Urine D-arabinitol/L-arabinitol ratio in diagnosis of invasive candidiasisin newborn infants

Infants treated in neonatal intensive care units suffer an increased risk f or invasive candidiasis, but the diagnosis is sometimes difficult, D-arabin itol is a metabolite of most pathogenic Candida species. An elevated urine D-arabinitol/L-arabinitol (DA/LA) ratio is a sensitive sign of invasive can didiasis in children with cancer, but the method has not been previously ev aluated for newborn infants. We therefore enrolled 117 infants in a neonata l intensive care unit, and 411 urine samples were obtained on filter paper. The DA/LA ratio was measured by gas chromatography-mass spectrometry, For 81 infants with no suspicion of superficial or invasive candidiasis, the ur ine DA/LA ratio was 2.7 +/- 0.7 (mean +/- standard deviation [SD]), The upp er cutoff level was set at 4.8 (mean plus 3 SD). Of 22 infants with mucocut aneous candidiasis and not given systemic antifungal treatment, two had ele vated DA/LA ratios, which normalized after removal of intravascular cathete rs, Eight other infants were given empiric antifungal treatment but had neg ative cultures; five of these had repeatedly elevated DA/LA ratios. Six inf ants with culture-positive invasive candidiasis all had one or more samples with elevated ratios. For seven infants, three with suspected and four wit h confirmed invasive candidiasis (for which follow-up samples were availabl e), ratios normalized during antifungal treatment. In conclusion, urine DA/ LA ratio determination is a rapid test and can be used for newborns. It is possibly more sensitive than fungal blood cultures in the diagnosis of inva sive candidiasis and can also be used for monitoring the effect of antifung al treatment.