The relationship between serum taurine and disease activity indices in rheumatoid arthritis patients

Background The anti-inflammatory properties of taurine have been described in the literature. This study aims to investigate the relationship between serum taurine levels, inflammatory markers, and composite disease activity indices in patients with rheumatoid arthritis (RA). Methods A prospective single-center case‒control study was conducted between August 2024 and April 2025 at Elazığ Fethi Sekin City Hospital. Patients diagnosed with RA on the basis of the 2010 ACR/EULAR criteria and varying disease activity levels (according to the DAS28-ESR, DAS28-CRP, CDAI, and SDAI) were enrolled. The control group consisted of individuals without inflammatory rheumatic diseases confirmed by clinical, laboratory, and/or imaging evaluation. Serum taurine levels were measured from blood samples obtained after clinical assessment and analyzed alongside inflammatory markers and disease activity scores. Results Fifty-seven RA patients and 23 noninflammatory controls were included. Compared with controls, RA patients had significantly greater ESR, CRP, phGlobal, and HAQ-DI scores (all p < 0.01). However, the serum taurine levels did not differ significantly between the groups (94.55 pg/ml vs. 76.89 pg/ml, p = 0.361). In all the participants, taurine levels were negatively correlated with the DAS28-ESR (r = -0.271, p = 0.041). Among RA patients, taurine was negatively correlated with phGlobal (r = -0.268, p = 0.044) and the DAS28-ESR. A negative correlation with DAS28-CRP was observed but did not reach statistical significance (r = -0.253, p = 0.058). Conclusion Low serum taurine levels may be associated with increased RA disease activity, particularly as assessed by the DAS28-ESR. These findings suggest a potential role for taurine in RA pathophysiology and highlight the need for larger-scale studies to explore its therapeutic implications. Clinical trial number: Not applicaple.