Characteristics and treatment responses of patients satisfying the BSR guidelines for anti-TNF in ankylosing spondylitis.

OBJECTIVE: We present the results of the response to anti-tumour necrosis factor (anti-TNF) of 30 ankylosing spondylitis (AS) patients where we have complied with the BSR guidelines.

METHOD: All patients had pre-assessments of Bath AS Disease Activity Index (BASDAIs) at two points a month apart prior to commencing anti-TNF. They then had 2 week and 2 month assessments followed by 3 monthly thereafter. BASDAI, visual analogue scales, blood count and erythrocyte sedimentation rate (ESR) were performed on each occasion.

RESULTS: All patients had stable active disease at the pre-assessments with a mean BASDAI of 6.8. Twenty-nine patients showed a rapid and dramatic response with a mean BASDAI at 2 months assessment of 3.2 (P < 0.001). This was maintained for up to 20 months of follow up. Haemoglobin rose significantly (mean of 13.0 g/dl to 13.8) and the ESR dropped from 49 mm/h to 23 (both P < 0.001). Fifteen patients (51.7%) were able to stop their non-steroidal anti-inflammatory drugs (NSAIDs) and a further eight reduced them.

CONCLUSION: Patients who fulfil the BSR guidelines for anti-TNF in AS have sustained active inflammatory disease prior to going onto etanercept or infliximab. Despite this, they show rapid, dramatic sustained responses to treatment, and over half are able to stop their NSAIDs. Any health economic analyses of anti-TNF in UK clinical practice need to take these observations into account.