Immune deficiencies are common in Hodgkin lymphoma (HL) patients during and after treatment, and splenic irradiation is one of the potential causes. This study investigates long-term radiation-induced functional hyposplenism and immune dysfunction in pediatric patients with HL.

This cross-sectional study included 20 patients with HL who underwent splenic irradiation, 20 patients with splenectomy, and 20 healthy controls. Demographic and clinical data were collected, and venous blood samples were analyzed for immune dysfunction, including flow cytometry, and B-lymphocyte subsets.

HL group had lower non-class switched memory B cells compared to healthy controls (p = 0.0001). No significant differences were found in the class-switched memory B cells, naïve B cells and MZBs (p = 0.07, p = 0.061 and p = 0.618, respectively). MZBs were significantly lower in the splenectomy group than in the HL group (p = 0.034), while no significant differences between the two groups were observed in other B-cell subsets. Non-class switched memory B cells and MZBs were numerically lowest in the splenectomy group, followed by the HL group, and highest in the healthy control group. In the splenectomy group, both the non-class switched memory B cells and the MZBs were lower compared to healthy controls (p = 0.001 and p = 0.0001, respectively). No statistically significant dose-response relationship was observed between the radiation dose and the MZBs (p = 0.325).

As a novel contribution, our findings highlight the presence of underrecognized functional hyposplenism in pediatric HL patients treated with splenic irradiation and provide a basis for future prospective studies evaluating immune recovery in childhood cancer survivors.