Relationship between TLR4 and CCL2 expression and recurrent spontaneous abortion

The increasing incidence of recurrent spontaneous abortion (RSA) severely affects women's health. The involvement of the immune system during pregnancy and its contribution to RSA draw researchers' attention. Both Toll-like receptor 4 (TLR4) and chemokine (C-C motif) ligand 2 (CCL2) have been linked to various pregnancy disorders. In this study, we quantified TLR4 and CCL2 levels in a case-control study in order to elucidate the correlation between these factors and RSA, and the potential to use them as disease markers. A total of 36 RSA patients and 36 healthy control individuals were recruited for the donation of decidual and chorionic tissues and venous blood samples. Fluorescent quantitative-polymerase chain reaction was used to measure mRNA levels and enzyme linked immunosorbent assay was used to quantify serum levels of TLR4 and CCL2. RSA patients had higher TLR4 and CCL2 mRNA levels compared to controls (P < 0.05). Serum levels of the two factors were also significantly higher in RSA patients than in the control group (P < 0.05). Positive correlations were found between serum levels and tissue mRNA levels of TLR4 and CCL2. In conclusion, both TLR4 and CCL2 were closely related to the occurrence of RSA, suggesting that serum TLR4 and CCL2 levels could be used as indices for monitoring RSA in pregnant women.