Ischemic stroke is the leading cause of death and disability among adults worldwide. T lymphocytes can be divided into αβT cells and γδT cells. Among them, αβT cells can be further divided into subgroups such as CD4? T cells, CD8? T cells, and natural killer (NK) cells. In CD4? T cells, T helper cells (Th) 1 and Th17 secrete pro-inflammatory cytokines, which can exacerbate ischemic brain injury; Th2 secretes anti-inflammatory factors, which can improve neurological function. Regulatory T cells (Tregs) exert neuroprotective effects through various mechanisms. CD8? T cells exacerbate ischemic brain injury by secreting cytokines and releasing granzyme, while NK cells can cause neuronal damage and blood-brain barrier damage by secreting interferon-γ. In addition, interleukin-17 secreted by γδT cells also plays a significant pro-inflammatory role in the pathological process of stroke. Therefore, a deeper understanding of the role of T lymphocytes can provide new ideas for the treatment of ischemic stroke.

Objective To analyze the predictive value of patient-reported outcomes(PRO)com-bined with hematological indicators for moderate-to-severe endoscopic activity in patients with ulcera-tive colitis(UC).Methods Clinical data of UC patients were retrospectively collected,including PRO,hematological parameters and endoscopic findings.Based on the Mayo endoscopic score,pa-tients were divided into remission and mild activity group(＜2 points)and moderate-to-severe activity group(≥ 2 points).Independent influencing factors for moderate-to-severe endoscopic activity were screened through multivariate Logistic regression analysis,and a binary Logistic regression model was constructed.The receiver operating characteristic(ROC)curve was used to evaluate the discriminato-ry ability of the predictive model.The calibration of the model was assessed using calibration curves and the Spiegelhalter Z-test,and the model's performance was further validated in an external valida-tion cohort.Results Rectal bleeding(RB),C-reactive protein/albumin(CAR)and erythrocyte sed-imentation rate(ESR)were independent influencing factors for moderate-to-severe endoscopic activity(P＜0.05).The area under the curve(AUC)of the nomogram predictive model constructed based on the logistic regression analysis results was 0.848(95％CI,0.798 to 0.900),with sensitivity of 76.6％and specificity of 79.6％.In the external validation cohort,the model's AUC was 0.778(95％CI,0.699 to 0.857),and there was no statistically significant difference compared with the AUC of the training cohort model(P＞0.05).In both the training and validation cohorts,the Spiegelhalter Z-test results indicated that the model had good goodness-of-fit(P＞0.05).Conclu-sion RB,CAR and ESR are independent influencing factors for moderate-to-severe endoscopic ac-tivity in UC patients.The combination of RB,CAR and ESR has high predictive value for moderate-to-severe endoscopic activity in UC patients,with good discriminatory and calibration abilities.