Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042384 (vasculitis)
 20,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Expression of the C3b/C4b receptor (CR1) on erythrocytes is decreased in patients with systemic lupus erythematosus (SLE) compared to normal individuals, and the CR1 antigen is absent from podocytes in severe diffuse proliferate nephritis of SLE. In the present study, we examined the relationship between the number of CR1 on erythrocytes and the occurrence and severity of SLE nephritis, and assessed the expression of CR1 on erythrocytes and the occurrence and severity of SLE nephritis, and assessed the expression of CR1 on erythrocytes in non-SLE nephritis and other systemic inflammatory diseases by measuring the binding of 125I-labeled rabbit F(ab')2 and murine monoclonal IgG anti-CR1 antibodies to erythrocytes of normal individuals and patients in a French population. The number of binding sites for monoclonal anti-CR1 antibody on erythrocytes of 116 normal individuals was 743 +/- 22 (mean +/- SEM) with a range of 169-1,333, and the frequency distribution of this number in the population was bimodal. In 112 patients with SLE, the mean number of CR1 sites on erythrocytes was decreased to 62% of the mean for normal individuals (p less than 0.001). No correlation was found between CR1 expression on erythrocytes and the presence or immunohistopathological type of glomerulonephritis in biopsy specimens from these patients. The mean number of CR1 on erythrocytes of 29 patients with non-SLE glomerulonephritis was slightly decreased to 89% of the normal mean (p greater than 0.05), which could not be attributed to glomerular immune complex disease or vasculitis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Decreased expression of C3b receptor (CR1) on erythrocytes of patients with systemic lupus erythematosus contrasts with its normal expression in other systemic diseases and does not correlate with the occurrence or severity of SLE nephritis. 294 97

The deposition of immune complexes (IC) may play an important part in the pathogenesis of vasculitis. An increase in permeability of the vascular endothelial lining is a prerequisite for IC deposition. We used an in vitro model to examine the effects of interactions between IC, neutrophils, and endothelium on the integrity of endothelial cell monolayers. Human umbilical vein endothelial cells were grown to confluence on an FITC-labeled matrix, and monolayer integrity was assessed by the exclusion of an 125I-anti-FITC Ab. Alteration in endothelial monolayer permeability was associated with increased uptake of 125I-anti-FITC Ab, expressed as a percentage of the maximal uptake of Ab onto the FITC-matrix from which endothelial cells had been stripped. Neither resting nor cytokine-stimulated endothelial cells bound hepatitis B surface Ag (HBsAg/anti-HBsAg) IC. Immune complexes were shown to activate neutrophils to induce a 9.5% increase in the permeability of IL-1 beta-stimulated endothelium. This increase in endothelial permeability was abrogated by the addition of RBC bearing normal complement receptor type 1 (CR1) numbers (3.2%). This protective effect was shown to be related to the binding of IC to erythrocyte CR1 and was reduced by CR1 blockade using polyclonal rabbit anti-CR1 Abs. These observations demonstrate that IC are capable of directly activating neutrophils to induce increases in endothelial permeability, which may facilitate the deposition of circulating IC. The results support the hypothesis that the binding of IC to erythrocyte CR1 may inhibit damaging interactions between IC, neutrophils, and endothelium.
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PMID:Erythrocyte complement receptor type 1 and interactions between immune complexes, neutrophils, and endothelium. 808 93