Capture enzyme-linked immunosorbent assay to detect specific immunoglobulin E in sera of patients with paracoccidioidomycosis

Paracoccidioidomycosis (PCM) is the most frequent systemic mycosis in South America. The disease is characterized by a polyclonal activation of B cell s, resulting in hyperimmunoglobulinemia. The production of immunoglobulin ( Ig) E in deep mycosis has been related to the severity of the disease. Howe ver, the detection of specific IgE in sera of patients is difficult because of the competition with the IgG. We compared a capture and an indirect enz yme-linked immunosorbent assay (ELISA) technique to detect Paracoccidioides brasiliensis IgE. We found that the capture ELISA presented higher perform ance and lower background values than the indirect assay, resulting in a si gnificant quantitative discrimination between sera from patients with the 2 major clinical forms of PCM. Patients with the juvenile form presented sig nificantly higher levels of P. brasiliensis IgE, as compared with patients with the adult form. The capture ELISA was used in the follow-up of patient s receiving treatment, showing that the levels of specific IgE decreased as the patient's clinical conditions improved.