To observe the changes of helper T (Th) cells in peripheral blood of patients with senile vascular dementia, and to explore its clinical significance.

Ninety six patients with vascular dementia treated in the Geriatrics Department of Xuzhou First People’s Hospital from February 2019 to January 2020 were selected as the disease group, and 92 elderly healthy volunteers were selected as the health group at the same time. The ratios of Th1, Th2 and Th17 were detected by flow cytometry, and the level of cytokines (IL-2, TNF-α, IL-17, IL-4, IL-10) were detected by enzyme-linked immunosorbent assay. The ratios of Th1, Th2, Th17 and level of cytokines in peripheral blood of disease group and healthy group were compared. The ratios of Th1, Th2, Th17 and level of cytokines in peripheral blood and the scores of activity of daily living (ADL) of patients with different degrees of cognitive dysfunction before and after treatment were compared. Patients in the disease group were given conventional treatment. The patients were followed up for 6 months, and the relationships between the ratios of Th1, Th2 and Th17 in peripheral blood and poor prognosis were analyzed.

The ratios of Th1, Th17 and level of cytokines in peripheral blood of the disease group was higher than that of the healthy group (P<0.05), of which the patients with severe cognitive dysfunction were higher than those with mild cognitive dysfunction (P<0.05). The ratios of Th2 and level of cytokines in peripheral blood of the disease group were lower than those of the healthy group (P<0.05), of which the patients with severe cognitive dysfunction was lower than those with mild cognitive dysfunction (P<0.05). Before and after treatment, the ADL scores of patients with severe cognitive impairment were lower than those of patients with mild cognitive impairment (P<0.05), and the ADL scores of patients after treatment were higher than those before treatment (P<0.05). In the disease group, the ratios of Th1, Th17 and level of cytokines (IL-2, TNF-α, IL-17) in peripheral blood were negatively correlated with ADL scores (P<0.05), and the ratio of Th2 and level of cytokines (IL-4, IL-10) in peripheral blood were positively correlated with ADL scores (P<0.05). The incidence of poor prognosis in the disease group was 29.17%, and the risk factors of poor prognosis in the disease group were age, severe cognitive dysfunction, smoking, alcohol abuse, ratios of Th1 and Th17 in peripheral blood (P<0.05), while the protective factors were Th2 ratio in peripheral blood and treatment compliance (P<0.05).

The ratio of Th1 and Th17 and level of cytokines in peripheral blood of elderly patients with vascular dementia are high, while the ratio of Th2 and level of cytokines are low, which are related to the degree of cognitive dysfunction and prognosis.