Role of western blot assay for the diagnosis of histoplasmosis in AIDS patients from a National Institute of Infectious Diseases in Rio de Janeiro, Brazil

Background Histoplasmosis is a frequent fungal infection in HIV/AIDS patients, with high morbimortality rates when diagnosis and treatment are delayed. Antibody detection, which is faster than the gold standard culture test, hastens the laboratory investigation. Objectives To evaluate the role of WB for antibody detection in the diagnosis of histoplasmosis among HIV/AIDS patients. Patients and Methods Fifty patients with proven or probable histoplasmosis were included. Clinical, epidemiological and laboratory data were described in the same population after a review of their medical records. WB was performed using deglycosylated histoplasmin. Results About 82% of patients were adult males and the mean age was 39.3 years. CD4(+) T lymphocyte count less than 150 cells/mm(3) was observed in 62% patients. Antibodies against Histoplasma capsulatum M antigen were detected in 62% of patients, and against both M and H antigens in 28% of individuals. Sera from 10% of patients were nonreactive. Histoplasmosis was the first opportunistic infection in 38% of the cases. Disseminated and pulmonary histoplasmosis occurred in 84% and 16% of patients, respectively. The overall mortality was 16%. Conclusion WB could be useful for the histoplasmosis diagnosis in HIV/AIDS patients because of its easefulness and good sensitivity in a population where antibody production is hampered.