HLA class II genotypes associated with chronic hepatitis C virus infectionand response to alpha-interferon treatment in Poland

Aims/Background: Recent evidence suggests that spontaneous clearance of hep atitis C virus (HCV) may be associated with the HLA DQB1*0301 allele but th ere is still some debate over the role of other alleles and HLA haplotypes in HCV infection. As this may best be resolved by studying genetically diff erent populations, we have investigated HLA class II-encoded susceptibility and resistance to HCV infection in a relatively sedentary population of pa tients from northwestern Poland. Methods: The distributions of HLA class II DRB1, DQA1, DQB1 and DPB1 alleles were determined by standard PCR-protocol in 129 unrelated patients with chronic hepatitis C (anti-HCV and HCV-RNA p ositive) and 103 healthy unrelated racially-matched control subjects. Fifty -five patients were treated with cc-interferon (5 MIU thrice weekly for 6 m onths) out of whom 29 showed a complete response and 26 were non-responders . Results: A significantly reduced frequency of the DQBI*0301 allele in the patients was observed (24.0% vs. 38.8%; p=0.015). Additionally, two differ ent DR-DQ hapIotypes were found to be associated with chronic HCV infection : DRB1*I501-DeA1*01-DQB1*0602 (24.0% vs. 12.6%; p= 0.027) and DRB1*0701-DQA 1*0201-DQB1*02 (31.8 vs. 12.6%; p=0.0006), the latter difference being most pronounced in those patients who responded to cr-interferon treatment (41. 4% vs. 12.6%; p=0.00038). Conclusions: The results confirm the negative ass ociation between chronic HCV and DQB1*0301 and identify two novel genetic a ssociations. In particular, the DRB1*0701-DQA1*0201-DQB1*02 haplotype is as sociated with both chronic infection and response to alpha-interferon. Inte restingly, the same haplotype is reportedly associated with non-response to hepatitis B vaccination.