BCG and MTB, but not LPS, induce apoptosis in macrophages from leprosy patients in vitro. The rate of apoptosis (%) was assessed by flow cytometry in CD14+ cells following staining of PBMC cultures with 7-AAD and anti-CD14 antibody. Cells were stimulated (hatched bars) or not (solid bars) either with LPS 1 μg/ml, or live BCG, or heat-killed MTB (10 : 1 bacteria : cell ratio), as indicated in the figure. Results represent mean ± SEM of five individual experiments. *Significant differences (P < 0·05) when compared to the unstimulated cultures.