Restrictive allograft syndrome (RAS): A novel form of chronic lung allograft dysfunction Academic Article uri icon

  • Overview
  • Research
  • Identity
  • Additional Document Info
  • View All


  • BACKGROUND: Bronchiolitis obliterans syndrome (BOS) with small-airway pathology and obstructive pulmonary physiology may not be the only form of chronic lung allograft dysfunction (CLAD) after lung transplantation. Characteristics of a form of CLAD consisting of restrictive functional changes involving peripheral lung pathology were investigated. METHODS: Patients who received bilateral lung transplantation from 1996 to 2009 were retrospectively analyzed. Baseline pulmonary function was taken as the time of peak forced expiratory volume in 1 second (FEV(1)). CLAD was defined as irreversible decline in FEV(1) < 80% baseline. The most accurate threshold to predict irreversible decline in total lung capacity and thus restrictive functional change was at 90% baseline. Restrictive allograft syndrome (RAS) was defined as CLAD meeting this threshold. BOS was defined as CLAD without RAS. To estimate the effect on survival, Cox proportional hazards models and Kaplan-Meier analyses were used. RESULTS: Among 468 patients, CLAD developed in 156; of those, 47 (30%) showed the RAS phenotype. Compared with the 109 BOS patients, RAS patients showed significant computed tomography findings of interstitial lung disease (p < 0.0001). Prevalence of RAS was approximately 25% to 35% of all CLAD over time. Patient survival of RAS was significantly worse than BOS after CLAD onset (median survival, 541 vs 1,421 days; p = 0.0003). The RAS phenotype was the most significant risk factor of death among other variables after CLAD onset (hazard ratio, 1.60; confidential interval, 1.23-2.07). CONCLUSIONS: RAS is a novel form of CLAD that exhibits characteristics of peripheral lung fibrosis and significantly affects survival of lung transplant patients.


  • Sato, Masaaki
  • Waddell, Thomas K
  • Wagnetz, Ute
  • Roberts, Heidi C
  • Hwang, David M
  • Haroon, Ayesha
  • Wagnetz, Dirk
  • Chaparro, Cecilia
  • Singer, Lianne G
  • Hutcheon, Michael A
  • Keshavjee, Shafique

publication date

  • July 2011

has subject area