RESUMO
Different studies have demonstrated that a small proportion of healthy individuals receiving the hepatitis B [HB] vaccine do not produce protective levels of anti-HB antibody, a phenomenon which could be linked to certain human leukocyte antigen [HLA] class-II alleles or haplotypes. The present study was undertaken to determine the frequency of HLA class-II alleles in Iranian healthy adult responders and non-responders to HB vaccine. Twelve non-responders [anti-HBs antibody < 10 IU/L] and 46 responders [anti-HBs antibody > 100 IU/L] were tissue typed for HLA class-II. HLA-DRB1, DQB1 and DQA1 alleles were determined using polymerase chain reaction based on sequence specific primers [PCR-SSP] technique. Accessibility to excess amount of genomic DNA was possible using Epstein-Barr virus [EBV]-transformed B-cells established from all vaccinees. Our results demonstrated increased frequencies of HLA- DRB1*07, DRB1*03, DRB1*04, DQB1*0201, DQA1*0201 alleles and HLA- DRB1*07/DQB1*0201/DQA1*0201 and DRB1*04/DQB1*0302/DQA1*03011 haplotypes in the non-responder group. Comparison between responders and non-responders revealed only a significant difference for DQB1*0201 allele [p < 0.05]. These findings confirm the association of certain HLA alleles and haplotypes with the lack of antibody response to HB vaccine in an Iranian population