Measurement of the D-Arabinitol/L-Arabinitol Ratio in Urine of Neutropenic Patients Treated Empirically with Amphotericin B

The aim of the present study was to evaluate the diagnostic significance of the D-arabinitol/L-arabinitol ratio in urine of neutropenic patients with suspected fungal infection. D-arabinitol/L-arabinitol ratios were determined in 373 serial urine samples of 104 patients with haematological malignancies receiving empirical amphotericin B treatment for suspected invasive fungal infection. Twenty-eight (8%) urine samples obtained from 17 (16%) patients were positive (ratio≥4). Eight (47%) patients had positive urine samples at the initiation of empirical amphotericin B treatment and the rest from 7 to 30 days after empirical therapy was started. Several urine samples were positive in six patients. Only one of the five patients with candidemia had elevated D-arabinitol/L-arabinitol ratios (persistent Candida krusei fungaemia). Four patients with transient candidemia and seven patients with invasive mould infections were negative. Patients who died during the study period had significantly higher D-arabinitol/L-arabinitol ratios than patients who survived (P=0.0002). Pneumonia was the most common manifestation of infection (53% of patients with elevated D-arabinitol/L-arabinitol ratios) and was associated with an especially high mortality (67%). The present study shows that elevated urine D-arabinitol/L-arabinitol ratios are common in febrile, neutropenic patients. However, the urine arabinitol test did not detect transient candidemia at elevated levels during the course of infection. Furthermore, D-arabinitol/L-arabinitol ratios were often elevated in the late phase of infection only. This contests the use of this test in guiding the initiation of antifungal therapy. The detection of elevated arabinitol levels in neutropenic patients during empirical amphotericin B treatment is associated with poor prognosis.