Viral clearance in hepatitis C (1b) infection: Relationship with human leukocyte antigen class II in a homogeneous population

The aim of this study was to investigate the possibility of a significant r elationship between human leukocyte antigen (HLA) class II and the clearanc e of hepatitis C virus (HCV). The study group consisted of 156 Irish women who iatrogenically received HCV 1b-contaminated Anti-D immunoglobulin betwe en May 1977 and November 1978. Thus, the study population was homogeneous i n terms of gender, source of infection, and ethnicity. On Screening in 1994 , all individuals were anti-HCV antibody positive by recombinant immunoblot assay, while 46% (n = 72) of the group were HCV-positive by reverse transc riptase-polymerase chain reaction (RT-PCR). HLA DRB1 and DQB1 status was mo lecularly defined by high resolution reverse line probe hybridization metho dology. Clearance of HCV 1b was found to be associated with DRB1*01. Howeve r, this association was lost after Bonferroni correction for multiple compa risons. Extended haplotype analysis between specific DRB1 and DQB1 allelic combinations identified a significant reduction in the frequency of DQB1*05 01 in the presence of DRB1*0701 in the persistently infected individuals in the study group (P < .05). No associations with either viral clearance or persistence were found at the DQB1 locus. Our results suggest that HLA DRB1 *01 appears to contribute to the spontaneous resolution of a primary HCV in fection in the Irish population. The presence of DRB1*0701 in the absence o f DQB1"0501 possibly reflects an influence of this allele in persistence of HCV infection. Defined and homogeneous patient populations offer the best opportunity to illuminate previously disguised immunogenetic factors import ant in the clearance of HCV 1b.