# Expression of Serum Adenosine Deaminase in Pediatric Non-Hodgkin Lymphoma and Its Association with Clinical Outcomes and Survival

## TL;DR

High levels of a blood enzyme called adenosine deaminase (ADA) in children with non-Hodgkin lymphoma are linked to more aggressive cancer and worse treatment outcomes.

## Contribution

This study is the first to show that elevated serum ADA levels are a potential biomarker for poor prognosis in pediatric non-Hodgkin lymphoma.

## Key findings

- Children with precursor cell lymphomas had significantly higher ADA levels compared to those with mature cell lymphomas.
- Elevated ADA levels were strongly associated with poor prognosis and were an independent predictor of worse outcomes.
- ADA levels could help identify high-risk patients for more aggressive treatment strategies.

## Abstract

Childhood non-Hodgkin lymphoma is a serious cancer where some children respond well to treatment while others do not. Doctors need simple blood tests to identify high-risk patients early. Our research focused on a blood enzyme called adenosine deaminase (ADA). We measured ADA levels in 215 children with lymphoma at the time of their diagnosis. We found that children with more aggressive types of lymphoma, especially those whose cancer cells were less mature, had much higher ADA levels in their blood. Importantly, children with high ADA levels were significantly more likely to have a poor response to standard chemotherapy. Our study suggests that a routine blood test for ADA could help doctors better predict which children have high-risk disease. This may allow for earlier treatment adjustments and closer monitoring, potentially improving care for these patients. Further studies are needed to confirm these findings.

Background: Pediatric non-Hodgkin lymphoma (NHL) is a heterogeneous malignancy with variable outcomes. Adenosine deaminase (ADA), a key enzyme in purine metabolism, has been implicated in tumor progression and immune evasion, yet its role in pediatric NHL remains underexplored. Methods: This retrospective study included 215 pediatric NHL patients categorized into precursor cell lymphoma (n = 88) and mature cell lymphoma (n = 127) groups based on pathology. Patients were further defined into good (n = 143) and poor prognosis (n = 72) groups according to international response criteria. Serum ADA and other laboratory parameters were measured at diagnosis. Results: Precursor cell lymphomas showed higher rates of bone marrow involvement, peripheral blood involvement, and clinical stage IV disease compared to mature cell lymphomas. ADA levels were significantly elevated in precursor cell lymphomas and in the poor prognosis group. Elevated ADA was strongly correlated with a poor prognosis. Multivariable analysis identified precursor cell lymphoma, fever, bone marrow involvement, elevated LDH, and elevated ADA as independent predictors of poor prognosis (all p < 0.05). Conclusions: Serum ADA is significantly elevated in pediatric NHL, particularly in precursor cell subtypes and poor prognosis cases, and serves as a potential prognostic marker. ADA may help improve risk stratification and guide personalized treatment strategies.