Evaluation of enzyme linked immunosorbent-assay and western blot for diagnosis of histoplasmosis.

This study evaluates the use of a enzyme linked immunosorbent assay (ELISA) for the diagnosis of histoplasmosis and it compares it with a complement fixation test. The results showed a sensitivity of 86% in this diagnosis of acute pulmonary histoplasmosis and specificity of 91% using anti-human IgG. For antihuman IgM the sensitivity was 66% and the specificity 100%. There was a good correlation between the titer of complement fixation test and the optical density index by ELISA. Neither ELISA or complement fixation were useful for the diagnosis of disseminated histoplasmosis in immunocompromised patients. Using Western blot we identified antibodies against four different histoplasma antigens (91, 83, 70 and 38 kD) in sera from patients with histoplasmosis. These antigens were identified also in patients with disseminated histoplasmosis. We conclude that ELISA is a useful test for the diagnosis of histoplasmosis, and the Western blot could be useful for the diagnosis of disseminated histoplasmosis.