BACKGROUND: Leprosy is an infectious-contagious disease caused by Mycobacterium leprae that remain endemic in 105 countries. This neglected disease has a wide range of clinical and histopathological manifestations that are related to the host inflammatory and immune responses. More recently, the inflammasome has assumed a relevant role in the inflammatory response against microbiological agents. However, the involvement of inflammasome in leprosy remains poorly understood.
OBJECTIVES: The aim is to associate biomarkers of inflammasome with the different immunopathological forms of leprosy.
METHODS: We performed an observational, cross-sectional, and comparative study of the immunophenotypic expression of inflammasome-associated proteins in immunopathological forms of leprosy of 99 skin lesion samples by immunohistochemistry. The intensity and percentage of NLRP3, Caspase-1, Caspases-4/5, interleukin-1β and interleukin-18 immunoreactivities in the inflammatory infiltrate of skin biopsies were evaluated.
FINDINGS: Strong expression of NLRP3 and inflammatory Caspases-4/5 were observed in lepromatous leprosy (lepromatous pole). In addition, were observed low expression of caspase-1, interleukin-1β, and interleukin-18 in tuberculoid and lepromatous leprosy. The interpolar or borderline form showed immunophenotype predominantly similar to the lepromatous pole.
MAIN CONCLUSIONS: Our results demonstrate that the NLRP3 inflammasome is inactive in leprosy, suggesting immune evasion of M. leprae.
}, year = {2020}, journal = {Memorias do Instituto Oswaldo Cruz}, volume = {115}, pages = {e190324}, month = {01/2020}, issn = {1678-8060}, url = {http://www.scielo.br/pdf/mioc/v115/1678-8060-mioc-115-e190324.pdf}, doi = {10.1590/0074-02760190324}, language = {eng}, }