The relationship between the TGF-β1 gene −509C/T polymorphism and tubulointerstitial damage resulting from primary nephrotic syndrome

Abstract

Background: The aim of this study was to investigate the correlation between the transforming growth factor (TGF)-β1 gene −509C/T polymorphism and the susceptibility to primary nephrotic syndrome (PNS), and in particular to the severe degree of tubulointerstitial damage (TID) seen in Chinese. Methods: Ninety-eight PNS patients and 128 normal controls were studied. The extent of tubulointerstitial changes was evaluated and patients were divided into two groups according to the severe or mild degree of TID. The TGF-β1gene −509C/T polymorphism was detected with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique, and the serum level of TGF-β1 was determined by enzyme-linked immunosorbent assay (ELISA). Results: No statistical differences in genotype or allele frequency of the TGF-β1 gene −509C/T were found between PNS and normal subjects. However, T allele and CT + T T genotype frequency were higher in the PNS with severe TID than the mild TID and controls. Additionally, the serum concentration of TGF-β1 was significantly higher in the PNS with severe TID group than the other two groups and in the T T genotype individuals than the CC and CT genotype individuals. A logistic regression analysis demonstrated that TGF-β1 gene −509C/T genotype was the risk factor of TID in PNS patients [OR (odd ratio) 2.34, confidence interval (CI) 0.98–3.46, p = 0.012]. Conclusion. TGF-β1 gene −509C/T polymorphism was associated with severe TID. The higher value in serum concentration of TGF-β1 was also associated with severe TID and the T T genotype/T allele. T allele gene might be the important risk factor for susceptibility.