A human autoantibody to renal collecting duct cells associated with thyroid and gastric autoimmunity and possibly renal tubular acidosis.

A complement fixing autoantibody reacting with certain renal collecting duct cells, possibly so called dark cells, is described in 113 patients. Clinically, the antibody was strongly associated with thyroid disorders and pernicious anaemia. The patients also showed a markedly increased frequency of thyroid antibodies and antibodies to gastric parietal cells and to intrinsic factor. One of the patients had a distal renal tubular acidosis (RTA) and pernicious anaemia. The antibody was also found in all of three other patients with either latent or manifest RTA. RTA is associated with various immunological diseases, and the renal collecting duct cell antibody may turn out to be a marker of this disorder, either involved in its pathogenesis or representing a secondary phenomenon.