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)

Neutrophils from patients suffering from severe congenital neutropenia (SCN), who were receiving recombinant human granulocyte colony-stimulating factor (rhG-CSF), were investigated in order to analyze the previously described decrease in chemotaxis. This study demonstrated the decreased chemotaxis to five well-known chemoattractants, FMLP, C5a, IL-8, LTB4 and PAF. To further investigate this impairment of patients' neutrophils, receptors and receptor turnover for chemoattractants were examined using flow cytometry. We found 1) increased FMLP receptor and decreased C5a receptor expression, 2) a normal expression of intracellular FMLP receptors after incubation with PMA, 3) increased loss and decreased re-expression of FMLP receptors after incubation with this peptide, 4) normal expression of adhesion glycoproteins CR3 (CD11b/CD18) and LFA1 (CD11a/CD18), 5) further signs of in vivo preactivation: high expression of Fc gamma-RI (CD64) and Fc gamma-RII (CD32), decreased expression of Fc gamma-RIII (CD16), increased expression of CD14, and low expression of HLA-DR. These data demonstrate that the decrease of chemotaxis of neutrophils from SCN patients is not due: a) to a decrease in the number of intra- or extracellular FMLP receptors; b) to a decrease of adhesion molecules. However, the decreased chemotaxis could result from an altered FMLP receptor turnover. The relevance of the altered Fc gamma-receptor pattern for the in vivo occurrence of side-effects, e.g. the necrotic vasculitis, of G-CSF treatment is discussed.
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PMID:Altered function and surface marker expression of neutrophils induced by rhG-CSF treatment in severe congenital neutropenia. 137 Apr 19

A defect of a functional epitope of the complement receptor 3 is described in a patient with SLE and immune vasculitis. This defect interferes with the interaction of CR3 with its ligand C3bi.
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PMID:[Complement receptor 3 deficiency in systematic lupus erythematosus]. 161 32

Eosinophils (EOs) participate in a variety of inflammatory states characterized by endothelial cell damage, such as vasculitis, pneumonitis, and endocarditis. We find that 100 U/ml TNF-alpha/cachectin (TNF), a concentration attainable in the blood of humans with parasitic infestations, stimulates highly purified populations of EOs to damage human umbilical vein endothelial cells (HUVEC), a model of human endothelium. This TNF-dependent EO cytotoxicity is strongly inhibited by heparin and methyprednisolone but unaffected by the platelet-activating factor antagonist BN52012 or scavengers of superoxide anion and H2O2, superoxide dismutase and catalase. However, addition of a physiologically relevant concentration of Br- (100 microM) enhances EO/TNF damage to HUVEC, implicating the possible participation of EO peroxidase (EPO) in the killing mechanism. EOs adherent to FCS-coated plastic wells more than double their production of superoxide anion and the cytotoxic EPO-derived oxidant HOBr when exposed to TNF, showing that TNF activates the respiratory burst of EOs attached to a "physiologic" surface. Unlike PMNs, EOs were not irreversibly activated to kill unopsonized endothelium by previous exposure to TNF, and did not degranulate or upregulate CR3 expression as detected by Mo1 in the presence of 100 U/ml TNF. HUVEC exposed 18 h to TNF were considerably more susceptible to lysis by PMA-activated EOs and reagent H2O2, demonstrating a direct effect of TNF upon endothelium, perhaps through inhibition of antioxidant defenses. These findings suggest that abnormally elevated serum levels of TNF may provoke EOs to damage endothelial cells and thereby play a role in the pathogenesis of tissue damage in hypereosinophilic states.
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PMID:Tumor necrosis factor alpha/cachectin stimulates eosinophil oxidant production and toxicity towards human endothelium. 197 79

We investigated whether a decreased complement receptor expression or function of monocytes isolated from peripheral blood of 52 patients with rheumatoid arthritis (RA) and rheumatoid vasculitis (RV) could account for the previously observed diminished degradation of immune complexes by monocytes of patients with RA and RV. On average, monocytes from all patients expressed significantly less CR1, and degraded significantly less AC3b when compared with monocytes of healthy controls. In addition, monocytes from RV patients degraded significantly less AC3b when compared with monocytes from patients with RA. The expression of both CR1 and CR3 on monocytes of RV patients was lower compared with RA patients but this difference was only significant for CR3. No differences were found between AC3b degradation and the expression of CR1 and CR3 between patients with active and inactive RA. Using linear discriminant analysis on the variables AC3b, CR1 and CR3, 94% of the patients could be classified correctly as healthy controls, RA or RV, suggesting a true multi-variate relationship between these parameters and patients groups. Our results suggest that the diminished capacity of monocytes from RA patients to degrade AC3b is due partly to a decreased expression of CR1 and CR3.
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PMID:Degradation of aggregates of activated C3 (C3b) by monocytes of patients with rheumatoid arthritis is related to vasculitis. 214 58

Lymphocytes displaying iC3b (Type 3) complement receptors (CR3) were quantified by flow cytometry in patients with systemic lupus erythematosus. The percentages and absolute numbers were compared to age and sex matched controls. Total CR3+ lymphocytes identified by the monoclonal antibodies OKM1 or Leu 15 were significantly decreased in patients with symptomatic arthritis, serositis or vasculitis and those with lupus nephritis, whereas values for CR3+ lymphocytes in patients with inactive disease were similar to normal donors. The phenotype of CR3+ lymphocytes was markedly different in patients with active SLE. In normals granular lymphocytes bearing Fc receptors for IgG (L cells) comprised two-thirds of CR3+ lymphocytes. However, in SLE this subset was reduced to 20% and there was a corresponding increase in CR3+ lymphocytes co-expressing the T3 marker. Percentages of CR3 T4+ but not CR3+ T8+ lymphocytes were significantly increased in SLE. Although patients with active disease were lymphopenic, absolute numbers of CR3+ lymphocytes co-expressing T cell markers were similar to normal controls. Since L cells are non-specific suppressors of Ig production, the reduction of this subset along with the increase in CR3 T4+ cells could contribute to unregulated antibody production characteristic of SLE.
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PMID:Studies on human blood lymphocytes with iC3b (type 3) complement receptors: III. Abnormalities in patients with active systemic lupus erythematosus. 295 74

Antibodies to neutrophil cytoplasmic antigens (ANCA) can be detected in patients with Wegener's granulomatosis and systemic vasculitis. During pregnancy or following transfusion, subjects sometimes produce alloantibodies to neutrophil antigens. If patient sera being tested for ANCA contain alloantibodies directed at neutrophil antigens that residue in the cytoplasm, the results may be difficult to interpret. At least one neutrophil antigen, NB1, is expressed on both neutrophil plasma membranes and secondary granules. We tested alloantibodies specific for neutrophil antigens NA1, NA2, NB1, NB2, 5b, 9a, and Mart in an ANCA-indirect immunofluorescence (ANCA-IF) assay to determine if these alloantibodies reacted with neutrophil cytoplasmic or granule antigens. Alloantibodies specific for neutrophil antigens NA1, NA2, NB2, 5b, and 9a did not react with neutrophil cytoplasmic components. However, all three NB1 alloantibodies studied demonstrated a cytoplasmic pattern of immunofluorescence (C-ANCA) when NB1-positive neutrophils were tested. While control ANCA resulted in cytoplasmic immunofluorescence of all neutrophils from each donor tested, NB1 antibodies reacted with a subpopulation of neutrophils from some donors. Cytoplasmic immunofluorescence was also observed with an antibody directed against the Mart neutrophil antigen. The Mart antigen is located on integrin CR3 (CD11b/CD18). To confirm that these reactions were due to anti-Mart, monoclonal antibodies to CD11b and CD18 were also tested and found to cause cytoplasmic immunofluorescence. When the ANCA-IF assay was performed using neutrophils that did not express Mart or NB1 antigen, cytoplasmic immunofluorescence was seen with the ANCA control antisera, but not with the NB1 or Mart alloantibodies.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Neutrophil alloantibodies react with cytoplasmic antigens: a possible cause of false-positive indirect immunofluorescence assays for antibodies to neutrophil cytoplasmic antigens. 846 14

Erythema elevatum diutinum (EED) is a type of leucocytoclastic vasculitis of unknown aetiology. We report a patient with unusually widespread and disabling EED that had been unresponsive to corticosteroids and antibiotics, but resolved on dapsone. Biopsies of fresh lesions showed typical features of leucocytoclastic vasculitis, with prominent neutrophil infiltration, marked expression of the beta(2)-integrins CR3 and LFA-1, and increased mast cell numbers. Older lesions exhibited granulation tissue and fibrosis, macrophages were more dominant, beta(2)-integrins were expressed less markedly, and mast cell numbers were lower. In vitro chemotaxis of the patient's peripheral blood neutrophils prior to treatment showed increased random migration and directed migration towards interleukin-8 (by 424%), but a profoundly decreased responsiveness towards the bacterial peptide analogue N-formyl-methionyl-leucyl-phenylalanine (fMLP) (by 98%). These values returned to normal after dapsone treatment and clinical improvement 5 months later. These findings support the concept that in EED, activation via cytokines such as interleukin-8 allows a selective recruitment of leucocytes to tissue sites, while immune complexes and bacterial peptides sustain the persistent local inflammatory infiltrate and the leucocytoclastic vasculitis.
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PMID:Erythema elevatum diutinum--evidence for disease-dependent leucocyte alterations and response to dapsone. 1095 Nov 56