“…Although selective deficiency of IgA occurs in healthy populations [13], it has been reported more often in association with recurrent respiratory tract infections, intestinal disorders, rheumatoid arthritis and other autoimmune diseases [4, 8,10,12,171. Human anti-IgM isoantibodies and antibodies against tissue IgG, human collagen, basement membrane and bovine milk and colostrum may occur in this condition [l, 5, 7, 20, 211.…”