Balance of CD4⁺IFNγ+ and CD4⁺CD25^hiT cells as early predictor of a 3-month outcome in ischemic stroke patients

Abstract

Early prediction for ischemic stroke (IS) outcome is a major challenge since it may help to optimize treatment program and to make it more personalized. Since T cells with regulatory activity are involved in different pathophysiological processes in brain stroke, including inflammation, immune suppression, brain damage and repair, the study of T cells as potential biomarkers has essential importance. The present work aimed to study the circulating T cell subsets with phenotype of type 1 T helper cells (Th1) and regulatory T cells (Treg), and their ratio during the acute phase of IS, depending on stroke severity, inflammatory response and 3-month outcome (according to modified Rankin scale, mRs). Patients and methods. The study included 61 patients with a newly diagnosed IS (severity according to NIHSS ≥ 5), in the first 24-48 h after stroke onset, and 20 age/sex-related healthy donors. Laboratory examination included assessment of leukocytosis, neutrophillymphocyte ratio (NLR) and CRP concentration. Mononuclear cells were isolated from peripheral blood to study T cell subsets. Th1 and Tregs were measured by FACS analysis as CD4+IFNγ+ and CD4+CD25hiT cells, respectively. During the first 24-48 h after stroke, the patients had elevated values of leukocyte counts, NLR and CRP. Higher levels of these parameters in severe stroke compared with mild stroke, as well as direct correlation of NIHSS with NLR and CRP evidenced that the stroke severity was associated with more pronounced inflammatory response. Patients were also characterized by a significant decrease in CD4+IFNγ+Th1 cells, an increase in CD4+CD25hiTreg, and a marked decrease in Th1/Treg ratio. Furthermore, in patients with NIHSS ≥ 8 (moderate and severe stroke), the percentage of CD4+IFNγ+T cells was in direct correlation, and the number of CD4+CD25hiT cells was inversely related to CRP and NLR values. The changes of T cell subsets were more pronounced in patients with a favorable 3-month outcome (mRs > 3). As a result, the patients with poor outcome (mRs ≤ 3) had higher CD4+IFNγ+T cell proportion, lower CD4+CD25hiT cell percentage and 4-fold higher CD4+IFNγ+/CD4+CD25hi ratio compared with opposing group. ROC analysis revealed a “good” quality of prognosis based on evaluation of the CD4+IFNγ+/CD4+CD25hi ratio as a monopredictor of adverse outcome (AUC = 0.75) and “very good” quality of prognosis when the indicated ratio was combined with NIHSS scale (AUC = 0.82). The data obtained suggest that a decrease of Th1/Тreg ratio, due to a decrease in CD4+IFNγ+ and increased CD4+CD25hiT cell counts during the acute phase of ischemic stroke is a compensatory reaction directed at inhibition of inflammatory response, and has a prognostic significance as early predictor of the outcome at 3 months.

Keywords

• cd4+ifnγ+
• cd4+cd25hi
• ischemic stroke
• outcomes