Alterations of Cytokine Profiles in Patients With Recurrent Implantation Failure

Abstract

Serum cytokine profile and T helper (Th)1/Th2 cell balance are related to the success of embryo implantation, although not yet firmly linked to recurrent implantation failure (RIF), a repeated failure to achieve clinical pregnancy following multiple high-quality embryo transfer. In this prospective study, comprehensive bioinfomatic analysis and logistic regression analysis were used to compare the serum cytokine profiles of 41 RIF patients with those of 29 subjects with first-cycle successful pregnancy in the mid-luteal phase and to assess the alterations of cytokine profiles in patients with clinical pregnancy at five weeks post-transplantation. We found several elevated pro-inflammatory cytokines, decreased anti-inflammatory cytokines, and increased Th1/Th2 cytokine ratios in RIF patients compared to control subjects. Specifically, the receiver operating characteristic (ROC) curve generated using multiple indicators provides a high predictive value for diagnosing RIF (area under the curve [AUC] = 0.94, 95% confidence interval [CI] 0.87-1.00, P < 0.0001), with a sensitivity of 96.55% and a specificity of 87.50%. Meanwhile, at five weeks post-transplantation, patients in both groups diagnosed with clinical pregnancy exhibited increased levels of several cytokines compared with pre-pregnancy levels, and a gradual shift in Th1/Th2 balance toward Th2. These findings suggest that inflammatory serum cytokines and the predominance of Th1 cells likely contribute to RIF and possibly reflect the immune environment at the maternal-fetal interface, suggesting their value as outcome indicators in assisted reproductive therapy.

Keywords: Th1/Th2; cytokines; in vitro fertilization; logistic regression analysis; recurrent implantation failure.

Figure 1

Cytokine profile screening with heatmap and PCA. Heatmap and PCA of 10 cytokine profiles in serum. Each row in the heatmap represents an individual differentially expressed cytokine, and the column displays the sample number. Cytokines with lower levels are displayed in green, while cytokines with higher levels are displayed in red. The points in the PCA diagram represent the samples, red for the control group and blue for the RIF group. The arrows represent the contribution and correlation of the corresponding original variables to the principal component.

Figure 2

Serum cytokine profiles in the mid-luteal phase between RIF patients and control women. Every different cytokine is shown as density (violin shap), and data are shown as the median (interquartile range) for the two groups. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001; NS, not significant.

Figure 3

Relationships between serum cytokine profiles and the occurrence of RIF. (A), The relationship between the serum cytokine profiles in the mid-luteal phase and the occurrence of RIF was analyzed by univariate logistic regression analysis and visualized as a forest map. (B), After correcting for maternal age and endometrial thickness on the day of embryo transfer, the relationship between the serum cytokine profiles and the occurrence of RIF was analyzed by logistic regression analysis. OR > 1 indicates a risk factor, and OR < 1 indicates a protective factor.

Figure 4

ROC curve evaluation of the logistic regression model. The AUC of the predictive model was 0.94 (95% CI 0.87-1.00, P < 0.0001), with a sensitivity of 96.55% and a specificity of 87.50%. AUC, area under the curve; CI, confidence interval.