Immunogenetic association in patients with antineutrophil cytoplasmic antibodies (ANCA) from Mumbai, Maharashtra, India.

Considerable genetic evidence exit for ANCA-associated vasculitis and pathogenesis. HLA A and B alleles identified serologically from 84 ANCA-positive patients were compared with 101 controls. Further subtyping were done in the 27 "pauci-immune" vasculitis patients using the polymerase chain reaction based PCR-SSOP technique and compared with controls (67). The results revealed that HLA A1 (OR=4.00; p value 2.72E-05), B17 (OR=3.38; p value 0.0008) and HLA B40 (OR=2.74; p value 0.001) were significantly increased among ANCA-positive patients when compared with the controls. Further, the molecular subtypes A*0101 (OR=5.04; p value 0.0005), B*5801 (OR=4.47; p value 0.0002) and haplotype A*0101-B*5801 (OR=4.47; p value 0.0001) were significantly increased among the autoimmune patients. The study revealed that HLA A1, B17 and B40 alleles are associated in production of antineutrophil autoantibodies and A*0101-B*5801 haplotype is significantly associated with autoimmune diseases and they may be invariably involved in disease pathogenesis in India.

Increased incidence of cytoplasmic ANCA (cANCA) and other autoantibodies in leprosy patients from western India.

The prevalence of various autoantibodies was studied in 75 leprosy patients comprising eight patients with lepromatous leprosy (LL), 36 patients with borderline lepromatous leprosy (BL) and 31 patients with borderline tuberculoid leprosy (BT), along with 100 normal controls. Certain autoantibodies such as anti-nuclear antibodies (ANA), anti-single stranded DNA (anti-ssDNA) and anti-neutrophil cytoplasmic antibodies (ANCA) were raised among leprosy patients. When ANCA specificities to anti-myeloperoxidase (anti-MPO), anti-proteinase3 (anti-PR3) and anti-lactoferrin (anti-LF) were studied, it was found that the patterns of immunofluorescence such as perinuclear (p-ANCA), cytoplasmic (c-ANCA) and atypical (X-ANCA) and specificity by ELISA to anti-MPO, anti-PR3 and anti-LF varied in the LL, BL and BT groups. However, a higher amount of c-ANCA was observed in 62.5% of leprosy cases, while the incidences of p-ANCA and X-ANCA were lower. The LL group showed a higher incidence of autoantibodies as compared with the BL and BT groups, along with a male preponderance for autoantibody development. Some unusual antibody profiles such as 'X'-ANCA were also observed. The study suggests that autoantibody formation could be quite prevalent and also variable in the spectrum of leprosy cases, and there seems to be a serological overlap among leprosy and autoimmune disease, which could have pathogenetic importance in the leprosy patients developing complications.