Rheumatologists considered both disease activity and severity as determinants in starting tumor necrosis factor-alpha (TNF-a) blockers in ankylosing spondylitis (AS) patients, according to a real world practice study conducted prior to the 2003 dissemination of the Assessment in AS (ASAS)  international working group recommendations. Rheumatologists wanted to initiate TNF-blocking drugs in approximately half of AS patients. However, there is a wide variation across countries and physicians, according to the study, which appears in the online edition of the Annals of Rheumatic Disease.¹

In the new study, rheumatologists from 10 different countries evaluated patients to determine whether they were candidates for anti-TNF-a treatment based on their routine clinical practice. A metrologist then assessed the patient for disease activity and severity, and collected data on demographics and treatment. Overall, the rheumatologists indicated that they would initiate TNF-blocking agents in 49.3% of patients, ranging from 37.2% in Canada to 78.3% in Australia. Potential candidates had higher disease activity, higher levels of acute phase reactants, worse spinal mobility, worse function, more frequent hip involvement, and a higher prevalence of sick leave.

However, of all the patients considered candidates, 40% did not fulfill ASAS recommendations with respect to previous nonsteroidal anti-inflammatory drug (NSAID) use of at least two NSAIDs and/or the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) level of >4. Moreover, 36% of patients who did not fulfill the NSAID/BASDAI recommendations were still considered candidates for TNF-blocking treatment by the physicians, according to the new report.

Overall, objective variables, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and magnetic resonance imaging (MRI) activity, were considered less important than disease activity in the decision to start TNF blockade, the study showed. The only important objective criterion in the study was rapid radiographic progression.

"The data show that there is only moderate agreement between the patients selected by rheumatologists and ASAS recommendations," says study author Désirée van der Heijde, MD, professor of rheumatology at University Hospital, Maastricht University, in the Netherlands. "One of the reasons might be that rheumatologists at the time of the study were not very familiar with the use of TNF blockade in AS."

"The study will be repeated in the near future to see what the influence of the ASAS recommendations is," Dr. van der Heijde tells CIAOMed. "The ASAS recommendations are the ones to follow when starting TNF blockade."

Reference

1. Pham T, Landewé  R, van der Linden S, et al. An international study on starting TNF-blocking agents in ankylosing spondylitis. Ann Rheum Dis [serial online]. February 7, 2006; doi:10.1136/ard.2005.042630.