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

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