AB0676 THE ROLE OF ACPA AND ANA IN SPONDYLOARTHRITIS: HOW THE AUTOIMMUNE DYSREGULATION CAN AFFECT THE COURSE OF DISEASE AND THERAPEUTIC SUCCESS OF MONOTHERAPY DMARDS AND bDMARDs
Authors: D. Cici, C. Rotondo, A. Corrado, S. Berardi, N. Mansueto, L. Lops, F. P. Cantatore
Journal: Annals of the Rheumatic Diseases (2020)

Background: Occasional findings of anti-citrullinated-protein-antibodies (ACPA) and anti-nuclear-antibodies (ANA) were rarely described in literature on Psoriatic Arthritis (PsA) and on Spondyloarthritis (SpA) in general. How these autoimmune dysregulations can affect the course of them is not yet understood. Objectives: The aim of our study is to evaluate if the presence of ACPA and ANA can determine different disease subsets and influence the DMARDs monotherapy (methotrexate) drug survival (DSM) and b-DMARDs multi-failure patients (MF). Methods: We conducted a retrospective study on patients with Psoriatic Arthritis (PsA) and Spondyloarthritis that fulfilled the ASAS and CASPAR criteria. Patients with diagnosis of connective tissue disease and rheumatoid arthritis and patients ≤ 18 years old were excluded from the study. For each patient, the following variables were considered: age, ACPA, ANA, time between arthritis onset and start of DMARDs (start-time), DSM, switch to b-DMARDs (sw-bDMARDs), arthritis subset (oligoarticular (OA), polyarticular (PA), enthesitis (EA), axial involvement (AI)), number of comorbidities (NC), Charlson Comorbidity Index (CCI). Results: 150 patients (55% with PsA and 45% with another SpA) were included in the study. No differences were found in age, ANA rate, ACPA rate, start-time, OA, PA, EA, AI, NC and CCI between the PsA and SpA groups. In the whole group of patients, the ACPA+ subjects(11%) had a significant increase of NC (2.47 ± 1.5 vs 1.6 ± 1.4, p=0.035), a trend to higher CCI, to switch to b-DMARDs, and to be MF compared to those without ACPA. In the same group, the ANA+ patients (12%) showed shorter DSM (233.5 wk ± 45.9 vs 548.0 wk ± 56.8, p=0.362) with similar trend in each subgroup (PsA and SpA). In SpA group, the ACPA+ patients(6,3%) had a trend to shorter DSM (269.0 weeks ± 125vs 603.96 wk± 92.8, p=0.492),to higher sw-bDMARDs, and to be MF, higher NC and CCI compared to those without ACPA. No differences in clinical subset (OA, PA, EA, AI) were observed. In the same group the ANA+ patients had significant higher rate of PA (100% vs 65%, p=0.026) rather than OA (0% vs 35%, p=0.025). No significant differences were found in NC, CCI, MF. In the PsA group, ACPA+ patients showed a trend to develop PA and EA subsets, shorter DSM (187.5 wk ± 48.7 vs 299.6 wk ± 31.4, p=0.415), higher rate to sw-bDMARDs and to be MF. The ANA+ PsA patients had higher trend to develop PA and AI subsets rather than OA and EA. All ANA+ patients were MF (100% vs 42%, p=0.046). Conclusion: The ACPA and ANA positivity in PsA and SpA patients could be suggestive of more severe clinical disease manifestation, higher frequency of comorbidities and lower predicted 10-year survival (CCI). Moreover, this autoimmune dysregulation could be associated with worse drug survival in monotherapy with methotrexate and higher chance to be MF. Therefore, they can be taken into account for clinical management of these patients. Disclosure of Interests: None declared