Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In recent studies extrahepatic manifestations of viral hepatitis have been recognized as immune complex diseases. Hepatitis B surface antigen (HBsAg) has been successfully identified in immune complexes, but the pathogenic role of HBsAg-containing immune complexes (IC) remains questionable. The subject of the present study was the antigen-specific determination of IC in the course of hepatitis B virus infection using a new HBsAg-specific IC test (Pernice & Sedlacek, 1978). This test is based on the following principle: rabbit anti-HBs-coated polystyrole test tubes are incubated with the IC-containing test sample. The HBsAg-containing IC bind to the solid phase by their free antigenic determinants. There they can be quantified using a peroxidase-labelled anti-human IgG antibody. A good correlation was found between the level of HBsAg-containing immune complexes and the clinical state of six patients in a follow-up study. IC could be detected simultaneously with HBsAg and either decreased or disappeared before the occurrence of free anti-HBs. In the sera of an additional twenty-eight patient suffering from chronic active hepatitis, HBsAg-containing immune complexes were detected in 85% of cases. One patient suffering from polyarteritis nodosa was also positive. Occasionally, extremely high levels of IC were found in the course of these diseases.
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PMID:Antigen-specific detection of HBsAG-containing immune complexes in the course of hepatitis B virus infection. 9 65

Antineutrophil cytoplasmic autoantibodies (ANCA) react with proteins found in the granules of neutrophils and the peroxidase-positive lysosomes of monocytes, including myeloperoxidase (MPO), proteinase 3 (PR-3), and elastase. ANCA-associated diseases, such as Wegener's granulomatosis and polyarteritis nodosa, are characterized by necrotizing vascular inflammation. The inflammatory lesions typically contain both neutrophils and mononuclear phagocytes, with the latter sometimes predominating, for example, in the granulomatous lesions of Wegener's granulomatosis. We investigated the presence of the ANCA target antigens PR3, MPO, and elastase in mononuclear phagocyte cytoplasm during the course of differentiation in vitro and in alveolar and peritoneal macrophages. We observed that ANCA antigens were down-regulated during mononuclear phagocyte differentiation, with the loss corresponding to that of peroxidase-positive granules. This suggests that ANCA can directly interact only with monocytes and early exudative macrophages and not with mature macrophages.
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PMID:Reactivity of antineutrophil cytoplasmic autoantibodies with mononuclear phagocytes. 131 Oct 14

We conducted a prospective study of 651 Mediterranean patients from Catalonia (Spain) with well-defined forms of systemic vasculitis, connective tissue diseases, and renal and pulmonary disorders to determine the prevalence and clinical value of antineutrophil cytoplasmic autoantibodies (ANCA) with myeloperoxidase (MPO) specificity (MPO-ANCA). ANCA were first tested by indirect immunofluorescence on ethanol-fixed neutrophils. When a positive result was obtained, then MPO-ANCA were identified by performing the immunofluorescence assay again on neutrophils from a voluntary donor known to have a complete and selective deficiency of MPO. This disorder was detected by automated flow cytochemistry with the Technicon system and was further verified by cytochemical and biochemical studies. We detected MPO-ANCA in 61 of 70 (87%) patients with a perinuclear pattern (p-ANCA), but in none of 25 with a cytoplasmic pattern (c-ANCA). These results were corroborated by enzyme-linked immunosorbent assay (ELISA) using human purified MPO as a substrate. On immunofluorescence microscopy, all patients with MPO-ANCA were found to have a typical and restrictive immunostaining pattern. In our study, while c-ANCA were mainly found in patients with biopsy-proven Wegener's granulomatosis, MPO-ANCA identified those with idiopathic and polyarteritis nodosa-associated necrotizing and crescentic glomerulonephritis. In addition, pulmonary hemorrhage with necrotizing alveolar capillaritis as the main morphologic substrate occurred frequently among patients with MPO-ANCA, including three affected by polyarteritis nodosa and three who had pulmonary hemorrhage as the only clinical finding. On the other hand, these antibodies could be also detected in 30% of patients with a proven diagnosis of anti-glomerular basement membrane (GBM) disease.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Anti-myeloperoxidase autoantibodies in patients with necrotizing glomerular and alveolar capillaritis. 132 37

We report a case of microscopic polyarteritis nodosa associated with myeloperoxidase-antineutrophil cytoplasmic autoantibodies (MPO-ANCA). A 38 year-old female was admitted to our hospital, because of proteinuria, recurrent pyrexia, polyarthralgia, abdominal pain and purpura. She had a history of severe pulmonary hemorrhage and 4 kg weight loss for 8 months. On admission perinuclear ANCA without cytoplasmic ANCA was detected by indirect immunofluorescence assay and MPO-ANCA was detected by enzyme linked immunosorbent assay. But anti-nuclear antibodies, immune complexes and anti-glomerular basement membrane antibodies were not detected. Renal biopsy showed necrotizing crescentic glomerulonephritis without immune deposits. Skin biopsy revealed leukocytoclastic vasculitis. Diagnosis of microscopic polyarteritis nodosa was made by these clinical and histological evidence of vasculitis. As renal failure progressed after admission, corticosteroid and cyclophosphamide administration were started. Renal function and other symptoms improved paralleled with decreased MPO-ANCA titer to normal values. It is suggested that MPO-ANCA may be closely related to the pathogenesis of microscopic polyarteritis nodosa and it may be a good serological marker for diagnosis and disease activity of this disease.
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PMID:[A case of microscopic polyarteritis nodosa associated with myeloperoxidase-antineutrophil cytoplasmic autoantibodies (MPO-ANCA)]. 136 30

Antibodies against cytoplasm of neutrophil leucocytes (ANCA) with a high sensitivity are found in idiopathic necrotizing vasculitis and idiopathic glomerulonephritis with formation of sickles (IGS). C-ANCA are directed against the myeloid lysosomal enzyme--proteinase 3 and are found above all in Wegener's granulomatosis and microscopic polyarteritis. P-ANCA are directed mainly against myeloperoxidase, less against leucocytic elastase or lactoferrin and are found above all in microscopic polyarteritis, IGS, polyarteritis nodosa or Churg-Strauss syndrome. The elevated ANCA level correlates with the activity of the disease or precedes a relapse. These autoantibodies activate probably neutrophil leucocytes for respiratory exacerbation and degranulation which may lead to extensive tissue damage.
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PMID:[Antineutrophil cytoplasmic antibodies--ANCA]. 146 72

Antineutrophil cytoplasmic antibodies (ANCA) have been described as sensitive and specific markers for active Wegener's granulomatosis (WG). ANCA in WG produce a characteristic cytoplasmic staining pattern of neutrophils (c-ANCA) and are directed against proteinase 3 (Pr3), a serine protease from the azurophilic granules. c-ANCA, more or less equivalent to anti-Pr3, occur in more than 90% of patients with extended WG, in 75% of patients with limited WG without renal involvement, and in some 40% to 50% of patients with vasculitic overlap syndromes suggestive of WG such as microscopic polyarteritis. The presence of c-ANCA is highly specific for those diseases (greater than 98%). Changes of levels of c-ANCA precede disease activity and may be used as guidelines for treatment. Antibodies producing a perinuclear staining of ethanol-fixed neutrophils (p-ANCA) occur in a wide range of diseases. They are directed against different cytoplasmic constituents of neutrophils. Among those, antibodies to myeloperoxidase are found in patients with idiopathic crescentic glomerulonephritis, the Churg-Strauss syndrome, polyarteritis nodosa with visceral involvement, and vasculitic overlap syndromes. Their specificity for this group of necrotizing vasculitides is high (94% to 99%), although they may occur in patients with hydralazine-induced glomerulonephritis, anti-glomerular basement membrane disease, and possibly in some patients with idiopathic systemic lupus erythematosus. Antibodies to leukocyte elastase are incidentally found in patients with vasculitic disorders, whereas lactoferrin antibodies are detected in patients with primary sclerosing cholangitis with or without ulcerative colitis and in rheumatoid arthritis. Their diagnostic significance awaits further studies. p-ANCA of undefined specificity may distinguish ulcerative colitis (sensitivity of 75%) from Crohn's disease (sensitivity of 20%). p-ANCA also occur in autoimmune liver diseases: in 75% of patients with chronic active hepatitis, in 60% to 85% of those with primary sclerosing cholangitis, and in about 30% of patients with primary biliary cirrhosis. Finally, p-ANCA are detected in chronic arthritides and in some 5% of healthy controls. Assessment of their diagnostic value has to await further characterization of the antigens involved, allowing the development of antigen-specific assays.
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PMID:Antineutrophil cytoplasmic antibodies: a still-growing class of autoantibodies in inflammatory disorders. 782 11

Polymorphonuclear leukocyte (PMN) respiratory burst was stimulated by heterologous antibodies against PMN granule proteins but not by control antibodies. Fluorescence-activated cell sorter (FACS) analysis of activated PMN demonstrated the presence of two primary granule proteins, proteinase 3 (PR-3) and cationic protein 57 (CAP-57) at the membrane surface. The presence of myeloperoxidase (MPO) at the cell surface of primed and unprimed PMN was confirmed by immunoelectron microscopy. Priming doses of recombinant tumor necrosis alpha (rTNF alpha) enhanced the rate of superoxide (O2-) production by these antibodies and increased the amount of surface protein accessible to these antibodies. Anti-neutrophil cytoplasmic autoantibodies (ANCA) with specificities for PMN granule proteins are present in patients with Wegener's granulomatosis, polyarteritis nodosa, and idiopathic and crescentic glomerulonephritis. The demonstration that antibodies against granule proteins activate PMN supports the hypothesis that the vasculitis seen in these diseases is due in part to PMN mediated oxidative injury following PMN stimulation by ANCA.
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PMID:Antibodies against granule proteins activate neutrophils in vitro. 165 70

Antineutrophil cytoplasmic autoantibodies (ANCA) are specific for constituents of neutrophil primary granules and monocyte lysosomes. There are different types of ANCA with different specificities. By indirect immunofluorescence microscopy using alcohol-fixed neutrophils as substrate, two major categories of ANCA can be recognized, one with cytoplasmic staining (C-ANCA) and the other with artifactual perinuclear staining (P-ANCA). Some C-ANCA have specificity for proteinase 3 (PR3-ANCA) and some P-ANCA have specificity for myeloperoxidase (MPO-ANCA), but there are additional C-ANCA and P-ANCA specificities. ANCA are found in the blood of patients with necrotizing systemic vasculitis, such as Wegener's granulomatosis and polyarteritis nodosa, and patients with idiopathic crescentic glomerulonephritis. The glomerular lesion in patients with systemic and renal-limited ANCA-associated diseases is the same, ie, a pauci-immune necrotizing and crescentic glomerulonephritis. No matter where the vascular lesions of ANCA-associated disease are (eg, kidney, lung, gut, muscle, skin), they are characterized by necrotizing inflammation and a paucity of immune deposits. The distribution of disease correlates to a degree with the ANCA specificity, although there is substantial overlap. For example, patients with Wegener's granulomatosis most often have C-ANCA and patients with renal-limited disease most often have P-ANCA. In patients with P-ANCA-associated glomerulonephritis, approximately 90% of the P-ANCA have specificity for MPO. The clinical manifestations of ANCA-associated diseases often begin following a flu-like illness. The onset is most often in the winter and least often in the summer. The renal disease usually presents as rapidly progressive renal failure with nephritis. One of the most life-threatening components of the systemic involvement is pulmonary hemorrhage caused by a necrotizing alveolar capillaritis. Intravenous cyclophosphamide plus steroids is as effective as oral cyclophosphamide plus steroids for controlling ANCA-associated diseases. Using life-table analysis, the 2-year patient and renal survival rate in both patients with renal-limited and systemic disease is greater than 70%. There is evidence that in addition to being a useful serologic marker, ANCA are directly involved in the pathogenesis of the vascular injury in patients with ANCA-associated diseases. Although ANCA antigens are normally in the cytoplasm of neutrophils and monocytes, priming of these cells, as occurs following exposure to certain cytokines, results in the release of small amounts of ANCA antigens at the cell surface. In vitro, ANCA-IgG causes cytokine-primed neutrophils to undergo a respiratory burst and degranulation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Antineutrophil cytoplasmic autoantibodies and associated diseases: a review. 197 31

Anti-neutrophil cytoplasmic autoantibodies have been found in patients with systemic arteritis and glomerulonephritis. We studied the disease distribution and antigen specificity of these autoantibodies. Anti-neutrophil cytoplasmic autoantibodies were identified by indirect immunofluorescence microscopy in 27 of 35 patients with idiopathic necrotizing and crescentic glomerulonephritis, in whom the manifestations of disease ranged from injury limited to the kidney to systemic arteritis. The incidence and titers of the autoantibodies did not differ between patients with disease limited to the kidney and those with systemic disease. Anti-neutrophil immunostaining was detected in 5 of 11 patients with lupus nephritis, 4 of 71 patients with other renal diseases, and none of 50 normal controls. This distribution of autoantibodies was confirmed by an enzyme-linked immunosorbent assay (ELISA) using neutrophil lysate as antigen. According to ELISA, anti-neutrophil cytoplasmic autoantibodies were found to be specific for constituents of primary granules. Two types of autoantibodies were identified; one with reactivity with myeloperoxidase on ELISA produced an artifactual perinuclear immunostaining of alcohol-fixed neutrophils, and another with no reactivity with myeloperoxidase on ELISA produced diffuse cytoplasmic immunostaining. The presence of the same serologic marker in patients with kidney-limited and arteritis-associated necrotizing and crescentic glomerulonephritis, including Wegener's granulomatosis and polyarteritis nodosa, suggests that these clinically diverse diseases may have a similar pathogenesis, initiated by autoantibody-mediated activation of neutrophils.
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PMID:Anti-neutrophil cytoplasmic autoantibodies with specificity for myeloperoxidase in patients with systemic vasculitis and idiopathic necrotizing and crescentic glomerulonephritis. 245 2

Panarteritis nodosa, Wegener's granulomatosis and idiopathic necrotizing glomerulonephritis, regarded by some as a vasculitis restricted to the glomerulus, are those forms of primary vasculitis most often encountered in renal biopsy. The histopathologic differential diagnosis can be difficult and has to rely on the finding of vascular inflammation in preglomerular vessels and of granulomata. In a majority of renal biopsies only a necrotizing and crescentic glomerulonephritis without inflammation of arteries or arterioles can be seen. Also the clinical manifestation of these three diseases can be very similar. A new impetus for the differential diagnosis of vasculitis was the discovery of antineutrophilic cytoplasmic antibodies (ANCA). In alcohol fixed leukocytes a cytoplasmic immunofluorescence (c-ANCA) represents an autoantibody to a serine protease of 29 kD - probably Protease 3-, and a perinuclear stain (p-ANCA), often a reaction against myeloperoxidase. ANCA antibodies seem to be a useful marker for the diagnosis of Wegener's granulomatosis, although ANCA positive tests have also been obtained in microscopic panarteritis nodosa and seemingly even in lupus nephritis. ANCA autoantibodies apparently are a reliable parameter to assess activity of the vasculitic process, and may thus be helpful in therapeutic decisions. Despite of current aggressive immunosuppressive therapy long term survival of patients or their kidneys still is rather bleak, in case a severe renal vasculitic process is diagnosed. Extracapillary proliferation (crescents) in more than 50% of glomeruli is also associated with an increased mortality.
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PMID:[Vasculitis of the kidney]. 248 4


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