Detection of Candida antigen and antibody in serum from patients with invasive candidiasis

Abstract Objective: To compare the sensitivity and specificity of three different assays for diagnosis of invasive candidiasis. Methods: A passive hemagglutination assay (PHA), counter-immunoelectrophoresis assay (CIE), and Cand-tec were used to test sera from 125 patients with hematologic malignancies and 65 other hospitalized patients. The former group included 15 patients with invasive candidiasis, 38 patients with Candida colonization, and 72 patients without candidiasis. Results: Sensitivity/specificity of PHA, CIE, and Cand-tec were 87%/85%, 67%/98%, and 33%/97%, respectively. The measurement of antibody in paired sera, by PHA, was sensitive and specific; however, increased antibody titers usually occurred late in the disease. Conclusions: The combination of PHA and CIE, with a sensitivity of 67% and specificity of 98%, appeared to be the best assays for detection of invasive candidiasis in this cohort. The Cand-tec assay for Candida antigen had poor sensitivity for diagnosis of infection.