Interferon gamma expression during human pregnancy and in association withlabour

In this study, the expression of the type 1 cytokine, interferon gamma (IFN gamma) during human gestation and in association with labour was assessed. Immunoreactive (ir) IFN gamma concentrations (ng/ml) were quantified in ma ternal plasma (n = 136) and amniotic fluid (n = 68). In addition, irIFN gam ma content (pg/mg protein) was determined in term gestational tissues (plac enta, amnion and choriodecidua, n = 39), In peripheral plasma, irIFN gamma was detected in 34% of all samples assayed, Where detected, the concentrati on averaged 0.19 +/- 0.03 ng IFN gamma/ml plasma (mean +/- SEM). During pre gnancy, irIFN gamma concentrations in maternal plasma declined significantl y (p < 0.05). irIFN gamma was identified in all gestational tissues examine d and content increased significantly with labour status (p < 0.01). irIFN gamma was not detectable in amniotic fluid (as say sensitivity = 0.02 ng/ml ) at any stage of pregnancy. The data obtained are consistent with the hypo thesis that, during pregnancy, cell-mediated immunity is suppressed, At ter m and in association with labour and delivery, lower plasma IFN gamma conce ntrations and high tissue content may indicate a contributing role for IFN gamma in parturition.