Evaluation of the Candigen Enzyme-Linked Immunosorbent Assay for Quantitative Detection of Candida Species Antigen

Abstract

Abstract Objective.—To assess the clinical utility of an enzyme-linked immunosorbent assay method for the quantitative detection of Candida species antigen (Candigen; Biomerica Inc, Newport Beach, Calif) in patients with suspected disseminated candidiasis. Methods.—Specimens of blood or cerebrospinal fluid from 75 patients with suspected disseminated candidiasis were analyzed by the Candigen test. Results were compared with those obtained by culture and polymerase chain reaction (PCR) analysis. Results.—Thirty-seven patients had specimens positive for Candida species by either culture or PCR. Of these specimens, 4 were positive by both culture and PCR, 21 were culture positive but PCR negative, and 12 were PCR positive but culture negative. Five specimens were positive by the Candigen test, all of which were PCR positive but culture negative. The sensitivity, specificity, and positive and negative predictive values of the Candigen test compared to culture plus PCR were 13.5%, 100%, 100%, and 54.3%, respectively. Turnaround time for the Candigen test was approximately 3 hours. Conclusion.—The Candigen test showed excellent specificity and turnaround time, but its poor sensitivity coupled with its inability to provide species information or susceptibility data make its clinical utility questionable.