Rituximab Can Induce Remission in a Patient with Ankylosing Spondylitis Who Failed Anti-TNF-α Agent

Patient: Male, 38 Final Diagnosis: Ankylosing spondylitis Symptoms: Back pain • morning stiffness Medication: — Clinical Procedure: Not applicable Specialty: Rheuamatology OBJECTIVE: Unusual or unexpected effect of treatment BACKGROUND: Ankylosing spondylitis (AS) is a chronic inflammatory disease that predominantly affects the axial skeleton. The ability of anti-TNF-α agents to reduce disease activity in patients with axial spondyloarthritis (axSpA), including AS, has been demonstrated in multiple randomized trials and several meta-analyses. Reports on the efficacy of rituximab in treatment of AS have described good results. We report on a patient with AS who failed anti-TNF-α therapy but showed good clinical improvement with rituximab therapy. CASE REPORT: A 38-year-old male patient was diagnosed with AS and showed poor response to sulfasalazine and non-steroidal anti-inflammatory drugs (NSAIDs). Infliximab was initiated with marked improvement as per the Bath ankylosing spondylitis disease activity index (BASDAI). Due to disease flare, the patient was switched to etanercept. He subsequently acquired papillary thyroid cancer and etanercept was discontinued. He underwent a total thyroidectomy followed by radioiodine therapy. For his ongoing active disease, NSAIDs and sulfasalazine were resumed with a lack of response (BASDAI=7.1). Rituximab was started and resulted in significant improvement (BASDAI=2.3). CONCLUSIONS: Rituximab can be a potential target therapy for patients who start to lose response to TNF-inhibitors or for those who develop solid malignancies. Further placebo-controlled studies are required.