He had acute kidney injury and urinalysis showed proteinuria, dysmorphic RBCs, and rare RBC cast. individual was treated with corticosteroids and intravenous cyclophosphamide. At one-year follow-up, he had no symptoms and anemia experienced resolved. Kidney function improved dramatically. Serology showed undetectable PR3 ANCA and minimally elevated MPO ANCA. To our knowledge, hydralazine-associated PR3 ANCA CX546 has not been previously reported. The possibility of ANCA systemic vasculitis should be included in the differential diagnosis of any patient with hydralazine use and pulmonary renal syndrome. This is a potentially life threatening condition requiring prompt cessation of the drug and treatment with glucocorticoids and immunosuppression. 1. Introduction Hydralazine was first launched in 1951 and is widely used as an adjunctive treatment for hypertension . It has been associated with autoimmune diseases. Hydralazine-induced lupus was first reported in 1953 and may be present in as many as 5.4C10.4% of the patients . Occurrence of systemic vasculitis is usually a rare complication. Drug-induced vasculitis has been associated with hydralazine, propylthiouracil, allopurinol, sulfasalazine, and several other medications . The clinical spectrum can be variable, ranging from arthralgia, myalgia, CX546 petechiae, or rash to single- or multiorgan involvement . When it presents as pulmonary renal syndrome, it can have a rapidly progressive course and can be fatal. It is important to have a high index of suspicion, as early diagnosis and treatment can prevent progression of the disease. Discontinuation of drug is usually the first step but many patients subsequently require glucocorticoids and immunosuppressive brokers. Here we spotlight a rare but severe complication of hydralazine presenting as pulmonary hemorrhage and rapidly progressive glomerulonephritis. 2. Case Presentation A 62-year-old Hispanic man presented to the hospital with generalized weakness, near syncope, and excess weight loss of 25?lbs over the past four months. He complained of early satiety and lack of appetite. He denied any fever, rash, nasal congestion, myalgia, arthralgia, shortness of breath, cough, hemoptysis, urinary symptoms, or gastrointestinal bleeding. Upon introduction he was found to have severe anemia. He had a history of hypertension, stroke, and hyperlipidemia and was being treated with lisinopril 20?mg daily, metoprolol 100?mg twice a day, aspirin 325?mg daily, simvastatin 40?mg daily, and hydralazine 100?mg three times a day. He had been on hydralazine for the last four and half years. He had no history of renal or lung disease. He quit smoking 20 years ago. Physical exam was unremarkable with stable vital signs. Oxygen saturation was managed on room air flow. Upon introduction, he received blood transfusion and his symptoms improved. Initial labs showed hemoglobin of 4.1?g/dL, hematocrit of 14.6%, MCV of 64?fl, and platelet count of 557,000/In vivodata suggests that ANCAs are by themselves pathogenic . MPO knockout mice that lack functioning B- and T-lymphocytes when injected with anti-MPO splenocytes developed severe necrotizing crescentic glomerulonephritis and hemorrhagic pulmonary capillaritis. It has been postulated that hydralazine accumulates in neutrophils where it binds to myeloperoxidase. This induces neutrophil apoptosis and cytotoxic products. The apoptotic blebs of neutrophils act as a source of immunogens as obvious by the presence of numerous antibodies that are associated with hydralazine-induced ANCA vasculitis . These antibodies either alone or by complex conversation with contamination brokers or genetic factors may contribute to the disease. Antibodies associated with hydralazine-induced vasculitis include MPO ANCA, ANA, anti-histone antibody, anti-elastase antibody, and anti-phospholipid antibody [10, 11]. Surprisingly, our patient was positive for PR3 ANCA in addition to MPO ANCA, ANA, and anti-histone antibody. To our knowledge, the association of hydralazine with PR3 ANCA has not been previously reported. Anti-histone antibody is commonly seen with drug-induced vasculitis and is absent with ANCA-associated vasculitis. The combination of anti-histone antibody, MPO, and/or PR3 ANCA and absence of anti-dsDNA antibody could be used to support the diagnosis of hydralazine-induced vasculitis in the CX546 appropriate clinical setting with evidence of pauci-immune glomerulonephritis . A causal role for hydralazine in the pulmonary renal syndrome in the present case is most likely in view of the clinical data, but a definite association would require reexposure to CX546 the drug, which is not feasible due to ethical reasons. In summary, hydralazine-induced ANCA-associated glomerulonephritis with pulmonary hemorrhage is usually a rare adverse event. Cxcr7 Our case demonstrates for the first time that hydralazine may induce both MPO and PR3. Whether coexpression of both ANCAs impacts disease response and/or progression would be of interest. In our case, a short course of immunosuppression with corticosteroids and cyclophosphamide ameliorated the disease. Importantly, our findings indicate that early diagnosis of hydralazine-induced ANCA vasculitis is essential for prompt treatment with cessation of the drug. Conflict of Interests The.