To investigate the course of active inflammatory and fatty lesions seen on magnetic resonance imaging (MRI) in patients with early axial spondyloarthritis (SpA) treated with the tumor necrosis factor (TNF) inhibitor infliximab added to naproxen as compared to those treated with naproxen alone.
A total of 158 patients with active axial SpA were randomized (2:1) to receive 28 weeks of treatment with either infliximab 5 mg/kg plus naproxen 1,000 mg/day or placebo plus naproxen 1,000 mg/day. MRI of the sacroiliac (SI) joints and of the spine was performed at baseline and week 28. Images were scored for active inflammation and for fatty lesions.
After 28 weeks, there was a significant reduction of inflammation in the spine and in the SI joints in both treatment groups, which was, however, more prominent in the infliximab plus naproxen group (mean ± SD spine osteitis change score -2.9 ± 5.1, versus -2.0 ± 4.2 in the placebo plus naproxen group [P < 0.001]; SI joint osteitis change score -4.3 ± 5.2 in the infliximab plus naproxen group versus -3.9 ± 3.7 in the placebo plus naproxen group [P = 0.003]). Similarly, there was a significant increase in the fatty lesion score after 28 weeks in both groups; this change did not, however, differ significantly between groups (spine fatty lesion change score 0.8 ± 1.7 in the infliximab plus naproxen group versus 1.0 ± 1.8 in the placebo plus naproxen group [P = 0.72]; SI joint fatty lesion change score 1.7 ± 2.7 in the infliximab plus naproxen group versus 1.4 ± 2.6 in the placebo plus naproxen group [P = 0.86]).
These findings indicate that effective antiinflammatory treatment of axial SpA is associated with an increase in fatty lesion scores, independent of concomitant treatment with or without anti-TNF.