Anti-A autoantibodies with unusual properties in a patient on renal dialysis.

A blood group A1 patient on renal dialysis developed transient low-titre, high-avidity anti-A autoantibodies and concurrently a gross depression of the A antigen. The antibodies were clearly anti-A and had no association with I, i or N antigens. They reacted in saline, papain and antiglobulin systems but were inactivated by albumin. Their pathogenesis is obscure.