AMMONIUM URATE NEPHROLITHIASIS IN A VARIANT OF BARTTERS-SYNDROME WITHINTACT RENAL TUBULAR FUNCTION

In two patients with Bartter's syndrome proximal tubular function and distal chloride reabsorption were intact on admission; however, chlori de reabsorption and distal tubular acidifying capacity decreased in on e patient over a period of 10 years. Renal prostaglandin E excretion a nd urinary and plasma uric acid were in the normal range, but urinary ammonium was significantly elevated during controlled diet. One patien t developed ammonium urate nephrolithiasis. In both patients renal bio psy demonstrated lymphocytic infiltration of the interstitial tissue a nd hypercellularity of the macula densa. Indomethacin treatment improv ed serum potassium concentration and decreased plasma renin activity, plasma aldosterone concentration, and urinary prostaglandin E but had to be discontinued because of side effects. It is likely that our pati ents represent a variant form of the syndrome originally described by Bartter.