PROFILE OF CYTOKINE MESSENGER-RNA EXPRESSION IN PERIIMPLANTATION HUMAN ENDOMETRIUM

The human embryo and subsequent fetus is a semi-allograft and immunolo gically foreign to the mother. Successful embryonic implantation and m aintenance of normal pregnancy depends on intricate interactions betwe en the invading embryo, maternal endometrium and maternal-immune respo nse. Cytokines are pivotal in determining the type of maternal T-helpe r immune response, which can be divided into T-helper 1 (TH1)-mediated delayed hypersensitivity and T-helper 2 (TH2)-mediated humoral immuni ty. We examined the pattern of TH1 [interleukin (IL)-2, IL-12 and inte rferon-gamma] and TH2 (IL-4 and IL-6) cytokine expression in the peri- implantation endometrium of 10 fertile, multiparous women. Endometrial samples were timed to the mid-cycle luteinizing hormone (LH) surge, w ith collection on days LH+7 to LH+9. Analysis for cytokine mRNA was by mRNA extraction and reverse transcription-polymerase chain reaction. The results show a lack of TH1 and predominant TH2 cytokine expression . We postulate that endometrial cytokines may contribute to the local modulation of maternal adaptive immune response in peri-implantation e ndometrium, to facilitate successful embryonic implantation and mainte nance of pregnancy.