What is the recommended treatment for a patient presenting with ankylosing spondylitis?

Ankylosing Spondylitis: Presentation and Treatment

Clinical Presentation

Ankylosing spondylitis presents as chronic inflammatory arthritis characterized by sacroiliitis, enthesitis, and progressive sacroiliac joint and spinal fusion. 1

Key diagnostic features include:

• Low back pain and stiffness lasting >3 months that improves with exercise but not rest 2
• Radiological evidence of sacroiliitis on imaging 2
• Elevated inflammatory markers (ESR, CRP) and positive HLA-B27 in most cases 2
• Extra-articular manifestations including uveitis, inflammatory bowel disease, and peripheral arthritis 3

Treatment Algorithm

First-Line: NSAIDs + Physical Therapy

NSAIDs are the cornerstone first-line pharmacological treatment and should be initiated immediately for all patients with pain and stiffness. 1, 2

• Continuous NSAID therapy is preferred over on-demand use for patients with persistently active disease, as emerging evidence suggests it may retard radiographic progression 3
• Level Ib evidence demonstrates NSAIDs improve spinal pain, peripheral joint pain, and function over 6 weeks 2, 3
• For patients with gastrointestinal risk, prescribe either non-selective NSAIDs plus gastroprotective agents or selective COX-2 inhibitors 2, 3

Physical therapy and regular exercise must be initiated immediately upon diagnosis and continued throughout the disease course. 1, 2

• Group physical therapy demonstrates superior patient global assessment outcomes compared to home exercise alone 3
• Both supervised and home exercise programs improve function with Level Ib evidence 3

Second-Line: TNF Inhibitors

TNF inhibitor therapy should be initiated in patients with persistently high disease activity (BASDAI >4) despite adequate trials of at least two different NSAIDs at maximum tolerated doses for at least 3 months each. 1, 2, 3

• All TNF inhibitors (infliximab, etanercept, adalimumab, certolizumab, golimumab) show equivalent efficacy for axial and peripheral manifestations 3
• For patients with concomitant inflammatory bowel disease or recurrent uveitis, TNF inhibitor monoclonal antibodies (infliximab, adalimumab, certolizumab, golimumab) are strongly preferred over etanercept 1
• There is no evidence requiring DMARD use before or concomitant with anti-TNF therapy for axial disease 3

Third-Line: IL-17 Inhibitors

For patients with inadequate response to the first TNF inhibitor, either switch to a different TNF inhibitor (for secondary non-responders) or consider IL-17 inhibitors like secukinumab or ixekizumab (for primary non-responders). 1

• Secukinumab 150 mg subcutaneously at weeks 0,1,2,3,4, then every 4 weeks demonstrates ASAS20 response rates of 61% at week 16 4
• For secondary TNF non-responders, switching to a different TNF inhibitor is conditionally recommended over non-TNF biologics 1
• For primary TNF non-responders, secukinumab or ixekizumab are conditionally recommended over switching to another TNF inhibitor 1

What NOT to Do

Systemic glucocorticoids are strongly contraindicated for axial disease due to lack of efficacy and significant side effects. 1

• Local glucocorticoid injections may be used for isolated sacroiliitis, peripheral arthritis, or enthesitis when axial disease is stable 1
• Avoid peri-tendon injections of Achilles, patellar, and quadriceps tendons 1

Conventional synthetic DMARDs (sulfasalazine, methotrexate) have no proven efficacy for axial disease and should not be used as monotherapy. 1

• Sulfasalazine may have modest benefit for peripheral arthritis only 1
• Adding methotrexate to TNF inhibitors is conditionally recommended against 1

Common Pitfalls to Avoid

Inadequate NSAID trials before declaring treatment failure - must try at least two different NSAIDs at maximum tolerated doses for at least 3 months each before escalating to biologics 2

Switching from originator TNF inhibitor to its biosimilar in stable patients - this is strongly recommended against as a mandated approach 1

Discontinuing or tapering biologics in stable disease - both are conditionally recommended against as standard approaches 1

Overreliance on imaging without clinical correlation - diagnosis and treatment decisions must integrate clinical symptoms with imaging findings 2

Failure to screen for tuberculosis before initiating biologics - evaluate for active or latent TB and treat latent TB before starting TNF inhibitors or IL-17 inhibitors 4

Surgical Considerations

Total hip arthroplasty should be considered for patients with refractory pain or disability and radiographic evidence of advanced hip arthritis, independent of age. 1, 3

Spinal corrective osteotomy may be considered for severe disabling deformity. 3