FOXP3+/CD68+ ratio within the tumor microenvironment may serve as a potential prognostic factor in classical Hodgkin lymphoma

Classical Hodgkin lymphoma (CHL) is characterized by extensive inflammatory immune cells, which predict the disease prognosis. Therefore, this study aimed to explore the significance of different tumor-infiltrated immune cells and subpopulation ratios observed in the tumor microenvironment of CHL, particularly relating to the disease's prognosis-focusing on overall survival (OS) and event-free survival (EFS). Utilizing immunohistochemistry, the quantification and exploration of selected immune cells' subsets, including CD3+, CD4+, CD8+, FOXP3+, CD20+, and CD68+ were conducted on 102 histological samples with primary CHL. Eosinophils were pathologically assessed. Besides, we determined the ratios between different tumor-infiltrated immune cells for each patient. Kaplan-Meier method and Cox regression modeling were used for survival analysis. We demonstrated that among all ratios and immune cells individually, only a higher FOXP3+/CD68+ ratio (≥1.36 cutoff) displayed a tendency towards a favorable OS (p = 0.057, HR = 0.43 [0.18-1.02]) and EFS (p = 0.067, HR = 0.44 [0.18-1.06]) using Cox regression modeling. Moreover, the Kaplan-Meier method showed an association of a higher FOXP3+/CD68+ ratio with a longer 5-years OS (p = 0.037) and a tendency to a better EFS (p = 0.051); however, neither the combined FOXP3+ and CD68+ nor FOXP3+ or CD68+ separately was correlated to the CHL survival. Together, these results demonstrated that the FOXP3+/CD68+ ratio could predict the outcomes of CHL, providing more informative significance than FOXP3+ and CD68+ combined or FOXP3+ and CD68+ individually and might be a potential indicator of risk stratification, which has an important value for guiding the clinical treatment.