Treatment with anti-TNF-alpha therapies can lead to improved lumbar spine curvature and better clinical outcomes in patients with ankylosing spondylitis, study shows.
The study, “Radiologic parameters of ankylosing spondylitis patients treated with anti-TNF-α versus nonsteroidal anti-inflammatory drugs and sulfasalazine,” was published in the European Spine Journal.
Ankylosing spondylitis is a chronic, inflammatory rheumatic disease mainly characterized by painful inflammation and bone changes affecting the spine. At advanced stages of the disease, patients can experience spinal deformities, including flattening of the normal lumbar curvature or exacerbation of the thoracic spinal curve, which can lead to severe structural and functional impairments and decreased quality of life.
Researchers at Pusan National University School of Medicine, South Korea, explored the long-term impact of current treatment strategies for ankylosing spondylitis in spinal deformities as determined by radiologic assessments.
The study enrolled 133 patients diagnosed with ankylosing spondylitis who were all initially treated with nonsteroidal anti-inflammatory drugs (NSAIDs) and sulfasalazine (marketed by Pfizer under the brand name Azulfidine). Among these patients, 69 achieved excellent pain control with this standard treatment approach, while 64 continued to experience intractable low back pain and switched to treatment with anti-TNF-alpha therapy.
“The choice of TNF-α inhibitor (infiximab, adalimumab, or golimumab) was based on the judgment of the treating orthopedic surgeon and/or the specifc preference of the patient,” researchers said.
Anti-TNF-alpha agents are widely used to treat patients with active ankylosing spondylitis who are unable to manage their condition with NSAIDs as a first-line treatment. There are a variety of anti-TNF agents available, including infliximab (brand names Remicade, Remsima), adalimumab (brand names Humira, Imraldi), golimumab (brand name Simponi), certolizumab (Cimzia), and etanercept (Enbrel).
Disease features and symptoms, as well as 12 radiographic parameters, were measured at enrollment, upon changing treatment agents, and every six months during a mean period of 1.5 years of follow-up.
Analysis of the two groups of patients — those who were kept in standard treatment and those who switched — showed significantly different baseline characteristics.
Those who switched to anti-TNF-alpha agents were older and had significantly worse mean Bath AS Disease Activity Index (BASDAI) scores (a measure of disease activity and severity) and inflammatory status, as measured by erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values, in the beginning of the study.
Concerning baseline radiologic parameters, the team found that thoracic kyphosis — curvature of the spine in the thoracic region — was significantly higher among anti-TNF-alpha treated patients, whereas other radiologic parameters were similar between the two groups.
After treatment, those who switched to anti-TNF-alpha therapies showed significantly greater lumbar lordosis — the normal spine curvature in the upper and lower back — than those treated with NSAIDs and Azulfidine. Patients who switched treatments also showed significantly better clinical outcomes, including reduced ESR, CRP, and BASDAI scores.
Treatment with NSAIDs and Azulfidine did not induce significant changes in any of the radiologic parameters analyzed. However, it effectively reduced disease activity from 6.2 points in BASDAI score before the treatment to 2.7 points afterwards.
“This study is the first to demonstrate a clear association between treatment agents and radiologic parameters in ankylosing spondylitis,” researchers stated.
Researchers think that greater lumbar lordosis could be a relevant predictor of BASDAI score improvement among patients treated with anti-TNF-alpha therapies. However, additional studies are still warranted to better understand the relevance of these findings and the correlation of such radiographic changes.