Objective: To investigate the serum level of C-C chemokine ligand 19 (CCL19) and its clinical significance in rheumatoid arthritis.
Methods: The serum CCL19 levels in both rheumatoid arthritis (RA) patients and health controls were detected by ELISA. The proportion of peripheral blood B cells and memory B cell subsets were also detected in some patients. Then the clinical and laboratory data of the patients were collected. The CCL19 levels in patients with different clinical features were analyzed. And the correlation between the clinical data, laboratory parameters, B cell subsets proportion and serum CCL19 levels were also analyzed. Independent samples t test, paired t test, Pearson and Spearman correlation were used for statistical analysis.
Results: The levels of CCL19 was higher in the RA patients than the health controls (P<0.05). The serum CCL19 levels were decreased in the RA patients who accepted disease-modifying anti-rheumatic drugs (DMARDs) treatment for 6 months (P<0.001). Serum CCL19 levels were correlated with the titers of both rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibody (r=0.42, P=0.002; r=0.33, P=0.013), but not with erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and disease activity score in 28 joints (DAS28) (P>0.05). The levels of CCL19 were higher in the serum positive (RF and anti-CCP antibody) patients, but there were no differences between low and high disease activity RA, as well as early and non-early RA. There was no correlation between the serum CCL19 levels and the proportion of B cells as well as memory B subsets. All the proportion of peripheral blood CD27+ memory B cell subsets in RA was lower than the healthy controls, including CD27+IgD+, CD27+IgD- and CD27+ B cells.
Conclusion: The increased serum CCL19 levels in RA patients are associated with the activity of B cells, so CCL19 might predict whether the RA type is a B cell mediated RA, and specify the treatment directions for the rheumatologist.