The contribution of HLA class I antigens in immune status following two doses of rubella vaccination.

The variability of humoral and cellular immune responses modulated by human leukocyte antigen (HLA) genes is a significant factor in the protective effect of rubella vaccines. We performed HLA class I typing in a group of 346 healthy schoolchildren and young adults who previously received two doses of measles-mumps-rubella-II vaccine. Rubella virus-specific humoral (serum antibody) immunity and cell-mediated immunity (lymphocyte proliferation) were assessed. Median values for antibody levels and stimulation indices (SI) were 38.63 IU/ml and 2.29 IU/ml, respectively. The alleles that provided suggestive, but not conclusive, evidence of HLA association with rubella seropositivity were HLA-B*2705 (median, 24.68 IU/ml; p = 0.160), B*4501 (median, 61.22 IU/ml; p = 0.098), Cw*0303 (median, 30.34 IU/ml; p = 0.102) and Cw*0704 (median, 26.58 IU/ml; p = 0.144). These alleles approach, but do not achieve, statistical significance. Of all the alleles analyzed, HLA-B*3503 (median SI, 3.00; p = 0.031) and HLA-Cw*1502 (median SI, 3.19; p = 0.035) were positively associated with lymphoproliferative responses to rubella virus antigens, whereas the HLA-B*3901 (SI, 1.34; p = 0.066) allele was negatively associated. This suggests that class I HLA alleles may have limited associations with humoral and cellular immune responses to rubella vaccine. These data may facilitate our understanding of immune response variation in a genetically outbred heterogeneous population.