Suppression of IL-2 and IFN-γ production in women with spontaneous preterm labor

Aims: To determine the TH-1/TH-2 cytokine pattern in peripheral blood leukocytes (PBL) in late second- and third trimester in normal pregnancies, in comparison to patients with spontaneous preterm delivery (PTD; <37 completed weeks' gestation). Methods: A cross-sectional retrospective study was performed in a tertiary care obstetric unit with healthy non-pregnant women (n=7); healthy pregnant women (n=25); patients (n=25) with preterm labor (defined as uterine contractions or changes in cervical length). The phenotypic analysis of TH-1/TH-2 immune deviation was examined in PBL. Results: 26% PTD (n = 13) were recorded. Patients delivering at term (n=37, 74%) were characterized by an upregulation of IL-2, IFN-γ and IL-4 production during weeks 20-25, followed by a strong suppression in cytokine production, except for TGF-β. Towards the end of pregnancy cytokine levels returned to normal as observed in non-pregnant women. In contrast, PTD showed an inverse pattern for IL-2 and IFN-y with marked suppression in IL-2 and IFN-y production between weeks 20-25, followed by a strong stimulation of these cytokines. No differences were observed in IL-4 and TGF-β production. Conclusion: An inverse pattern in IL-2 and IFN-γ production in PBLs between weeks 20-30 is seen in PTD as compared to patients delivering at term.