AB1141 PREDICTORS OF X-RAY PROGRESSION IN PATIENTS WITH PSORIATIC ARTHRITIS

Abstract

BackgroundPsoriasis arthritis (PsA) is a systemic chronic inflammatory disease, which leads to irreversible destruction of the joints. Multiple factors drive the development of this heterogeneous disease including genetic predisposition, environmental triggers, and immunologic dysfunction. Even structural damage differs significantly between patients, with a subset of patients suffering from severe and rapid (rheumatoid arthritis-like) bone destruction (arthritis mutilans), while others experience only modest signs of bone damage, or develop new bone formation.[1]ObjectivesThe study aims to identify potential predictors for radiographic such as clinical, radiographic, and laboratory parameters.MethodsIn this retrospective data analysis 231 patients with PsA and at least two available x-rays were included. Radiographs were scored according to Sharp-van-der-Heijde-total Score (mSvdHTH) modified for PsA and a mean annual progression (MAP) rate was calculated by dividing the change in mSvdHTS between two x-rays number of years between them. For each patient, the median of the annual progression rates was calculated. Patients were grouped in no progressors (MAP ≤ 0.5), low progressors (MAP 0.5 < MAP ≤ 2.5) and high progressors (MAP > 2.5). Clinical data such as the clinical disease activity index (CDAI), radiographic data and laboratory data (CRP, ESR, C-terminal Telopeptide) were analysed for their predictive value of radiographic progression using parametric and non-parametric statistical analysis according to the distribution of data. For correlation analysis Spearman´s rank coefficient was used. For group analysis ANOVA was used. Dichotomous variables such as gender or nail involvement were analysed using χ2-test. Multiple linear regression analysis was used to identify factors influencing radiographic progression.ResultsThe mean baseline mSvdHTS in high progressors was 41.59 (43.53), 19.89 (34.93) in low progressors and 16.25 (26.77) in non-progressors. Baseline mSvdHTS was significantly correlated with MAP (ρ=0.27, p=0.002) rate. Group analysis comparing clinical and laboratory parameters in patients again showed significant difference baseline mSvdHTS. The high progression cohort also exhibits greater mean CRP, ESR, CDAI, median first year CDAI, TJC68, SJC66 and a higher percentage of nail involvement than low- or non-progressors but no statistically significant result was found. In a multiple linear regression analysis baseline SvdHS (β = 0.51, 95%CI 0.28-0.73, p=<0.001), median CDAI in the first year after baseline (β = 0.51, 95%CI 0.19-0.83, p=0.018) and CDAI at baseline (β = -0.62, 95%CI -1.05 – -0.19, p=0.043) were significantly associated with mean annual progression. No association was found between MAP and bone turnover markers.ConclusionThis study shows a clear association of Sharp-van-der-Heijde score at baseline with future radiographic progression. Moreover, the median CDAI in the first year after baseline was associated with radiographic progression.Reference[1]FitzGerald O, Ogdie A, Chandran V, et al. Psoriatic arthritis. Nat Rev Dis Primers 2021;7(1):59AcknowledgementsThe authors thank Gabriela Supp and Susanna Mössmer for scoring the radiographs.Disclosure of InterestsNone Declared.