An ELISA test for the serodiagnosis of chromoblastomycosis caused by Cladophialophora carrionii

Objective. An indirect ELISA was standardized to detect circulating antibod ies in patients suffering from chromoblastomycosis by Cladophialophora carr ionii. Methods. For this purpose, a somatic antigen (AgSPP) was prepared from a Ve nezuelan strain of the fungus. A total of 132 human sera were studied. Of t hese, 40 originated from healthy subjects, 74 from patients with chromoblas tomycosis (46 caused by C. carrionii,, 27 caused by Fonsecaea pedrosoi and one caused by Rhinocladiella aquaspersa) and 18 From patients with other my cosis. Preliminary experiments served to select antigen concentration, seru m and conjugate dilution, and other experimental conditions to produce the highest signal/noise radio. Results. The cutt-off value for a positive reaction was 0.233 (O.D.) at 99. 5% significance. The method showed 82.5% sensitivity and 81.1% specificity. Inter-assay precision for control sera were 9.4% (positive) and 6.9% (nega tive). Corresponding values for intr-assay were 4.7% and 4.3%, respectively . Conclusion. These results show that ELISA can be a valuable tool for the di fferential serodiagnosis of chromoblastomycosis caused by C. carrionii.