AB0795 ABNORMAL LEVELS OF PERIPHERAL LYMPHOCYTES SUBSETS IN PATIENTS WITH PSORIATIC ARTHRITIS AND RESTORATION AFTER RECEIVING OUR NEW IMMUNOREGULATORY COMBINATION THERAPIES: A CROSS-SECTIONAL STUDY

Background: Psoriatic arthritis (PsA) is a chronic autoimmune disease characterized by skin and joint inflammation with lymphocytes disturbance [1,2] . However, the statuses of immune cell subsets are unclear. In addition, although, during the past 20 years, the treatment of the PsA has progressed rapidly, it still remains an unmet need [3] . Objectives: To compare the lymphocyte subsets in peripheral blood of PsA patients and healthy controls and, evaluate effects of immunoregulatory combination therapies, such as low-dose interleukin-2, rapamycin, metformin, and retinoic acid, on the proliferation and functional recovery of lymphocyte subsets in PsA patients. Methods: From September 2014 to December 2019, 218 PsA patients (107 male and 111 female) and 206 healthy controls (78 male and 128 female) were enrolled, including 112 patients (50 male and 62 female) who received immunoregulatory combination treatments (low-dose interleukin-2, rapamycin, metformin, retinoic acid and coenzyme Q10, ect). The absolute numbers and ratio of T, B, NK, CD4 + T, CD8 + T, Th1, Th2, Th17 and Tregs in peripheral blood were measured by flow cytometry with absolute counting beads. The data were subject to normal distribution, which was expressed as the mean ± standard deviation. Independent-samples T test and paired-samples T test were applied. P value <0.05 were considered statistically significant. Results: The absolute numbers of B, CD4 + T and Th17 in PsA patients were significantly higher than those of healthy controls ( P <0.01), while the absolute numbers of NK and the percentage of Th1 and Tregs were decreased significantly ( P <0.01). The ratio of Th17/Tregs was significantly increase ( P <0.001) (Figure 1). After receiving our new immunoregulatory combination therapies, the percentage of B, Th2 and Th17 were lower than before ( P <0.05) and the absolute numbers of T, CD8 + T, NK, Th1 and Tregs in PsA patients were increased ( P <0.05). Further, the ratios of Teffs/Tregs had a tendency to decrease (rebalance of them): Th2/Tregs ( P <0.01) and Th17/Tregs ( P =0.095) (Figure 2). Conclusion: The abnormal levels of peripheral lymphocyte subpopulations resulted in an imbalance of Teffs/Tregs, which might play an important role in PsA pathogenesis. Our new immunoregulatory combination therapies could promote the proliferation of Tregs and may help for PsA patients’ symptom remission. References: [1]Gladman DD, Antoni C, Mease P, et al. Psoriatic arthritis: epidemiology, clinical features, course, and outcome. Ann Rheum Dis 2005;64 Suppl 2:ii14-7. doi: 10.1136/ard.2004.032482 [published Online First: 2005/02/15] [2]Ritchlin CT, Colbert RA, Gladman DD. Psoriatic Arthritis. N Engl J Med 2017;376(10):957-70. doi: 10.1056/NEJMra1505557 [published Online First: 2017/03/09] [3]Winthrop KL, Weinblatt ME, Crow MK, et al. Unmet need in rheumatology: reports from the Targeted Therapies meeting 2018. Ann Rheum Dis 2019;78(7):872-78. doi: 10.1136/annrheumdis-2018-214280 [published Online First: 2019/02/04] Figure 1. Article selection Acknowledgments: None. Disclosure of Interests: None declared