The protein “mycoarray”: a novel serological assay for the laboratory diagnosis of primitive endemic mycoses

A protein microarray containing fungal antigens (the “mycoarray”) has been set up to provide rapid and appropriateserodiagnosis of primitive endemic mycoses, an important cause of morbidity and mortality in an increasingly highnumber of patients. The mycoarray consists of three antigen extracts (histoplasmin, coccidioidin and Coccidioides “TP”)and antibody dilution curves were spotted on microarray slides. The arrays were processed with coccidioidomycosisand histoplasmosis patients’ sera or with control sera and the occurring immunocomplexes were detected by indirectimmunofluorescence. In agreement with clinical and microbiological diagnosis, the results distinguished betweenhistoplasmosis and coccidioidomycosis patients. In addition, the assay could clearly discriminate between IgM andIgG antibody reactivity. No reactivity was ever observed in the arrays processed with negative control sera. Therefore,this pilot study demonstrates that the “mycoarray” is sensitive and specific enough to discriminate between healthyindividuals and patients with histoplasmosis or coccidioidomycosis. Because of miniaturization and multiparametricity,the new assay cuts costs and processing time. Thus, once clinically validated and implemented as a large-scale array,the “mycoarray” will be ready to be applied to the daily clinical practice.