Background Psoriatic arthritis (PsA) is a potentially destructive inflammatory chronic arthropathy, with a wide range of clinical manifestations. Currently, biological therapy (BT) is the second step of treatment after an inadequate response to conventional disease-modifying anti-inflammatory drugs.
Objectives The goal of our study was to identify baseline characteristics of patients with PsA associated with the need for BT use during the follow-up.
Methods This is a single-centre, case-control study. Unselected PsA patients diagnosed after December 31st, 1999 and fulfilling CASPAR classification criteria were included. Reviewing medical records identified epidemiological, clinical, analytical and imaging features. The main outcome was the need of BT during the follow-up. The local ethical committee authorized the study. Chi-square, Student t test, and Mann-Whitney U test were used to establish statistical significance in the univariate analysis. Logistic regression was used for the multivariate analysis. A p<0.05 was considered significant.
Results One hundred and fifty-nine patients were included (75 women and 84 men), with a mean age of 48 years. During the follow-up, 66 patients (41%) needed BT (BT+ patients). No significant differences in age, sex, race, presence of cardiovascular risk factors, smoking, alcohol consumption, initial joint pattern, presence of dactylitis, presence of onychopathy, HLA B27 positivity, presence of radiographic erosions, presence of axial radiographic involvement, mean C-reactive protein, or mean erythrocyte sedimentation rate were found in BT+ patients when compared with BT negative (BT−) patients. Twenty per cent of BT− patients had enthesitis at the beginning, compared with 39% of BT+ patients [Odds ratio 2.53 (CI 95%: 1.25–5.12); p=0.009]. Mean time from the onset of symptoms to the first appointment with a rheumatologist was significantly associated with the need for further use of BT (20 weeks in BT− patients versus 108 weeks in BT+ patients; p<0.001). Multivariate analysis showed that the delay in rheumatology consultation and presence of enthesitis were independent factors significantly associated with the need for BT.
Conclusions In PsA patients, the initial presence of enthesitis is an independent risk factor associated with the need for biological therapy during the follow-up.
Disclosure of Interest None declared