Background Psoriatic arthritis (PsA) is a heterogeneous condition with variable clinical phenotype and highly variable radiographic progression. Previous radiographic data in early PsA from the Dublin cohort recruited between 1994 and 2000 showed that 27% of patients had erosions at baseline assessment and this increased to 47% at 2 year follow up despite active treatment1. Since that time there has been an improving awareness of PsA and better access to effective therapies which may have impacted on radiographic changes seen in early PsA.
Objectives To assess extent of radiographic change seen in an early PsA cohort at presentation and after one year of active treatment.
Methods 206 patients recruited to the TICOPA trial between 2008 and 2012 had radiographs of the hands and feet performed at baseline and 48 weeks. All patients were required to be DMARD naïve with symptom duration of less than 2 years. During the course of the trial all patients received active therapy either with a treat-to-target approach or standard care. The majority of patients received only standard DMARDs but 23.4% of patients were on anti-TNF therapy at the end of the trial. Radiographs were scored using the modified Sharp van der Heijde (SvdH) scoring system for PsA including DIPJs of the hands.
Results Radiographs of the hands and feet were available for 195 patients at baseline and 176 at follow up. Overall SvdH scores were low at both baseline and follow up (see table).
Although median erosion scores were zero, 25.4% of patients had some erosive disease at baseline rising to 30.1% at 48 weeks. Presence of erosive disease was not associated with the presence of rheumatoid factor or anti-citrillinated peptide antibodies (ACPA). Of 9 patients with positive ACPA titres, only 1 had any erosive disease. There was also no significant association with raised C-reactive protein (CRP) levels or pattern of arthritis (polyarticular vs oligoarticular) although there was a trend suggesting that erosive patients were more likely to be polyarticular (78.0 vs 69.6%) or have a raised CRP (45.0 vs 39.6%).
The majority of radiographic change seen represented JSN in the hands. Patients with JSN were slightly older than those without but this did not reach significance (p=0.053)
Conclusions This study highlights the low level of radiographic change seen in early PsA but does confirm that a similar proportion of patients present with some, albeit very few erosions compared to a decade earlier (25 vs 27%). Progression of erosive disease once patients are on active therapy is low with only an additional 5% developing erosive change. There was a suggestion of association between radiographic erosions and known predictors such as polyarticular disease and raised CRP.
1. Kane et al, Rheumatology 2003; 42(12): 1460.
Acknowledgements The TICOPA study was funded by Arthritis Research UK and Pfizer.
Disclosure of Interest L. Coates Grant/research support: Pfizer, P. Helliwell Grant/research support: Pfizer