Serum lipocalin-2 levels are decreased in patients with leprosy

Background Leprosy is an infectious disease caused by Mycobacterium leprae affecting the skin, peripheral nerves and mucosae. Lipocalin-2 is a key component of the immune system's antimicrobial defence - it prevents iron uptake by binding and sequestering iron-scavenging siderophores and thus inhibits bacterial growth. Aim We evaluated serum lipocalin-2 levels in leprosy patients and its relationship to the pathogenesis and prognosis of the disease. Materials and methods In this case-control study, serum lipocalin-2 levels were measured by ELISA in 20 patients with leprosy and 20 healthy controls. Results Serum levels of lipocalin-2 were significantly reduced (P < 0.001) in leprosy patients as compared to controls. The levels were significantly higher (P < 0.014) in patients with multibacillary leprosy than in those with paucibacillary leprosy. Although the levels of lipocalin-2 were higher in patients with multiple nerve involvement as compared to those with involvement of 1 or 2 nerves, the results were not statistically significant. Limitation of the study The small sample size and the lack of different ethnic groups in the study were the major limitations of this study. Conclusion The lower lipocalin-2 concentrations in leprosy patients point to the importance of the protective functions of lipocalin-2. The elevated levels of lipocalin-2 observed in leprosy patients with neural involvement may be related to the reported neurodegenerative role of lipocalin-2.