AB0813 MULTICENTER ASSESSMENT OF ACRO-OSTEOLYSIS IN PORTUGUESE PATIENTS WITH SYSTEMIC SCLEROSIS

BackgroundAcro-osteolysis is a disabling manifestation of Systemic Sclerosis (SSc). Few is known about its prevalence and clinical associations.ObjectivesTo define the prevalence of acro-osteolysis among Portuguese SSc patients, to determine the most sensitive radiological location for its diagnosis and to clarify the phenotype of SSc patients with acro-osteolysis.MethodsA cross-sectional multicenter study was conducted evaluating SSc patients from 14 Portuguese centers, registered in the Rheumatic Diseases Portuguese Registry (Reuma.pt), that fulfilled Leroy/Medsger 2001 or ACR/EULAR classification criteria for SSc. The presence of acro-osteolysis was assessed through systematic plain radiographs of hands and feet. Statistical analysis with independent parametric or non-parametric tests, multivariate logistic regression of the significant variables in univariate analysis and sensitivity calculation of each radiographed site for the diagnosis of acro-osteolysis were performed.ResultsWe included 195 patients, of whom 167 (85.6%) were female, with a median [min, max] age of 64 [20, 90] years-old and a median [min, max] disease duration of 11.2 [2, 57] years. Regarding disease classification, 146 (75.3%) patients had limited SSc, 32 (16.5%) had diffuse SSc, 9 (4.6%) had sine scleroderma SSc and 7 (3.6%) had early SSc. Acro-osteolysis was present in 62 (31.8 %) patients, with the hands (n=49, 25.1%) being more frequently affected than the feet (n=22, 11.3%). The most sensitive location to detect acro-osteolysis was the hand (79.0%). The presence of overall acro-osteolysis was significantly associated with digital ulcers (p=0.001), flexion contractures (p=0.031), oesophageal (p=0.006), gastric (p=0.014) and lung (p=0.004) involvements, higher mRSS score (p<0.001), anti-topoisomerase I positivity (p=0.034) and radiological calcinosis (p=0.018). Patients with hand acro-osteolysis had longer disease duration (p=0.02) and were more often affected by digital ulcers (p=0.004), flexion contractures (p=0.041), oesophageal (p=0.001), gastric (p=0.015) and lung (p=0.001) involvements, higher mRSS score (p<0.001), anti-topoisomerase I positivity (p=0.004) and radiological calcinosis (p=0.008). No significant differences were found between patients with and without feet acro-osteolysis. In multivariate analysis, anti-topoisomerase I positivity (OR 4.6, 95%CI 1.3-16.4, p=0.017) was predictor of hand acro-osteolysis.ConclusionThe prevalence of acro-osteolysis found in Portuguese SSc patients is within the range found in the literature (20-40%) [1]. The hands were the most sensitive location to detect acro-osteolysis – a novel aspect since, to our knowledge, this is the first study evaluating acro-osteolysis in the feet besides the hands. Our data replicated some previously reported associations between acro-osteolysis and other hand involvements (digital ulcers, calcinosis and flexion contractures) and systemic complications (esophagogastric and pulmonary systems) [2-4]. Anti-topoisomerase I positivity appears to increase the risk for hand acro-osteolysis.References[1]Sandler RD et al. Musculoskeletal hand involvement in systemic sclerosis. Semin Arthritis Rheum. 2020 Apr;50(2):329-334. [2]Sakchaikul et al. Prevalence and clinical association with acro-osteolysis in early systemic sclerosis. Clin Exp Rheumatol. 2021 Sep-Oct;39(5):1093-1098 [3]Sakata et al. Association of radiographic findings in hand X-ray with clinical features and autoantibodies in patients with systemic sclerosis. Clin Rheumatol. 2020 Jan;39(1):113-118 [4]Johnstone et al. Acro-osteolysis in systemic sclerosis is associated with digital ischaemia and severe calcinosis. Rheumatology 2012;51:22342238Acknowledgements:NIL.Disclosure of InterestsNone Declared.