COMPARISON OF PRE- VS POST-LUNG TRANSPLANT CAUSE OF INTERSTITIAL LUNG DISEASE

Abstract

SESSION TITLE: Transplantation Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: The aim of this study is to compare the clinical diagnosis of interstitial lung disease to that determined on post-explant evaluation. METHODS: Retrospective study conducted through chart review of 50 consecutive lung transplants performed in patients with interstitial lung disease (ILD) at The University of Health Sciences Center at San Antonio. All charts of patients over 18 years of age who underwent lung transplantation with the diagnosis of ILD were carefully reviewed to determine the clinical pre-transplant diagnosis. Studies included high-resolution computed tomography (HRCT), serologic evaluation of connective tissue disease in all patients. Data from transbronchial biopsy or open lung biopsy were reviewed in determining the pre-transplant diagnosis. We compared the pre-lung transplant diagnosis to the post-transplant, pathologic diagnosis determined from the explanted lungs. RESULTS: A total of 50 patients with ILD who had either single or bilateral lung transplant were analyzed. Thirty-three patients (66%) had pre-transplant (pre-tx) diagnosis of usual interstitial pneumonia (UIP), eight patients (16%) had pre-tx diagnosis of nonspecific interstitial pneumonia (NSIP), six patients (12%) had a pre-tx diagnosis of connective tissue disease – ILD (CTD-ILD), one patient (2%) with pre-tx diagnosis of hypersensitivity pneumonitis (HSP) while four patients (8%) had other diagnoses, including indeterminate end stage lung disease (ESLD), type I congenital cystic adenomatoid malformation (CCAM) and constrictive bronchiolitis with fibrosis. After lung explant biopsies were reviewed, seventeen (34%) cases were reclassified compared to the pre-tx diagnoses. However, out of these seventeen cases, only six cases (12%) were clinically significant. Out of the six clinically significant misdiagnoses, three had a final diagnosis of HSP and three had a final diagnosis of NSIP. The remaining discrepancies in diagnosis were disorders t hat are known to progress to UIP. CONCLUSIONS: Almost two-thirds (66%) of all cases had consistent pre-transplant diagnoses when compared to post- transplant diagnoses. Most of the remaining cases (22%) had disorders known to progress to UIP. However, in 12% of cases, the diagnosis changed from a disorder with a progressive course to one that carries a different prognosis and might have responded to alternative therapies (NSIP and HSP). CLINICAL IMPLICATIONS: Definitive diagnosis in patients with ILD is both difficult and challenging. However, it is imperative to be cautious and observant when searching for disorders that are more responsive to environmental changes or responsive to immunotherapy. Early diagnosis of accurate ILD along with the use of multi-disciplinary discussion (MDD) can improve appropriate therapy in patients with ILD. DISCLOSURES: No relevant relationships by Sarah Hackman, source=Web Response No relevant relationships by Tasnim Islam, source=Web Response No relevant relationships by Jay Peters, source=Web Response