SESSION TITLE: Tuesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM INTRODUCTION: Microscopic Polyangiitis (MPA) is a P-ANCA autoimmune small vessel disease characterized by extensive small vessel inflammation with a variable clinical presentation. Autoimmune vasculitis necessitates heightened clinical suspicion and workup in otherwise healthy patients presenting with acute hemoptysis without an immediately known inciting event. CASE PRESENTATION: A previously healthy 75-year-old Caucasian male presented to the hospital service following 3 weeks of fever, dyspnea, and hemoptysis that was unrelieved with inhalers, steroids, or antibiotics. He has a 15 pack-year smoking history with significant exposure to asbestos as a youth when he worked as an electrician. On admission, he was hypoxic requiring high flow nasal cannula for relief with an exam significant for audible course lung sounds. Pertinent labs include CRP: 82, ESR: 30, LD: 357 IU/L (Ref Range 100-248), P-ANCA: 1:160 (Ref Range <1:20), and myeloperoxidase: 150 AU/mL (Ref Range 0-19 AU/mL). At this time, his creatinine progressively worsened while his urinalysis and sediment exam showed protein, blood, RBC dysmorphic cells, and casts. ANA, C-ANCA, anti-GBM, coagulopathy and fungal panels were normal. A chest radiograph revealed extensive bilateral airspace disease with fibrosis. A preformed bronchoscopy showed ulcerations and gross blood in the distal main bronchi without perforations. Given these findings, the patient was diagnosed with microscopic polyangiitis with DAH and started on plasma exchange (PLEX) therapy. His treatment included 4 doses of therapeutic PLEX, rituximab, and a tapered course of IV methylprednisolone at 1gm daily for 3 days followed by oral prednisone daily. His symptoms eventually improved as his supplemental oxygen use was weaned to room air. Following the improvement of his symptoms, the patient was discharged on immunosuppressive medications and outpatient monitoring of his pulmonary and renal status. DISCUSSION: Hemoptysis can present as a medical emergency especially in a previously healthy individual without known inciting factors. Workup should include autoimmune disease as a potential cause of acute hemoptysis and kidney injury following an asymptomatic disease course as in this case scenario. CONCLUSIONS: Previous studies indicate that MPA is an uncommon cause of acute hemoptysis with an annual incidence of 1:100000. Clinical presentations can be variable with a prognosis based upon rapid initiation of appropriate treatment. Management includes immediate identification with serology and bronchoscopy, airway support, and immunosuppression to control progression. We recommend workup for autoimmune disease in otherwise previously healthy patients presenting with new-onset of hemoptysis and kidney disease. Reference #1: Ficker, J H, et al. “[Haemoptysis : Intensive Care Management of Pulmonary Hemorrhage].” Current Neurology and Neuroscience Reports., U.S. National Library of Medicine, Mar. 2017 Reference #2: Prost, N. de, et al. “Diffuse Alveolar Haemorrhage: Factors Associated with in-Hospital and Long-Term Mortality.” European Respiratory Society, European Respiratory Society, 1 June 2010 Reference #3: Watts, R A, et al. “The Contrasting Epidemiology of Granulomatosis with Polyangiitis (Wegener's) and Microscopic Polyangiitis.” Current Neurology and Neuroscience Reports., U.S. National Library of Medicine, May 2012 DISCLOSURES: No relevant relationships by C, Bryan Huang, source=Web Response