Stereoisomeric configuration of arabinitol in serum, urine, and tissues in invasive candidiasis

Because routine analytical methods cannot differentiate D- from L-arabinitol, a combined microbiological and gas chromatographic method was developed to study the stereoisomeric configuration of the arabinitol in humans and rats with invasive candidiasis. D-Arabinitol was defined as the difference between arabinitol concentrations measured with and without incubation with 5.0 x 10⁵ blastospores of Candida tropicalis strain CT 12 at 37 C for 24 hr. The yeast consumed at least 95% of the D-arabinitol and none of the L-arabinitol added to normal serum and urine. D-Arabinitol as a fraction of D,L-arabinitol was 0.43 ± 0.15 (mean ± SD) in the urine of 10 normal humans, 0.82 ± 0.12 in the serum or urine of five patients with cancer and invasive candidiasis (P < .001), and 1.0 in the kidneys of rats with candidiasis. Because most or all of the excess arabinitol in body fluids or tissues in candidiasis was the D isomer, which is produced by fungal metabolism, stereospecific quantitation of arabinitol should improve the sensitivity of this approach to diagnosis of candidiasis.