[Relations between IL-2-330 polymorphisms and the outcome of hepatitis B and/or hepatitis C virus infection]

To study the relationship between polymorphisms in interleukin-2 gene at position -330 (IL-2-330) and the clinical outcome of hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infection.

277 subjects were recruited including 79 chronic HCV co-HBV infection, 55 chronic HCV infection, 69 chronic HBV infection and 74 controls. Single nucleotide polymorphisms of IL-2-330 was investigated by restricted fragment long polymorphism-PCR (RFLP-PCR). Hepatocellular injury, as revealed by alanine aminotransferase (ALT) was detected by Beckman LX-20 analyzer. The presence of hepatitis C viral particles in serum was determined by RT-nPCR.

(1) IL-2-330 polymorphisms showed close association with persistent HBV and/or HCV infection. IL-2-330 TT was associated with an increased risk, but IL-2-330 GG with a reduced risk of persistent HBV and/or HCV infection (χ(2) = 14.24, P = 0.03) with ORs (95%CI) as 7.14 (2.13 - 23.81), 3.46 (1.17 - 10.02) and 2.93 (1.15 - 7.46) respectively. However, IL-2-330 TT/GG did not significantly differ between patients with HBV and/or HCV infection (χ(2) = 2.09, P = 0.72). IL-2-330 T allele was associated with an increased risk, but the -330G allele was associated with a reduced risk of chronic HBV/HCV infection (χ(2) = 12.33, P = 0.01), with ORs (95%CI) as 2.26 (1.39 - 3.69), 1.82(1.09 - 3.03) and 1.73 (1.10-2.73) respectively. (2) IL-2-330 polymorphisms showed significant association with the outcome of HBV and HCV infection (χ(2) = 13.52, P = 0.04). IL-2-330 TT was associated with an increased risk, but -330 GG with a reduced risk of mild CH, moderate/severe CH, and cirrhosis. The ORs (95%CI) appeared to be 3.33 (1.75 - 6.32), 3.31 (1.75 - 6.26), 11.23 (3.09 - 40.76) respectively. IL-2-330 T allele was associated with an increased risk, but the -330 G allele was associated with a reduced risk of mild CH, moderate/severe CH and cirrhosis (χ(2) = 12.32, P = 0.01), with ORs as 1.86 (1.32 - 2.63), 1.71 (1.27 - 2.31) and 2.77 (1.57 - 4.89) respectively. (3) The polymorphisms of IL-2-330 showed no association with HCV RNA replication (χ(2) = 0.83, P = 0.66; χ(2) = 0.20, P = 0.66). The polymorphisms of IL-2-330 were not significantly associated with abnormal ALT (χ(2) = 1.10, P = 0.58; χ(2) = 0.08, P = 0.78).

These results suggested that IL-2-330 TT/T was associated with an increased risk, but IL-2-330 GG/G was associated with reduced risk of persistent HBV and/or HCV infection, and with the development of mild CH, moderated/severe CH, and cirrhosis.