Radiographic progression in patients with ankylosing spondylitis after 2 years of treatment with the tumour necrosis factor alpha antibody infliximab

Abstract

Background: Anti-tumour necrosis factor (TNF) treatment is clinically efficacious in patients with active ankylosing spondylitis (AS) and leads to improvement of spinal inflammation, as assessed by magnetic resonance imaging. It is unclear whether anti-TNF treatment affects chronic spinal changes in AS.

Objectives: To analyse the effect of infliximab on the radiographic course of AS over 2 years.

Methods: Complete sets of lateral radiographs of the cervical spine and lumbar spine were available from 82 patients from two sources: 41 patients (group 1) had been treated with infliximab (5 mg/kg/6 weeks) as part of a recent randomised controlled trial and 41 patients (group 2) were part of the early German AS cohort (GESPIC), without controlled interventions. Radiographs were obtained at baseline and after 2 years and scored by the modified Stokes AS Spinal Score (mSASSS).

Results: Patients in the infliximab group were older, had a longer disease duration, and more radiographic damage at baseline. The mean (SD) mSASSS change was 0.4 (2.7) and 0.7 (2.8) for groups 1 and 2, respectively (p = NS). Radiographic damage at baseline was a predictor for more radiographic progression. Patients with baseline damage who were treated with infliximab showed a trend for less radiographic progression. No correlations between clinical parameters and radiographic progression were found.

Conclusions: Patients with AS treated with infliximab had less radiographic progression after 2 years. Patients with prevalent radiographic damage are prone to develop more damage over time. Infliximab may decelerate radiographic progression in such patients. Larger studies are needed to prove that anti-TNF treatment inhibits structural damage.

Figure 1

The mSASSS. Chronic spinal changes are assessed by scoring the anterior vertebral edge of each vertebra between the lower edge of C2 and the upper edge of Th1, and between the lower edge of Th12 and the upper edge of S1.

Figure 2

Comparison of the mean radiographic progression over the 2 year study period for all patients in the two assessed groups.

Figure 3

Example of a patient with radiographic progression. Erosion and sclerosis worsened to bridging syndesmophytes after 2 years.

Figure 4

Comparison of the mean radiographic progression over the 2 year study period for patients with definite radiographic damage at baseline in the two assessed groups.