Diagnosis of disseminated candidiasis by measurement of urine D-arabinitol/L-arabinitol ratio.

Relative amounts of D-arabinitol (fungal origin) and L-arabinitol (part of normal human metabolism) in urine were determined by gas chromatography and mass spectrometry from 61 hospitalized patients with hematological malignancies. Seventeen neutropenic patients with acute leukemia (with 53 samples) had disseminated yeast infections and received empiric antifungal therapy before confirmation of the diagnosis. Control groups consisted of 22 hematologic patients (76 samples) with either mucosal (n = 10) or urinary (n = 12) Candida colonization and 22 neutropenic patients (34 samples) with no clinical or laboratory signs of invasive yeast infection. Reference values were also obtained from 50 healthy adults (50 samples). The mean urine D-arabinitol/L-arabinitol ratio +/- standard deviation (range) was 16.91 +/- 41.79 (1.41 to 254.75) in patients with disseminated infection, 2.73 +/- 2.48 (1.11 to 19.00) in colonized hematologic patients, 2.12 +/- 0.84 (1.16 to 5.84) in neutropenic controls, and 1.95 +/- 0.34 (0.97 to 3.44) in healthy adults (P < 0.001 between patients with disseminated infection and all control groups). The sensitivity and specificity of the assay for detecting disseminated yeast infection were, respectively, 88 and 91% per patient (upper limit of normal, 4.00). Seventy-one percent of patients already expressed elevated values at the onset of empiric antifungal therapy. The diagnosis of disseminated infection was confirmed on average 21.7 days after the first elevation of the D-arabinitol/L-arabinitol ratio. The method contributes to diagnosis of disseminated yeast infection and helps in monitoring patients at risk, to support the initiation of antifungal therapy at an early stage of the disease.