Comparison of maternal serum NRG-4 levels in healthy and preeclamptic pregnancies

Objective: The new adipokine, neuregulin-4 (NRG-4), acts as a signaling protein and plays a role in lipogenesis, inflammatory events and atherosclerosis. The aim was to investigate maternal levels of NRG-4 in preeclampsia (PE) disease. Material and Methods: Pregnant women with PE, divided into severe and mild PE, and gestational age-matched healthy pregnant women, as a control group, were recruited. NRG-4 levels were measured using an ELISA. NRG-4 levels in the groups and the relation between NRG-4 and clinical and laboratory parameters were analyzed. Results: There were 41 women in the PE group, 11 (26.8%) in the severe and 30 (73.2%) in the mild subgroups and 41 controls. There were no significant differences between the groups in terms of maternal age, gravidity, parity, abortion, gestational week at the time of blood sampling, levels of hemoglobin, platelet count, alanine and aspartate transaminases (p=0.067, p=0.819, p=0.957, p=0.503, p=0.054, p=0.217, p=0.306, and p=0.270 respectively). The PE group had higher body mass index, nitrogen urea and creatinine values, and diastolic and systolic blood pressure (p=0.005, p<0.001, p<0.001, p<0.001, and p<0.001 respectively). In addition, earlier gestational week at delivery, lower birth weight and Apgar scores at 1 and 5 minutes and the occurrence of non-reassuring fetal heart rate tracing were found in the PE group (p=0.010, p=0.004, p=0.005, p=0.005, and p=0.026 respectively). There were no significant differences between the groups in terms of NRG-4 (p=0.611). No correlation was identified between clinical parameters examined and NRG-4 levels (p=0.722). Conclusion: No association was found between NRG-4 concentrations and PE patients, regardless of severity of PE, compared to healthy pregnancies. Future longitudinal studies are needed to confirm this lack of association in PE.