Midkine can not be accepted as a new biomarker for unexplained female infertility

Abstract Objectives This study aimed to investigate whether a growth factor and a cytokine midkine (MK) can be a new biomarker for the diagnosis and treatment of unexplained female infertility (UFI) cases. Methods Serum (S), follicle fluid (FF), and cumulus cells (CCs) of the patients aged 20–42 years, diagnosed with male factor (MF) and UFI were used. Patients underwent Intracytoplasmic Sperm Injection (ICSI). The Anti-Müllerian Hormone (AMH) and MK levels with other hormone levels (FSH, LH, E2, PRL, INHB, TSH), the oocyte and embryo qualities, the fertilization and pregnancy rates, and cumulus cells (Cell number and ultrastructure, apoptosis rate) were evaluated. Student-T-test was performed and p<0.05 was considered statistically significant. Results and Discussion The lowest numbers of CCs were found at UFI (p<0.05). The lowest apoptosis rate with the highest CC viability rate was evaluated at MF (p<0.05). The lowest AMH and MK levels (S, FF) were detected at UFI in comparison to MF (p<0.05). MK and AMH levels of non-pregnant subjects were much lower than pregnant subjects (p<0.05). In addition, these levels were lower in the subjects above 35 age (p<0.05). Structural analysis of CCs showed that the number of lytic cells with cell remnants and apoptotic bodies was higher in non-pregnant subjects. It seems that MK did not show any resistance to both AMH and apoptosis. Conclusions MK can not be accepted as a new biomarker for the diagnosis and treatment monitoring of UFI cases.