What TNF (Tumor Necrosis Factor) inhibitor is recommended for sacroiliitis involving the SIJ (Sacroiliac Joint)?

TNF Inhibitors for Sacroiliitis

For patients with active sacroiliitis involving the sacroiliac joint (SIJ), TNF inhibitors are strongly recommended as the treatment of choice after failure of NSAIDs. 1

Treatment Algorithm for Sacroiliitis

First-line Treatment:

• Begin with NSAIDs for 2-4 weeks
• Trial at least two different NSAIDs at maximal doses for at least 2-4 weeks each
• NSAID failure is defined as lack of response after 1 month of continuous use with at least two different NSAIDs 2

Second-line Treatment (When NSAIDs Fail):

• TNF inhibitors (TNFi) are strongly recommended as the next step 1
• Options include:
  • Etanercept
  • Adalimumab
  • Infliximab
  • Golimumab

Choice of TNF Inhibitor:

• No particular TNFi is recommended over others for typical sacroiliitis cases 1
• Selection considerations:
  • For patients with concomitant inflammatory bowel disease: Consider infliximab or adalimumab
  • For patients with recurrent uveitis: Consider monoclonal antibodies (adalimumab, infliximab) over etanercept
  • For patients at higher risk of tuberculosis or recurrent infections: Consider TNFi other than infliximab 1
  • Patient preferences regarding dosing frequency and administration route

Evidence for TNF Inhibitors in Sacroiliitis

TNF inhibitors have demonstrated significant efficacy in treating sacroiliitis:

• Etanercept has shown effectiveness in reducing bone marrow edema in the SIJ by 46.9% versus 10.9% with placebo (p<0.001) 3
• Etanercept treatment is associated with rapid improvement in symptomatic disease activity, function, and inflammation in axial spondyloarthritis 3
• A study showed that etanercept therapy over 2 years resulted in improvement in total SIJ score (-0.14) while patients not receiving biologics showed worsening (0.08) 4

Alternative Options

If TNF inhibitors fail or are contraindicated:

1. IL-17 inhibitors (secukinumab or ixekizumab) are strongly recommended as alternatives 1, 2

2. Sulfasalazine is conditionally recommended only for patients who:

   • Have contraindications to TNFi
   • Have failed more than one TNFi
   • Have predominant peripheral arthritis 1, 2

3. Methotrexate monotherapy is strongly recommended against for sacroiliitis, though it may be useful as adjunct therapy for concomitant peripheral polyarthritis 1, 2

Adjunctive Therapies

• Glucocorticoids: Short-term oral glucocorticoids (<3 months) may be used as bridging therapy during initiation or escalation of other treatments 1, 2

• Intra-articular injections: Conditionally recommended for isolated active sacroiliitis that fails to respond to NSAIDs 2

• Physical therapy: Conditionally recommended throughout treatment, focusing on pelvic girdle stabilization exercises 1, 2

Monitoring Response

• Assess treatment response after 2-4 weeks of NSAID therapy and 6-12 weeks of TNFi therapy
• Use standardized measures like ASDAS to monitor disease activity
• Consider MRI to assess reduction in bone marrow edema as a marker of response 5

Cautions and Considerations

• Screen for tuberculosis, hepatitis B, and other infections before initiating TNFi therapy
• TNFi may increase risk of infections, particularly with infliximab 6
• Etanercept is less effective for extra-articular manifestations like inflammatory bowel disease and possibly uveitis 6
• Consider dose tapering of TNFi in patients who show quick decrease of bone marrow edema in SIJ 5

By following this treatment algorithm and selecting the appropriate TNF inhibitor based on individual patient factors, optimal control of sacroiliitis can be achieved with improved outcomes in terms of pain, function, and quality of life.