Clinical transplantation | 2021
Chronic lung allograft dysfunction subtype analysis by computed tomography volumetry.
Abstract
BACKGROUND\nChronic lung allograft dysfunction (CLAD) limits long-term survival after lung transplantation. Of the two subtypes, restrictive allograft syndrome (RAS) is characterised by a larger lung volume decrease and worse prognosis than bronchiolitis obliterans syndrome (BOS). We used computed tomography (CT) volumetry to classify CLAD subtypes and determined their clinical impact.\n\n\nMETHODS\nAdult primary lung transplants performed 2003-2015 (n = 167) were retrospectively evaluated for CLAD and subclassified with CT volumetry. Lung volume decrease of <15% from baseline resulted in BOSCT-vol and ≥15% resulted in RASCT-vol diagnosis. Clinical impact of CLAD subtypes was defined, and the prognostic value of different lung function, radiological and lung volume parameters present at the time of CLAD diagnosis were compared.\n\n\nRESULTS\nCLAD affected 43% of patients and was classified with CT volumetry as BOSCT-vol in 89% and RASCT-vol in 11%. Median graft survival estimate in RASCT-vol was significantly decreased compared to BOSCT-vol (1.6 vs. 9.7 years, p = 0.038). At CLAD onset, RASCT-vol diagnosis (p = 0.05), increased lung density (p = 0.007), and more severe FEV1 (p = 0.004) decline from baseline, increased graft loss risk in multivariate analysis.\n\n\nCONCLUSIONS\nCT volumetry serves to identify lung transplant patients with a poor clinical outcome but should be validated in prospective trials. This article is protected by copyright. All rights reserved.