OPN gene polymorphism and the serum OPN levels confer the susceptibility and prognosis of ischemic stroke in Chinese patients.

AIM To investigate the association of Osteopontin (OPN) gene polymorphism and serum thrombin-cleaved OPN level with the susceptibility to ischemic stroke (IS) and its prognosis. METHODS A total of 377 patients with IS and 551 healthy individuals were recruited. The OPN gene polymorphisms at -156 G>GG, -443 C>T and -66 T>G were genotyped. Serum full-length and the thrombin-cleaved OPN were determined. RESULTS We found that only the -443 C>T polymorphism was significantly associated with the susceptibility to IS. The -443 CC represented a near 2 time higher risk for IS incidence than TT carriers. Also, the -443 CC genotype had significantly poorer outcome and they significantly had higher occurrence for bad recovery as determined by modified Rankin Scale (mRS) (OR=2.18, p=0.043) and Barthel Index (BI) (OR=2.12, p=0.05). The mean serum thrombin-cleaved OPN level in IS group were significantly higher than that in control group. ROC analysis showed that the thrombin-cleaved OPN level (cut-off value, 166.8 ng/ml) can discriminate IS patients from controls with a specificity of 86.3% and a sensitivity of 57.7%. The serum thrombin-cleaved OPN was significantly associated with the clinical outcome at 12 months after discharge from hospital. CONCLUSION These results suggest that the -443 C>T polymorphism of OPN gene and serum thrombin-cleaved OPN can be used as a biomarker for the susceptibility and prognosis of IS patients.