RÉSUMÉ
Some mycobacterial infections, such as tuberculosis, are characterized by apoptosis in infected or by-stander mononuclear immune cells. For localized (paucibacillary, PB) and diseminated (multibacillary, MB) leprosy, characterized by polarized Thl-like vs, Th2-like immune responses, respectivelly little is known about lesional apoptosis. We analyzed sections of paraffin-embedded, untreated leprosy lesions from 21 patients by an indirect immunofluorescent terminal deoxynucleotide-transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay. Some TUNEL (+) PB sections were then reacted with phycoerythein-conjugated (red)antibodies against T cells, monocytes, or antigen-presenting (Langerhans) cells. TUNEL (+) bodies were detected in 9 of 16 PB lesions (56%) and in 1 of 5 MB lesions (20%). Some TUNELL (+) bodies in PB disease were CD3+ (T cell), as well as CD4+ (T-helper) or cd8+ (T-cytotoxic) Apoptosis characterizes PB and MB leprosy lesions and may be more freqeunt in PB disease. In PB disease, some TUNEL (+) bodies may derive from T cells