TNF inhibitors may slow radiographic progression in ankylosing spondylitis
medwireNews: Patients with ankylosing spondylitis taking tumor necrosis factor (TNF) inhibitors experience slower rates of radiographic progression than those not taking TNF inhibitors, suggest long-term, real-world findings.
The researchers analyzed data from a single center pertaining to 338 patients (90% male) who were treated with a TNF inhibitor at least once between 2001 and 2018. They identified 1281 intervals of exposure to TNF inhibitors, which were calculated from prescription records and took into account the typical dosing intervals for each drug and washout periods, and 1083 intervals when patients were not taking TNF inhibitors.
TNF inhibitor use was significantly associated with a reduced rate of change in mSASSS, indicative of a slower rate of radiographic progression. Indeed, in a marginal structural model with inverse probability of treatment weighting, which allowed the assessment of causal effects, the adjusted annual change in mSASSS change was 0.848 when patients were taking TNF inhibitors versus 0.960 when not taking TNF inhibitors, giving a β estimate of –0.112.
The results were similar in a multivariable analysis, with adjusted changes in mSASSS scores per year of 0.914 and 0.970 in TNF inhibitor exposed versus unexposed intervals, and a β estimate of –0.054.
As reported in the Annals of the Rheumatic Diseases, female sex (β=–0.561) and higher BASDAI score at the start of the interval (β=–0.225) were also significantly associated with reductions in mSASSS change rates in the multivariable analysis.
On the other hand, eye involvement (β=0.420) and higher erythrocyte sedimentation rate at the start of the interval (β=0.199) were significantly associated with increases in mSASSS change rates.
Tae-Hwan Kim (Hanyang University Hospital for Rheumatic Diseases, Seoul, Republic of Korea) and colleagues conclude that TNF inhibitor treatment “is among the modifiable factors for radiographic progression in patients with [ankylosing spondylitis].”
But they caution that the study had several limitations, including not accounting for smoking status, which is known to significantly affect radiographic progression, as well as the exclusion of patients who had never been exposed to TNF inhibitors.
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