Exhausted and Senescent CD4⁺ T Cells in Peripheral Blood and Their Impact as a Biological Marker for the Diagnosis of Benign and Malignant Ovarian Tumors

Introduction: Serum biomarkers such as CA-125 and HE4, along with the ROMA score, (which integrates both markers) are widely used to distinguish between benign and malignant ovarian tumors. In ovarian cancer, chronic exposure to tumor-associated antigens (TAAs), such as CA-125 and HE4, can lead to T cell exhaustion and senescence, thereby facilitating immune evasion. This study aimed to evaluate exhausted and senescent T cells in the peripheral blood of patients with benign or malignant ovarian tumors, and compare these findings to those of healthy donors, and assess their correlation with the ROMA score. Methods: The expression of senescent and exhaustion markers was evaluated on peripheral CD4⁺ T cells from patients with benign and malignant ovarian tumors, as well as healthy donors. Multicolor flow cytometry was performed to evaluate the expression of CTLA-4, PD-1, Tim3, CD28, CD57, and CD27. Results: PD1⁺Tim3⁺CD4⁺ expression was significantly higher in the malignant group compared to both the benign group (p = 0.05) and healthy donors (p = 0.015). A positive and significant correlation was observed between ROMA and PD-1⁺Tim3⁺ T cells (r = 0.44, p = 0.0006). The confusion matrix demonstrated good classification accuracy, and in the ROC analysis, the combination of ROMA and PD-1⁺Tim3⁺ yielded the highest Youden Index (0.75) and superior specificity (88.8%) compared to ROMA alone, albeit with a slight reduction in sensitivity (86.9% vs. 91.3%). A nomogram integrating ROMA and PD-1⁺Tim3⁺ exhibited strong predictive performance, with a concordance index (C-index) of 0.91. Conclusion: The combination of the ROMA score with the expression of PD-1⁺ and Tim-3⁺ in CD4⁺ T cells creates a simple yet highly effective model to differentiate between benign and malignant ovarian tumors.