Brochado Maria José Franco, Nascimento Margarida Maria Passeri do, Louzada Junior Paulo, Figueiredo José Fernando C, Roselino Ana Maria
Faculdade de Medicina de Ribeirão Preto, USP, São Paulo, SP, Brasil.
An Bras Dermatol. 2009 Jul-Aug;84(4):355-9. doi: 10.1590/s0365-05962009000400006.
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.
To evaluate the Val247Leu polymorphism of beta2GP1 gene and its correlation with anti-beta2GP1 antibodies in leprosy patients.
The Val247Leu polymorphism was performed by PCR-RFLP and anti-beta2GP1 antibodies were measured by ELISA.
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.
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.
背景 - 多菌型（MB）麻风可能表现为抗磷脂抗体（aPL），其中包括抗β2糖蛋白1（β2 - 糖蛋白1）。高滴度的aPL与抗磷脂综合征（APS）相关，其特征为血栓形成。β2糖蛋白1结构域V中的Val247Leu突变会暴露隐藏表位，从而导致抗β2糖蛋白1抗体的产生。
评估麻风患者中β2糖蛋白1基因的Val247Leu多态性及其与抗β2糖蛋白1抗体的相关性。
采用聚合酶链反应 - 限制性片段长度多态性（PCR - RFLP）检测Val247Leu多态性，采用酶联免疫吸附测定（ELISA）检测抗β2糖蛋白1抗体。
与对照组相比，麻风组中Val/Val基因型更为普遍。在7例患有APS的MB患者中，4例为杂合子，3例为Val/Val纯合子。虽然在具有Val/Leu和Val/Val基因型的MB麻风组中观察到抗β2糖蛋白1 IgM抗体的滴度较高，但与Leu/Leu基因型相比无统计学差异。
麻风组中Val/Val纯合子的普遍性可以部分解释MB麻风中抗β2糖蛋白1 IgM抗体的存在。7例MB麻风合并血栓形成患者中杂合子和Val/Val纯合子的描述证实了β2糖蛋白1异常表型表达及抗β2糖蛋白1抗体产生的影响，进而导致血栓形成和APS。
