Concentration of lactoferrin and interleukin-6 in cervical mucus from patients being treated for infertility

Background:  The concentrations of the iron-binding protein lactoferrin (LF) and interleukin-6 (IL-6) were measured in the cervical mucus of patients being treated for infertility throughout the menstrual cycle. Methods:  A total of 251 cervical mucus samples were obtained from the patients throughout the menstrual cycle. One hundred and fifty samples were from primary infertility patients with unexplained infertility and 101 samples were from secondary infertility patients as a control. The concentrations of LF and IL-6 were measured by enzyme immunoassays. The standard curve of LF concentrations ranged from 1.6 to 50 ng/mL. Results:  The mean LF and IL-6 concentrations in the cervical mucus of primary infertility patients were higher than that of the control patients (P= 0.04, P= 0.032, respectively) The LF and IL-6 concentrations were highly correlated (P < 0.0001). Conclusion:  Elevated levels of IL-6 and LF in the cervical mucus were obtained from primary infertility patients. We speculate that LF might also be one of the causes of infertility and might play an important role in reproductive processes in the cervix. (Reprod Med Biol 2006; 5: 105-109).