Lymphocyte cytotoxicity for kidney cells in renal tubular acidosis of autoimmune liver disease.

Sensitisation to a renal tubular antigen, Tamm-Horsfall glycoprotein, has been shown to be common in patients with renal tubular acidosis complicating autoimmune liver disease, and it has been suggested that this immune reaction, by damaging renal tubular cells, might be responsible for the acidification defect. The lymphocytes from 10 out of 13 patients with chronic active hepatitis or primary biliary cirrhosis and an associated renal tubular acidosis were shown to be cytotoxic for a kidney cell line known to secrete Tamm-Horsfall glycoprotein. The cytotoxic reaction was blocked by this antigen, but not by two other proteins, indicating that sensitisation to the renal glycoprotein was the likely cause of the target cell damage. Significant reduction in cytotoxicity after the addition of aggregated IgG suggested that the reaction was of the antibody-dependent cell-mediated type. These results, together with the finding of antigenic material in the surface membrane of liver cells that cross reacts immunologically with Tamm-Horsfall glycoprotein, provide an explanation for the association between chronic liver disease and renal tubular dysfunction.