Related Experiment Video
Updated: Aug 26, 2025
A Rat Lung Transplantation Model of Warm Ischemia/Reperfusion Injury: Optimizations to Improve Outcomes
Published on: October 28, 2021
Transition from BOS to RAS impairs prognosis after lung transplantation-CLAD subtype analysis by CT volumetry
Laura Peräkylä1, Antti Nykänen1, Anneli Piilonen2
1Department of Cardiac Surgery, Heart and Lung Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
Background:
Chronic lung allograft dysfunction (CLAD), subclassified into bronchiolitis obliterans syndrome (BOS) or restrictive allograft syndrome (RAS), limits survival after lung transplantation. Information concerning transition from BOS to RAS is limited. We aimed to characterize the lung volume change after BOS diagnosis by computed tomography (CT) volumetry and to determine the incidence, risk factors and clinical significance of BOS to RAS transition.
Methods:
CT volumetry measurements were performed from 63 patients with CLAD initially classified as BOS by CT volumetry. BOS patients with lung volume remaining >85% of baseline were classified as persistent BOS, whereas BOS patients whose lung volume permanently decreased to ≤85% of baseline were classified as BOS to RAS transition.
Results:
During follow-up (median 9.8 years) eight patients (12.7%) were classified as BOS to RAS transition, which decreased recipient (p = 0.004) and graft survival (p = 0.020) in comparison to patients with persistent BOS. Opacities on chest imaging preceded BOS to RAS transition in 88% of patients. Opacities on chest imaging at BOS diagnosis and early CLAD diagnosis after transplantation were risk factors for transition.
Conclusion:
Based on lung volume decrease measured by CT volumetry, a small proportion of BOS patients transitioned to RAS which had an adverse effect on recipient and graft survival.
