Background: Tumor-associated macrophages (TAM) are pivotal in remodeling of the tumor immune microenvironment and clinical outcome. Herein, we aim to evaluate the impact of immunohistochemical (IHC) expression of CD68 and CD163 in TAM on clinico-pathological features, patients' response to therapy and the overall survival (OS).
Results: This retrospective study was performed on paraffin-embedded tissue blocks of 100 classic Hodgkin Lymphoma (cHL) cases diagnosed and treated at our Institution. Immunohistochemical scores of CD68 and CD163 were statistically related to bulky disease (p value = 0.005 for both), tumor stage (p value = 0.02 for both), International Prognostic Score (IPS) (p value = 0.04 and 0.02 respectively), and the overall response rate (ORR) (p value = 0.001). Additionally, CD163 was also statistically related to gender (p value = 0.02), serum albumin level (p value = 0.03), and B symptoms (p value = 0.04). HCV seropositivity did not relate to either CD68 or CD163 score. Using univariate analysis revealed that B symptoms, bulky disease, IPS ≥ 3, and CD163 > 25% were associated with lower OS (p values = 0.003, 0.006, 0.001, and < 0.001 respectively), while after multivariate cox regression analysis, B symptoms, IPS ≥ 3, and CD163 > 25% were related to inferior OS (p values 0.02, 0.02, and 0.003).
Conclusion: CD163 expressing TAM is a powerful predictor for OS in cHL, unlike CD68.
Keywords: CD163; CD68; Classic Hodgkin lymphoma (cHL); Disease free survival (DFS); Overall survival (OS); Tumor-associated macrophage (TAM).