Context: Central serous chorioretinopathy (CSCR) is a poorly understood disease and the choroidal circulation abnormality induced by the plasminogen activator inhibitor type 1 (PAI-1) seems to be associated with the pathogenesis. There are many reports indicating that 4 G/5 G polymorphism of the PAI-1 gene is a risk factor for several diseases related to the elevated serum levels of PAI-1.
Objective: To evaluate the 4 G/5 G polymorphism of the PAI-1 gene and its association with serum levels of PAI-1 in acute CSCR patients.
Materials and methods: Sixty CSCR patients and 50 healthy control patients were included. The PAI-1 4 G/5 G was genotyped using the polymerase chain reaction-restriction technique. Serum PAI-1 level was measured using enzyme-linked immunosorbent assay. Demographic data consisting of age, sex, body mass index (BMI) as well as genotype disturbances and serum PAI-1 levels were compared between the groups. Statistical significance for differences in the serum PAI-1 levels of each group with different genotypes was also analyzed.
Results: The CSCR group consisted of 40 male (66.7%) and 20 female (33.3%) patients with a mean age of 46.7 ± 8.39 years. The control group consisted of 32 male (64%) and 18 female (36%) healthy subjects with a mean age of 45.8 ± 8.39 years. There was no statistically significant difference between the groups in terms of age, sex and BMI. In the CSCR group the genotype frequencies were 4 G/4G: 30% (n = 18), 4G/5 G: 50% (n = 30), 5 G/5G: 20% (n = 12) and in the control group genotype frequencies were 34% (n = 17), 42% (n = 21) and 24% (n = 12), respectively. There was no statistically significant difference in the distribution of genotypes among the groups (chi-squared, p = 0.70). The CSCR group had a significantly higher serum PAI-1 concentration than the control group (p = 0.001). In both groups the mean plasma PAI-1 concentration did not vary significantly among the different genotypes (p > 0.05).
Discussion and conclusion: Although our results demonstrated that the patients with acute CSCR have higher serum PAI-1 concentrations than the controls, no significant difference was found in the genotype disturbances of the PAI-1 gene between the groups. The current study indicates that 4 G/5 G polymorphism in the promoter of the PAI-1 gene cannot be considered a risk factor for the elevated serum PAI-1 levels and consequent development of CSCR.
Keywords: 4G/5G polymorphism of PAI-1 gene; central serous chorioretinopathy; serum PAI-1 level.