Presence of subclinical inflammation in axial spondyloarthritis patients with NSAID/anti-TNF-α drug-induced clinical remission

To investigate the rate of subclinical inflammation in patients with axial spondyloarthritis (axSpA) with nonsteroidal anti-inflammatory drug (NSAID)/anti-tumor necrosis factor (TNF)-α drug-induced clinical remission and to explore factors influencing clinical and imaging remission.One hundred twenty-five patients with axSpA followed up for at least 6 months were enrolled in this prospective study and randomly divided into two groups. Ninety patients were treated with anti-tumor necrosis factor (TNF)-α or anti-TNF-α combined with nonsteroidal anti-inflammatory drugs (NSAIDs) (anti-TNF-α treatment group), and thirty-five patients were treated with only NSAIDs (non anti-TNF-α treatment group). The improvements in the clinical remission rate, imaging remission rate, and disease parameters before and after the different treatments were compared. Risk factors for clinical and imaging remission were analyzed by multivariate logistic regression analysis.The clinical and imaging remission rate was increased after treatment especially in the anti-TNF-α group (P 0.001). The remission rate of imaging in the group with clinical remission was higher than that in the group with clinical non-remission (P 0.05). After treatment, the remission rates of imaging in the clinical remission and non-remission group were significantly higher than those before treatment (P 0.0001). The results of multivariate logistic regression analysis showed that higher CRP was a risk factor for failure of clinical remission in axSpA (OR = 2.034, 95% CI:1.595 ~ 2.617, P 0.001), while higher ASDAScrp was a risk factor for failure of imaging remission (OR = 1.306, 95% CI:1.026 ~ 1.688, P 0.05). Anti-TNF-α treatment was a protective factor for both clinical (OR = 0.234, 95% CI:0.091 ~ 0.605, P 0.05) and imaging remission (OR = 0.511, 95% CI:0.286 ~ 0.914, P 0.05).Even after regular treatment, some clinical remission patients continued to have evidence of subclinical inflammation. Higher CRP and ASDAScrp are risk factors for clinical and imaging non-remission in axSpA respectively, Continuous NSAID treatment (more than 1 year) can effectively improve clinical and MRI inflammation in patients, but anti-TNF-α treatment is more beneficial for clinical and imaging remission. Key Points • Some patients achieving ASDAScrp remission status continue to have inflammation when assessed with objective imaging techniques. • MRI can sensitively measure bone marrow inflammation and may provide a more accurate assessment of remission. • Controlling inflammation, especially reducing CRP and ASDAScrp levels, is a key factor for achieving clinical and imaging remission in patients with axSpA.