Possible Role of Leukemia Inhibitory Factor and Inflammatory Cytokines in The Recurrent Spontaneous Abortion: A Case-Control Study

BACKGROUND: Despite of long-lasting efforts, in more than 50% of cases, the etiology of recurrent spontaneous abortion (RSA) remains unknown. Leukemia inhibitory factor (LIF) has an essential role in the reproductive process, such as modulating inflammatory responses. This study aimed to evaluate the relationship between the LIF gene expression as well as serum levels of inflammatory cytokines and occurrence of RSA in infertile women with a history of RSA. MATERIALS AND METHODS: In this case-control study, the relative gene expression levels of LIF, concentrations of tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-17 were measured in peripheral blood and serum of women with a history of RSA (N=40) compared with non-pregnant and fertile women as the control group (N=40) using quantitative real-time polymerase chain reaction and the enzyme-linked immunosorbent assay, respectively. RESULTS: The mean age of patients and controls was 30.1 ± 4.28 and 30.03 ± 4.23, respectively. Patients had a history of at least 2 and at most 6 abortions. The mRNA levels of LIF were significantly lower in the women with RSA in comparison with the healthy participant (P=0.003). Regarding cytokine levels, no significant difference was seen between the two groups (P≥0.05). There was no correlation - between the LIF mRNA levels and TNF-α and IL-17 serum concentrations. The U-Mann-Whitney test and the Pearson correlation coefficient were applied to comparison variables between groups as well as a correlation between LIF mRNA and cytokine levels in serum. CONCLUSION: Despite a significant reduction in the LIF gene mRNA level in patients with RSA, it was not associated with increases in inflammatory cytokines. Dysfunction in the production of LIF protein may be involved in the onset of RSA disorder.