MELISA and CF were compared using sera from paracoccidioidomycosis patients before treatment and patients undergoing antimycotic treatment. With MELISA it was possible to distinguish different antibody levels in both groups of patients whereas such distinction was not observed by using CF tests. MELISA is thus an advantageous alternative to CF in the diagnosis of paracoccidioidomycosis, including the possibility of testing sera with anticomplementary activity.

The erythro-immunoassay, a new serological procedure in which a hybrid antibody conjugate is able to bind erythrocytes, was used for the titration of antibodies against P. brasiliensis in sera from patients with paracoccidioidomycosis. A peptide-polysaccharide and a lyophilized yeast culture filtrate of P. brasiliensis were used as antigens. Absorption with dead Candida albicans whole cells was necessary to decrease cross reactions observed with heterologous sera. Erythroimmunoassay provides a sensitive system for titration of antibodies in paracoccidioidomycosis with serum dilutions up to 1:102000.

A magnetic solid phase enzyme-linked immunosorbent assay (MELISA) for quantification of IgG antibodies to somatic and metabolic antigens of Paracoccidioides brasiliensis was developed. Activation of magnetic polyacrylamide agarose beads with concanavalin A was superior to glutaraldehyde activation, and test sensitivity was higher for somatic than for metabolic antigens. Comparative MELISA, counterimmunoelectrophoresis and erythroimmunoassay tests with sera from 33 proven cases of paracoccidioidomycosis, 14 cases of histoplasmosis and 20 normal human sera showed the MELISA could distinguish antibody levels in paracoccidioidomycosis from those in normal sera; however two sera from histoplasmosis cases cross-reacted in the MELISA. MELISA is a rapid test (5-6 h) and the results suggest it has considerable potential value for assay of anti-P. brasiliensis antibodies.

An enzyme-linked immunosorbent assay (ELISA) for detection and quantification of antibodies anti-Paracoccidioides brasiliensis is described. Polystyrene plates have been used as solid phase to absorb P. brasiliensis metabolic yeast phase antigen. Twenty sera of proven paracoccidioidomycosis, 11 of histoplasmosis due Histoplasma capsulatum, 20 of aspergillosis and 20 human normal sera were tested. Ninety-five percent of the paracoccidioidomycosis sera had O.D. superior to 0.150 (from 0.163 to 2.650) at 1/400 serum dilution. ELISA assay was compared with counterimmunoelectrophoresis and erythro-immunoassay tests; a correlation was observed only with erythro-immunoassay. ELISA test should give new perspectives for the serodiagnosis of paracoccidioidomycosis.