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)

Immune complex nephritis induced by bovine serum albumin (BSA) and horseradish peroxidase (HRP) was superimposed upon spontaneous hypertensive rats (SHR rats) which were pretreated with polyvinyl alcohol (PVA). PVA accumulated predominantly in the mesangium, and the superimposed nephritis developed more accelerated glomerular damage with marked capillary deposition of immune complexes than control animals which were not pretreated with PVA.
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PMID:Accelerated immune complex nephritis due to mesangial overloading in spontaneous hypertensive (SHR) rats. 16 94

Clinical and laboratory findings and drug history were studied in 17 patients with suspected hydralazine-associated nephritis, five of whom only had renal disease, while twelve also had extrarenal manifestations. Renal biopsies revealed extracapillary proliferative or focal segmental proliferative glomerulonephritis in 10 patients, and tubulo-interstitial nephritis in five patients. Antinuclear antibody (ANA) was found in 16 patients, but none of the 14 patients tested had antibodies to DNA. Tests for antibodies to myeloperoxidase (anti-MPO) and antibodies to neutrophil cytoplasm antigen (ANCA) were performed by ELISA. Twelve of the 14 patients tested had anti-MPO; five of these 14 patients had ANCA, while one had borderline levels. These findings suggest that hydralazine facilitates the induction of a systemic disease with multiple autoantibody production.
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PMID:Autoantibodies to leucocyte antigens in hydralazine-associated nephritis. 131 98

The correlation between glomerular immune deposition and histological alteration was studied in serial paraffin sections of kidney biopsy specimens from patients with IgA nephritis using the peroxidase-antiperoxidase (PAP) method. IgA deposition was detected in preserved glomerular extracellular matrix or in newly formed interposed matrix along the capillary loops (mesangial interposition). On the other hand, deposition of IgA was scanty or absent in the distorted extracellular matrix where severe exudative inflammation or extracapillary escape of exudates was occurring segmentally. Ultrastructurally such extracellular matricial destruction was expressed as splitting or thinning of the lamina densa, as well as mesangial edema, reticulation or mesangiolysis of the axial matrix. Therefore it appears that at least two types of change in the extracellular matrix are induced by IgA immune complexes in IgA nephritis; immunogenic deposition and destruction.
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PMID:Immunogenic deposition and destruction of glomerulus in IgA nephritis. 156 86

Circulating anti-neutrophil cytoplasmic antibodies (ANCA) have been described in most patients with "pauci-immune" necrotizing and crescentic glomerulonephritis. A 29-kDa serine protease (p29 or proteinase 3) and myeloperoxidase are the two best characterized antigens recognized by ANCA. The study presented here was conducted to define the diagnostic value of assays for antibodies against these two antigens in rapidly progressive glomerulonephritis. Radioimmunoassays were developed for anti-p29 and anti-myeloperoxidase antibodies, with purified antigens, and the results of the radioimmunoassays were compared with those obtained by immunofluorescence tests for ANCA. We performed assays on serum samples from 123 patients with the syndrome of rapidly progressive glomerulonephritis, as well as from 200 blood bank donors and from 717 additional control patients. Without knowledge of the results of ANCA tests, the renal pathologic findings in the 123 patients with rapidly progressive glomerulonephritis were analyzed, and 42 were classified as pauci-immune necrotizing and crescentic glomerulonephritis, 18 were classified as anti-glomerular basement membrane nephritis and 63 were classified as other forms of renal disease. We found radioimmunoassays to be more reliable in the diagnosis of pauci-immune necrotizing and crescentic glomerulonephritis than immunofluorescence testing. By radioimmunoassay, ANCA were found in 40 of 42 patients (95% sensitivity) with pauci-immune necrotizing and crescentic glomerulonephritis (14 with anti-p29 and 26 with anti-myeloperoxidase antibodies). The tests for antibodies to p29 and myeloperoxidase were 99.9 and 99.5% specific for pauci-immune necrotizing and crescentic glomerulonephritis, respectively. In the setting of rapidly progressive glomerulonephritis, a positive radioimmunoassay for anti-p29 or anti-myeloperoxidase antibodies (together with a negative test for anti-GBM antibodies) gives a probability of pauci-immune necrotizing and crescentic glomerulonephritis of over 99%.
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PMID:Antigen-specific radioimmunoassays for anti-neutrophil cytoplasmic antibodies in the diagnosis of rapidly progressive glomerulonephritis. 165 91

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

The hydroxylamine and nitroso metabolites formed by N4-oxidation of sulfonamides are thought to be involved in the pathogenesis of idiosyncratic reactions to this class of drugs. Idiosyncratic reactions to sulfonamides are characterized by multisystemic toxicity, including hepatitis, nephritis, dermatitis, and blood dyscrasias (aplastic anemia, agranulocytosis). We have previously shown that cytochrome P-450 in the liver metabolizes sulfamethoxazole to its hydroxylamine metabolite. In this paper we report the N4-oxidation of sulfamethoxazole by activated monocytes and neutrophils (human and canine) to form sulfamethoxazole hydroxylamine and nitrosulfamethoxazole. The presumed nitroso intermediate was not detected. Purified myeloperoxidase and prostaglandin H synthase were also capable of mediating the oxidation of sulfamethoxazole. The present studies suggest that myeloperoxidase is responsible for the observed oxidation by phagocytic cells. Oxidation by neutrophils may play a role in agranulocytosis, and oxidation by monocytes may facilitate antigen presentation. Extrahepatic bioactivation of sulfonamides by peroxidases in phagocytic cells and other tissues may be important in determining the range of adverse reactions to sulfonamides that occur.
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PMID:Peroxidase-dependent oxidation of sulfonamides by monocytes and neutrophils from humans and dogs. 217 79

Many earlier studies have shown that the intravenous injection into rats of sheep antibodies against rat glomerular basement membrane (GBM) induces a rapid influx of neutrophils and proteinuria (nephrotoxic nephritis or NTN). The GBM antigens recognized by nephrotoxic antibodies (NTAbs) have not been identified conclusively. Our experiments presented here, however, showed that NTAbs did not significantly reduce binding of anti-laminin IgGs to laminin-coated enzyme-linked immunosorbent assay (ELISA) plates or to the GBM in vivo, indicating little cross-reactivity between the NTAbs and laminin. To evaluate possible changes in GBM architecture during acute stages of NTN, the ultrastructural distribution of laminin was determined by postfixation, postembedding immunogold labeling, and compared between normal and nephritic rats. The density of immunoreactive GBM laminin was significantly reduced in rats with acute NTN. In addition, conjugates of anti-laminin IgG and horseradish peroxidase were intravenously injected into rats that then received injections of NTAbs. Anti-laminin peroxidase conjugates were also injected after administering NTAbs. In both cases, an overall decrease in anti-laminin peroxidase reaction product was observed as compared to normal controls. The densest labeling was seen in the lamina rara interna, especially in areas of endothelial cell detachment. Some immunoperoxidase reaction product was also bound to basal surfaces of detaching endothelial cells, demonstrating the removal of at least some laminin from the GBM. A decrease in GBM binding of intravenously injected anti-laminin IgG, both before and after injection of rats with NTAbs, was also confirmed by postembedding immunogold labeling. Furthermore, morphometry showed that the GBM was significantly wider in nephritic rats than in controls, indicating a redistribution of laminin over a greatly increased area. These immunoultrastructural findings show, therefore, that GBM architecture is altered in the early phase of NTN.
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PMID:Loss and rearrangement of glomerular basement membrane laminin during acute nephrotoxic nephritis in the rat. 219 15

Autologous (Heymann) nephritis was induced by immunizing Sprague-Dawley rats with a crude membrane extract (Fx1A) prepared from renal cortical tubules. Urine protein excretion was monitored to determine the onset of nephritis and then the spleens of nephritic rats were fused with a non-secretor rat myeloma cell line. Supernatants from hybridoma cultures were first screened for production of anti-brush border membrane (BBM) antibody by immunodot blotting of highly purified rat BBM on nitrocellulose. Positive hybrids were then tested by indirect immunofluorescence for the presence of IgG, which binds to the brush border of rat renal proximal tubules. Those hybrids which were positive by both screening assays were subcloned twice. Two monoclonal antibodies (C5, D11) were studied in some detail. Both C5 and D11 immunoprecipitated a single polypeptide from BBM, labelled with 125I by the lactoperoxidase method. Radioautography of gradient 4-11% slab sodium dodecyl sulphate polyacrylamide gels revealed that the polypeptide against which C5 and D11 were directed co-migrated with the polypeptide immunoprecipitated by (i) IgG eluted from the renal cortex of nephritic rats, and by (ii) a mouse anti-rat monoclonal against gp 330 [a BBM constituent with proven pathogenicity [9]]. Supernatants which tested positive by immunodot blotting but negative by indirect immunofluorescence showed no detectable immunoprecipitate after reaction with BBM. Immunocytochemical staining by immunoperoxidase and immunogold methods localized C5 and D11 to the BBM of the renal proximal tubule and to the urine face of the glomerular epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A rat hybridoma model of Heymann nephritis: production of a monoclonal anti GP330 from a nephritic rat. 227 21

171 kidney biopsies were tested with the peroxidase- antiperoxidase (PAP)-method on paraffin sections. A comparison of the PAP-results with corresponding ones for the immunofluorescence method (IMF) on frozen sections was possible in 131 of the biopsies. When results of the 2 techniques were compared, outcomes showed a very strong accordance for both methods in tissues of postinfectious and perimembraneous GN an a strong accordance in mesangioproliferative GN tissue. In membrano-proliferative GN the immunopathological findings were more readily delinated with the PAP-method than with IMF. Cases involving IgA-nephritis, focal sclerosis and lupus nephritis with smaller deposits did not show consistant reactivity in the PAP-method as compared with IMF. 40 kidney biopsies, not examined by IMF, were diagnosed as GN by light microscopy and could be shown in 29 cases to contain evidence of an immune pathogenesis with the PAP-method.
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PMID:[The value of immunofluorescence on frozen sections and immunoperoxidase methods on paraffin sections with different types of glomerulonephritis comparative study]. 248 94

Immune complex deposits found on the subepithelial side of the glomerular basement membrane (GBM) are characteristic of membranous glomerulonephritis. In order to clarify the mechanism of subepithelial immune complex deposition, we investigated the manner of localization of preformed immune complexes (IC) composed of native ferritin (NF) and anti NF antibody (aNFab) in a 40-fold antigen great excess using the system of passive serum sickness nephritis of mice. The following results were obtained. (1) The ferritin particles in the GBM of animals given NF alone, as controls, were mainly restricted to the lamina rara interna (LRI) with very few penetrating the entire depth of the GBM. (2) In animals given the IC, greater numbers of ferritin particles were seen, in comparison with the control animals, not only in the lamina densa (LD) but also in the lamina rara externa (LRE). (3) Immunoelectron microscopy (IEM) demonstrated that each NF particle was accompanied by aNFab, which was found to be peroxidase positive material, throughout the GBM. (4) On the grounds that ICs were prepared in Ag great excess, it is suggested that ICs seen in the GBM are composed of a low avidity antibody with a low Ag/Ab ratio, probably Ag1Ab1. From these results, it is suggested that circulating ICs are necessary to give rise to IC deposition on the GBM and that NF and aNFab exist together as ICs throughout the GBM. We concluded that subepithelial IC deposits arise from the circulation, and that after GBM trapping, circulating small-sized IC can pass through the LD to reach the subepithelial side of GBM.
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PMID:[Studies on the mechanism of glomerular localization of immune complexes (1). Localization of preformed native ferritin immune complexes on the glomerular basement membrane in passive serum sickness nephritis of mice]. 258 31


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