130. Monocyte subpopulations and monocyte-related chemokines profile in the peripheral blood from patients with Takayasu arteritis
Creators: name: Aguiar1, Mariana
name: Heron Torquato2
name: Paredes-Gamero3, Edgar
name: Salu2, Bruno
name: Oliva2, Maria Luiza
name: Wayel Abdulahad4
name: Brouwer4, Elisabeth
name: De Souza1, Alexandre Wagner
Publisher: name: Zenodo
Year: 2022
Subjects: Vasculitis
ANCA
Abstracts
Giant Cell Arthritis
MPA
GPA
EGPA
Takayasu
IgA vasculitis

description: <strong>Background:</strong> Takayasu arteritis (TAK) is a chronic large-vessel granulomatous vasculitis that affects the aorta and its main branches. The pathogenesis of TAK is poorly understood. Although a macrophage-rich vessel wall granulomatous inflammation is a hallmark of TAK pathology, no previous studies have analyzed the monocytes’ role in the pathogenesis of the disease. Therefore, this study aito evaluate the distribution of monocytes subpopulations and the monocyte-related chemokines profile in the peripheral blood of TAK patients and healthy controls (HC). <strong>Methods:</strong> A cross-sectional study with a control group was performed. TAK patients were evaluated for current disease activity and current therapy. Monocyte’s subpopulations were identified by flow cytometry according to the surface expression of CD14 and CD16 as classical (CD14<sup>+</sup>CD16<sup>-</sup>), intermediate (CD14<sup>+</sup>CD16<sup>dim</sup>), and non-classical (CD14<sup>dim</sup>CD16<sup>high</sup>) in the peripheral blood. Multiplex was used to measure serum monocytes-related chemokines including CCL2, CCL3, CCL4, CCL5, CCL7, CXCL10 and CX3CL1. <strong>Results:</strong> Thirty-two consecutive TA patients and 30 HC were evaluated. TAK patients presented a higher number of circulating intermediate monocytes compared to HC [25.0 cells x 10<sup>6</sup>/L (16.6-52.0) vs. 17.2 cells x 10<sup>6</sup>/L (9.2-25.3); <em>p</em> &lt; 0.014]. Active disease was associated with monocytosis (<em>p </em>= 0.003<em>)</em> along with the increase of the classical (<em>p</em> = 0.002) and intermediate (<em>p</em> = 0.004) subtypes compared to HC. However, no significant differences were found between disease activity and the remission states in TAK (Table 1). Prednisone use reduced the percentage of non-classical monocytes [3.7% (1.3-4.1) vs. 6.9% (3.9-8.5);<em> p</em> = 0.011]. TAK patients had lower CCL3 [6.22 pg/mL (4.9-8.1) vs. 9.3 pg/mL (5.7-14.7); <em>p </em>= 0.009] and CCL4 [37.4 pg/mL (24.6-47.9 vs. 45.4 pg/mL (37.8-63.7); <em>p </em>= 0.008] levels than HC, whereas CCL22 levels were higher in active TAK compared to the remission state (2030.5 ± 982.5 pg/mL vs. 1222.3 ± 552.6 pg/mL; <em>p = </em>0.008). Therapy glucocorticoids, immunosuppressive agents or biologics did not impact serum chemokines concentrations. In TAK patients, CCL4 concentration correlated with the number of total monocytes (Rho = 0.441; <em>p</em> = 0.012) and classical monocytes (Rho = 0.400; <em>p</em> = 0.023) in the peripheral blood. <strong>Conclusion:</strong> TAK is associated with altered distribution of monocytes subtypes in the peripheral blood compared to HC and CCL22 is the chemokine mostly associated with active disease in TAK. <strong>Disclosures:</strong> The authors declare no conflicts of interests. <strong>Table 1.</strong> Monocyte’s subsets in the peripheral blood of TAK patients presenting active disease, TAK patients in remission, and healthy controls. Variables Active TAK (n = 6) TAK in remission (n = 26) Healthy controls (n = 30) <em>p</em> Total monocytes, cells x10<sup>6</sup>/L 976.1 (601.6-1504.8) 465.8 (288.9-718.5) 461.26 (313.9-544.1) 0.022* Classical monocytes, cells x10<sup>6</sup>/L 818.8 (572.8-1280.3) 404.0 (258.5-647.0) 420.7 (278.0-506.4) 0.018* Classical monocytes, % 88. 5 (80.5-91.7) 88.6 (83.9-91.6) 90.9 (87.5-94.7) 0.279 Intermediate monocytes, cells x10<sup>6</sup>/L 55.4 (28.4-127.0) 22.3 (15.8-35.7) 17.2 (9.2-25.3) 0.008* Intermediate monocytes, % 6.5 (4.6-8.1) 5.5 (4.1-7.2) 3.7 (2.8-6.7) 0.153 Non-classical monocytes, cells x10<sup>6</sup>/L 43.3 (12.4-161.9) 19.1 (8.4-40.5) 14.2 (6.5-28.3) 0.183 Non-classical monocytes, % 4.4 (2.6-10.9) 5.1 (3.3-7.5) 3.4 (1.4-6.8) 0.345 TAK – Takayasu arteritis, n – number of patients, * - significant differences. <em>Post hoc</em> analyses for total monocytes: active disease vs. remission (<em>p</em> = 0.038), active disease vs. healthy controls (<em>p</em> = 0.003*), remission vs. healthy controls (<em>p</em> = 0.706). <em>Post hoc</em> analyses for classical monocytes: active disease vs. remission (<em>p</em> = 0.026), active disease vs. healthy controls (<em>p</em> = 0.002*), remission vs. healthy controls (<em>p</em> = 0.755). <em>Post hoc</em> analyses for intermediate monocytes: active disease vs. remission (<em>p</em> = 0.053), active disease vs. healthy controls (<em>p</em> = 0.004*), remission vs. healthy controls (<em>p</em> = 0.082). Bonferroni’s correction for <em>post hoc</em> analyses (<em>p</em> = 0.016).