HLA-E and immunobiology of pregnancy.

Recently, it has been suggested that non-classical antigens such as human leukocyte antigen (HLA)-G and HLA-E may interact with KIR receptors of NK cells which results into downregulation of immune response and helps in the maintenance of pregnancy. In the present study, we have investigated HLA-E polymorphism in normal fertile women and recurrent spontaneous aborters to assess the effect of HLA-E alleles on the success of pregnancy. Allele E*0101 was found to be significantly higher in patients with recurrent spontaneous abortion (chi(2) = 4.097 and P = 0.0430). Differential expression, peptide affinity, and stability of E*0101 may be one of the reasons.