Serum immune markers as triggers of reactional episodes in multibacillary patients with leprosy

Abstract

Introduction: The development of leprosy reactions is one of the main challenges in the management of patients with leprosy. The reactions can be divided into type 1 (RR) and type 2 (ENL), representing comorbidities that can cause nerve damage and disability. This study aimed to correlate the production of immunological markers in the serum of leprosy patients with and without reactions. Methods: Cytokines and chemokines were measured in serum by sandwich ELISA in a cross-section of 69 leprosy patients: 24 without evidence of reactions (NR), 23 with RR and 22 with ENL. Results: We identified an increase in CXCL-9 and CXCL-10 in the multibacillary forms (MB) of leprosy that might have a role in the development of reactions, since both chemokines were positively correlated with the pro-inflammatory cytokine IL-6 in reactional patients. IL-8 was also noted as a marker for reactions and was correlated with TNF and CCL4 in this group. Even in patients without reactions there was a strong correlation between IL-8 and IL-6, which led us to think that the concomitant increase in these two markers in MB patients may signal impending reactions. Conclusions: All together, we suggest CXCL-9, CXCL-10, IL-8 and CCL4 as markers for leprosy reaction development, in addition to the interactions with inflammatory cytokines incriminated in MB, such as IL-6 and TNF.