Aberrant expression of leukemia inhibitory factor receptor (LIFR) and leukemia inhibitory factor (LIF) is associated with tubal pregnancy occurrence.

Tubal pregnancy is a major cause of maternal death in the first trimester and exploration of its underlying molecular mechanism is of great importance. This study aimed to explore the association of tubal pregnancy with leukemia inhibitory factor (LIF) and leukemia inhibitory factor receptor (LIFR) expression in oviduct tissues. Materials and methods: Immunohistochemistry was performed to probe the differential expression of LIF and LIFR in oviduct tissues among a control group (including NP group, n = 11; and IP group, n = 12), tubal pregnancy group (Ect-N group, n = 31; and Ect-A group, n = 40), and chronically inflamed group (including Inf-S group, n = 11; and Inf-P group, n = 9), followed by semiquantitative analysis. Results: Semiquantitative immunohistochemical analysis demonstrated that there was no significant difference in LIF expression in either the epithelial or stromal cells of oviduct tissues between the tubal pregnancy group and the control group (P < 0.05). However, LIF expression was remarkably elevated in the Inf-S and Inf-P group compared to the other groups (P < 0.05). In the epithelial cells of the fallopian tubes, LIFR expression was highest in the chronically inflamed group, followed by the tubal pregnancy group, outnumbering the control group (P < 0.05). More interestingly, an opposite expression trend of LIFR was observed in the stromal cells of the fallopian tubes among these groups (P < 0.05). Conclusion: Aberrant expression of LIF and LIFR might be associated with the occurrence of tubal pregnancy.