Increased CD5+ B-cells are associated with autoimmune phenomena in lepromatous leprosy patients

Abstract

Background and objective: Leprosy is a chronic slowly progressive infection caused by Mycobacterium leprae that primarily affects the skin and peripheral nerves. Lepromatous leprosy is characterized by absence of T-cell responses to M. leprae and advanced clinical disease. It is frequently associated with the presence of autoantibodies, which might be related to CD19+CD5+ and CD19+CD5− B lymphocyte percentages. Therefore, the aim of this study was to evaluate the percentages of CD19+CD5+ and CD19+CD5− B cell subsets as well as the total B cells in lepromatous leprosy patients. Materials and methods: Twenty lepromatous leprosy patients and ten healthy subjects served as control were included in this study. Venous blood samples were analyzed by flow cytometry to determine the B cell subsets and total B cell percentages. Results: Compared to healthy controls, the percentages of CD19+CD5+ B cell subset and total B cells were found to be significantly higher in the patient group. While, the percentage of CD19+CD5− B cell subset was found to be higher in the patient group than the control without any significantly difference. Regarding the eye affection, the percentage of total B cells was observed to be significantly higher in affected patients compared to the non-affected group. Conclusion: The observed significant increases in CD19+CD5+ and total B cell percentages in patients with lepromatous leprosy suggests a possible role of these cells in the disorganized protective immune response as well as the development of eye complications in these patients. Keywords: CD5+B-cells, Autoimmunity, Lepromatous leprosy