[Val247Leu polymorphism of beta2 glycoprotein 1 gene may justify the genesis of anti beta2GP1 antibodies and antiphospholipid syndrome in multibacillary leprosy].

UNLABELLED: BACKGROUND - Multibacillary (MB) leprosy may be manifested with antiphospholipid antibodies (aPL), among which anti-beta2GP1 (beta2-glycoprotein 1). High titers of aPL are associated with APS (Antiphospholipid Syndrome), characterized by thrombosis. The mutation Val247Leu in the domain V of beta2GP1 exposes hidden epitopes with consequent development of anti-beta2GP1 antibodies.

OBJECTIVE: To evaluate the Val247Leu polymorphism of beta2GP1 gene and its correlation with anti-beta2GP1 antibodies in leprosy patients.

METHODS: The Val247Leu polymorphism was performed by PCR-RFLP and anti-beta2GP1 antibodies were measured by ELISA.

RESULTS: The genotypic Val/Val was more prevalent in the leprosy group, compared to controls. Regarding the 7 MB patients with APS, four presented heterozygosis and three, Val/Val homozygosis. Although higher titrations of anti-beta2GP1 IgM antibodies were seen in MB leprosy group with Val/Leu and Val/Val genotypes, there was no statistical difference when compared to Leu/Leu genotype.

CONCLUSION: The prevalence of Val/Val homozygosis in leprosy group can partially justify the presence of anti-beta2GP1 IgM antibodies in MB leprosy. The description of heterozygosis and Val/Val homozygosis in 7 patients with MB leprosy and thrombosis corroborates the implication of anomalous phenotype expression of beta2GP1 and development of anti-beta2GP1 antibodies, with consequent thrombosis and APS.