[Polymorphism of codon25 in signal peptide region of transforming growth factor beta 1 and its association with chronic hepatitis C virus infection].

Objective: To investigate the possible relationship between polymorphism of codon25 in signal peptide region of transforming growth factor beta 1 (TGFb1) and hepatitis C virus (HCV) infection susceptibility.

Methods: Genotypes of TGFb1 of 191 subjects (85 HCV infected patients and 106 healthy controls) were studied. Genotypes of TGFb1 codon25 were determined by amplification refractory mutation system (ARMS).

Results: Differences of codon25 polymorphism were not found between HCV infected patients and the controls (P more than 0.05), which showed a similar pattern between the chronic hepatitis C group and HCV-associated liver cirrhosis group (P more than 0.05). There were no differences of genotype distribution of codon25 between ALT normal and ALT elevated patients (P more than 0.05), but G allele frequency was higher in ALT elevated group (P=0.040). There were great differences between the distribution of genotypes (P=0.005) and allele frequency (P=0.000) of the HCV RNA positive and the negative groups in that the HCV RNA positive group differed greatly from the negative group.

Conclusion: Polymorphism of TGFb1 codon25 may influence the grade of liver inflammatory activity. High G allele frequency of codon25 may be associated with viremia in patients with chronic HCV infection. It seems that polymorphism of codon25 in the signal peptide region of TGFb1 may contribute to the outcome of HCV infected patients.