SESSION TITLE: Medical Student/Resident Pulmonary Manifestations of Systemic Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Diffuse alveolar hemorrhage (DAH) as the presenting symptom in occult vascular disease is a rare occurrence. We present an exceedingly unique case of hydralazine-induced lupus vasculitis who improved after emergent plasmapheresis and combined maintenance therapy of rituximab and steroids. CASE PRESENTATION: A 70-year-old male with hypertension and coronary artery disease, on hydralazine 100mg TID, presented to the emergency department after 10 days of dyspnea and hemoptysis. On presentation, he was hypoxic and lab work revealed an acute kidney injury, new-onset anemia, and peripheral eosinophilia. His erythrocyte sedimentation rate and C-reactive protein were markedly elevated at >145mm/h and 105.1mg/L, respectively. Urinalysis was concerning for a nephritic syndrome and CT scan of the chest suggested multifocal pneumonia with fibrotic lung pattern and ground-glass nodularity. Bronchoalveolar lavage and bronchoscopy confirmed DAH, and he was emergently started on intravenous (IV) methylprednisolone and plasmapheresis. Autoimmune workup revealed a hypocomplementemia with elevations in multiple antibodies including ANA, MPO, PR3, pANCA, anti-cardiolipin, and antiphospholipid. Renal biopsy showed acute tubular necrosis without immune complex nephropathy. His symptoms resolved after plasmapheresis, IV steroids, combined rItuximab/prednisone, and discontinuation of hydralazine. DISCUSSION: Hydralazine-induced vasculitis is a rare occurrence in medicine and presentation as DAH has not been described in the literature. This case is unique in that its antibody biomarker distribution was positive for a multitude of diagnostic markers suggestive of Lupus-associated vasculitis or ANCA-associated vasculitis. There is agreement upon initial treatment with IV glucocorticoids, however, efficacy comparing plasmapheresis, cyclophosphamide, and rituximab is debated. PLEX, PLEXIVAS, and RAVE trials suggested non-inferiority in mortality. However, these trials suggest differing secondary endpoints when comparing plasmapheresis vs non-plasmapheresis therapy in regards to end-stage renal disease and renal recovery time. PLEXIVAS also suggests a therapeutic benefit of low dose glucocorticoids combined with rituximab as maintenance therapy. CONCLUSIONS: We present a case of presumed hydralazine-induced lupus vasculitis presenting as DAH that resolved after discontinuation of the culprit agent, plasmapheresis, and maintenance therapy. Early autoimmune workup and diagnosis via bronchoscopy and renal biopsy are paramount. Further treatment guidelines for pulmonary-renal vasculitis require additional clinical trials to decipher a clear therapeutic benefit. Reference #1: McGeoch L, Twilt M, Famorca L, Bakowsky V, et al. CanVasc Recommendations for the Management of AntiNeutrophilic Cytoplasm Antibody-associated Vasculitides. J Rhematol. Jan 43(1);97-120. doi 10.3899/jrheum.150376 Reference #2: Walsh M, Merkel PA, Jayne D. The Effects of Plasma Exchange and Reduced-Dose Glucocorticoids during Remission-Induction for Treatment of Severe ANCA-Associated Vasculitis [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 10). Reference #3: Jayne DR, Gaskin G, Rasmussen N, Abramowicz D et al. Randomized trial of plasma exchange or high dose methylprednisolone as adjunctive therapy for severe renal vasculitis. J Am Soc Nephrol. 2007 Jul; 18(7):2180-8 DISCLOSURES: No relevant relationships by Andrew Pajak, source=Web Response No relevant relationships by Shivam Thakur, source=Web Response