Interest of Continuous Non-Steroidal Anti-Inflammatory Drug Treatment in Ankylosing Spondylitis Patients Treated by Anti-TNF Therapy in the Prevention of Radiographic Outcomes

Ankylosing spondylitis (AS) is a frequent chronic inflammatory rheumatic disease that affects the axial skeleton, starting in the sacroiliac joints and spreading to the spine in most patients. Non-steroidal anti-inflammatory drugs (NSAIDs) are the primary treatment for AS. Even if the use of anti-TNF agents has demonstrated good clinical efficacy in controlling inflammation, in contrast to other conditions such as rheumatoid arthritis and psoriatic arthritis, anti-TNF treatment has failed to demonstrate any benefit on the structural progression of AS, some data even suggesting that it may accelerate the formation of syndesmophytes that seems to be an independent process of TNF. Conversely, NSAIDs inhibit ossification phenomena independently of their anti-inflammatory properties, owing to a specific action on bone formation via prostaglandin inhibition.

Several features suggest that a continuous NSAID therapy is needed, in addition to anti-TNF treatment, to prevent syndesmophyte formation in AS patients.