[Relation between histo-compatibility antigen immunogenetics and pregnancy induced hypertension]

Fourty cases with pregnancy induced hypertension (PIH) and 100 normal pregnant women were selected for this study. The distribution of histo-compatibility antigen D region (HLA-DR) frequency, the frequency of homozygosity and the HLA-DR antigens sharing between partners were investigated. The results showed that the frequency of HLA-DR4 was significantly higher in PIH than that in normal pregnancy (P < 0.001). There was a very high DR antigen sharing between partners in PIH as compared to normal pregnancy (P < 0.01), specially obvious in the frequency of DR4 antigen sharing in PIH (P < 0.0001). There was, however, no significant difference in the frequency of homozygosity or heterozygosity between HLA-DR and DR4 locus. This study suggested that HLA-DR4 may be related to the genetic susceptibility of PIH. This correlation is presumably due to a linkage imbalance of susceptible gene of PIH and DR4, but whether DR4 acts directly as an immunodeficient gene remains to be determined.