Circulating Th17/Treg as a promising biomarker for patients with rheumatoid arthritis in indicating comorbidity with atherosclerotic cardiovascular disease.

Background: Immune and inflammatory responses have a pivotal role in the pathogenesis of rheumatoid arthritis (RA) and atherosclerotic cardiovascular disease (ASCVD). This study aims to explore the change of peripheral lymphocytes, especially the absolute and relative changes in peripheral T cells in RA patients with and without ASCVD.

Hypothesis: The changes in the lymphocyte subsets were assessed to provide a novel insight in diagnosing and preventing ASCVD in patients with RA.

Methods: A propensity score matching system (1:1) was conducted to perform a matched case-control study with 169 pairs RA-ASCVD and RA participants. Univariate and multivariate analyses were performed to determine the association between peripheral lymphocytes and RA-ASCVD.

Result: Multivariate logistic regression analysis demonstrated that Th17 cell absolute, Th17 cell Ratio, Th17/Treg were associated with a significantly higher risk of ASCVD after model adjustment. Then we focused on Th17/Treg, multivariate logistic analyses in tri-sectional Th17/Treg groups showed that the odds of ASCVD is gradually increasing with Th17/Treg rank's rising after model adjustment. Finally, the restricted cubic spline of Th17/Treg and odds ratio of RA-ASCVD was conducted. Interestingly, we found a critical point of Th17/Treg (critical point = 0.2399). Th17/Treg shows a protective role in the odds of ASCVD when Th17/Treg < 0.2399. With smaller Th17/Treg, the protective efficiency is more obvious when Th17/Treg < 0.2399.

Conclusions: Our study suggested that increasing absolute and percentage of Th17 cells in the peripheral blood of patients with RA was associated with the development of ASCVD. And Th17/Treg may be a promising biomarker for patients with RA in indicating comorbidity with ASCVD.