Human immunodeficiency virus type 1 (HIV-1) and Mycobacterium leprae co-infection: HIV-1 subtypes and clinical, immunologic, and histopathologic profiles in a Brazilian cohort

Co-infections with human immunodeficiency virus (HIV) and Mycobacterium leprae represent unique opportunities to investigate the interaction of both pathogens. We determined the immunologic, virologic, and histopathologic characteristics of 22 co-infected Brazilian patients (median age = 38 years, 81.8% males, 72.2% with paucibacillary leprosy, and 95.4% with acquired immunodeficiency syndrome). The HIV-1 subtypes B and BF predominated in envelope and gag heteroduplex mobility analysis. Borderline tuberculoid (BT), tuberculoid, lepromatous, and indeterminate morphology with CD3+, CD8+, and CD68+ cell distributions compatible with leprosy patients not infected with HIV were observed. Histologic evidence of nerve damage was observed in BT lesions. IgM antibody to M. leprae-specific phenolic glycolipid I was not detected. Two of six co-infected patients monitored during highly active antiretroviral therapy (HAART) developed a leprosy type 1 reaction after an increase in CD4+ cells, suggesting an immune restoration phenomenon. Clinical, immunologic, histopathologic, and virologic features among these HIV-leprosy co-infected patients indicate that each disease progressed as in single infection. However, HAART immune reconstitution may trigger potential adverse effects, such as leprosy acute inflammatory episodes.