The role of ige in interstitial lung disease

SESSION TITLE: Diffuse Lung Disease Posters 7 SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/11/2023 12:00 pm - 12:45 pm PURPOSE: While the role of IgE has been extensively studied in conditions such as asthma and allergic bronchopulmonary aspergillosis (ABPA), its role in interstitial lung disease (ILD) has not been elucidated. This study aims to describe the clinical and radiological manifestations as well as outcomes of patients with ILD and elevated IgE levels. METHODS: A retrospective review of adult patients with ILD with an elevated IgE level (>500 UI/ml), between 1/2011 and 12/2022, was performed. The diagnosis of ILD was confirmed by a multidisciplinary meeting. We report baseline characteristics and mortality. RESULTS: A total of 40 patients were included in the study. The median age was 61 years (IQR 49-70). Thirty patients (75%) were male. Twenty-seven patients (67%) carried the diagnosis of asthma. The median IgE level was 933 (IQR 628-1891). Eighteen patients (45%) had an eosinophil count >500 cells/mcl. Only four patients (10%) met criteria for ABPA. The most common abnormality detected on pulmonary function tests was intrinsic restrictive defect in (n=16, 40%) followed by obstructive ventilatory defect (n=15, 38%), and isolated reduction in DLCO (n=3, 7.5%). Amongst radiological findings described, ground glass opacities were most common (n=32, 80%) followed by traction bronchiectasis (n=23, 58%), honeycombing (n=12, 30%), micronodules (n=5, 13%) and macronodules (n=1, 3%). The most common ILD pattern recognized was non-specific interstitial pneumonia (NSIP: n=17, 43%) followed by usual interstitial pneumonia (UIP: n=11, 28%) and organizing pneumonia (OP: n=5, 13%). Bronchoalveolar lavage was performed in 22 patients: mixed cellularity (n=7), neutrophil predominant (n=7), eosinophil predominant (n=4) and lymphocyte-predominant (n=4). Most patients were on systemic steroids (n=37, 93%) and/ or inhaled steroids (n=33, 83%). The most common cytotoxic agents used include mycophenolate mofetil (n=10, 25%) and azathioprine (n=5, 13%). Eleven patients died (28%) and one was transplanted during the study period. After controlling for IgE levels, age, eosinophil count, presence of asthma and oxygen requirement, a UIP pattern was associated with increased odds of mortality (OR: 8.9, 95% CI: 1.0-77.3, p=0.04). CONCLUSIONS: The most common radiographic pattern in patients with elevated IgE levels was NSIP. Most patients were prescribed steroids and steroid sparing agents for disease control. ILD in patients with elevated IgE levels is associated with high mortality in patients with a UIP pattern. CLINICAL IMPLICATIONS: The disease process in patients with ILD and elevated IgE tends to be aggressive, especially in patients with a UIP pattern. Further investigation is required to identify the role of anti-IgE therapy in this patient population. DISCLOSURES: No relevant relationships by Lyda Cuervo-Pardo No relevant relationships by Diana Gomez Manjarres No relevant relationships by Bruno Hochhegger No relevant relationships by Keval Patel No relevant relationships Added 10/20/2022 by Divya Patel, source=Web Response, value=Consulting fee Removed 12/06/2022 by Divya Patel, source=Web Response No relevant relationships Added 10/20/2022 by Divya Patel, source=Web Response, value=Grant/Research Support Removed 12/06/2022 by Divya Patel, source=Web Response No relevant relationships by Moustafa Younis