CD79A and ankylosing spondylitis: Previous studies have shown that excess serum IgA or production of IgA autoantibodies contributes to chronic inflammation and tissue damage in many autoimmune diseases including rheumatoid arthritis, IgA nephropathy, IgA vasculitis, dermatitis herpetiformis, celiac disease, inflammatory bowel disease, Sjögren’s syndrome, ankylosing spondylitis, alcoholic liver cirrhosis, and acquired immunodeficiency syndrome (28).