First‑Line and Subsequent Management of Patients with Co‑existing Ulcerative Colitis, Rheumatoid Arthritis, and Ankylosing Spondylitis

1. TNF‑Inhibitor Selection for Triple‑Disease Presentation

• Infliximab or adalimumab are the preferred TNF‑inhibitor monoclonal antibodies because they are FDA‑approved for ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis, providing simultaneous disease control. Strong recommendation 3
• Golimumab may be used when infliximab or adalimumab are unsuitable, as it has regulatory approval for ulcerative colitis and ankylosing spondylitis, although data in the combined disease setting are limited. Conditional recommendation 4
• Etanercept should be avoided in this population; it lacks efficacy for ulcerative colitis and has been linked to new‑onset Crohn’s disease. Strong recommendation 1
• Certolizumab is contraindicated because, despite approval for Crohn’s disease and ankylosing spondylitis, it has no demonstrated efficacy in ulcerative colitis. Strong recommendation 1

2. Essential Pre‑Treatment Screening

• Screen all patients for latent tuberculosis, hepatitis B, and hepatitis C before initiating any TNF inhibitor to prevent fatal reactivations. Strong recommendation 6
• Obtain baseline complete blood count with differential, liver enzyme panel, and assess for active infections prior to therapy start. Strong recommendation 7
• Specifically test for hepatitis B surface antigen, given the high risk of fatal HBV reactivation with TNF‑blockade. Strong recommendation 6

3. Management After Primary Non‑Response to the First TNF Inhibitor

• Switch to a JAK inhibitor (upadacitinib or tofacitinib) rather than another TNF inhibitor when the initial TNF inhibitor fails to produce a primary response. Strong recommendation 4
• Upadacitinib 15 mg once daily is the preferred JAK inhibitor for this cohort, as the EMA has approved it for both ulcerative colitis and ankylosing spondylitis. Strong recommendation 6
• Tofacitinib is an acceptable alternative JAK inhibitor with proven efficacy in ulcerative colitis and ankylosing spondylitis. Conditional recommendation 1
• Filgotinib should not be used because it lacks an indication for ankylosing spondylitis. Strong recommendation 8

4. Management After Secondary Non‑Response or Intolerance to the First TNF Inhibitor

• Attempt dose escalation of the current TNF inhibitor before changing therapy in patients with secondary loss of response. Conditional recommendation 4
• If dose escalation fails or intolerance occurs, switch to a different monoclonal‑antibody TNF inhibitor (e.g., from infliximab to adalimumab). Conditional recommendation 4
• JAK inhibitors remain an appropriate alternative in this scenario, with expert agreement ranging from 95 % to 100 %. Strong recommendation 5

5. Therapies That Are Absolutely Contraindicated

• IL‑17 inhibitors (secukinumab, ixekizumab) must not be used in patients with active or quiescent ulcerative colitis because they can trigger new‑onset inflammatory bowel disease or worsen existing disease. Strong recommendation 1
• IL‑17 inhibitors may only be considered in exceptional cases of long‑term IBD remission after failure of all other options, with close intestinal monitoring. Conditional recommendation 5
• Sulfasalazine and methotrexate are ineffective for axial ankylosing spondylitis and should not be employed for the spinal component of disease. Strong recommendation 1
• Systemic glucocorticoids have no proven benefit for axial disease and should be avoided in ankylosing spondylitis. Strong recommendation 10
• Non‑steroidal anti‑inflammatory drugs (NSAIDs) are contraindicated in active ulcerative colitis; a short (2–4 week) course of a selective COX‑2 inhibitor is acceptable only when IBD is in remission. Conditional recommendation 4

6. Monitoring Requirements While on TNF Inhibitors

Infection Surveillance

• Continuously monitor for serious infections, especially tuberculosis, as TNF blockade markedly increases infection risk. Strong recommendation 6
• Watch for herpes zoster reactivation, which is common under immunosuppression. Strong recommendation 6
• Discontinue the TNF inhibitor immediately if a serious infection develops and treat the infection according to standard protocols. Strong recommendation 7

Laboratory and Disease‑Activity Monitoring

• Perform serial complete blood counts to detect cytopenias during therapy. Strong recommendation 6
• Regularly monitor liver enzymes to identify potential hepatotoxicity. Strong recommendation 6
• Assess inflammatory markers (ESR, CRP) periodically to gauge disease activity and therapeutic response. Conditional recommendation 7

7. Long‑Term Therapeutic Strategy

• Continue TNF‑inhibitor monotherapy without methotrexate for the ankylosing spondylitis component, as low‑dose methotrexate co‑treatment offers no added benefit. Strong recommendation 12
• Maintain TNF‑inhibitor therapy indefinitely after remission, because discontinuation is associated with a high risk of disease recurrence. Strong recommendation 5
• Do not routinely taper or stop biologic therapy once stable disease is achieved. Strong recommendation 9
• Preserve a structured physical‑therapy program for ankylosing spondylitis throughout treatment; this is a strong recommendation with moderate‑quality evidence. Strong recommendation 10

8. Common Pitfalls to Avoid

• Do not switch a stable patient from an originator TNF inhibitor to its biosimilar; this is strongly discouraged. Strong recommendation 9
• Do not substitute a biosimilar for the first TNF inhibitor when switching due to treatment failure; a different biologic class should be chosen instead. Strong recommendation 1
• Do not add sulfasalazine or methotrexate to a failing TNF inhibitor for axial disease; instead, switch to another biologic agent. Strong recommendation 1
• Do not use rituximab, abatacept, ustekinumab, or IL‑6 inhibitors for ankylosing spondylitis, as they lack efficacy for axial involvement. Strong recommendation 1