AB0825 TIME-COURSE CHANGE IN AXIAL MOBILITY IN PSORIATIC ARTHRITIS PATIENTS UNDER bDMARD
Authors: M. Rato, F. Pinheiro, S. Garcia, B. M. Fernandes, S. Ganhão, R. Gaio, M. Bernardes, A. Bernardo, L. Costa
Journal: Annals of the Rheumatic Diseases (2020)

Background: Spinal mobility is assessed frequently in patients with psoriatic arthritis (PsA) using Bath Ankylosing Spondylitis Metrology Index (BASMI) to provide baseline measurement, monitor changes over time and to assess the impact of clinical interventions. BASMI comprises 4 measures of spinal mobility (cervical rotation, tragus-to-wall distance, modified Schober’s test and lumbar lateral flexion) and one hip mobility measurement (intermalleolar distance). Objectives: The aim of this study is to investigate the time-course change of BASMI in PsA patients after 6 months of Biologic Disease-modifying Antirheumatic Drug (bDMARD) therapy. The authors also pretend to evaluated, at baseline and after 6 months of treatment, the association between BASMI, disease activity scores and physical function. Methods: An observational retrospective study was performed in patients with PsA under bDMARD followed in the Rheumatology department of a tertiary university hospital. Were included patients treated with only one bDMARD. Demographic and clinical data were collected from the Rheumatic Diseases Portuguese Register. For spinal mobility calculation BASMI was used. Disease activity was evaluated with Ankylosing Spondylitis Disease Activity Score (ASDAS) and Bath Ankylosing Spondylitis Activity Index (BASDAI). Physical function was assessed with Bath Functional Index (BASFI). The variation of BASMI, ASDAS, BASDAI and BASFI was calculated as the difference between values registered at 6 months and at baseline and presented as Δ. Correlations between ΔBASMI, ΔASDAS and ΔBASFI was calculated using Pearson test. Results: A total of 55 patients were included. Thirty patients were males (54.5%). The mean age at diagnosis was 44.6 ± 12.6 years and the median disease duration at start of bDMARD was 5.4 years (min: 0.30; max: 25.5). In total, 19 (34.5%) patients had predominant axial involvement, 36 (65.5%) peripheric and 36 (65.5%) enthesopathic. Almost all patients fulfilled the CASPAR criteria for PsA (n=50, 90.9%). According to ASDAS criteria, at the baseline 20 patients (36.4%) had high disease activity and 34 (61,8%) very high. The most used bDMARD was etanercept (n=21, 38,3%) followed by golimumab (n=19, 34.5%) and adalimumab (n=8, 14.5%). Three patients were treated with infliximab, two with certolizumab and other two with secukinumab. Forty-one patients (75.9%) were concomitantly treated with conventional synthetic DMARDs. Axial PsA patients had more limitations in spinal mobility (BASMI mean 4.5 ± 1.5) and more functional limitation (BASFI mean 6.8±1.9) than patients with predominant peripheric involvement (BASMI mean 3.3± 1.2, p=0.004; BASFI mean 5.4±3, p=0,0048). Statistically significant differences in ASDAS and BASDAI in these two groups were not observed (p=0.332 and p=0.605, respectively). For all patients, BASMI did not vary significantly (p=0.691) at baseline (mean 3.7± 1.4) and after 6 months (mean 3.8±1.3) of treatment. Although the ΔBASMI for etanercept was negative (mean -0.12±0.9) and for golimumab positive (0.14±0.8), it was not statistically significant. At baseline there is a significant positive association between BASMI and ASDAS (r=0.435, p=0.001), BASMI and BASDAI (r=0.567, p&lt;0.001) and BASMI and BASFI (r=0.510, p&lt;0.001). However, there was not a statistically significant association between ΔBASMI and: ΔASDAS, ΔBASDAI and ΔBASFI (r=0.158; p=0.269, r=0.019; p=0.096 and r=0.121; p=0.397, respectively). Conclusion: In PsA patients treated with bDMARDs, at least in short-term follow-up, BASMI does not improve with time. Changes in BASMI did not correlate with changes in activity disease and in functional outcome. Studies with longer follow-up and with more patients are needed to better evaluate these associations. Disclosure of Interests: Maria Rato: None declared, Filipe Pinheiro: None declared, Salomé Garcia: None declared, Bruno Miguel Fernandes: None declared, Sara Ganhão: None declared, Rita Gaio: None declared, Miguel Bernardes Speakers bureau: Abbvie, Amgen, Biogen, Eli-Lilly, Glaxo-Smith-Kline, Pfizer, Janssen, Novartis, Alexandra Bernardo: None declared, Lúcia Costa: None declared