Falde, S D

Abstract Introduction Hydralazine is a common arterial vasodilator used in the treatment of hypertension and heart failure. Rarely, hydralazine can cause an overlapping syndrome of drug-induced lupus and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The clinical spectrum of this disease process includes features of systemic lupus erythematous and AAV Case Presentation A 62-year-old male previous smoker with 50 pack-year history and hypertension presented with an eight-month history of exertional dyspnea and pleuritic chest pain. Prior to his presentation, he was treated for pneumonia with antibiotics without improvement. His subsequent chest imaging showed a right sided pleural effusion, evaluated by thoracentesis which was exudative and lymphocytic with negative cultures. He then developed progressive ground glass opacities, anemia, lymphopenia, splenomegaly, and acute kidney injury. With concern for underlying malignancy, he underwent a PET/CT and bone marrow biopsy which were not suggestive of malignancy. Serology revealed strongly a myeloperoxidase (MP) antibody (>8 U) with low titer proteinase-3 (PR3) antibody (1.2 U) and p-ANCA by immunofluorescence. Additional serology were notable for positive anti-double stranded DNA (dsDNA), positive ANA by hep2A, normal C3/C4, and creatinine peaking at 1.78 mg/dL, subnephrotic range proteinuria, and hematuria without RBC casts. Bronchoscopy noted progressively bloody return and 99% hemosiderin laden macrophages consistent with diffuse alveolar hemorrhage. Hydralazine was promptly discontinued with a clinical presentation consistent hydralazine-associated AAV and overlapping drug-induced lupus. They received remission induction therapy with IV methylprednisolone followed by tapering course of prednisone, rituximab, and avacopan. He was managed and monitored closely in the outpatient setting. With gradually improvement in renal function, a renal biopsy was deferred. Discussion Drug-induced lupus and drug-associated AAV can overlap in patients exposed to hydralazine, which can present up to several years after drug initiation. Renal and pulmonary involvement in hydralazine-induced lupus is uncommon and should prompt concern for drug-associated AAV. Compared with primary AAV, features suggestive of hydralazine-associated AAV include an adequate history of drug exposure and frequently a unique ANCA profile, hypocomplementemia, cytopenias, and additional seropositivity-including anti-histone and anti-dsDNA antibodies. Conclusion The cornerstone of management in hydralazine-induced lupus and hydralazine-associated AAV is early recognition and discontinuation of the offending medication. Induction of remission with standard immunosuppression is generally warranted, with specific therapies dictated by organ manifestations at diagnosis, similar to patients with primary AAV. Long-term outcomes in hydralazine-associated AAV appear comparable to those in primary AAV. The need for and duration of maintenance immunosuppression should be individualized based on patient presentation. This abstract is funded by: None

Abstract Introduction Pulmonary artery masses have a broad differential. CT may offer initial characterization, but cardiac MRI and PET/CT provide more definitive information. Histopathologic evaluation is often required. We present a rare case of a pulmonary artery mass with an elevated IgG4 index, initially misclassified as more common benign and malignant entities. Case-Presentation: A 61-year-old never smoking female was referred to the pulmonary clinic for abnormal imaging. Her history was only for patent ductus arteriosus repair in infancy. She initially presented with pleuritic chest pain and was found to have near occlusive mass in the distal main pulmonary artery extending into the proximal left main pulmonary artery. This was presumed to be pulmonary embolism, and anticoagulation was started. At presentation, she reported mild dyspnea and improving chest pain, without constitutional symptoms. Cardiac MRI revealed restricted diffusion and enhancement consistent with pulmonary artery sarcoma. PET-CT revealed FDG avid pulmonary artery mass (SUV max 14.5) without other hypermetabolic lesions. She subsequently underwent resection of the main and proximal left PA mass resection with bovine pericardial reconstruction. Histopathology showed a dense lymphoplasmacytic infiltrate with prominent plasma cell infiltration, IgG4/IgG ratio of 40%, and > 10 IgG4 positive plasma cells per high power field. No histiocytic proliferation or evidence of other atypia. Her serum IgG4 level, CRP, ANCA serology, and fungal serology were normal. Discussion Here we present the case of isolated pulmonary artery mass with elevated IgG4 index of greater than 40% without other organ manifestations of IgG4 related disease (IgG4-RD). Cases of IgG4-RD related infiltration with a pulmonary artery mass have been reported, yet these typically present with other systemic manifestations, vascular inflammation, luminal stenosis, and/or pulmonary hypertension. Based on ACR 2019 IgG4 related disease classification criteria, these patients would not strictly meet criteria for IgG4 related disease. After extensive multidisciplinary discussion, we have elected to hold systemic treatment for IgG4-RD. She will be followed closely, monitoring new evidence of organ infiltration that would warrant systemic treatment. Conclusion Pulmonary artery masses should raise suspicion for various benign etiologies, such as chronic thromboembolism, and malignant entities, including pulmonary artery sarcoma. Cardiac MRI, PET/CT, and histopathology were critical in this patient’s evaluation. IgG4-related disease can rarely present as an intimal pulmonary artery mass. However, this is typically accompanied by systemic findings suggestive of IgG4-RD, other vascular infiltration, and/or pulmonary hypertension, all of which were absent in this patient. This abstract is funded by: None