Background Rheumatoid arthritis (RA) is a chronic inflammatory and autoimmune disease regulated by T lymphocyte subsets. Th17 lymphocytes reportedly play significant roles in the development of this disease.
Objectives We investigated the correlation of circulating Th17 cells with the clinical and biological activity parameters in patients with RA.
Methods This is a prospective study including patients with RA (1987 ACR criteria). Disease activity was evaluated by global pain intensity visual analog scale (VASP), visual analog scale for patient’s overall assessment of disease activity (VASOA), duration of morning stiffness, tender joint counts (TJCs), swollen joint counts (SJCs), erythrocyte sedimentation rate (ESR), C-Reactive Protein (CRP) and Disease Activity Score (DAS28). Peripheral blood Th17 cell frequency (LTh CD4+ IL-17+ IFNγ-) was determined with flow cytometry. Clinical examination and blood samples were performed on the same day. The significance level for Pearson correlation was set at p <0.05.
Results Thirty-eight patients were included, 35 women and 3 men, with a mean age of 52.4 ± 10.3 years and a mean disease duration of 124 ± 98 months (7-456 months). The mean VASP arose to 57 mm [0-100], the mean VASOA to 58 mm [0-100] and the mean duration of morning stiffness to 37.76 minutes [0-240]. The mean TJCs and SJCs were 7 and 6, respectively. A biological inflammatory syndrome was noted in 33 patients with a mean ESR of 46 ± VS 25 mm [15-110] and a mean CRP of 16.8 ± 15 mg / l [5-59]. The mean DAS28 was 5.2. Distribution according to the activity level of the disease showed a high activity for 20 patients according to the DAS28. There was no significant correlation between the percentage of peripheral LTh17 and the various parameters of clinical and biological activity studied.
Conclusions Even though Th17 cells involvement in the pathogenesis of RA is now well established, our study shows that the peripheral percentage of Th17 cells is not correlated with the disease activity. Their frequency in rheumatoid synovial fluid might show a better activity index.
References Gullick NJ, Evans HG, Church LD, Jayaraj DM, Filer A, et al. (2010) Linking Power Doppler Ultrasound to the Presence of Th17 Cells in the Rheumatoid Arthritis Joint. PLoS ONE 5(9): e12516. doi:10.1371/journal.pone.0012516
Disclosure of Interest None Declared