An inflammatory burden higher than previously suspected was found among patients with early peripheral spondyloarthritis (pSpA), according study results published in Annals of the Rheumatic Diseases.
Researchers sought to evaluate axial involvement on magnetic resonance imaging (MRI) among patients with early pSpA and to explore whether axial inflammation was predictive of relapse on treatment withdrawal.
A total of 56 participants from the single-center, double-blind, placebo-controlled Clinical Remission in Peripheral Spondyloarthritis (CRESPA) study who had early, active, newly diagnosed pSpA received MRI of the sacroiliac joints (SIJs) and the spine before initiation of the tumor necrosis factor (TNF) inhibitor golimumab. The treatment was withdrawn and a second MRI was conducted at sustained clinical remission of pSpA.
Bone marrow edema was scored by 3 readers based on use of the Spondyloarthritis Research Consortium of Canada (SPARCC) technique, and these scores were then compared to those from an axial SpA group, the Belgian Arthritis and Spondylitis Cohort. All structural lesions were evaluated using a similar method. In addition, the researchers examined the fulfilment of the Assessment of Spondyloarthritis International Society (ASAS) definition of a positive MRI for sacroiliitis. The Canada-Denmark MRI spine scoring system was used to evaluate all of the spinal images for BME and structural lesions.
Overall, 36% of patients had SIJ BME at baseline, all of whom met the ASAS definition of sacroiliitis. No relationship with back pain was revealed. The SIJ structural lesions were observed in 21% of study participants. Further, spinal BME was limited, with low median inflammation scores and no patients having 5 or more inflammatory lesions.
At clinical remission, a significant reduction in SIJ SPARCC scores with TNF inhibitor therapy was observed among participants with SIJ BME at baseline (P =.041). No significant differences in SIJ SPARCC scores were observed between patients who experienced a relapse and those who were maintained on drug-free remission after treatment discontinuation (P =.51).
A study limitation was the lack of performing MRIs in patients who did not achieve clinical remission.
Researchers concluded, “In patients with early pSpA, a surprisingly high prevalence of sacroiliitis on MRI was observed; SPARCC scores decreased significantly on [TNF] inhibition. Residual inflammation on MRI was not predictive of relapse of peripheral manifestations.” Additional research is warranted to further elucidate the added value of screening for subclinical sacroiliitis, including structural lesions, in patients with suspected pSpA.
Renson T, Carron P, De Craemer AS, et al. Axial involvement in patients with early peripheral spondyloarthritis: a prospective MRI study of sacroiliac joints and spine. Ann Rheum Dis. Published online October 28, 2020. doi:10.1136/annrheumdis-2020-218480