HUMAN ENDOMETRIAL LEUKEMIA INHIBITOR FACTOR (LIF) SECRETION AND ITS RELATIONSHIP TO SONOGRAPHIC ENDOMETRIAL APPEARANCE

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 growt h we evaluated the possible relationship between endometrial LIF secre tion and endometrial growth. METHOD: The present is prospective, blind ed study with clinical and immunobiochemical correlation between endom etrial LIF concentration and endometrial ultrasound pattern. Twenty-fo ur patients who were candidates for IVF and oocyte donation are includ ed 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: Endometri al LIF production significantly negatively correlated with endometrial thicknesses (P < 0.05). There was a 4-fold elevation in LIF productio n when the endometrial thickness was below 5 mm. Strong correlation wa s found also between endometrial LIF production and sonographic endome trial 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 ne gatively correlated with endometrial thickness and pattern. The low am ount of cytokine is a normal uteral environment for endometrial develo pment, whereas deregulation of cytokine production toward its overexpr ession may lead to a strong inhibitory effect on endometrial growth. T his finding might have an important clinical implication.