Dados do Trabalho

Título

Alternaria alternata (Ascomycota) as an etiological agent of Chromoblastomycosis in Brazil - first records

Introdução

Chromoblastomycosis (CBM) is a neglected chronic subcutaneous disease of progressive development caused by a diversity of melanized fungal species, which are inoculated into the skin after a trauma with materials contaminated by hyphae. The main etiological agent of CBM in Brazil and the world is Fonsecae pedrosoi, however, a real gap inknowledge on the relationship between other species of CBM agents and the host is observed and, indeed, needs to be investigated. 

Objetivo (s)

This work aimed to identify the etiological agents of CBM in skin biopsies of three patients admitted to the Dermatology Service of the Hospital das Clínicas da Faculdade de Medicina da USP (HCFMUSP) and to characterize the T immune responses in such patients. 

Material e Métodos

DNA from skin biopsies was isolated, PCR reactions were performed using the primers ITS1-ITS4; obtained amplicons were sequenced. To investigate histological changes of the skin, histological sections were stained with hematoxilin and eosin. The CD4, CD8, IFN-g, IL-17, IL-10 and IL-4 markers were analyzed by immunohistochemistry. 

Resultados e Conclusão

By sequencing the regions ITS1-ITS4 of fungal ribosomal DNA, for the first time, it was possible to incriminate Alternaria alternata (Ascomycota) as the etiological agent of CBM in three patients admitted to the HCFMUSP Dermatology Service. Inflammatory infiltrates from these patients revealed the presence of polymorphonuclear and mononuclear cells, as well as muriform cells distributed inside or outside multinucleated giant cells. CD4+ and CD8+ cells were observed in the skin, along with a high density of IL-10+ cells, followed by IFN-γ+,IL-17+ and IL-4+ cells. This is the first report incriminating Alternaria alternata as the etiological agent of CBM in Brazil. This infection caused a predominant IL-10-associated immune response in patients, which can be associated with the persistence of fungus in the skin of human patients.

Palavras Chave

Chromoblastomycosis; Alternaria alternata