CD79A and rheumatic disorder: An earlier study of 80 AS patients and 80 controls free of rheumatic disease [9] did not find any difference in positivity rates for IgG ASCA, IgA ASCA, anti-OmpC, anti-CBir1 or ANCA between the two groups, although higher quantitative antibody quartile scores for ASCA IgG and ASCA IgA were reported in AS compared to controls.