Progressive tubulointerstitial renal disease in infancy with associated hepatic abnormalities.

Clinical, pathologic, and biochemical data are reported in two male infants who had rapidly progressive renal failure, enlarged kidneys, hepatosplenomegaly, and fat malabsorption. One infant, studied prior to the onset of significant renal insufficiency, manifested renal Fanconi syndrome, hyperparathyroidism, and marked hypocalcemia. After a brief period of dialysis, both received renal transplants. Neither has clinical evidence of reoccurrence of the renal disorder in the transplant, but both still have hepatic abnormalities. Morphologic features present in both patients include a renal lesion characterized by tubulointerstitial injury with a tubulocystic component and hepatic abnormalities with bile duct proliferation, portal fibrosis, and inflammation. These cases do not readily conform to any single published diagnostic category, including nephronophthisis-congenital hepatic fibrosis or infantile polycystic kidney disease, and appear to be unique.