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)

The majority of antineutrophil cytoplasmic antibodies (ANCA) in patients with systemic vasculitis (a subset of whom exhibit eosinophilia associated with systemic vasculitis) recognize two neutrophil primary cytoplasmic granule constituents, namely myeloperoxidase (MPO) and proteinase-3. As eosinophil peroxidase (EPO) shares 68% amino acid identity with neutrophil MPO, we have investigated whether serum ANCA reactive with MPO (P-ANCA) also reacts with EPO. In this study we demonstrate that P-ANCA-reactive serum binds to ethanol-fixed neutrophils but not to eosinophils in a perinuclear pattern as assessed by indirect immunofluorescence. In addition, P-ANCA reactive serum did not bind to purified EPO or alter purified EPO function as assessed in a guaiacol assay of EPO activity. These studies suggest that the antigenic epitope recognized by P-ANCA-reactive serum is not determined by the homologous 68% peroxidase sequence shared by neutrophil MPO and EPO.
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PMID:Eosinophil peroxidase differs from neutrophil myeloperoxidase in its ability to bind antineutrophil cytoplasmic antibodies reactive with myeloperoxidase. 792 15

Vasculitis associated anticytoplasmic autoantibodies (ANCA) are directed against enzymes in the granules of both neutrophils and monocytes. These autoantibodies can be detected by indirect immunofluorescence technique (IIFT) using ethanol-fixed cytospins. We here report the identification of a novel specificity of autoantibodies, present in the sera of eight patients, that reacted only with eosinophils in the IIFT. By immunoprecipitation and ELISA experiments it was shown that the autoantibodies in these sera were directed against eosinophil peroxidase (EPO). There was no apparent influence on initial substrate conversion rate, but reduced plateau levels suggested increased inactivation of the enzyme in the course of the peroxidase reaction. Flow cytometry studies demonstrated the presence of EPO on the surface of primed eosinophils. Anti-EPO sera and purified anti-EPO immunoglobulins significantly increased the release of reactive oxygen species from primed eosinophils. The patients with anti-EPO antibodies suffered from clinically diverse disorders, with more or less generalized manifestations involving the kidneys, blood vessels, lungs and/or joints.
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PMID:A novel specificity of anticytoplasmic autoantibodies directed against eosinophil peroxidase. 838 87

Using immunoperoxidase techniques, we examined the histological changes of exercise-induced lesions of urticarial vasculitis over a 24 h period. At 3 h, endothelial swelling and an eosinophilic infiltrate was seen. Neutrophils were increased in number by 10 h. Typical leucocytoclastic vasculitis with red blood cell extravasation developed by 24 h. Maximal deposition of eosinophil peroxidase was at 10 h compared to significant neutrophil elastase deposits at 24 h. This demonstrates the importance of the eosinophil in the development of the lesions of urticarial vasculitis.
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PMID:Time-course analyses of exercise-induced lesions in a patient with urticarial vasculitis. 871 15