A 48-year-old man with known GPA (granulomatosis with polyangiitis, formerly Wegener's) is in remission on azathioprine. He develops worsening haematuria and is found to have anti-PR3 ANCA titre rising from 1:40 to 1:320. Creatinine is stable at 1.1 mg/dL. The MOST appropriate next action is:

• A Immediate high-dose cyclophosphamide and prednisolone pulse
• B Monitor clinically; rising ANCA alone without organ-threatening manifestations does not mandate treatment escalation ✓
• C Switch azathioprine to rituximab maintenance immediately
• D Start plasma exchange to reduce ANCA titre before organ damage occurs

Explanation

EULAR and ACE guidelines do not recommend escalating immunosuppression based on rising ANCA titre alone in the absence of clinical relapse or new organ-threatening manifestations. ANCA titres can fluctuate without clinical relapse. Close monitoring is appropriate; treatment is escalated only when clinical or biopsy evidence of active vasculitis appears. Rituximab is an alternative maintenance agent but should not replace azathioprine without clear clinical indication.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.