CD4 and leprosy: Treg cells in individuals with both forms of leprosy (tuberculoid and lepromatous) than in healthy controls. In patients affected by leprosy, the secretion of IL-35 acted as an amplifier, significantly increasing the number of Treg CD4+CD25+ cells. The presence of IL-35 producing B cells was found in leprosy cases. It was verified that the levels of IL-35 were increasing as it passed from the tuberculoid point to the Lepromatous point, and that the expression of this cytokine was responsible for the Tregs and Bregs.