Interleukin-28B polymorphisms and interferon gamma inducible protein-10 serum levels in seronegative occult hepatitis C virus infection

摘要

Polymorphisms upstream interleukin (IL)-28B gene and serum levels of interferon gamma inducible protein-10 (IP-10) are associated with spontaneous and treatment-induced hepatitis C virus (HCV) clearance. Patients with seronegative occult HCV infection are anti-HCV and serum HCV-RNA negative but have viral RNA in liver and abnormal values of liver enzymes. We examined if the rs12979860 polymorphism of IL-28B and serum IP-10 levels differ between chronic and seronegative occult CV infection. IL-28B polymorphism was determined with allele specific TaqMan probes in total DNA isolated from peripheral blood mononuclear cells and IP-10 by an enzyme-linked immunosorbent assay in serum from 99 patients with seronegative occult HCV infection and 130 untreated patients with chronic hepatitis C. IL-28B genotypes were also determined in 54 healthy volunteers. Prevalence of the IL-28B CC genotype was significantly higher in seronegative occult HCV infection (52/99; 52.5%) than in chronic hepatitis C (32/130; 24.6%, P<0.0001) or healthy controls (19/54: 32.5%, P=0.039). Among patients with seronegative occult HCV infection, HCV-RNA load in liver was significantly lower in those with the IL-28B CC genotype than in those with CT+TT genotypes (2.8x10(5)+/- 5.8x10(4) vs. 4.1x10(5)+/- 5.9x10(4)copies/g of total RNA respectively; P=0.023). Mean serum IP-10 levels were significantly lower in patients with seronegative occult HCV infection than in patients with chronic hepatitis C (160.8 +/- 17.9 vs. 288.7 +/- 13.3pg/ml respectively; P<0.0001). These findings suggest that the host immune response plays an important role in seronegative occult HCV infection in comparison with chronic hepatitis (C) 2015 Wiley Periodicals, Inc.