The contribution of IL-10 and IL-6 as potential biomarkers for detecting central nervous system involvement in non-Hodgkin lymphomas

Introduction: A significant clinical challenge in the management of hematologic malignancies is the occurrence of central nervous system (CNS) involvement. In non-Hodgkin lymphoma (NHL), it occurs in varying percentages depending on the subtype and identifying patients is crucial but challenging. Furthermore, a definitive gold standard for diagnosing leptomeningeal involvement is still lacking. Conventional cytology (CC) of cerebrospinal fluid (CSF) has high specificity but low sensitivity. Multiparametric flow cytometry offers superior sensitivity but is limited by CSF cellularity and the need for specialized expertise, a resource not available at every institution. CSF cytokine analysis is emerging as a promising diagnostic approach, with IL-6 and IL-10 showing potential as biomarkers. Objective: This prospective study investigated the utility of dosing the aforementioned cytokine in serum and CSF samples for diagnosing CNS involvement in non-primary CNS lymphoma patients. Methods: CSF samples were analyzed using CC and IL-6/IL-10 assays. IL-6 and IL-10 levels were then compared between CC-positive (CC + ) and CC-negative (CC-) patients. Results: The study cohort included 27 patients, with a median age of 71 years. Six patients (22.2 %) were CC + . In CSF, statistically significant differences were observed for both IL-6 (p = 0.02) and IL-10 (p = 0.04) levels between CC + and CC- patients, with higher levels in CC + patients. Elevated CSF IL-6 and IL-10 levels were also associated with elevated LDH, advanced disease stage, and elevated CSF protein. Conclusions: This study suggests that CSF IL-6 and IL-10 are potential, widely available biomarkers for early detection of CNS involvement in NHL, offering a complement to traditional cytological analysis in clinical laboratories.