Renal manifestations and abnormal calcium metabolism in sarcoidosis.

Forty-two patients with sarcoidosis were studied with special attention to renal disease and disturbance of calcium metabolism. Abnormal calcium metabolism was found in 19 patients and prednisone corrected hypercalcaemia in those affected within two weeks, except in one patient who had concomitant primary hyperparathyroidism. Renal failure was found in 19 patients, 15 of whom had hypercalcaemia. Prednisone had a beneficial effect on kidney function within four weeks in all patients except in one with co-existing glomerulonephritis. Arterial hypertension was found in six patients, proteinuria in six, and calcinosis in six. Among 14 patients who underwent renal biopsy, granulomas were found in five. In only one of these was granulomatosis extensive bringing out renal failure and death within two years after temporary remission with prednisone. Co-existent non-sarcoid diseases affecting the kidneys or calcium metabolism occurred in ten out of 23 patients with sarcoidosis and kidney disease/calcium abnormality. In most cases these conditions contributed more to the prognosis than did sarcoidosis. From the present series and review of the literature it appears that young males within the first two years of diagnosis are at the greatest risk of hypercalcaemia or kidney disease.