Abstract Introduction This case describes a patient who developed diffuse alveolar hemorrhage (DAH) as a complication of Antineutrophil Cytoplasmic Antibody (ANCA)-associated vasculitis, specifically Granulomatosis with Polyangiitis (GPA), highlighting its atypical manifestations and diagnostic challenges. Case This is a 79-year-old male with known history of hypertension and chronic sinusitis. He initially presented with palpitations for the past month and was found to have Atrial Fibrillation (A. fib) with Rapid Ventricular Rate (RVR). Further tests revealed leukocytosis, anemia, hematuria, and proteinuria. A CTA of the chest ruled out pulmonary embolism but noted multiple patchy airspace opacities concerning for multifocal pneumonia. The patient was started on rate and rhythm control along with anticoagulation and broad-spectrum antibiotics. Respiratory viral panel, Legionella, and Mycoplasma were negative. Despite hematuria and proteinuria, a kidney biopsy was deemed not necessary at that time. The patient’s hospitalization course was complicated by “2 tablespoons” of hemoptysis, with a differential diagnosis including pneumonia, anticoagulation-associated, or an autoimmune etiology. He was transitioned to therapeutic enoxaparin as he had no further episodes of hemoptysis. At this time, he endorsed a history of easy nosebleeds in the past. Further testing showed a positive c-ANCA titer of 1:160 and elevated proteinase-3 (PR3) antibodies at 624, concerning for GPA. Glomerular Basement Membrane antibodies were negative. Anticoagulation was held, and the patient was started on IV Methylprednisolone 60mg QID. A bronchoscopy with Bronchoalveolar lavage (BAL) showed bronchial alveolar hemorrhage with abundant macrophages and inflammatory cells, but no organisms on Gram stain, suggesting an autoimmune cause. Three serial BALs in the posterior segment of the left lower lobe were performed, revealing increasingly bloody fluid in sequential lavages confirming DAH. Steroids were increased to IV Methylprednisolone 250mg QID for three days and the patient was started on IV Rituximab 750mg. The patient was eventually discharged on an oral prednisone taper with PJP prophylaxis and scheduled for additional rituximab infusions. Discussion Granulomatosis with polyangiitis (GPA) is the most common ANCA-associated vasculitis. Pulmonary involvement is frequent, but diffuse alveolar hemorrhage (DAH) is rare and may occur without hemoptysis. DAH can be difficult to distinguish from multifocal pneumonia. Although uncommon, atrial fibrillation has been reported as a primary manifestation of GPA. Other organ involvement, including renal (hematuria, proteinuria) and ENT (sinusitis, epistaxis), should also be considered. This case highlights the diagnostic complexity of GPA in atypical presentations and underscores the importance of maintaining a high index of suspicion for multiorgan involvement. This abstract is funded by: None
Banda et al. (Fri,) studied this question.