Valine/Leucine247 polymorphism of beta2-glycoprotein I in patients with antiphospholipid syndrome: lack of association with anti-beta2-glycoprotein I antibodies.

In antiphospholipid syndrome (APS) the presence of anti-beta2-glycoprotein I (beta2GPI) antibodies is strongly associated with thromboembolic complications. It has been suggested that the common beta2GPI Valine/Leucine247 (Val/Leu247) polymorphism could be found more commonly in APS and might influence the generation of anti-beta2GPI antibodies. Therefore we studied beta2GPI Val/Leu247 single-nucleotide polymorphism (SNP) by PCR in 338 patients with various autoimmune diseases (46 with secondary and 84 with primary APS) and 147 sex and age-matched healthy controls. In all patients lupus anticoagulant, anticardiolipin and anti-beta2GPI antibodies (both IgG and IgM) were also determined. All patients and controls were Caucasians. Frequencies of the SNP genotypes in patients did not depart from genetic equilibrum and did not differ from those found in controls. There was also no association between the presence of beta2GPI Val/Leu247genotypes and the presence or absence of lupus anticoagulant, anticardiolipin antibodies, anti-beta2GPI antibodies or clinical APS symptoms in all patients studied. In conclusion, among the exclusively Caucasian, Polish population of autoimmune patients beta2GPI Val/Leu247SNP has the same distribution as in healthy subjects and does not influence the production of anti-beta2GPI antibodies.