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


CONCLUSIONS
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.
Brochado
Maria José Franco
MJ
Faculdade de Medicina de Ribeirão Preto, USP, São Paulo, SP, Brasil.
Nascimento
Margarida Maria Passeri do
MM
Louzada Junior
Paulo
P
Figueiredo
José Fernando C
JF
Roselino
Ana Maria
AM
D016736:Antiphospholipid Syndrome / Q000097:blood / Q000235:genetics* / Q000276:immunology*; D001323:Autoantibodies / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D056006:Leprosy, Multibacillary / Q000097:blood / Q000235:genetics* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011110:Polymorphism, Genetic; D053482:beta 2-Glycoprotein I / Q000235:genetics* / Q000276:immunology*
D001323:Autoantibodies; D053482:beta 2-Glycoprotein I