Antineutrophil cytoplasm antibodies (ANCA) of IgA isotype in adult Henoch-Schönlein purpura

Abstract

SUMMARYANCA are associated with certain forms of systemic vasculitis, and have been reported previously to be of Ihe IgG and IgM isotype. We examined ihc possible association between IgA ANCA and the IgA-relaled diseases Henoch-Schonlein purpura (HSP) and IgA nephropaihy (IgAN). IgA and IgG ANCA were detected by isotype-specifie solid-phase assays with a erude neutrophil extract, and their presence was confirmed by antigen-specific fluid-phase competitive inhibition tests and by indirect inimunofiuorescence. The possible interference by IgA rheumatoid faeior was excluded. IgA ANCA were detected in sera from 11/I4 HSP patients (79%). from 1/30 IgAN paLicnts 0"A>), from 1/40 patients with vasculitldes classically associated with IgG ANCA (2-5%), and in none or60 sera from healthy blood donors. IgG ANCA were present with IgA ANCA in three patients with HSP. Only one HSP serum had anti-myeloperoxidase (MPO) activity by both IgA and IgG isotypc-specific ELISA, and none was positive for proteinase 3 (PR3). Western blot analysis performed with neutrophil extract showed that the four strongest IgA ANCA-positive HSP sera reacted with a 51-kD protein; Western blot performed on cellular fractions showed that this protein is primarily membrane-assoeiated, and different from fibronectin. Our study suggests that adult HSP is elosely associated with cireulating IgA ANCA. which may be directed against a different autoantigen than that recognized by IgG ANCA.

IgA- and SIgA anti-PR3 antibodies in serumversusorgan involvement and disease activity in PR3-ANCA-associated vasculitis

“…With regard to mucosal manifestations in GPA, and as secretory IgA (SIgA) is the dominating isotype at mucosal sites, it is of interest to study IgA-and SIgA-class PR3-ANCA in relation to organ manifestations and disease activity in AAV. Circulating IgA-class PR3-ANCA has been described previously in GPA [25], and IgA-ANCAs have been observed in IgA vasculitis (formerly known as Henoch-Sch€ onlein purpura) [26], IgA-nephropathy [27], cutaneous vasculitis [28], liver cirrhosis [29] and inflammatory bowel diseases [30,31]. SIgA PR3-ANCA, however, has not been described previously in AAV.…”

The Significance of Antineutrophil Cytoplasmic Antibody in Adult Patients with Henoch-Schönlein Purpura Presenting Mainly with Gastrointestinal Symptoms

“…It was reported that ANCA is also detectable in patients with HSP. However, the prevalence of HSP remains controversial, ranging 0%-79% [10][11][12][13] . It has been shown that the positive ANCA rate is as high as 82.3% [14] , suggesting that ANCA can be used to confirm the diagnosis of HSP in children.…”

“…Till now, most studies were confined to children, only a few studies have been done in adults [12,13] and no reports on adult HSP patients presenting mainly with gastrointestinal symptoms are available. The aim of this study was to evaluate the clinical significance of ANCA in adult HSP patients who presented mainly with gastrointestinal symptoms and its role in the diagnosis of HSP and its relationship to the disease severity.…”

The clinical presentation and therapy of diseases related to anti-neutrophil cytoplasmic antibodies (ANCA)

“…In Kawasaki's disease, ANCA is infrequent [21]. In IgA-vasculitis (formerly known as Henoch-Schönlein purpura) there are reports of IgA-ANCA during episodes of active disease, but IgG-ANCA is rare [22].…”