HLA-G regulatory polymorphisms are associated with susceptibility to HCV infection.

Background Hepatitis C virus ( HCV) is able to bypass the immune system modulating innate and adaptive immune response and blocking T helper 1 (Th1) cell production. Because the human leukocyte antigen ( HLA)-G molecule has immunomodulatory properties inhibiting the function and production of natural killer and cytotoxic lymphocyte T cells, as well as promoting shift from Th1 toward Th2 response, we hypothesized its involvement in susceptibility to HCV infection. Materials and Methods Considering that HLA-G mRNA expression has been reported to be under genetic control, an association study was conducted analyzing 800 base pairs upstream the ATG at the 5′upstream regulator region ( URR) and 850 base pairs from ATG to exon 3 and the 3′untranslated region ( UTR) of HLA-G gene in Italian HCV-positive patients and uninfected controls. Results Four 5′ URR polymorphisms (− 725C>G>T, − 509C>G, − 400G>A and − 398G>A), 7 polymorphisms at coding region (+ 15G>A, + 36G>A, + 243G>A, insC506, 531G>C, delA615 and 685G>A), the + 644G>T polymorphism, and 1 haplotype ( TTGTTCCIGAC) showed different frequency distributions between HCV patients and uninfected controls. Conclusion The results from our study suggest a possible involvement of HLA-G in the risk modulation toward HCV infection. [ABSTRACT FROM AUTHOR]