Immunohistochemical analysis of the mucosal lesion in mucocutaneous leishmaniasis.

Using antibodies against surface antigens of inflammatory cells and against extra-cellular matrix components, immunocytochemical studies permit the investigation of the in situ cellular immune response and the associated fibrosis, in mucosal lesions. 57 paraffin embedded skin biopsies of mucocutaneous leishmaniasis originating from Bolivia, and due to Leishmania (Viannia) braziliensis, were studied. Memory T cells predominate within a non-organized granulomatous reaction, in which were observed proliferating macrophages. At the top of the lesion, epithelial cells expressed HLA-DR. Some characteristics of this lesion, particularly its chronic destructive pattern, presently lack any clear explanation.