Hydralazine associated pauci-immune glomerulonephritis.

: Hydralazine is a medication that has been used to manage hypertension and heart failure. In this case series, we report 4 patients who presented to a large, Midwestern academic medical center on chronic hydralazine therapy with acute kidney injury, nephritic urine sediment on urine microscopy, and the simultaneous presence of autoantibodies suggesting both drug-induced lupus and drug-induced vasculitis. All of them had evidence of pauci-immune glomerulonephritis on kidney biopsy. All the patients reported in our series are white women older than 60 years who were receiving hydralazine for more than 12 months at a dose of 150 mg or more. On initial presentation, all had evidence of acute kidney injury with nephritic sediment. These patients also had high titers of serum anti-neutrophil cytoplasmic antibodies of the antimyeloperoxidase subtype and simultaneous presence of multiple autoantibodies. All of them subsequently underwent a kidney biopsy, which revealed pauci-immune glomerulonephritis. This case series draws rheumatologists' attention to the possibility of pauci-immune glomerulonephritis in patients taking hydralazine, highlights the presence of multiple antibodies in these cases, and questions the long-term use of hydralazine especially in an elderly female population.