Familial microscopic hematuria caused by hypercalciuria and hyperuricosuria

We report 12 patients belonging to five different families in whom persiste nt isolated microhematuria was associated with hypercalciuria and/or hyperu ricosurla, Four patients had episodes of gross hematuria, three patients ha d passed renal stones, and a history of nephrolithiasis was obtained in fou r of the families (80%), Calcium oxalate and uric acid crystals were common ly observed in the urine sediments. Urinary erythrocytes had a normal appea rance on phase-microscopic examination. Reduction of calciuria and uricosur ia by thiazide diuretics, allopurinol, forced fluid intake, and dietetic me asures led to a persistent normalization of urine sediment with complete di sappearance of hematuria. Determination of calcium and uric acid urinary ex cretions should be included in the study of familiar hematuria. (C) 2000 by the National Kidney Foundation, inc.