Drug-induced liver injury due to avacopan improved by mycophenolate mofetil: A case report.

RATIONALE: Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is a systemic necrotizing vasculitis that predominantly affects small vessels. Glucocorticoids are the standard therapeutic agents for AAV; however, their long-term use can cause damage. Avacopan is a small-molecule complement component 5a receptor antagonist that reduces vasculitis and can potentially be used as an alternative to glucocorticoids. However, its therapeutic efficacy remains unknown, and drug-induced liver injury (DILI) is a concern associated with its use.

PATIENT CONCERNS: A 74-year-old woman with a history of granulomatosis with polyangiitis was admitted to our hospital with a 1-week history of fatigue and anorexia.

DIAGNOSES: She had started avacopan 3 months before hospitalization. Blood tests showed severe liver injury, and since other diseases were ruled out, she was diagnosed with DILI secondary to avacopan.

INTERVENTIONS: Avacopan was discontinued, and glucocorticoid doses were increased and ursodeoxycholic acid was administered; however, the liver injury did not resolve. Therefore, mycophenolate mofetil (MMF) was started.

OUTCOMES: The liver injury was resolved after starting MMF.

LESSONS: MMF is effective in treating DILI caused by avacopan.