Diagnosis of disseminated candidiasis based on serum D/L-arabinitol ratios using negative chemical ionization mass spectrometry.

The main objective was to appraise the diagnostic specificity of the serum D/L-arabinitol ratio technique in a patient population biased for renal dysfunction. The D/L ratio (mean +/- S.D.) in normal serum (n = 29) was 1.76 +/- 0.47 (range 0.77-2.75). D/L-Arabinitol greater than 3.18 (mean + 3 S.D.) are considered indicative of disseminated candidiasis. Of 49 patients without candidiasis, but 46% with serum creatinine greater than 1.5 mg/dl, diagnostic specificity was 88%. In confirmed candidiasis (n = 16) sensitivity was 94% (D/L range 3.2-50.1). Switching from positive to negative chemical ionization permits the use of as little as 5 microliters sample (20 microliters used routinely; D/L ratios constant in the 5-200 microliters range) permitting the extension of the technique to pediatric applications. Results can obtained in 2 h. Suggested areas of clinical application include aiding diagnosis, monitoring patients as risk so that treatment could be initiated while fungus load is still small, and following the course of antifungal chemotherapy.