Restrictive Allograft Syndrome (RAS) is one kind of chronic lung allograft dysfunction that may develop after lung transplantation.
Criteria for RAS – both of the following:
(1) irreversible decline in total lung capacity (TLC) to < 90% of baseline
(2) irreversible decline in FEV1 to < 80% of baseline (= chronic lung allograft dysfunction)
There is a restrictive pattern of pulmonary function decline.
Histologic findings seen in RAS include:
(1) pleuroparenchymal fibroelastosis
(2) diffuse alveolar damage (DAD)
(3) obliterative bronchiolitis
