Differentiation of intestinal candidial colonization from invasive candidiasis by measuring serum level of D-arabinitol in combination with oral administration of low dose amphotericin B

The measurement of D-arabinitol in serum has been reported to be useful for the diagnosis of invasive candidiasis. However, excessive proliferation of Candida species in intestinal tract often leads false positive result of serum D-arabinitol. Based on the evidence that amphotericin B (AMPH) is scarcely absorbed from intestinal tract and inhibits the proliferation of Candida species only in intestinal tract, we have developed a simple differentiation method of intestinal candida colonization from invasive candidiasis by measuring serum level of D-arabinitol in combination with oral administration of low dose AMPH. AMPH, 600 mg/day for 2 days was orally administered to five patients with hematological malignancies who showed more than 1.7 mumol/mg of D-arabinitol/creatinine ratio (D/C ratio) in serum without any evidence of invasive candidiasis. D/C ratios were markedly decreased and normalized after the oral administration of low dose AMPH. While, in a patient with invasive candidiasis in whom Candida species was detected by blood cultures, D/C ratio remained unchanged in spite of oral administration of AMPH. These observations suggest that this method is a simple and reliable diagnostic method to distinguish intestinal candida colonization from true invasive candidiasis.