Assessing the Immune Status of Children with Retinoblastoma During Organ-Preserving Treatment and Enucleation

Retinoblastoma is a malignant tumour of the optic part of the retina of neuroectodermal origin, occurring in young children.
Objective. To study changes in the subpopulation composition of peripheral blood lymphocytes in children with advanced retinoblastoma after enucleation and organ-preserving treatment.
Material and methods. From 20 December 2023 to 1 September 2025, 45 children (90 eyes) with newly diagnosed retinoblastoma, aged between 1.5 and 84 months (mean age 28.9 months), were examined at the Department of Ophthalmic Oncology and Radiology of the Helmholtz National Medical Research Center (mean age 28.9 months). The study included children with advanced retinoblastoma (aged 2–5 years) in group D – 5 patients, and group E – 12 patients. The material for immunological examination was whole blood from patients. The subpopulation composition of lymphocytes was assessed using a BD FACS Canto II flow cytometer (BectonDickinson, USA) with Multitest 6-Color TBNK Reagent monoclonal antibodies in BD Tru Count tubes (BectonDickinson, USA).
Results. Prior to treatment, an increase in the total number of lymphocytes and a significant increase in the total number of T cells were observed in the blood of children in groups D and E compared to the control group (p<0.05). In both groups, significant shifts in the absolute and relative content of natural killer cells relative to the norm were found: the indicators significantly exceeded and differed from those of healthy children (p<0.05). In other indicators of the immune status of children with advanced retinoblastoma of groups D and E, statistically insignificant differences were revealed. When assessing the absolute and relative number of NK cells (CD16+CD56+) in the blood of patients in group E after treatment, these indicators normalized relative to the control group, which is probably due to the removal of the tumor mass and a decrease in the impact on the immune system. In the blood of patients undergoing organ-preserving treatment (group D), a similar trend in the studied indicators was observed: a significant decrease in the absolute number of NK cells after chemotherapy. In both groups, some changes in the qualitative and quantitative composition of adaptive immune cells were noted after treatment: a slight decrease in B-lymphocytes, the total number of T-cells, and T-cytotoxic lymphocytes. In group D, there was a statistically significant decrease in the relative content of T-helpers and, as a result, a decrease in the CD4+/CD8+ ratio. Conclusion. Both types of treatment have a pronounced effect on NK cells, significantly reducing their absolute and relative count in peripheral blood. Assessment of the dynamics of the main parameters of immune status did not reveal a pronounced adverse effect of chemotherapy on the cellular composition of the adaptive immune system. Further study of the characteristics of the subpopulation composition of lymphocytes in large clinical samples is required. Keywords: retinoblastoma, immune status, lymphocytes, subpopulations, flow cytometry, organ-preserving treatment, radical treatment
Conflict of interest. The authors declare that the research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest.
Funding. The work was performed without sponsorship.