• Rheumatology Clinical Trials
• Inflammatory Disorders

When the inflammation of ankylosing spondylitis (AS) subsides, it may be replaced by repair tissue and fatty lesions, a process that leads to osteoproliferation and development of syndesmophytes. Results from clinical trials suggest that new bone formation is not inhibited or enhanced by anti-tumor necrosis factor (TNF) therapy. Xenofon Baraliakos, MD, Rheumazentrum Ruhrgebiet Herne, Herne, Germany, presented results from the European Ankylosing Spondylitis Infliximab Cohort [EASIC] study, an open-label extension of the Ankylosing Spondylitis Study for the Evaluation of Recombinant Infliximab Therapy [ASSERT]. The objective of the EASIC study was to directly compare the effect of inflammation and fatty degeneration on the development of syndesmophytes in patients with AS after 5 years of anti-TNF therapy.

The aim of the ASSERT Study was to evaluate the effect of infliximab on the progression of structural damage over 2 years in patients with AS. A total of 279 patients participated. After a mean of 1.3±0.9 years, 103 patients from ASSERT were enrolled in the EASIC substudy. Complete magnetic resonance imaging (MRI) data at baseline and 2 years and x-ray data at baseline, 2 years, and 5 years were available for 73 EASIC patients. Assessments were blinded with respect to the time points of MRI and x-ray studies. Only the anterior edges of the cervical and lumbar spine were analyzed. Baseline lesions were compared with radiographic progression at 2 and 5 years after adjustment for within-patient variation.

At baseline, the mean (± standard deviation [SD]) age of patients was 40.5±10.5 years; 86.3% of patients were men, and the mean (±SD) disease duration was 10±8.4 years. Patients had mean (±SD) Bath Ankylosing Spondylitis (BAS) Disease Activity Index scores of 6.5±1.4, BAS Functional Index scores of 5.9±1.6, BAS Metrology Index scores of 4.1±1.7, and C-reactive protein (CRP) levels of 2.9±2.3 mg/dL, and 83.6% was human leukocyte antigen B27-positive.

At 2 years, radiographic progression had occurred in 0.7% (n=10) of patients with baseline inflammation and 0.9% (n=13) of patients with baseline fatty degeneration. At 5 years, radiographic progression was present in 1.0% (n=14) of patients with baseline inflammation and 1.4% (n=21) of those with fatty degeneration. Among patients with both inflammation and fatty degeneration at baseline, radiographic progression was present in 2.1% (n=20) at 2 years and 3.7% (n=35) at 5 years.

Bone formation in the cervical and lumbar spine was limited in patients with AS who received anti-TNF therapy for 5 years. Bone inflammation and fatty changes at baseline appear to influence new bone formation. The combination of inflammatory lesions and fatty lesions is most likely to lead to development of new syndesmophytes. Numerically, most new syndesmophytes could not be explained by baseline inflammation or fatty changes. The author concluded that early treatment of active lesions should be the aim of anti-TNF therapy for regression of syndesmophytes in patients with AS.

• © 2012 MD Conference Express®