The arabinitol appearance rate in laboratory animals and humans: estimation from the arabinitol/creatine ratio and relevance to the diagnosis of candidiasis

Abstract

The effects of renal function on serum concentrations of the candidal metabolite arabinitol were studied by examining the accumulation and elimination of arabinitol in animals and humans. Serum concentrations of arabinitol rose sharply and in direct proportion to creatine concentrations after nephrectomy in rats. The serum half-life of exogenous arabinitol was 20.8 hr in anephric rats but only 0.62 hr in sham-nephrectomized control animals. The mean +/- SD apparent space of distribution of arabinitol was 419 +/- 26 ml/kg. The fraction of exogenously administered arabinitol recovered in the urine was 0.73 +/- 0.13 in uremic rats, 0.85 +/- 0.28 in control rats, and 0.95 +/- 0.10 in normal dogs. The arabinitol/creatinine clearance ratio was 0.99 +/- 0.08 in normal dogs and 0.99 +/- 0.25 in 22 critically ill patients with cancer. Thus arabinitol is eliminated by nearly quantitative urinary excretion and its cleared at virtually the same rate as creatinine. Therefore, the rate of arabinitol appearance in the body from any source equals the urinary arabinitol excretion rate and is directly proportional to the concentration ratio of arabinitol to creatinine in serum or urine.