Spinal radiographic damage progression can be observed after just 2 years follow-up in patients with early axial spondyloarthritis (axSpA), according to data published in Arthritis Care & Research. Higher radiographic progression was associated with increased inflammation and damage, while the presence of baseline syndesmophytes was predictive of later structural damage even in the early stages of disease.
Researchers extracted data from the DESIR cohort study, a 10-year follow-up of inflammatory back pain conducted in France. Patients with axSpA and available cervical and lumbar spinal radiographs were included in the present analyses (n=549). Radiographs had been performed at baseline and at 2 and 5 years follow-up, according to the DESIR protocol. The presence of syndesmophytes was captured at each radiographic visit. Analyses were performed by patient subgroup defined at baseline according to the Assessment of Spondyloarthritis International Society (ASAS) criteria, the modified New York Criteria (mNYC), and the presence or absence of syndesmophytes.
Patients who were positive for axSpA per the ASAS criteria were further divided into imaging and clinical groups, based on which measures were available from the DESIR dataset. Patients in the imaging group had magnetic resonance imaging (MRI) data available, through which they were classified as either positive or negative for axSpA. Patients in the clinical group were instead classified based on C-reactive protein positivity. Radiographs were scored using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), with an mSASSS value >0 indicating axSpA progression.
Participants in the study were mean age 34, with mean symptom duration 1.5 years. Nearly half (46%) were men and 61% were HLA-B27 positive. The majority of patients (63%) fulfilled the ASAS classification criteria, while just 13% fulfilled the mNYC. Of the participants, 7% had ≥1 baseline syndesmophytes, of whom 42% did not fulfill the ASAS classification criteria. At baseline, mean mSASSS was 0.5 in all patients, 0.6 in patients who did not fulfill ASAS criteria, and 0.4 in patients who fulfilled the ASAS criteria. The mean 2-year and 5-year mSASSS progression scores were 0.2 and 0.4, respectively, across all patients. After adjustments for baseline differences, 5-year progression was slightly higher in patients who did not fulfill ASAS criteria (0.6) compared with patients who fulfilled the criteria (0.3). Patients who fulfilled mNYC had higher 5-year progression scores (1.0) compared with mNYC-negative patients. Within the imaging group, patients with MRI-positive axSpA who fulfilled mNYC had the highest 5-year progression score (1.3), followed by patients with by MRI-negative axSpA with positive mNYC (0.3) and patients with MRI-positive axSpA with negative mNYC (0.3).
Patients with syndesmophytes at baseline had the highest 5-year progression (2.7) compared with those without syndesmophytes (0.2). At the 5-year follow-up, 23% of patients showed mSASSS progression (mSASSS >0). Progression was more common in those who fulfilled ASAS (26%) or mNYC (30%) and highest in those with baseline syndesmophytes (74%). At 5-year follow-up, 91% of patients did not indicate any new syndesmophytes. The percentage of patients showing any new syndesmophytes was 7% in all patients, 17% in patients who fulfilled mNYC, and 10% in the imaging groups. Within the imaging group, 5% of mNYC-negative patients indicated new syndesmophytes compared with 18% of mNYC-positive patients. In addition, 42% of patients with baseline syndesmophytes developed new syndesmophytes, the highest percentage for any baseline axSpA category.
According to these data, it appears that spinal radiographic damage progression can be captured at 2- and 5-year follow-up in individuals with early axSpA. The imaging group indicated more progression than the clinical group, with the highest progression observed in patients with MRI-positive axSpA who fulfilled mNYC. Inflammation and damage in the sacroiliac joint according to ASAS and mNYC appear to be associated with higher spinal radiographic progression. In addition, syndesmophytes seem to be predictive of further structural damage. Further research is necessary to explore the influence of sociodemographic factors on radiographic progression, including gender, HLA-B27 positivity, smoking status, and medication use.
Ramiro S, van der Heijde D, Sepriano A, et al. Spinal radiographic progression in early axial spondyloarthritis: Five-year results from the DESIR cohort [published online October 24, 2018]. Arthritis Care Res. doi:10.1002/acr.23796