Renal Excretion of Uric Acid and its Relation to Relapse and Remission in Acute Myeloid Leukaemia

Abstract

The role of the kidney in uric acid homeostasis was investigated in 11 patients with acute myeloid leukaemia. Renal clearance studies were performed in all patients before and after the first course of anti-leukaemic therapy; in 5 patients at remission and in 2 of these during relapse. Urinary excretion of uric acid was much higher at lower serum urate levels in leukaemic patients than in normal subjects. The main renal regulatory mechanism of urate excretion appeared to be operated through variations in the rate of tubular secretion of urate (TSurate); with an increase in TSurate during anti-leukaemic therapy and during relapse. Proximal renal tubular dysfunction developed in all patients and large quantities of urate escaped reabsorption in the renal tubule during active disease. The size of the fraction of urate excretion attributable to incomplete tubular reabsorption was unpredictable, but often increased after chemotherapy and during relapse with a fall in the serum urate level and fell during remission with an increase in serum urate. This component of urinary excretion of urate interfered with the usual dependence of TSurate on serum urate, with the result that the urate profile of remission (normal serum urate and low TSurate) could be distinguished from that of relapse (low serum urate and high TSurate).