Evaluation of maternal serum progesterone-induced blocking factor levels in pregnancies complicated with early- and late-onset preeclampsia

The aim of present study was to evaluate maternal serum progesterone-induced blocking factor (PIBF) levels in pregnancies complicated with early-onset (EO-PE) and late-onset (LO-PE) preeclampsia. Patients with preeclampsia were divided in two groups according to preeclampsia onset and compared to healthy control group: EO-PE and LO-PE defined as being diagnosed before 340/7 and >= 340/7 weeks, respectively. Maternal age, nulliparity, BMI at blood sampling, smoking, history of caesarean section and ethnicity were statistically similar among the groups. Statistically significant differences were found between the eo-PE and lo-PE preeclampsia groups in terms of gestational age at delivery, mean birth-weight percentile and foetal growth restriction rates. The mean serum PIBF level was 528.6 +/- 220 ng/mL in the eo-PE and 615.3 +/- 269.1 ng/mL in the lo-PE preeclampsia and 782.3 +/- 292.4 ng/mL in the control groups; the difference among groups was statistically significant. Our results indicated that decreased PIBF levels play an important immunologic role in preeclampsia onset. IMPACT STATEMENT What is already known on this subject? Maternal lymphocytes secrete PIBF that provides the immunological effects of progesterone during pregnancy by activating T-helper type 2 (Th2) cells and inhibiting any activated uterine natural killer (uNK) cells. The recent studies results have shown that there is disproportion in the Th1/Th2 rate in women with preeclampsia. This purports that Th1-mediated immunity is promoted through Th2-mediated immunity, which can be involved in the pathogenesis of preeclampsia. What do the results of this study add? In this study we found that PIBF levels in maternal serum were significantly lower in the EO-PE group than in LO-PE and control group. Our results indicated that decreased PIBF levels play an important immunologic role in preeclampsia onset. What are the implications of these findings for clinical practice and/or further research? We can speculate that first trimester maternal serum PIBF levels may be a useful biomarker for prediction of EO-PE. Using serum PIBF levels within the first trimester combined with Doppler values for the uterine artery, and some biochemical markers to predict onset and severity of preeclampsia appear to be a new screening method.