Association of the 4？g/5？g polymorphism of plasminogen activator inhibitor-1 gene with sudden sensorineural hearing loss. A case control study

The association of the 4？G/5？G PAI-1 polymorphism with the development and clinical outcome of SSNHL is evaluated via a case control study. 103 patients with SSNHL and 113 age and sex-matched controls were enrolled at University of Ferrara, Italy and hearing loss outcome was measured at least 3？months after the onset of hearing loss. DNA was isolated from peripheral blood using the QIAamp kit and the 4？G/5？G polymorphism in the ？675 promoter region was genotyped with an allele-specific PCR. Genotype distribution was tested in patients and compared to controls by chi-square and odd-ratio analysis. The codominant and recessive models were used for the multiple logistic regression analyses of the PAI-1 gene allele.In this population, 5？G/5？G genotype had a two-time lower frequency in SSNHL patients compared to healthy controls (15.5% vs 30.1%) and was associated with decreased odds compared to 4？G/5？G genotype (OR 0.37, 95% CI 0.19-0.75, p？=？0.005). In addition, the patients with 5？G/5？G genotype showed a trend of more than 2 times higher ratio of hearing recovery (> 20？dB) after systemic corticosteroid treatment compared to 4？G/5？G genotype (OR 2.3, 95% CI 0.32 - 16.83, p？=？0.39), suggesting a better clinical outcome.The 5？G/5？G genotype of PAI-1 may be associated with a reduced risk of SSNHL in the Italian population.