Evaluation of the effects of tumor necrosis factor-а inhibitors versus nonsteroidal anti-inflammatory drugs on spinal inflammatory changes from magnetic resonance imaging data in patients with ankylosing spondylitis

Abstract

Objective: to evaluate the time course of inflammatory changes (ICs) in the spinal column and sacroiliac articulations (SIA) from magnetic resonance imaging (MRI) data in patients with ankylosing spondylitis (AS) during treatment with tumor necrosis factor-α (TNF-а) inhibitors or nonsteroidal anti-inflammatory drugs (NSAIDs), which were first used. Subjects and methods. MRI of the most painful part of the spine and SIA was performed in 58 patients with AS at baseline and 12 weeks later. MRI T2 STIR and T1 (SIGNA EXCITE, General Electrics; 0.35 T, matrix 288x192) regimens were used. Bone marrow edema was regarded as active inflammation. Active ICs in the most painful part of the spine were assessed by the AS spinal MRI activity (ASspiMRI-a) score and those in SIA by the Leeds scoring system. MRI was interpreted independently by two specialists; one of them did not know about the number of a visit and performed therapy. The patients were divided into two groups: 1) those who first used TNF-а inhibitors and 2) those who were first given NSAIDs. Both groups were matched for demographic indicators. Results. In both groups, the mean pain level in the spinal part under study decreased significantly in both groups: from 5.7±1.7 to 2.3±1.8 in the TNF-а inhibitor group (p = 0.000006) and from 4.8±2.3 to 2.6±2.3 in the NSAID group (р = 0.00001). After 12 weeks of treatment, the patients receiving TNF-а inhibitors (n = 28) showed a considerable reduction in the MRI signs of spinal ICs from 4.8±2.3 to 1.6±1.6 (p = 0.00001); moreover, this trend was more pronounced in patients (n = 17) with more baseline IC foci (≥ 5) than in those (n = 11) with fewer baseline IC foci (< 5) (the mean а was 4.3±1.5 and 1.6±1.4, respectively; р = 0.0003). In the patients taking NSAIDs (n = 30), the decrease in the number of spinal MRI ICs (from 2.8±2.5 to 2.3±2.1) was insignificant (p = 0.17). After 12 weeks, regression of active sacroiliitis was noted in 28 patients from the TNF-а inhibitor group with lower Leeds scores from 2.1±2.0 to 0 (p = 0.01). At baseline, 28.5% of the patients had MRI signs of active sacroiliitis, which were not found in any case at 12 weeks. At this time, the reduction in active sacroiliitis was also observed in the NSAID group patients (n = 30), but it was insignificant; the Leeds scores decreased from 2.6±2.5 to 2.1±2.0 (р = 0.083). At baseline and 12 weeks, the MRI signs of active sacroiliitis were present in 73.3 and 60% of the patients, respectively. During treatment with TNF-а inhibitors, the mean reduction in MRI IC scores during the follow-up was more marked than that in the use of NSAIDs (p = 0.003 for the spinal column and p = 0.013 for SIA). Conclusion. Pain intensity in the examined spinal part was significantly reduced in both the use of both TNF-а inhibitors and NSAIDs. MRI ICs significantly decreased when treated with TNF-а inhibitors rather than NSAIDs. With the greater magnitude of baseline MRI ICs, their drop was more significant during treatment with TNF-α inhibitors.

Keywords

• inflammatory changes
• spondyloarthritis
• active sacroiliitis
• magnetic resonance imaging
• tumor necrosis factor-α (tnf-α) inhibitors
• nonsteroidal anti-inflammatory drugs