A RARE CASE OF PAUCI-IMMUNE PULMONARY CAPILLARITIS WITH PERIPHERAL EOSINOPHILIA

Abstract

TOPIC: Lung Pathology TYPE: Medical Student/Resident Case Reports INTRODUCTION: Diffuse alveolar hemorrhage (DAH) is a syndrome classically presenting with hemoptysis, diffuse alveolar infiltrates, and acute respiratory failure. It is usually associated with systemic vasculitis and auto-antibodies. Idiopathic pauci-immune pulmonary capillaritis (IPPC) is a rare form of isolated DAH that presents without other clinical features of systemic vasculitis or circulating auto-antibodies. We present a patient with DAH from IPPC, who was also found to have peripheral eosinophilia. CASE PRESENTATION: 76-year-old female presented with subacute complaint of generalized weakness and confusion. Her past medical history was significant for multiple sclerosis treated with rituximab. Initial vital signs were afebrile, BP 126/66, HR 78, RR 22, saturating 95% on 1 liter nasal cannula. Physical examination findings were significant for a markedly obese woman, decreased breath sounds and crackles noted in both lung bases, 3+ edema in both lower extremities. Laboratory workup revealed a WBC count of 7.9/µL with 30% eosinophils, hemoglobin 10 g/dL and platelets 84K. Urinalysis was consistent with urinary tract infection (UTI). Chest x-ray revealed a right basilar infiltrate and effusion, small left basilar infiltrate, pulmonary venous congestion and mild cardiomegaly. She was started on an antibiotic for UTI and a diuretic for preliminary diagnosis of heart failure. Despite diuretics, her oxygen requirements continued to increase. CT chest showed bilateral infiltrates and extensive bilateral ground glass changes. Infectious and auto-immune workup were negative. Bronchoscopy showed progressive bloody return on sequential lavage consistent with DAH. Cytology of the bronchial lavage (BAL) fluid was negative for malignancy and did not show any organisms or eosinophilia. She was treated with steroids and plasmapheresis. DISCUSSION: The differential diagnosis for DAH is broad, but mostly consists of various underlying systemic diseases, none of which our patient manifested with despite extensive work-up. The remaining practical diagnosis of exclusion was IPPC. Furthermore, her presentation included eosinophilia, although she did not appear to manifest with any of the common differentials for peripheral eosinophilia. Her presentation was not consistent with disorders such as acute eosinophilic pneumonia or acute interstitial pneumonia as her BAL did not reveal eosinophilia or neutrophilia, respectively. This may have been confounded by steroid treatment. It remains possible that her initial peripheral eosinophilia was due to an unrelated process from her pulmonary disease. CONCLUSIONS: Our patient manifested with pauci-immune pulmonary capillaritis. Our case also demonstrates concurrent peripheral eosinophilia which has not been previously described in this already rare disease. Further studies are needed to understand the pathogenesis of IPPC. REFERENCE #1: Park MS. Diffuse alveolar hemorrhage. Tuberc Respir Dis (Seoul). 2013;74(4):151-162. doi:10.4046/trd.2013.74.4.151 REFERENCE #2: Jason S. Oh, Uni Wong, Divyansh Bajaj, Stella E. Hines, "Isolated Pauci-Immune Pulmonary Capillaritis Associated with Hydrocarbon Inhalation and Marijuana Smoking: An Unusual Case of Severe Hypoxemia", Case Reports in Pulmonology, vol. 2020, Article ID 1264859, 5 pages, 2020. https://doi.org/10.1155/2020/1264859 DISCLOSURES: No relevant relationships by Joseph Bahgat, source=Web Response No relevant relationships by Frantz Hastrup, source=Web Response