Elevated Level of Plasma Interleukin-18 (IL-18) in Leprosy Patients with Reversal (T1R) and Enl (T2R) Reactions

The clinical management of leprosy type 1 and type 2 reactions poseschallenges mainly because they can cause severe nerve injury and disability. No laboratory test or marker is available for the diagnosis or prognosis of leprosy. This study screened IL-18 level in plasma in samples to identify circulating biomarker associated with type 1 and type 2 lepra reactions. In this study IL-18 level was compared in T1R (10) and T2R (9) with NRL (n=20) and NHC (n=43). IL-18 level was measured using commercial kit. IL-18 level was significantly higher in the T1R and T2R groups when compared to the NRL and NHC groups (p=0.0001). The level was significantly different in T1R group and T2R group (p=0.0343). The BTR group showed the highest IL-18 plasma levels among the other groups in the disease spectrum in reactional leprosy patients (mean±sD)(3483.38±1035.63). Bacteriological index (BI), was showed negative correlation with IL-18 plasma levels. The results specify that IL-18 plasma levels are elevated during T1R and T2R leprosy reactions and thus may play a role in the regulation of inflammatory responses associated with reactions in leprosy.

Keywords: Reactions; Cytokines; Interleukin-18 (IL-18), Bacterial Index (BI), Mycobacterium leprae (M. leprae).