Pancreatic alpha cell autoantibodies and glucagon response to arginine

The frequency and significance of cytoplasmic pancreatic alpha cell autoantibodies (ACA) were investigated in 2102 healthy controls, 879 patients with insulin-dependent diabetes mellitus (IDDM) who were negative for islet cell autoantibodies (ICA), and 1567 relatives of IDDM patients. ACA were found in approximately 1 in 200 people of all ages and were not significantly associated with IDDM, the IDDM-associated HLA phenotypes DR3 and DR4, or thyrogastric or adrenal autoantibodies. Of 11 ACA-positive patients studied by arginine stimulation tests, none had frank glucagon deficiency. Thus, ACA do not appear to be associated with defective alpha cell function or with IDDM.