CD4 and leprosy: We observed that significant number of T effector cells (CD4+CD25−) were converted into CD4+CD25+ Tregs when CD4+CD25− cells were cocultured with CD19+ B cells isolated from BT (4.11 ± 1.12%, p < 0.005) and BL/LL leprosy (12.61 ± 2.18%, p < 0.0005) patients (Figure 3A).