Peripheral Blood CD8+ CD28+ T Cells as an Independent Predictor of Treatment Response and Survival After Concurrent Chemoradiotherapy in Pediatric High-Grade Glioma Patients.

Abstract

Backgroud: The tumor immune microenvironment influences the efficiency of concurrent chemoradiotherapy (CCRT) in high-grade glioma (HGG). This study investigated peripheral blood T lymphocyte subsets as clinical indicators of therapeutic response and prognosis in pediatric high-grade glioma (pHGG).

Methods: This retrospective study included 77 patients with postoperative pHGG who were treated concurrently with temozolomide and external beam radiotherapy between January 1, 2012, and December 31, 2018. The median follow-up was 26 (range: 5-106) months. Peripheral venous blood samples were collected before and after CCRT. The proportions of peripheral blood T lymphocytes and their association with treatment outcome and survival were determined.

Results: Sixty-four (83.1%) patients achieved complete remission, partial remission, and stable disease, and 13 (16.9%) patients had progressive disease. Higher CD3⁺ T cell, CD4⁺ T cell, and CD8⁺ CD28⁺ T cell ratios were predictive of better response, while a higher CD8⁺ CD28^- T cell ratio was predictive of poorer response. Binary logistic regression analysis showed that the CD8⁺ CD28⁺ T cell ratio was a significant independent predictor of CCRT response (odds ratio [OR] = 53.521, 95% confidence interval [CI] = 4.294-667.119, P = .002). Univariate and multivariate analysis of prognostic factors associated with survival showed that the CD8⁺ CD28⁺ T lymphocyte ratio was a significant independent predictor of progression-free survival (hazard ratio [HR] = 1.80, 95% CI = 1.06-3.08, P = .03), but none of the subsets were significantly associated with overall survival.

Conclusion: Peripheral blood T lymphocytes have potential as predictors of CCRT response and prognosis in pHGG.