XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:45-2

Poster (Painel)

45-2	PERFORMANCE EVALUATION OF TWO IMMUNOLOGICAL ASSAYS FOR THE DIAGNOSIS OF ACUTE PULMONARY HISTOPLASMOSIS.
Authors:	Angela Noronha Passos (IAL - Instituto Adolfo LutzPG-CCD-SES-SP - Programa de Pos Graduacao em Ciencias) ; Valdelene Sayuri Kohara (IAL - Instituto Adolfo Lutz) ; Camila Mika Kamikawa (IAL - Instituto Adolfo Lutz) ; Lucia Cupertino Barreto (IAL - Instituto Adolfo Lutz) ; Adriana Pardini Vicentini (IAL - Instituto Adolfo Lutz)

Abstract

Histoplasmosis is a fungal infection caused by Histoplasma capsulatum. The acute pulmonary form of the disease when it affects healthy individuals is characterized by respiratory symptoms that arise from one to three weeks after exposure to the pathogen. The diagnosis in this case is usually confirmed by immunological assays and patient′s epidemiological history, since the finding of the fungus in respiratory secretions is uncommon. We evaluate the performance of two serological assays for diagnosis of acute pulmonary histoplasmosis (HPA). By double immunodiffusion in agarose gel (ID) and immunoblotting (IB), we analyzed 65 serum samples from patients with clinical suspicion of HPA: 34 samples from individuals with recent infection (within 30 days of exposure to fungal spores) and 31 samples of same individuals, collected about 60 days after exposure. The sensitivity of the ID was 48% (31⁄65) and IB, 80% (52⁄65) and analysis of concordance between the methods showed reasonable (κ = 0.37). Considering only the samples of recent infection, the sensitivity of ID reduced to 3% (1⁄34) of IB, 67% (21⁄34) and the methods showed only a slight agreement (κ = 0.03) among themselves . However, evaluating the samples sent later, the IB and ID methods showed sensitivity of 97% (30⁄31) and 100% (31⁄31), respectively, with as good agreement (κ = 0.7). The IB assay, showed more sensitive with the advantage of being able to identify patients with recent infection. In turn, brought the phenomenon of seroconversion, the ID is more suitable to monitor disease prognosis due to its semi-quantitative property. Both methods were efficient, skilled and complementary for the diagnosis of histoplasmosis, especially in cases where there is no mycological confirmation of the disease.

Keyword: Acute pulmonary histoplasmosis, Double immunodiffusion, Histoplasma capsulatum, Immunoblotting, Index Kappa

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