Renal Function Studies in Medullary Sponge Kidney

Abstract

Twenty-one patients with medullary sponge kidney but no clinical signs of renal infection underwent studies of renal function and repeated roentgenologic examinations. All but one of the patients had impaired tubular reabsorption of sodium, indicating damage to the tubules. As a result, the concentration capacity was greatly reduced. Measurements of pH and titrable acid in the urine after administration of ammonium chloride showed impaired capacity of the kidneys to equilibrate a metabolic acidosis. The extraction of PAH was diminished in 18 of 35 studied kidneys, suggesting that proximal tubules also are affected by the disease. No correlation was found between the severity of the roentgenologic changes and the renal function.