Hydralazine-Induced Vasculitis: A Case Report with Negative Kidney Biopsy

Introduction: Hydralazine, a commonly used vasodilator for hypertension, can rarely induce vasculitis, a serious adverse effect. This condition is characterized by the formation of autoantibodies that attack blood vessels, leading to inflammation and tissue damage. In severe cases, such as pulmonary-renal syndrome, it can be rapidly progressive and life-threatening. Here, we present a case of hydralazine-induced p-ANCA vasculitis with a negative renal biopsy. Case Description: 62yoM with CHF, HTN, CVA, T2DM, and PVD presents w/ hemoptysis, SOB, 30lb unintentional weight loss in 6 wks. Also: decr. appetite, nocturnal dyspnea, weakness, joint pain, and night sweats. He initially went to his PCP, who diagnosed him with pneumonia and prescribed Levaquin and Bactrim. He reported stopping his Plavix 3 days before presentation due to worsening hemoptysis. He was admitted for non-life-threatening hemoptysis, AKI, and acute blood loss anemia. Temp: 97.9F, HR: 69, RR: 20, BP: 182/75, O2 sat: 95% on 2L O2. Labs: BUN: 45, Cr: 4.43 (baseline 1.06), UA: 3+ blood, >100 RBC’s, Hg: 6.8. CXR: bilateral diffuse pulmonary opacities, upper lobe predom. CT: scattered ground-glass, consolidative opacities. Rx: Vancomycin, Zosyn, pulse dose steroids, and 1 unit PRBC's. Bronchoscopy showed diffuse alveolar hemorrhage. Elevated: Myeloperoxidase, p-ANCA, ANA, dsDNA, MPO antigen, anti-histone antibodies. Hydralazine, which he was taking for greater than 10 years was held. Renal biopsy: no obvious vasculitis. His hemoptysis and kidney function improved and he was discharged on a steriod taper. Discussion: Hydralazine-induced vasculitis, potentially dose-dependent, occurs in a minority of patients, with increased risk associated with higher doses and longer duration of use. While commonly affecting the kidneys and skin, our patient lacked skin manifestations. Management involves discontinuation of the drug, with severe cases requiring immunosuppressive therapy. Our patient responded well to steroids alone, underscoring the need for further research to guide treatment strategies for similar cases.