AB0036B LYMPHOCYTE SUBSET IMBALANCES IN PATIENTS WITH ANKYLOSING SPONDYLITIS
Authors: Mingcan Yang, LV Qing, Yutong Jiang, Zetao Liao, Jieruo Gu
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> 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 lymphocytes play important roles in the inflammatory process of AS. However, the role of comprehensive subtype lymphocyte subset imbalance in AS was rarely mentioned. <h3>Objectives:</h3> In the present study, the correlation of lymphocyte subset changes with the progression of AS was investigated. <h3>Methods:</h3> Flow cytometry analyses were carried out to detect the levels of a series of lymphocytes including different stages of differentiation CD4+T cells, CD8+T cells, helper T cells (Th), cytotoxic T cells(Tc), regulatory cells (Treg), B lymphocytes and so on. Evaluation of hip joint disease were by using Bath Ankylosing Spondylitis hip X-ray index. Ankylosing Spondylitis Disease Activity Score (ASDAS) was used to assess disease activity and AS patients were divided into inactive disease group (ASDAS&lt;1.3) and active disease group (ASDAS≥1.3). Bath Ankylosing Spondylitis Disease Activity Index(BASDAI) were also recorded. <h3>Results:</h3> A total of 67 AS patients and 50 healthy subjects were included in the study. The percentage of Th2 cells, Th17 cells, Tfh2 cells, inactive phase-specific CD8+ T cells and B cells were found to be significantly higher in the AS groups compared with the healthy individuals (P &lt; 0.05). However, the percentage of Th1 cells, Tc1 cells, Tfh1 cells, continuous expression of virus-specific terminally differentiated CD8+ T cellsplasma cells, memory B cells and convertible B cells were significantly lower in the AS groups (P &lt; 0.05). As a result, the percentage of Th1/Th2 and (Th1+Th17)/Th2 ratios were significantly lower in AS patients (P &lt; 0.05). In addition to the above differences, the percentage of Treg cells were higher but inactive phase-specific CD8+ T cells and continuous expression of virus-specific CD8+ T cells were lower in patients with hip joint involvement compared with the healthy individuals (P &lt; 0.05). But there was no significantly differences between hip joint involvement AS group (58.7%) and no involvement AS group (41.3%). In patients who had a history of peripheral arthritis (excluding hip involvement), the proportion of plasma cells was significantly higher than in patients without a history of peripheral arthritis.The percentage of Th1 cells, Th2 cells, effector memory CD4+ T cells were higher but naive B cells were lower in patients have uveitis/iritis history compared with no uveitis/iritis history AS group (P &lt; 0.05). AS patients with family history have significantly higher percentage of Treg cells and terminally differentiated CD8+ T cells but lower initialize CD8+ T cells and central memory CD8+ T cells compared with no family history group (P &lt; 0.05). The percentage of depleted CD4+ T cells, terminally differentiated CD8+ T cells, Th17 cells and Tfh 17 cells were significantly higher but functional CD4+ T cells, central memory CD4+ T cells were significantly lower in active disease group compared with inactive disease group. Central memory CD4+ T cells and central memory CD8+ T cells were negatively correlated with ASDAS (P &lt; 0.05). Depleted CD4+ T cells were positively correlated with BASDAI (P &lt; 0.05) but functional CD4+ T cells were negatively correlated with BASDAI (P &lt; 0.05). <h3>Conclusion:</h3> Imbalances in the numbers and functions of specific lymphocyte cell subsets are key pathogenic derangements in AS, and these insights are leading to changes in clinical practice. The present study provided further evidence on the function and underlying mechanism of lymphocyte subsets, which may be useful in the diagnosis and treatment of ankylosing spondylitis. <h3>References</h3> [1] Zhongliang Duan: The immune dysfunction in ankylosing spondylitis patients. BioScience Trends. 2017; 11(1):69-76. <h3>Disclosure of Interests:</h3> None declared