Relation between changes of T lymphocyte subsets and post-stroke infection in patients with stroke

Objective To study the changes of T lymphocyte subsets in the peripheral blood of patients with stroke to explore the risk factors of post-stroke infection. Methods A total of 37 patients with stroke and 20 age-matched controls were included in the study and blood was obtained from the controls and patients immediately at the admission and 1, 7 and 14 d after the admission. Fluorescein isothiocyanate was used to label the leukocyte subsets (CD3, CD4, CD8); the changes of CD3+, CD4+,CD8+ and CD4+/CD8+ were detected by flow cytometry. Patients met the infection standards were divided into infection group (n=12) and non-infection group (n=12); and logistic regression analysis was performed to determine the risk factors of post-stroke infection, accordingly. Results Stroke induced a dramatic and immediate loss of T-lymphocytes, mostly pronounced with the percentages of CD3+, CD4+and CD8+ T cells (P＜0.05). The percentages of CD3+, CD4+ and CD8+ T cells of infected patients were gradually increased on 1, 7 and 14 d after the admission; compared with those of controls, their percentages were still significantly lower throughout the observation period (P＜0.05). No significant differences on the percentage of CD4+ T cells were noted between the non-infected patients and the controls since the 1st admission day (P＞0.05). Logistic multivariate analysis indicated that the percentages of CD4+ and CD8+ T cells on admission, CD3+ and CD4+ T cells on the 1st d of admission, CD3+, CD4+and CD8+ T cells on the 7th d of admission, CD3+ T cells on the 14th d of admission were closely related to the post-stroke infection. Conclusion Stroke induces significant changes of T lymphocyte subsets in the peripheral blood and immunosuppression in humans; the alteration of T lymphocyte subsets may influence the development of post- stroke infection. Key words: Stroke; Infection; T lymphocyte; Risk factor