Interactive Effects of Immunoglobulin Gamma and Human Leucocyte Antigen Genotypes on Response to Interferon Based Therapy of Hepatitis C Virus

AIM: We examined the role that immunoglobulin GM 23 and KM allotypes—genetic markers of γ and κ chains, respectively—play in response to treatment of hepatitis C virus (HCV) infection in Egyptian patients. MATERIAL AND METHODS: A total of 120 persons who had responded to HCV treatment and 125 with persistent HCV infection were genotyped for the presence of GM23 and KM determinants. HLA –C genotyping was also done. RESULTS: Association of GM 23+ and KM3 was significantly associated with non response to treatment (P < 0.0001). Individuals who lacked this GM genotype (but were positive for KM1,2 and 3) were likely to respond to treatment (P=0.045). Association of heterozygous GM23 (+/-) with KM 1,2 and 3 or KM3 alone was significantly associated with SVR (P = 0.001) and (P = 0.0001) respectively. Particular combinations of HLA and GM genotypes were associated significantly with the response to HCV treatment. The combination of HLAC2C2 and GM23+ was associated with persistence of infection (P = 0.027) while the association of HLAC2C2 and heterozygous GM23+/- was associated with SVR (P = 0.001). The association of HLAC1C1 and heterozygous GM23+/- was significantly associated with SVR (P = 0.001) and also subjects with HLA C1/C2 and heterozygous GM23+/- were likely to respond to treatment (P = 0.003) while subjects with HLA C1/C2 and GM23+ show tendency to resist to treatment (P = 0.0001). CONCLUSION: Our results didn’t support a role for KM allotypes, GM23 allotype plays a role in the persistence of HCV infection in the presence or absence of KM1,3. Interaction between certain GM and HLA-C genotypes may favor adequate response to interferon based therapies.