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

These antibodies are specific for antigens in the cytoplasm of neutrophils. The main antigenic targets are proteinase 3(PR3) and myeloperoxydase (MPO) but other targets have been described without determinant conclusions for clinical practice. Staining patterns can be distinguished by an indirect immunofluorescence test (IFI), in which ethanol fixed neutrophils from healthy donors are incubated with patient's sera. Two patterns are distinguished: cytoplasmic pattern (c-ANCA) and perinuclear pattern (p-ANCA). When ANCA are detected by IFI, from a practical point of view, anti -MPO and anti-PR3 antibodies are tested. ANCA have been strongly associated with a spectrum of necrotizing small vessel vasculitides that includes Wegener's granulomatosis, microscopic polyangiitis, Churg and Strauss syndrome, pauci-immune focal necrotizing and crescentic glomerulonephritis. ANCA are a diagnosic marker and useful for the follow-up of the patients. ANCA can be observed in other pathologies: rhumatismal autoimmune diseases, inflammatory gut diseases, after drugs (hydralazine, minocycline, propylthiouracil), after silical exposition, infections (cystic fibrosis, endocarditis, HIV infection). The specificity is different and rarely anti-MPO. The ANCA role for the development of vasculitis is not completely elucidated. Some arguments are against a primary role of ANCA in the development of vasculitis. Certainly, amplification role for neutrophil activation is demonstrated but the primary event responsible of neutrophil activation is not yet defined.
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PMID:[Antineutrophil cytoplasm antibodies (ANCA): description and immunopathological role]. 1089 69

Anti-neutrophil cytoplasmic antibodies (ANCA) are mainly searched for the diagnosis of autoimmune vasculitis. They may be found also in other conditions with chronic inflammation. Testing ANCA is based on two main technics: indirect immunofluorescence (IFI) and immunochemical technics to identify the antigenic specificity of the autoantibodies. There is heterogeneity among the laboratories' daily practice. An international group called EASI (European autoimmunity standardisation initiative), composed of 15 countries, comprising France, works to harmonize the practices of the biological diagnosis of the autoimmune diseases. It elaborated a survey consisting of 54 questions related to the analytic parameters of the technics, the algorithms for their use and their biological interpretation; and submitted it to European laboratories. We propose an analysis of the answers obtained from 36 French laboratories specialized in autoimmunity. We compare them to the ones obtained from the other countries and discussed them according to the international recommendations. The analysis reveals a predominant use of IFI as a first step with variable strategies for the identification of the antigenic specificity of the autoantibodies. Overall, the practices are chiefly conformed to the recommendations for the diagnosis of vasculitis, but they are less consensual when the ANCA are performed in other clinical situations.
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PMID:Testing anti-neutrophil cytoplasmic antibodies (ANCA): analysis of the European EASI survey on the daily practice of the French laboratories. 2895 62

In adults, anti-neutrophil cytoplasmic antibodies (ANCA) are considered as serological markers of several diseases, especially vasculitis and glomerulonephritis. Since ANCA are rarely positive in children, few data about the clinical relevance of these auto-antibodies in pediatric population have been reported. Therefore, our study aims to describe the spectrum of disorders associated with positive ANCA in Tunisian children. This study had been carried out over a period of 12 years and a half. All patients under the age of 15 for whom ANCA screening was performed in our laboratory were included. Clinical data were collected retrospectively. Indirect immunofluorescence (IFI) technique for ANCA detection was performed using PNN smears fixed with ethanol, formalin and, if necessary, methanol. Positive results were tested using immunodot to characterize the antigenic targets (myeloperoxydase (MPO) and proteinase 3 (PR3)). Our results showed that 410/5,990 (6.8%) laboratory requests for ANCA screening were for children. Forty (9.7%) requests were positive (24 children). Clinical data were available for 19 patients only. Sex-ratio (F/M) was 1.25. The mean age was 9 years and a half (3-15 years). The most frequent IIF patterns were x-ANCA (n=12) and p-ANCA (n=7). In our patients, the most frequent conditions associated to ANCA were treatment with benzylthiouracil for hypothyroidism (n=6), inflammatory bowel disease (n=4) and hemolytic anemia (n=4). In conclusion, the positivity of ANCA in children seems to be a rare event. Associated conditions include clinical disorders specific to the pediatric population. Treatment with benzylthiouracil is an etiology to be taken into consideration.
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PMID:Positivity of antineutrophil cytoplasmic antibodies in children: prevalence and etiologies. 2938 46