Repair of radiographic joint damage in psoriatic arthritis: a cohort study.

OBJECTIVES

Robust evidence on the repair of radiographic damage in psoriatic arthritis (PsA) is limited. In this study, we determined the frequency of damage repair and identified its predictors.

METHODS

We performed biennial radiographic assessments of the hands and feet and graded them using the modified Steinbrocker score (mSS). Grades 0 and 1 were combined as a single state. We defined damage repair as a decrease in the joint-level mSS and summarized disease characteristics using descriptive statistics. We defined states based on the mSS and fitted multistate Markov models to estimate transition intensities and assess the impact of prognostic factors on damage repair.

RESULTS

We included 674 patients with PsA (54.7% male), with a mean age of 44.4 years (SD 12.8) and a mean disease duration of 6.3 years (SD 8.0) at baseline (clinic entry). Over a total follow-up of 7189.5 person-years, 428 patients (63.4%) developed at least one damaged joint (mSS ≥2) and 127 of them (29.7%) demonstrated evidence of repair in at least one joint. In total, 361 joints demonstrated radiographic improvement. Progression of damage was observed in patients prior to biologic DMARD therapy. Combination of methotrexate and biologic DMARDs was associated with a reduced progression rate for joint damage (RR = 0.48, 95% CI: 0.38-0.62) and an increased rate of damage repair (RR = 1.97, 95% CI: 1.13-3.45).

CONCLUSION

Radiographic improvement consistent with damage repair is not infrequent in PsA. Concomitant treatment with biologic DMARDs and MTX is a predictor of slower radiographic progression and damage repair.