XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:45-4

Poster (Painel)

45-4

IMPORTANCE OF THE ASSOCIATION OF IMMUNOLOGICAL AND MOLECULAR TECHNIQUES FOR THE PRESUMPTIVE DIAGNOSIS OF PATIENTS SUSPECTED OF FUNGAL INFECTION AND WITH ABSENCE OF MYCOLOGICAL RESULTS: A CASE REPORT

Authors:

Katia Cristina Dantas (IMT-SP - Instituto de Medicina Tropical de Sao Paulo) ; Roseli Santos Freitas (IMT-SP - Instituto de Medicina Tropical de Sao Paulo) ; Roberta Scholz Pinto Garcia (IMT-SP - Instituto de Medicina Tropical de Sao Paulo) ; Edna Cleide Mendes Muricy (IMT-SP - Instituto de Medicina Tropical de Sao Paulo) ; Marcos Vinicius da Silva (IIER - Instituto de Infectologia Emilio Ribas) ; Valdelene Sayuri Kohara (IAL - Instituto Adolfo Lutz) ; Angela Noronha Passos (IAL - Instituto Adolfo LutzPG-CCD-SES-SP - Programa de Pos-Graduacao em Ciencias, CCD-SES-SP) ; Adriana Pardini Vicentini (IAL - Instituto Adolfo Lutz)

Abstract

The definitive diagnosis of mycosis is still based on the isolation and identification of etiological agent. If neither cultural nor morphological proof of infection is available, other approaches like immunologycal or molecular diagnosis must be used. We present a case of HIV-negative young woman patient, who lives in Sao Paulo, presented to the Instituto Infectologia Emilio Ribas in January, 2008 with suspected pneumonia. At that time, the patient was not taking any medication and had no history of systemic disease. The patient report a history of traveling to rural area in Bahia, Brazil and related that had direct contact with the excreta of chicken and had taken inadequate precautions. Clinical examination demonstrated a patient with normal skin color, afebrile, well-hydrated, noncyanotic, and without edema, lymphadenopathy or hepatosplenomegaly. The patient had complained of chest pain for three months after the travel. Antibodies to HIV, viral hepatitis, leishmaniasis, Chagas disease, malaria, paracoccidioidomycosis, histoplasmosis, aspergillosis and skin tests for paracoccidioidomycosis and histoplasmosis were negative. Direct sputum examination was negative for fungus and alcohol-acid-resistant bacillus. Blood cultures were also negative. Radiological images proved to be inconclusive, with no pathological changes. The epidemiological history was compatible between histoplasmosis and cryptococcosis, and proceeded by immunodiagnostic and molecular biology. Immunoblotting analysis revealed reactivity to the fractions of H and M of H. capsulatum and gp 43 of P. brasiliensis. Nested PCR using species-specific primers was positive for H. capsulatum and C. neoformans and negative for P. brasiliensis, showing the possible infection by H. capsulatum observed in immunoblotting. The recognition of the gp43 can be attributed to cross reactivity with similar epitopes of these two pathogens. The failure to detect DNA fragment specific for P. brasiliensis seems to corroborate the hypothesis of cross-reactivity, as this technique is more specific than the immunoblot. The follow-up of asymptomatic patients with confirmed infection by H. capsulatum and C. neoformans may also have relevance in the prevention and monitoring of possible reactivation of quiescent foci, common in systemic mycoses and pathogenetic contribution to the knowledge of these diseases.

Keyword: Diagnosis, Histoplasmosis, Immunocompetent patient, Immunoblotting, Nested-PCR

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