Objective: To determine the prevalence of polymorphisms in the plasminogen activator inhibitor-1 (PAI-1) promoter 4G/5G polymorphisms in Chinese Han population and to investigate whether they are associated with pulmonary thromboembolism (PTE).
Methods: Samples of peripheral venous blood were collected from 101 patients with PTE diagnosed by high probability of lung ventilation/perfusion scan and/or multi-slice CT pulmonary angiography (CTPA) as well as medical history and clinical manifestations, 67 males and 34 females, aged 48 +/- 15, and 101 age and sex-matched healthy controls from the same geographic area as controls. The genome DNA was extracted from the whole blood using potassium iodide-phenol-chloroform method. Polymerase chain reaction (PCR), denaturing high performance liquid chromatography (DHPLC), and sequence analysis were used to screen the single nucleotide polymorphisms and the genotype distribution of -675 4G/5G located in the promoter region of the PAI-1 gene.
Results: The frequencies of the allele 4G of PAI-1 gene in the controls were 0.495, significantly lower than in the PTE patients (0.733, chi(2) = 24.060, P < 0.01). The frequencies of the allele 5G of PAI-1 gene in the controls were 0.505, significantly higher than that in the PET patients. The genotype frequency of 4G4G of the PET patients was 57.4%, significantly higher than that of the controls (30.7%, P = 0.000). The genotype frequencies of 4G5G and 5G5G of the PET patients were 31.7% and 10.9% respectively, not significantly different from those of the controls (37.6 and 31.7% respectively). The presence of 4G allele of PAI-1 gene was found to be a greater risk factor for PTE. In comparison with the controls, the OR of 4G4G + 4G5G, 4G4G, and 4G5G in the PET patients were 3.794 (1.786 - 8.060), 5.443 (2.416 - 12.260), and 2.450 (1.067 - 5.623) respectively with the P values of 0.001, 0.000, and 0.035 respectively.
Conclusion: The 4G/5G and 4G/4G genotypes are associated with the pathogenesis of PET.T.