Relationship between the reactivity to hepatitis B virus vaccination and the frequency of MHC class I, II and III alleles in haemodialysis patients.

To study the immunoreactivity genes in a heterogeneous human population needs a large number of individuals. Associations between HLA antigens and immunoresponse to viral or bacterial antigens have been studied with controversial results. As a homogeneous population, the MHC class I, II and III allele distribution was studied in 153 end-stage renal disease patients (ESRD, average duration of renal replacement: 8.2 + 5.1 years) immunized with a recombinant hepatitis B vaccine in accordance to the standard vaccination schedule. Thirty-four patients with an antibody titre of less than 10 U/l following the last booster injection were considered as non-responders while 119 patients with antibody titre equal to or more than 10 U/l were considered as responders. The responder group was divided into two subgroups: low responders (antibody titre: < or = 1000 U/l) and high responders (antibody titre: > 1000 U/1). Marked differences were observed between responders and non-responders in the occurrence of carriers of different MHC class I, II and III alleles. Homozygotes for HLA-A1, HLA-B8, HLA-DR3 and HLA-DQ2 were found almost exclusively in the non-responder group and significantly more heterozygotes for these alleles were found in the non-responder group compared to the responders. Similar albeit less marked differences were found in the frequency of some MHC class III alleles (C4A6, C4AQO, BfF, BfS0.7). Within the responder group, carriers of HLA-A2, HLA-B7 and HLA-DR4 were found to be clustered in the low responder sub-group whereas carriers of HLA-A1, HLA-B27, HLA-Cw2, C4A6 and BfF were observed more frequently in the group of high responders. Similar differences were found with extended haplotypes as well. For example, the extended haplotypes HLA-A1, B8, BfS, C4AQO, C4B1, DR3, DQ2 and HLA-A1, B8, BfF, C4A6, C4B2, DR3, DQ2 were present in nine of 34 cases of non-responders but only in one of 119 case of responders (P < 0.000001). These observations indicate that the presence or absence of certain MHC alleles even in heterozygous form determine the responsiveness to hepatitis B vaccination in end-stage renal disease patients, and among responders, the intensity of antibody response is also markedly influence by immunogenetic factors.