C3zy) was significantly enhanced on neutrophils from CDC class IV subjects when compared with controls. rGM-CSF and rTNF-alpha treatment significantly enhanced the spontaneous as well as C3zy-stimulated O2- production by neutrophils from controls and CDC class III subjects, and induced an upward trend in the CDC class IV group. These results indicate that the neutrophils of HIV+ patients are preactivated in vivo but they also indicate that these cells may correctly respond to a subsequent particulate stimulus as well as to activating cytokines. Our findings suggest that desensitization or functional exhaustion of complement receptors are not implicated in the abnormalities observed on neutrophils from HIV+ patients.

Adult↗
PubMed1994

Interactions of opsonized immune complexes with whole blood cells: binding to erythrocytes restricts complex uptake by leucocyte populations.

The binding of opsonized, fluorescein-labelled bovine serum albumin (BSA)/rabbit anti-BSA complexes (IC) to washed human whole blood cells and isolated leucocytes in the presence of autologous serum was investigated by flow cytometry. In the presence of erythrocytes (E), the IC-binding to granulocytes (PMN), monocytes and lymphocytes was inhibited by up to 46%, 61% and 48%, respectively, depending on the incubation time and the IC-concentration tested. The E-mediated inhibition of the binding to PMN was found to correlate with the average numbers of CR1 per E during the initial 15 min of incubation. Thereafter, the difference between IC binding to PMN in absence and presence of E, decreased in accordance with decreasing binding to E. IC-uptake by PMN induced a drop in side-scatter characteristics, attributable to degranulation, which could be prevented by the presence of E. In contrast to the findings for PMN, the difference between IC-binding to monocytes in the absence and presence of E increased progressively over the 90 min observation period, suggesting that different mechanisms are involved in the late-phase IC uptake by monocytes and PMN. Lymphocytes were heterogeneous with respect to IC binding, the main contributors being B cells. E initially inhibited and then later enhanced the IC binding to lymphocytes, suggesting that E promote B cell uptake of C3d,g-covered IC via CR2. Our findings, that E can restrict the IC uptake by circulating leucocytes, and that an IC-induced degranulation of PMN may be prevented by E, indicate that E may act as a high capacity buffer limiting inappropriate activation of phagocytes by circulating IC.

Antigen-Antibody Complex↗
PubMed2006

C5a, interleukin-8 and tumour necrosis factor-alpha-induced changes in granulocyte and monocyte expression of complement receptors in whole blood and on isolated leukocytes.

Treatments targeting complement receptors have been demonstrated to improve outcome in experimental sepsis. The regulation of the complement receptors in sepsis is not clear. Lipopolysaccharide (LPS) stimulation of granulocytes ex vivo has been shown to reduce C5a receptor (CD88) expression and to increase CD35 and CD11b/CD18 expressions in whole blood but not on isolated cells, indicating an indirect effect mediated via factors in the blood. With the aim to study whether these effects could be attributed to C5a, tumour necrosis factor (TNF)-alpha and interleukin (IL)-8, whole blood or isolated granulocytes and monocytes from healthy individuals were investigated. After incubation with C5a in a dose range of 1 x 10(-9)-1 x 10(-7) mol/l, and TNF-alpha and IL-8 at doses of 1-100 ng/ml, the expressions of the complement receptors CD88, CD35, CD11b/CD18 were analysed by flow cytometry. Incubation with C5a reduced granulocyte CD88 expression by 44+/-6.9% and 82+/-4.2%, whereas monocyte CD88 expression decreased by 21+/-4.0 and 30+/-17% (whole blood and isolated cells). IL-8 and TNF-alpha incubation of granulocytes induced similar results. Granulocyte CD35 expression was significantly increased by 367, 175 and 336% by C5a, TNF-alpha, IL-8, respectively; CD11b expression was similarly increased. Consistent with findings in septic patients and after LPS incubation, it is concluded that all stimuli reduced granulocyte CD88 expression, whereas CD35 and CD11b were increased.

Adult↗
PubMed1986

Erythrocyte CR1 determination using monoclonal antibody in a microtiter plate ELISA; receptors are not masked by immune complexes.

The microtiter plate ELISA using monoclonal antibody is a specific, sensitive and quantitative technique for measuring CR1 on human erythrocytes. The present investigations established that receptor occupancy by immune complexes did not affect the measurements. The monoclonal anti-CR1 antibody To5 bound unimpeded to receptors that had reacted with an excess of complement-opsonized tetanus toxoid anti-tetanus toxoid complexes prepared at antigen:antibody ratios between 32:1 and 1:8. The CR1 levels on erythrocytes from 11 patients with systemic lupus erythematosus (SLE) were not increased (P greater than 0.30) after release of CR1-bound immune complexes by incubation with factor I. Neither did the serum from these patients contain blocking anti-CR1 activity (P greater than 0.10). Additionally, the number of antigenic CR1 sites in 10 normals and in the 11 patients with SLE was well correlated with the number of functional receptor sites as assessed by binding of soluble complexes (P less than 0.001). These data establish that the true CR1 levels are determined using the microtiter plate ELISA for quantitation of CR1 in patients with diseases involving immune complexes and/or autoantibodies.

Antibodies, Monoclonal↗
PubMed1986

Release of immune complexes bound to CR1 on erythrocytes; suramin inhibits factor I in the presence of EDTA.

An experimental model was established in order to study the release of immune complexes (IC) bound by complement C3b receptors (CR1) on human erythrocytes (RBC). Soluble tetanus toxoid anti-tetanus toxoid complexes were incubated with RBC in the presence of autologous serum at optimal conditions for binding. The RBC carrying complement-opsonized complexes were incubated with appropriate serum reagents, and it was shown that factor I was required for release of the complexes, which occurred without loss of CR1. Suramin was, irrespective of factor I, found to induce release of CR1-bound IC in the absence of EDTA, whereas factor I-mediated release was inhibited by suramin in the presence of EDTA. EDTA probably interfered through a charge-dependent interaction. These observations are decisive for the interpretation of in vitro experiments involving these reagents. The combination of EDTA and suramin was found inappropriate for use in quantitative determination of in vivo CR1-bound IC.

Antigen-Antibody Complex↗
PubMed2005

Detection of differentiation- and activation-linked cell surface antigens on cultured mast cell progenitors.

BACKGROUND: Mast cells (MC) are multifunctional effector cells of the immune system. They derive from uncommitted CD34(+) hemopoietic progenitor cells (HPC). Depending on the stage of maturation and the environment, MC variably express differentiation- and activation-linked antigens. Little is known, however, about the regulation of expression of such antigens in immature human MC. METHODS: We analyzed expression of CD antigens on human MC grown from cord blood-derived CD34(+) HPC. The HPC were isolated by magnetic cell sorting (MACS) and FACS to >97% purity, and were cultured in stem cell factor (SCF) and interleukin (IL)-6 with or without additional cytokines (IL-4 or IL-10) in serum-free medium. The cell surface phenotype of MC was determined by monoclonal antibodies and flow cytometry. RESULTS: Cultured MC progenitors were found to react with antibodies against various CD antigens including CD58, CD63, CD117, CD147, CD151, CD203c, and CD172a, independent of the growth factors used and time-point investigated (days 14-42). CD116 [granulocyte-macrophage colony-stimulating factor receptor alpha (GM-CSFRalpha)] and CD123 (IL-3Ralpha) were expressed on MC precursors on day 14, but disappeared thereafter. Cultured MC did not express CD2, CD3, CD5, CD10, CD19, or CD25. Addition of IL-10 to MC cultures showed no effect on expression of CD antigens. However, IL-4 was found to promote expression of CD35 and CD88 on cultured MC without changing expression of other CD antigens. CONCLUSIONS: Most MC antigens may already be expressed at an early stage of mastopoiesis. Whereas IL-3R and GM-CSFRs are lost during differentiation of MC, these cells may acquire complement receptors (CD35, CD88) under the influence of distinct cytokines.

Animals↗
PubMed2006

Expression of human soluble complement receptor 1 by a pig endothelial cell line inhibits lysis by human serum.

The importance of complement activation and naturally occurring anti-pig antibodies in the hyperacute rejection (HAR) observed in models of pig-to-human xenotransplantation is well established. To overcome this, much effort has been dedicated to preparing transgenic pigs by knocking out Galalpha(1-3)Gal expression in these animals, or knocking in the expression of human complement regulatory proteins (CRPs), such as CD59 or decay accelerating factor. A soluble form of another membrane CRP, complement receptor type 1 (CR1), has also been shown to inhibit complement activation. Here, we show that transfection of a pig endothelial cell line with a truncated form of human soluble complement receptor 1 (sCR1) almost completely protected these cells from complement-mediated lysis by human AB serum. Pigs genetically manipulated to express human sCR1 may represent an additional strategy to inhibit HAR of pig-to-human transplanted organs.

Animals↗
PubMed1990

Quantification of complement receptor 1 on erythrocytes: follow-up of HIV-1-infected patients with AIDS-related complex/Walter-Reed 5 under treatment with intravenous immunoglobulin. The ARC-IVIG Study Group.

A sensitive flow-cytometric method was established to quantify the number of complement receptor 1 (CR1, C3b/C4b receptor, CD35) on the surface of purified erythrocytes of 12 patients infected by HIV-1 and showing two clinical AIDS-related complex/Walter-Reed 5 criteria. Erythrocytes were incubated with biotinylated monoclonal anti-CR1 antibody followed by phycoerythrin-streptavidin before analysis on a flow cytometer. As few as 50 binding sites/cell could be detected, making this method as sensitive as a radioimmunoassay with 125I anti-CR1. Seven of the patients studied received an immunoglobulin preparation suitable for intravenous use during the 6 months of the study, 5 got an equal amount of placebo preparation consisting of human serum albumin. For a year, erythrocytes were collected and purified every 3 months, frozen and stored at -70 degrees C until the end of the study, when the number of CR1 was determined. No difference between the two groups of patients was found. In 8 patients, small fluctuations of the amount of CR1/erythrocyte were seen during the period of observation, whereas in 4 of the patients a drop of the number of CR1 was observed towards the end of the study. No correlation was found between CR1 numbers on erythrocytes and circulating immune complexes, CH50, C3 and C4 concentrations or CD4-positive lymphocytes.

AIDS-Related Complex↗