ATYPICAL CASE OF EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS

Abstract

TOPIC: Lung Pathology TYPE: Medical Student/Resident Case Reports INTRODUCTION: Eosinophilic Granulomatosis with Polyangiitis (EGPA) is a multi-organ vasculitis. However, the hallmarks of the disease are eosinophilia, chronic sinusitis, and asthma. Vasculitic organ involvement might be absent early on, making the diagnosis challenging1. We present the case of a patient with atypical presentation and serology for EGPA. CASE PRESENTATION: A 71-year-old male with a history of non-asthmatic eosinophilic bronchitis, chronic sinusitis, and peripheral eosinophilia (peak 936 cells/uL; 17.6%) was admitted to the hospital with dyspnea and rapidly progressive acute hypoxemic respiratory failure requiring transfer to the intensive care unit. He was started on high flow nasal cannula (60LPM; FiO2 90%-100%). Bilateral crackles noted with no pitting edema. Chest CT showed bilateral airspace disease and ground glass opacities. He tested negative twice for SARS-CoV-2. White blood cell count, kidney function, and brain natriuretic peptide were normal. Autoimmune workup was ordered. He was started on empiric broad-spectrum antibiotic, and gently diuresed. As his presentation was suggestive of eosinophilic lung disease, and in light of significant oxygen requirement, the decision was made to hold on bronchoscopy and start solumedrol at 125mg/day. On ICU Day 3, autoimmune workup showed elevated anti-nuclear antibody titer of 1:160 with a speckled pattern, elevated anti-myeloperoxidase (MPO) antibody titer of 49.4 (p-ANCA), and elevated anti-proteinase-3 (anti-PR3) antibody titers of 18.8 (c-ANCA). Infectious workup was negative. The patient was diagnosed with possible EGPA. He was started on cyclophosphamide in addition to steroids. Oxygen requirement continued to improve. He was discharged home on oxygen at 4LPM and oral steroid with a plan for monthly cyclophosphamide infusion. Follow-up in 2 months with repeat chest CT showed marked improvement. DISCUSSION: The manifestations of EGPA are dynamic, with a few manifestations presenting earlier than others2. With the temporal spacing of signs and symptoms, it is often diagnosed late when more clues are evident. In 1990, the American College of Rheumatology (ACR) established a set of 6 criteria: asthma, peripheral eosinophilia >10%, mononeuropathy or polyneuropathy, migratory pulmonary infiltrates, paranasal sinus abnormality, and biopsy containing blood vessel with extravascular eosinophils2. At least 4 out of six of these criteria must be met to have a diagnosis of EGPA with a specificity of 99.7%. p-ANCA (anti-MPO) is present in around 70% of patients with active EGPA, whereas c-ANCA (anti-PR3) is nearly absent3. Our patient met 3 out of the 6 criteria, and his serology was atypical, showing high titers for both p-ANCA and c-ANCA. CONCLUSIONS: EGPA diagnosis in our patient was not a robust one. However, establishing a presumed diagnosis early and starting immunosuppressive therapy likely saved his life. REFERENCE #1: Guillevin L, Cohen P, Gayraud M, et al. Churg-Strauss syndrome. Clinical study and long-term follow-up of 96 patients. Medicine (Baltimore) 1999; 78:26. REFERENCE #2: Masi AT, Hunder GG, Lie JT, et al. The American College of Rheumatology 1990 criteria for the classification of Churg-Strauss syndrome (allergic granulomatosis and angiitis). Arthritis Rheum 1990; 33:1094. REFERENCE #3: Sablé-Fourtassou R, Cohen P, Mahr A, et al. Antineutrophil cytoplasmic antibodies and the Churg-Strauss syndrome. Ann Intern Med 2005; 143:632 DISCLOSURES: No relevant relationships by Tony Abdo, source=Web Response No relevant relationships by Ahel El Haj Chehade, source=Web Response No relevant relationships by Ahmad Hassan, source=Web Response