According to Dr. Robert Landewé, University Hospital Maastricht, Netherlands, “In ankylosing spondylitis (AS), unlike in RA, the relationship between clinical disease activity and signs of the disease as shown by imaging tools, is still very unclear. We expect that inflammation of the spine as measured by clinical tools is associated with inflammation as seen on MRI and leads to the formation of syndesmophytes, however the evidence for that is pretty scarce.” Recent work by Dr. Landewé and colleagues suggests that short tau inversion recovery (STIR) MRI imaging of inflammatory lesions in the spine provides on average the same information as gadolinium-enhanced T1-weighted imaging with fat saturation. Dr. Landewé recommends doing STIR and saving TI/gad for non-typical cases.

Two Studies Highlight Key Aspects

Dr. Désirée van der Heijde University Hospital, Maastricht, Netherlands, presented the results of a an open-label, long-term extension study which investigated the effects of two years of treatment with etanercept (25 mg twice weekly) on radiographic progression in patients with AS. Cervical and lumbar spine x-rays, performed at baseline and after 2 years, were compared with x-rays from subjects in the Outcome in AS International Study (OASIS) taken in the same time frame. In this study, although clinical findings demonstrate sustained, durable benefits with long-term etanercept therapy, x-ray evaluations suggested that progression of structural damage continued. The results of this study indicate that the effect of etanercept treatment beyond 2 years on progression of structural damage warrants further study.

Dr. Marte Heiberg, Diakonhjemmet Hospital, Oslo, Norway, presented the results of a study that compared the one-year survival rates of TNF-blocking agents in patients with RA, PsA and AS, which showed that anti-TNF+methotrexate (MTX) performed better than anti-TNF monotherapy in patients with RA and PsA. Data from 1168 patients (RA n=796; PsA n=161; AS n=211) who received treatment with TNF-blocking agents were analyzed. Crude overall survival rates for anti-TNF treatment were assessed in a Kaplan-Meier analysis, with adjustments for age, gender and treatment regimen in a Cox regression analysis. RA was used as the reference group. Within each diagnostic group survival rates were compared between anti-TNF monotherapy and TNF+ MTX, adjusting for age and gender.

Crude one-year survival rates for anti-TNF treatment in patients with RA, PsA and AS were 67.1%, 78.3% and 82.1%, respectively (p<0.001 for both PsA and AS vs RA). Within the respective groups 65%, 68% and 35% received concomitant MTX. The Relative Risk (95%CI) for withdrawal from TNF+MTX versus anti-TNF monotherapy was 0.54 (0.42, 0.69) in RA patients, 0.49 (0.25, 0.96) in PsA patients, and 0.83 (0.42, 1.62) in AS patients.

After adjustments for age, gender, and treatment regimens the survival rates were still superior in patients with AS vs RA, whereas the survival rates were similar in patients with RA and PsA.

Ankylosing spondylitis is the most severe of the diseases that make up the spondyloarthritides (SpA) and new approaches to assessment and treatment have been the subject of much interest over the last few years. Both clinicians and patients stand to benefit from this research.