Serum cytokine profile in leprosy and its correlation with clinico-histopathological profile

[[[ Objectives: ]]] To analyse the serum levels of cytokines in leprosy patients, to correlate them with clinico-histopathological profile, and to study the effect of standard multidrug therapy on serum cytokine levels. [[[ Design: ]]] Serum immunoassays of TNF-alpha, IFN-gamma, IL-1 beta and IL-10 were performed by ELISA in 61 newly diagnosed cases of leprosy before starting therapy and during reactional episodes. Of these, cytokine assays could be performed in 17 cases after completion of therapy. [[[ Results: ]]] Levels of all the studied cytokines were significantly raised in cases compared to controls (P < 0.05). Levels of TNF-alpha and IFN-gamma were significantly raised in paucibacillary cases whereas all the studied cytokines were raised in multibacillary cases with rise in IL-1 beta and IL-10 being statistically significant (P < 0.001). No significant difference was however noted between TT and BT type; and BB, BL and LL types. All the studied cytokines were raised in reactional cases as compared to non-reactional cases. Comparing Type 2 reaction (T2R) and Type 1 reaction (T1R) cases, levels of IFN-gamma, IL-1 beta and IL-10 were higher in T2R cases but only IL-10 was found to be statistically significant (P = 0.05) while TNF-alpha was higher in T1R cases. Post therapy serum levels of all the studied cytokines were significantly lower than pretherapy levels (P < 0.05) and were comparable to controls. Among the paucibacillary cases, levels of all the cytokines were seen to decrease after 6 months of standard multidrug therapy. In the multibacillary cases, mean levels of the cytokines were found to decrease after 1 year of therapy except IFN-gamma. [[[ Conclusion: ]]] Serum cytokine estimation may have a significant role in classifying various forms of leprosy and can be used to monitor therapy.