International ASAS consensus statement for the use of anti-tumour necrosis factor agents in patients with ankylosing spondylitis.

OBJECTIVE: To obtain an international consensus about the use of anti-tumour necrosis factor alpha (anti-TNF alpha) for treating patients with ankylosing spondylitis (AS).
METHODS: These recommendations were developed by a review of published reports in combination with expert opinion, including a Delphi exercise, and a consensus meeting of the ASsessments in AS (ASAS) Working Group.
RESULTS: The final consensus comprises the following requirements: (1) For the initiation of anti-TNF alpha therapy: (a) a diagnosis of definitive AS; (b) presence of active disease for at least four weeks as defined by both a sustained Bath AS Disease Activity Index (BASDAI) of at least 4 and an expert opinion based on clinical features, acute phase reactants, and imaging modalities; (c) presence of refractory disease defined by failure of at least two non-steroidal anti-inflammatory drugs during a single three month period, failure of intra-articular steroids if indicated, and failure of sulfasalazine in patients with peripheral arthritis; (d) application and implementation of the usual precautions and contraindications for biological therapy. (2) For the monitoring of anti-TNF alpha therapy: both the BASDAI and the ASAS core set for clinical practice should be followed regularly. (3) For the discontinuation of anti-TNF alpha therapy: in non-responders, consideration should be made after 6-12 weeks' treatment. Response is defined as improvement of (a) at least 50% or 2 units (on a 0-10 scale) of the BASDAI, (b) expert opinion that treatment should be continued.
CONCLUSION: This consensus statement on anti-TNF alpha treatment in AS may be used for guidance in clinical decision making and as the basis for the development of guidelines. Evaluation of the healthcare consequences of this consensus is subject to further research by the ASAS group.