• Abortion;
  • cytokines;
  • immunology of pregnancy;
  • intrauterine growth retardation;
  • Th1/Th2 balance

Vives A, Balasch J, Yagüe J, Quintó L, Ordi J, Vanrell JA. 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). AJRI 1999; 42:361–368 © Munksgaard, Copenhagen

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 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: Results favoring the T-helper 1 (Th1)/T-helper 2 (Th2) model during pregnancy were: significantly higher expression of interferon gamma (IFN-γ) 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-β (TNF)-β by the trophoblast in Group 5 versus 1. Against the Th1/Th2 paradigm were the following findings: the significantly increased expression of IFN-γ by decidual or trophoblast samples in Groups 1 versus 2, 2 versus 3, and 1 versus 5; and the significantly higher expression of TNF-α 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.

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-γ (a type-1 cytokine) and IL-10 (a type-2 cytokine) at the maternal–fetal interface.