[Immunohistochemistry diagnosis of fungal infections]

Because the mycosis incidence has increased a lot with the appearing of AIDS, the Immunohistochemistry study among fungus shows the importance of fast methods for their identification that have advantage of been a durable method in comparison with immunofluorescence and the possibility of making retrospective studies in material embedded in paraffin. The Immunohistochemistry reaction with Histoplasma capsulatum, Pneumocystis carinii; and Criptococcus neoformans antibodies were sensitive, specifics, and intensely positive in all the cases previously diagnosed as Histoplasmosis, Pneumocystosis and Cryptococcosis, without cross-reaction with other fungus; while the anti-Candida albicans antibody showed weak positiveness in four Histoplasmosis cases, in one of Paracoccidioidomycosis cases and Sporotrichosis case; and the reactions with the antibody anti-P. brasiliensis were intensely positive in all the Paracoccidioidomycosis cases and weakly positive in two Histoplasmosis and two of the four Candidiasis cases. The previous identification of each fungi on tissue sample was made by Grocott method. This preliminary study showed that it is necessary to use other kinds of antibody and fungus, in order to get more details about the possible occurrence of cross-reactions. We suggest the use of new antibodies, with new standardizations in order to find the best titles for each reaction and eliminate the cross-reactions.