Anti-neutrophil cytoplasmic antibody (ANCA) in malaria is directed against cathepsin G

Abstract

SUMMARYAutoantibodies of diverse specificities are detected in sera of patients with acute malaria. The clinical relevance of these autoantibodies is not clear, though there are reports associating some autoantibodies with specific disease manifestations. We have investigated the occurrence of ANCA in the sera of 93 patients during episodes of acute malaria. Sera were tested by indirect immunofluorescence (IIF) and by ELISA for antibodies to neutrophil cytoplasmic components proteinase 3 (PR3), myeloperoxidase (MPO), cathepsin G (CG), human leucocyte elastase (HLE), and lactoferrin (LF). Forty-seven sera samples (50 . 5%) were positive by IIF, all except one with the atypical ANCA pattern (a-ANCA). When screened by ELISA, anti-CG antibodies were detected in 52 samples (56%), while anti-PR3 and anti-MPO antibodies were detected in three and one samples, respectively. Antibody binding to HLE and LF was not significant. Anti-CG antibodies were detected in 93% of the IIF-positive sera. A combination of anti-CG and anti-PR3 antibodies was noted in three samples. Our study demonstrates the presence of ANCA in sera from patients with acute malaria, almost all with the a-ANCA pattern on IIF. The antibody specificity, noted for the first time in our study, appears to be predominantly directed against CG. The significance of CG and CG-ANCA in the pathogenesis and clinical manifestations of malaria has yet to be elucidated.

Elevated antilysosomal-associated membrane protein-2 antibody levels in patients with adult Henoch-Schönlein purpura

“…We found that serum anti‐LAMP‐2 antibody levels in the adult patients with HSP were significantly higher than in MPA and healthy controls. Some previous studies have indicated that ANCA target antigens include azurocidin, BPI, cathepsin G, elastase, lactoferrin and lysozyme in addition to LAMP‐2 17–21 . In the present study, we did not detect autoantibodies against azurocidin, BPI, cathepsin G, elastase, lactoferrin and lysozyme in any of the sera from the patients with HSP and the patients with MPA.…”

“…Some previous studies have indicated that ANCA target antigens include azurocidin, BPI, cathepsin G, elastase, lactoferrin and lysozyme in addition to LAMP-2. [17][18][19][20][21] In the present study, we did not detect autoantibodies against azurocidin, BPI, cathepsin G, elastase, lactoferrin and lysozyme in any of the sera from the patients with HSP and the patients with MPA. Based on these findings, we suggest that the anti-LAMP-2 antibody could play some role in the pathogenesis of adult HSP, and have excluded a role for MPO-ANCA and PR3-ANCA.…”

Chronic Malaria Revealed by a New Fluorescence Pattern on the Antinuclear Autoantibodies Test

“…These situations are particularly misleading because the last visit to an endemic area often occurred more than three months, sometimes several years before the onset of symptoms [5], justifying extensive laboratory explorations often including the search for antinuclear autoantibodies (ANA). The presence of ANA with speckled pattern [16], [17], [18], [19] as well as cytoplasmic fluorescence on anti-neutrophils cytoplasmic antibodies (ANCA) testings [20], [21] have been described in malaria but are not specific of this diagnosis. Here, we report an original fluorescence pattern on HEp2000™-cells defined as nuclear speckled with diffuse cytoplasmic pattern and perinuclear enhancement that is related to P. falciparum infection.…”

Immunological disturbances associated with malarial infection

“…Various autoantibodies had been reported in patients with malarial infections where vasculitic lesions related to falciparum malaria had been described (Pradhan et al 2002;Yahya et al 1997). Autoantibodies such as antinuclear antibodies (ANA), anti-neutrophil cytoplasmic antibodies (ANCA), anti-lactoferrin (anti-LF) antibodies were found to be associated with malarial infection.…”