Lipoprotein(a) and the significance of the association between platelet glycoprotein IIIa polymorphisms and the risk of premature myocardial infarction

Platelet glycoprotein IIb/IIIa may be involved in the pathogenesis of myocardial infarction as the key element in platelet aggregation and as the binding site of lipoprotein(a) to platelets, inhibiting plasminogen binding and activation. Recently, a strong association between the Pl(A2) polymorphism of the glycoprotein IIIa gene and acute coronary thrombosis has been reported, although this has not been confirmed. In an associated study, we determined plasma lipoprotein levels, the apo E genotype and the PIA genotype in 250 males under 55 years with myocardial infarction and they were compared with 250 age- and sex-matched controls. Patients showed an over-representation of the epsilon 3/4 genotype with respect to the control group. We found that there were no differences in the allelic frequency of Pl(A2) between case patients and age-matched controls (chi(2) = 0.05, P = 0.92) and that subjects bearing the Pl(A2) allele showed higher plasma lipoprotein(a) concentration than Pl(A1)/Pl(A1) individuals. Therefore, in this population there is no association between carriage of Pl(A2) allele and increased risk of myocardial infarction but the carriage of Pl(A2) is associated with higher plasma Lp(a) concentration, (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.