Type-1 and type-2 cytokines in human decidual tissue and trophoblasts from normal and abnormal pregnancies detected by reverse transcriptase polymerase chain reaction (RT-PCR).

Abstract

Cytokine expression at the maternal fetal interface has been well documented in rodents, but data in the human are scanty and controversial. We examined cytokine expression of human decidua and trophoblasts by semiquantitative visual grading of reverse transcriptase polymerase chain reaction (RT-PCR) products in five groups of patients: ten patients with uncomplicated term pregnancies undergoing elective cesarean section (Group 1); ten women having normal pregnancies at term and vaginal delivery (Group 2); ten patients having intrauterine growth-retarded infants of unknown cause after a spontaneous vaginal delivery at term (Group 3); ten childless women having their first, first-trimester spontaneous abortion (Group 4); and ten childless women with a history of one or more previous first-trimester spontaneous abortions and having a new miscarriage (Group 5). Results favoring the T-helper 1 (Th1)/T-helper 2 (Th2) model during pregnancy were: significantly higher expression of interferon gamma (IFN-gamma) in trophoblast samples from Group 3 versus 2 and in decidual tissue from Group 5 versus 4; stronger positivity of interleukin (IL)-10 in decidual tissue samples from Group 1 versus Groups 2 and 5; and higher expression levels of tumor necrosis factor-beta (TNF)-beta by the trophoblast in Group 5 versus 1. Against the Th1/Th2 paradigm were the following findings: the significantly increased expression of IFN-gamma by decidual or trophoblast samples in Groups 1 versus 2, 2 versus 3, and 1 versus 5; and the significantly higher expression of TNF-alpha in decidual samples from patients in Group 1 (but also Group 4) as compared with Group 5. IL-2 mRNA and IL-4 mRNA could not be detected. Overall, our findings suggest that there is a balance between type-1 and type-2 cytokines during pregnancy, which is mainly characterized by the expression of IFN-gamma (a type-1 cytokine) and IL-10 (a type-2 cytokine) at the maternal fetal interface.