Anticardiolipin antibodies (IgG and IgM), antinuclear antibodies (ANA), anti-dsDNA antibodies, anti-Sjögren's-syndrome-related antigens A and B, also called anti-Ro and anti-La angiotensin converting enzyme (ACE), and serum human T-lymphotropic virus (HTLV) 1 and 2 antibodies were negative in all patients and no coexisting autoimmunity or family history of autoimmune disease was observed. Here, ACE is linked to autoimmune disease.