Ninjurin 1 asp110ala single nucleotide polymorphism is associated with protection in leprosy nerve damage

Leprosy is the major cause of non-traumatic neuropathy. Herein, we investigated the role of ninjurin 1, an adhesion molecule involved in nerve regeneration in leprosy. Our results demonstrated that M. leprae stimulates in vitro up-regulation of ninjurin mRNA in cultured Schwann and blood cells as well as in vivo mRNA and protein expression in leprosy nerve biopsies. A polymorphism (asp110ala) was investigated in a case–control study (1123 individuals) and no association was found with leprosy per se or with disseminated forms. Nevertheless, ala110 was associated with functional nerve impairment (OR = 2.42; p = 0.02 for ala/ala) and with lower mRNA levels. Our data suggests that asp110ala could be a valuable genetic marker of nerve damage in leprosy.