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

PROBLEM: Cytokine expression at the maternal-fetal interface has been well documented in rodents, but data in the human are scanty and controversial. METHOD OF STUDY: We examined cytokine expression of human decidua and troph oblasts by semiquantitative visual grading of reverse transcriptase polymer ase chain reaction (RT-PCR) products in five groups of patients: ten patien ts with uncomplicated term pregnancies undergoing elective cesarian section (Group 1), ten women having normal pregnancies at term and vaginal deliver y (Group 2); ten patients having intrauterine growth-retarded infants of un known cause after a spontaneous vaginal delivery at term (Group 3)1 ten chi ldless women having their first, first-trimester spontaneous abortion (Grou p 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: Results favoring the T-helper 1 (Th1)/T-helper 2 (Th2) model durin g 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 decidu al tissue samples from Group 1 versus Groups 2 and 5: and higher expression levels of tumor necrosis factor-P (TNF)-beta by the trophoblast in Group 5 versus 1. Against the Th1/Th2 paradigm were the following findings: the si gnificantly increased expression of IFN-gamma by decidual or trophoblast sa mples in Groups 1 versus 2, 2 versus 3, and 1 versus 5; and the significant ly higher expression of TNF-alpha in decidual samples from patients in Grou p 1 (but also Group 4) as compared with Group 5. IL-2 mRNA and IL-4 mRNA co uld not be detected. CONCLUSIONS: 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-IO (a type-2 cyt okine) at the maternal-fetal interface.