Changes of B lymphocyte subsets in peripheral blood of patients with rheumatoid arthritis and their significance

Abstract

Objective To investigate the changes of B lymphocyte subsets (naive B cells, memory B cells and plasmablasts) in peripheral blood of patients with rheumatoid arthritis (RA) and their correlations with the clinical manifestation and laboratory indexes. Methods Sixty-six patients with RA were divided into two groups including the group with active RA and the group with inactive RA according to the disease activity score in 28 Joints (DAS28). A control group with healthy subjects was set up accordingly. The distributions of B lymphocyte subsets in peripheral blood samples were detected with flow cytometry analysis and their correlations with clinical manifestations and laboratory indicators were analyzed. Results (1) Compared with healthy subjevts, the mean fluorescence intensities (MFIs) of CD19 and the percentages of memory B cells in peripheral blood of the patients with RA were significantly decreased, while the percentages of naive B cells were increased (P<0.05). The percentages of plasmablasts in the patients with active RA were significantly increased as compared with those of healthy subjects and the patients with inactive RA (P<0.05). (2) The percentages of plasmablasts in peripheral blood of the patients with RA were positively correlated with the joint tenderness count, joint swelling count and joint swelling index (P<0.05). (3) A positive correlation was found between the MFIs of CD19 and the erythrocyte sedimentation rates (ESRs) among the patients with RA. The percentages of plasmablasts were positively correlated with C reaction protein (CRP) and anti-cyclic citrullinated peptide (anti-CCP) antibody (P<0.05). (4) The percentages of plasmablasts were also positively correlated with the DAS28 among the patients with RA (R2=0.343, P<0.01). Conclusion The distributions of B lymphocyte subsets varied among the patients in different stages of RA, which were related to the patient′s clinical symptoms and laboratory indexes. The study suggested that different subsets of the B lymphocytes might play an important role in the pathological process of RA. Key words: Rheumatoid arthritis; B lymphocyte subsets; CD19; CD27; CD38