Overlapping drug-induced vasculitis, ANCA-associated vasculitis, and lupus nephritis caused by low-dose hydralazine.

Introduction: We present a case of drug-induced vasculitis secondary to low-dose hydralazine with overlapping features of antineutrophil cytoplasmic antibody-associated vasculitis and drug-induced lupus nephritis.

Case Presentation: A 52-year-old Hispanic woman with a medical history of resistant hypertension treated with hydralazine 10 mg twice daily for 1 year presented with generalized weakness, dizziness, nausea, vomiting, and gross hematuria. There was fever, tachycardia, leukocytosis, lactic acidosis, hyperkalemia, renal failure, and anemia. Chest computed tomography and bronchoscopy revealed a left lower lobe infiltrate and diffuse alveolar hemorrhage. Serologic testing was positive for anti-double-stranded DNA, anti-Smith, lupus anticoagulant, anti-histone, anti-cardiolipin IgM antibodies, and antineutrophil cytoplasmic antibodies (myeloperoxidase and proteinase 3). A kidney biopsy revealed crescentic glomerulonephritis with an overlapping finding of membranous nephropathy. Broad-spectrum antibiotics, immunosuppressants, corticosteroids, and plasmapheresis were initiated. The patient survived but required continuous hemodialysis.

Conclusions: Although a few cases of simultaneous antibody-associated vasculitis and drug-induced lupus nephritis secondary to hydralazine use have been reported, this case is singular. Similar findings were previously reported with doses of 50-100 mg two to three times daily over 1-5 years. In our patient, a dose of only 10 mg twice daily for a year caused a severe disease presentation. This brings to light the combination of different vasculitides that can coexist and the potentially life-threatening adverse effects of low-dose hydralazine that should be kept in mind.