A Case of Hydralazine‐Induced ANCA Vasculitis/Lupus Overlap Syndrome Presenting as Persistent Bicytopenia

<b>Background:</b> Hydralazine is a commonly used arteriolar vasodilator that is associated with autoimmune side effects, including drug-induced lupus. A less well-recognized drug-induced vasculitis can be seen, often accompanying drug-induced lupus. This syndrome can cause long-standing vague symptoms, leading to missed diagnoses, and can result in permanent end-organ damage. We describe here such a case of hydralazine-induced vasculitis and lupus overlap syndrome. <b>Case Presentation:</b> An 85-year old male presented with chronic fatigue and weight loss associated with anemia, leukopenia, and acute renal injury in the setting of longstanding hydralazine use. Serologic studies were notable for a positive antinuclear antibody, antihistone antibody, along with anti-myeloperoxidase (MPO) and anti-proteinase 3 (PR3) antibodies. Hydralazine was discontinued, and treatment was initiated with high-dose prednisone. A renal biopsy revealed antineutrophil cytoplasmic antibody (ANCA)-associated focal necrotizing pauci-immune glomerulonephritis. The patient's clinical course was complicated by the development of oral ulcerations and recurrent hydrocele secondary to serositis. Rituximab was then employed without clinical improvement, with eventual progression to end-stage renal disease requiring hemodialysis. <b>Conclusions:</b> This case report helps highlight the vague symptoms that can be associated with hydralazine-induced vasculitis/lupus overlap syndrome. This case will increase clinician awareness for early recognition of such a syndrome, prompting early diagnosis, preventing end-organ damage, reducing hospitalizations and improving quality of life.