Decreased humoral antibody episodes of acute renal allograft rejection in recipients expressing the HLA-DQβ1*0202 allele

The present investigation was designed to show the effect of human leukocyte antigen (HLA) class II molecular allelic specificities in the recipient on the induction of humoral antibody rejection, identified by C4d peritubular capillary staining, as well as specific antibody identified by Luminex technology. Major histocompatibility complex (MHC) class II molecules are expressed on dendritic cells, macrophages, and B lymphocytes and they present antigenic peptides to CD4 positive T lymphocytes. Human renal peritubular and glomerular capillaries express class II MHC molecules upon activation. Expression of class II molecules on renal microvascular endothelial cells exposes them to possible interaction with specific circulating antibodies. We hypothesize that HLA-DQβ1*0202 expression in recipients decreases the likelihood of antibody-mediated renal allograft rejection. We found that 80% (=25) of DQ2 positive haplotype recipients failed to induce humoral antibody renal allograft rejection and 20% (n=25) of DQ2 positive haplotype recipients induced humoral antibody renal allograft rejection (p=0.008). By contrast, 48% (n=46) of DQ2 negative haplotype recipients failed to induce a humoral antibody component of renal allograft rejection and 52% (n=46) of DQ2 negative haplotype recipients induced humoral antibody-mediated renal allograft rejection. Our results suggest that recipients who express the DQβ1*0202 allele are less likely to induce a humoral antibody component of acute renal allograft rejection than are those expressing DQ1, DQ3, or DQ4 alleles. DQβ1*0202 allele expression in recipients could possibly be protective against acute humoral allograft rejection and might serve as a future criterion in recipient selection and in appropriate therapy for acute renal rejection episodes.