IgA autoantibodies, increased IgA or aberrant IgA immune complexes are found in several diseases, such as celiac disease (13, 14), IgA nephropathy (15–17), IgA vasculitis (18), rheumatoid arthritis (19), multiple sclerosis (20) and IgA blistering diseases (21). This evidence concerns the gene CD79A and Henoch-Schoenlein purpura.