IL9 and leprosy: T2R leprosy reaction group is characterised by intense systemic inflammation mediated by TNF, IFN-γ, IL-9 and IL-17 - The analysis of the results for the concentration of immunological mediators in the plasma samples from PB and MB leprosy was carried out in comparison with T1R and T2R leprosy reaction and data are shown in Fig. 2.