• Cytokines;
  • endometrium;
  • growth;
  • human;
  • LIF;
  • ultrasound

PROBLEM: LIF is believed to be involved in human reproduction. Because little is known about the function of this cytokine in proliferative phase of cycle and because LIF is found to regulate the cellular growth we evaluated the possible relationship between endometrial LIF secretion and endometrial growth.

METHOD: The present is prospective, blinded study with clinical and immunobiochemical correlation between endometrial LIF concentration and endometrial ultrasound pattern. Twenty-four patients who were candidates for IVF and oocyte donation are included in this study. At day 10 of their cycle the endometrial biopsy was performed, followed by vaginal sonographic measurements of endometrial thickness and pattern. Endometrial LIF concentration was measured by ELISA in supernatants taken from cultured explants.

RESULTS: Endometrial LIF production significantly negatively correlated with endometrial thicknesses (P < 0.05). There was a 4-fold elevation in LIF production when the endometrial thickness was below 5 mm. Strong correlation was found also between endometrial LIF production and sonographic endometrial pattern (P < 0.05). The most significant amount of LIF was found in nonfavorable endometria.

CONCLUSION: In the proliferative phase of cycle there is a dynamic relationship between endometrial sonographic appearance and local LIF secretion. Specifically LIF production is negatively correlated with endometrial thickness and pattern. The low amount of cytokine is a normal uteral environment for endometrial development, whereas deregulation of cytokine production toward its overexpression may lead to a strong inhibitory effect on endometrial growth. This finding might have an important clinical implication.