Evaluation of a metallopeptidase antigen from Candida albicans in serodiagnosis of andidosis: Comparison of technics

Purpose. We recently developed an enzyme-linked immunosorbent assay (Elisa) using a metallopeptidase of Candida albicans as antigen to detect anti-Can dida antibodies. The work presented here compares this method, called Elisa MP, with immunofluorescence assay, electrosyneresis, indirect hemagglutina tion and two Elisa kits precommercialized by Biomerica (Candiquant IgG) and Sanofi Diagnostics Pasteur (Platelia Candida Anticorps). Materials and Methods. Eighty-four sera from seventy-three patients were an alyzed with these six tests. The patients were divided into a control group free of candidosis, and three groups of patients: one with disseminated ca ndidosis, another with superficial candidosis and a last one composed of hi gh-risk immunocompromised patients. Results. Results obtained with immunofluorescence, electrosyneresis, indire ct hemagglutination and Platelia Candida Anticorps all correlated, with a s pecificity and a negative predictive value of 100 %, and a sensitivity of 8 8 %, 91 %, 63 % and 76 % respectively. On the contrary, the respective spec ificity of Candiquant IgG and Elisa MP was 37 % and 63 % with a common nega tive predictive value of 92 % and their sensitivity was 100 % and 97 %. Conclusion. None of the assays were able to discriminate superficial candid osis from deep-seated infections. From our knowledge, the best routine test s are those having the best negative predictive value and the best specific ity Therefore, the metallopeptidase isolated in our laboratory could not be used in the described conditions for the development of a serodiagnosis te st for Candida infections.