BackgroundNail ultrasonography (US) is a favourable visualisation method to evaluate the subunits of the nail. Little is known about the relation between the properties of nail structures and the clinical characteristics of patients with psoriatic arthritis (PsA).1 ObjectivesTo show the relationship between the clinical features and ultrasonographic evaluations of the nail in patients with PsA.MethodsPatients with PsA according to the CASPAR criteria were recruited into the study. All of the hand nails and toenails were examined by grayscale and power Doppler techniques. The relations between the characteristics of the patients and the sonographic findings of the nail structures were assessed. Concerning to patient characteristics, subtypes of PsA, gender, age, height, BMI, working status, smoking, PsA duration, psoriasis duration, history of dactylitis, history of uveitis, number of tender and swollen joints, Maastricht Ankylosing Spondylitis Enthesitis Score, CRP, disease activity, haemoglobin, sacroiliitis, inspectional nail involvement (INI), Nail Psoriasis Severity Index (NAPSI), PASI, HAQ, quality of life, and the biologic treatment were recorded. The nail plate thickness (NPT), number of nails with trilaminar irregularity (NTI), nail bed thickness (NBT), and the doppler activity score (DAS) were recorded as the sonographic nail findings. The Kruskal Wallis analysis, Spearman’s correlation, and Man Whitney U tests were used in statistical analysis. p<0.05 was accepted as significant.Results63 patients (756 nails) were evaluated. Among the PsA subtypes, 38% of patients were asymmetrical oligoarticular arthritis, 38% were symmetrical polyarthritis, 7.9% distal interphalangeal arthropathy, and 15.8% predominant spondylitis. All of the ultrasonographic nail parameters were independent of the PsA subtypes (p>0.05). The mean of NPT was higher in males and correlated with age, height, and the haemoglobin levels. The NTI score was higher in patients with INI and correlated with the NAPSI score. The mean of NBT was only correlated with the haemoglobin levels. The DAS was higher in workers and correlated with age and the NAPSI score. The other clinical parameters were not associated with the sonographic findings.Abstract THU0331 – Table 1Relationships between the patients’ characteristics and the ultrasonographic parameters*ConclusionsThe ultrasonographic findings of the nail structures were determined in PsA. These findings did not differ among the subtypes of the disease. Although the sonographic nail findings were not associated with the most of the clinical parameters; they had significant relations with some demographics, inspectional nail involvements, and haemoglobin levels in PsA.Reference[1] Acquitter M, Misery L, Saraux A, Bressollette L, Jousse-Joulin S. Detection of subclinical ultrasound enthesopathy and nail disease in patients at risk of psoriatic arthritis. Joint Bone Spine2017;84(6):703–707.Disclosure of InterestS. Acer: None declared, H. S. Baklacıoğlu: None declared, D. Erdem: None declared, ...