Clinical Significance of Peripheral Blood Th1 and Th17 Cell Content and Serum IL-35 and IL-17 Expression in Patients with Ankylosing Spondylitis

Abstract

Objective. To evaluate the clinical significance of peripheral blood T helper cell 1 (Th1) and T helper cell 17 (Th17) cell content and serum (interleukin) IL-35 and IL-17 expression in patients with ankylosing spondylitis (AS). Methods. In this retrospective study, we included and assigned 60 cases of AS patients enrolled in our hospital from January 2019 to January 2020 to an active group (ankylosing spondylitis disease activity score (ASDAS) ≥2.1, n = 28) and a static group (ASDAS<2.1, n = 32) according to the degree of disease activity. The logistic propensity score matching method was used to include 60 healthy individuals after a physical examination during the same period in the control group. The peripheral blood Th1 and Th17 cell content and the levels of serum IL-35 and IL-17 were determined and analyzed. Results. Statistically significant differences were found in the Th1 cell ratio and Th17 cell ratio between the control group and the other two groups ( $P<0.05$ ), and the static group yielded a higher Th1 cell ratio and a lower Th17 cell ratio than the active group ( $P<0.05$ ). Statistically significant differences were also observed in the serum IL-35 and IL-17 levels between the control group and the other two groups ( $P<0.05$ ), and the static group had a higher IL-35 level and a lower IL-17 level than the active group ( $P<0.05$ ). Conclusion. The imbalance of Th17/Th1 cell content of AS patients is characterized by high expression of IL-17 and low expression of IL-35. The increased activity of AS was associated with a dominant state of Th17 cells and a significant increase in IL-17 expression, indicating that Treg/Th17 imbalance is closely related to the development of AS, which may provide new ideas for the prevention and treatment of AS.