OBJECTIVETo investigate the relationship of interleukin-10 gene (IL-10) polymorphism and the serum IL-10 level with restenosis after percutaneous coronary intervention (PCI) in Tianjin Chinese Han population and study the effect of IL-10 gene polymorphism on serum IL-10 level.

METHODSFour hundred and thirty-seven patients who successfully underwent PCI with a follow-up angiography were divided into a restenosis group (n = 166) and non-restenosis group (n = 271). The IL-10 gene promoter polymorphism at position -592 was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Meanwhile their serum IL-10 level before and 24 h after PCI was determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS(1) There was no significant difference in frequencies of -592 genotypes and alleles between the two groups (P > 0.05); (2) The 24 h post-PCI IL-10 serum level of restenosis group was significantly lower than that of the non-restenosis group [(82.67 ± 35.02) ng/L vs. (95.08 ± 32.26) ng/L, P < 0.05]; (3) The serum level of the A allele carriers (AA+AC) was significantly lower than that of the CC carriers [(86.13 ± 34.77) ng/L vs. (102.50 ± 27.52) ng/L, P < 0.05]; (4) In the restenosis group, the 24 h post-PCI serum level of IL-10 in the A allele carriers was also significantly lower than that in those without the A allele [(78.51 ± 34.09) ng/L vs. (102.19 ± 33.66) ng/L, P < 0.05]; (5) Logistic regression analysis revealed positive correlations between acute coronary syndrome patients, pre-PCI degree of stenosis, length of target stenosis lesion and restenosis (OR = 5.90, 1.86, 2.83 respectively); and there were negative correlations between 24 h post-PCI serum level of IL-10, the stent diameter, the diameter of reference vessel before stent implantation and restenosis(OR = 0.99, 0.70, 0.46 respectively).

CONCLUSION(1) The IL-10 gene -592 C/A polymorphism was not associated with restenosis in the Tianjin Chinese Han population; (2) IL-10 is an early post-PCI inflammatory cytokine, 24 h post-PCI serum IL-10 level was an independent predictive factor for restenosis, the IL-10 A allele carriers may have increased incidence of in-stent restenosis (ISR) by reducing the serum IL-10 levels.