Objective: To examine whether pregnancy induced hypertension (PIH) is correlated with a polymorphism of human leucocyte antigen (HLA)-DRB1 in the Shanghai population.
Methods: We determined the HLA-DRB1 types of 17 PIH families and 14 normotension families by DNA typing utilizing the polymerase chain reaction (PCR) and hybridization of Dig-labeled sequence specific oligonucleotide (PCR-SSO).
Results: The antigens frequency and feto-material sharing of HLA-DR4 in PIH were increased and relative to that of the controls, and furthermore the 0405 allele occurred more often in PLH patients.
Conclusion: These results suggest that a PIH susceptibility gene is associated with HLA-DRB1 0405. We therefore propose the following working hypothesis; 0405 allele is presumably due to linkage disequilibrium or the possibility that it acts directly as an immune response gene; PIH is correlated with DR4 compatibility between PIH mother and fetus which leads to failure of the mother's nonresponsiveness to fetal antigen. Lack of blocking factor increases the risk for PIH.