Do NSAIDs Affect Sacroiliitis Visibility on MRI in axSpA?

TOPLINE:

Among patients with axial spondyloarthritis (axSpA) who showed active sacroiliitis on MRI after a washout of non-steroidal anti-inflammatory drugs (NSAIDs), complete resolution of MRI-visible sacroiliitis was seen in one fifth of cases, with close to half showing reduced inflammation after NSAID reintroduction.

METHODOLOGY:

• Researchers conducted a non-randomised crossover trial across 34 centres in the UK between June 2017 and February 2020 to assess whether NSAIDs could mask active sacroiliitis on MRI in patients with axSpA.
• They recruited 311 patients with established or suspected axSpA and daily NSAID usage requiring sacroiliac joint MRI (median age, 42 years; 62% men; 87% White). Data on the clinical assessment were obtained.
• Participants underwent NSAID washout for 1-2 weeks before initial MRI (scan 1). Those who showed positive results for active sacroiliitis underwent a second scan (scan 2) at 6 weeks after resuming daily NSAIDs.
• Images were evaluated by two independent readers using the Leeds MRI scoring method, with scores suggesting no to severe sacroiliitis.
• The primary outcome was the proportion of patients with axSpA who had active sacroiliitis at scan 1 (off NSAIDs) that resolved at scan 2 after NSAIDs were reintroduced (on NSAIDs).

TAKEAWAY:

• Among 286 patients who completed NSAID washout and underwent initial MRI, 146 showed active sacroiliitis, with follow-up scans obtained from 124 patients.
• Overall, 20.2% (95% CI, 13.5%-28.3%) of participants showed complete resolution of active sacroiliitis after NSAID reintroduction.
• Gender analysis showed no significant difference in the risk for sacroiliitis resolution between men and women.
• After NSAID reintroduction, 44% (95% CI, 35%-54%) of patients experienced a reduction in the Leeds score, suggesting improvement in severity.

IN PRACTICE:

“This provides evidence of the effect of NSAIDs on active sacroiliitis and shows that NSAID use prior to MRI may have an important impact on clinical diagnosis. Further, we show that, while patients may experience a deterioration in disease activity and spinal pain during NSAID washout, almost all patients who attempted NSAID washout were able to tolerate it. Thus, stopping NSAIDs for 1-2 weeks prior to MRI scanning in clinical practice should be considered,” the authors wrote.

SOURCE:

This study was led by Gareth T. Jones, PhD, University of Aberdeen, Aberdeen, Scotland. It was published online on June 13, 2025, in Arthritis Care and Research.

LIMITATIONS:

The study protocol did not specifically state NSAID treatment, allowing participants to continue their prescribed medications and dosages.

DISCLOSURES:

This study received funding from Versus Arthritis. Five authors reported having financial ties, such as receiving grant support, honoraria, and consultancy, with multiple pharmaceutical companies, including AbbVie, Biogen, Eli Lilly, Novartis, Pfizer, UCB, Janssen, and others.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.