TNF inhibitors may impact hip disease among patients with ankylosing spondylitis

Treatment with tumor necrosis factor inhibitors was associated with decreased radiographic hip progression among patients with ankylosing spondylitis, according to findings presented at the American College of Rheumatology Annual Meeting.

Daphne Scaramangas-Plumley, MD, a rheumatology fellow at Cedars-Sinai Medical Center in Los Angeles, and colleagues hypothesized that tumor necrosis factor (TNF) inhibitors would delay radiographic hip progression in patients with ankylosing spondylitis (AS).

The researchers enrolled 613 patients with AS who met modified New York criteria and had at least two sets of hip radiographs. The Bath Ankylosing Spondylitis Radiologic Index (BASRI) for the hips was used to define a progressor, a patient whose hip scores changed by at least two units between the first and last visits of the study. Patients with BASRI hip scores of less than 4 (n = 579) were included in the progression analysis.

The researchers used a grade 2 change in BASRI score to alleviate issues related to the reliability of reading grade 1 scores. A logistic regression analysis was conducted to examine multivariable associations between use of TNF inhibitors and hip progressors.

Patients were defined as users of TNF inhibitors if they had been treated with an inhibitor for more than 50% of the follow-up period. The logistic regression analysis was conducted after controlling for several factors, including follow-up period, baseline hip scores, baseline TNF inhibitor use, NSAID index throughout the follow-up period and study sites. Clinical and demographic variables were also accounted for, including disease duration, sex, education level, race, current smoking status, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores, C-reactive protein and comorbidities.

In total, 576 patients were included in the analysis. During a median follow-up of 3 years, most patients (n = 551) were determined to be non-progressors.

When measured at baseline, continuous hip score and TNF inhibitor use both correlated with a decreased likelihood of being a hip disease progressor [TNF inhibitor use (yes vs. no), odds ratio = 6.84 (95% CI, 1.21-38.54); hip score (continuous), odds ratio = 1.61 (95% CI, 1.07-2.43)]. Use of TNF inhibitors overall was also linked to a lower likelihood of being a hip disease progressor [TNF inhibitor use (yes vs. no), odds ratio = .02 (95% CI, 0.001-0.24)].

In their conclusion, the researchers wrote that TNF inhibitor use correlated with less radiographic hip progression among patients with AS. In addition, they noted “there was no significant interaction effect found between NSAID and TNF [inhibitor] use.” – by Julia Ernst, MS

Reference:

Scaramangas-Plumley D, et al. Abstract 723. Presented at: The American College of Rheumatology Annual Meeting; Nov. 11-16, 2016. Washington.

Disclosures: Scaramangas-Plumley reports no relevant financial disclosures. Please see the full study for a list of all other researchers’ relevant financial disclosures.