Immunocytochemical localization of neutrophil elastase in term placenta decidua and myometrium in pregnancy-induced hypertension.

Objective— The aim of the study was to determine whether there was evidence of elastase containing neutrophils at the materno-fetal interface in women with pregnancy-induced hypertension (PIH). Design— An observational prospective study. Setting— The Simpson Memorial Maternal Pavilion Edinburgh. Methods— Placentas were obtained at vaginal or abdominal delivery from 51 consecutive women, 23 had normal pregnancies (13 caesarean sections) and 28 had PIH (18 caesarean sections). An immunocytochemical technique was used to localize elastase containing neutrophils in the placenta, decidua and myometrium. Main outcome measures— The numbers of positively stained cells, estimated subjectively as minimal, moderate or heavy, in subchorionic plate, perivillous fibrin and decidua. Results— In both normal and PIH pregnancies neutrophils were absent from the myometrium. However, elastase containing neutrophils were located in areas of fibrin in the subchorionic plate and around the villi although there was no significant difference between the normal and PIH group. Neutrophils were also located in the fibrin of the decidua and in this case the number was significantly greater in the PIH group than in the normal group and correlated with plasma urate. Conclusion— The release of neutrophil elastase in the decidua could contribute to the vascular damage evident in PIH.