AB0036 THE IMPACT OF ANTI-TNF THERAPY ON CD4+T CELL SUBSETS IN DIFFERENT DIFFERENTIATION STAGES AND TREG CELLS IN ACTIVE ANKYLOSING SPONDYLITIS

Abstract

Background: Ankylosing Spondyloarthritis (AS) is a progressive, chronic, inflammatory skeletal disorder affecting the spine and sacroiliac joints. To date, the disease etiology remains unclear. Some studies have shown that T lymphocytes play important roles in the inflammatory process of AS, but imbalances in the numbers and functions of CD4+T cells and regulatory cells (Treg) in different differentiation stages are rarely mentioned. Tumornecmsis factor (TNF)-α blocker has been very effective in the treatment of ankylosing spondylitis, but its specific mechanism in the immune function of ankylosing spondylitis in active stage has not been fully revealed. Objectives: To investigate the role of Treg and CD4+T cells of different differentiation stages on the pathogenesis of active AS, and to study the machanism of TNF-α blocker on the treatment of active AS by detecting the number of Treg cells and CD4+T cells before and after the treatment. Methods: Ankylosing Spondylitis Disease Activity Score (ASDAS) was used to assess disease activity. AS patients who fulfilled the Assessment in Ankylosing Spondylitis Criteria in 1984 and ASDAS≥1.3 were enrolled in this study. The patients received subcutaneous injection of recombinant human tumor necrosis factor receptor-Fc fusion protein (rh TNFR-Fc) 50 mg weekly for 12 weeks. Healthy age and gender-matched subjects were also enrolled as control group. Flow cytometry analyses were carried out to detect the levels of a series of lymphocytes including different stages of differentiation CD4+T cells and Treg cells. C-reactive protein(CRP) levels in serum were determined by immunoturbidimetry. Results: A total of 23 active AS patients(Age: 31.74±10.20 yrs, M/F:19/4) and 50 healthy subjects (Age: 34.66±9.72 yrs, M/F: 45/15) were included in the study. The percentage of initialization CD4+T cells(CD3+CD4+CD45RA+CCR7+) and central memory CD4+T cells (CD3+CD4+CD45RA-CCR7+) were found to be significantly higher in the AS groups compared with the healthy individuals (P Conclusion: Initialization CD4+T cells (CD3+CD4+CD45RA+CCR7+), central memory CD4+T cells (CD3+CD4+CD45RA-CCR7+) and Treg cells (CD3+CD4+CD25+CD127-) may play a role in the pathogenesis of AS. The down regulation of initialization CD4+T cells and central memory, and the up regulation of Treg cells in active AS patients are significant for the evaluation of the curative effect of rhTNFR-Fc.