Session Type: ACR Concurrent Abstract Session
Session Time: 4:30PM-6:00PM
Background/Purpose: Enthesitis-related arthritis (ERA) is a category of juvenile idiopathic arthritis encompassing most cases of juvenile spondyloarthropathy. Two different clinical patterns (axial /peripheral) have been recognized, possibly identifying distinct subpopulations. Different pro-inflammatory cytokines linked to Th1 and Th17 T-cell subsets have been implicated in the pathogenesis of ERA. Our objectives were to assess Th1 and Th17 cell subsets in ERA patients and to examine the association between clinical features and Th1 / Th17 cell subsets.
Methods: Patients with ERA (ILAR criteria) were included in a cross sectional study. Patients were classified according to their pattern of joint involvement into axial or peripheral as per ASAS1 criteria. Patients were clinically assessed on the same day blood samples were collected. Recorded features: active joint count (AJ), pain score (0-10), sacroiliac pain (SIP) , lumbar pain (LP), lumbar limitation (LL) by Schöber´s test, patient wellbeing using a visual analogue scale (VASp, 0-10), disease activity according to the physician (VASphy), JADAS-10, JSpADA (Juvenile Spondyloarthritis Disease Activity index), ESR/CRP, active enthesitis (AE), functional capacity (CHAQ), radiologic sacroiliitis (MRI/X-rays) and therapy with TNF inhibitors (TNFi). Inactive disease was defined as JADAS-10 ≤ 1 and JSpADA =0. Quantification of Th-1 and Th-17 cells was done by flow cytometry in PBMCs stimulated with PMA/IO in the presence of Brefeldin A. Staining with surface and intracellular components defined Th1 and Th17 phenotypes (CD4+ IFN+ and CD4+ IL-17+ respectively). Mann-Whitney U-test and Chi2 were used as appropriate.
Results: 30 patients (90 % M) were included. HLA-B27 was positive in 13 (45%). Median age was 12 years, disease duration was 4 years. Clinical features (medians): AJ 1 (0-16), pain 0 (0-8.5), VASp 0.75 (0-8.5), VASphy 0 (0-8.5), JADAS-10 4.75 (0-25.8), JSpADA 1.75 (0-5.5); LL 4.5 (3-7) cm, ESR 15 (4-95) mm/h; CRP 1.64 (0-57) mg/dl. SIP in 13 (43%), LP in 18 (60%), AE in 1 (3%), CHAQ ≥ 0.5 in 7 (23%), and sacroiliitis in 18(60%) children. All patients fulfilled ASAS criteria: 17 (57%) ASAS-peripheral and 13 (43%) ASAS-axial; 8 patients (27%) met modified New York Criteria for Ankylosing Spondylitis (AS). Twenty (67%) patients were treated with TNFi. Ten (33%) patients showed inactive disease according to JADAS-10 and 6 (20%) according to JSpADA. Th1 cell percentage was 8.5±3.4 (4-17.4), Th17 cell % 0.90±0.44 (0.39-2.34%) in the whole group. Patients with peripheral and axial involvement showed similar Th1cell percentage: 7.55±2.83 (4.3-14.9) and 10.1± 3.84 (4-17.4) and different Th17 cell percentage: 0.70±0.32 (0.39-1.72) and 1.10±0.44 (0.82-2.34) respectively (p=0,0009). Patients with AS exhibited higher Th17 cell percentage (p=0.01). LP (p=0.0001) and sacroilitis (p=0.0024) showed significant associations with Th17 cell.
Conclusion: ERA patients with axial pattern exhibit peripheral Th17 cell expansion. These findings suggest a pathogenic role for Th17 cells and support the potential use of IL-17 blocking strategies for the treatment of these patients.
1- Rudwaleit et al. Ann Rheum Dis 2011;70:25-31.
To cite this abstract in AMA style:Katsicas MM, Carrara C, Russo R. Enthesitis-Related Arthritis: Axial -Pattern Is Associated with an Expansion of Peripheral Th17 Populations . [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 10). https://acrabstracts.org/abstract/enthesitis-related-arthritis-axial-pattern-is-associated-with-an-expansion-of-peripheral-th17-populations/. Accessed September 24, 2021.
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