Primary graft dysfunction following lung transplantation: From pathogenesis to future frontiers

Table 2 Basic phenotypes of chronic lung allograft dysfunction

Phenotypes	Spirometry changes	CT opacities
CLAD	Persistent ≥ 20% decline in FEV1 (based on 2 FEV1 values ≥3 wk apart) compared to baseline
BOS	CLAD and obstruction (FEV1/FVC < 0.7)	No
RAS	CLAD and restriction (≥ 10% decline in TLC from baseline)	Yes
Mixed phenotype	CLAD with obstruction and restriction	Yes
Undefined phenotype	CLAD with obstruction and/or restriction	Yes/No

Adapted from the 2019 Consensus Definition. FVC: Forced vital capacity; BOS: Bronchiolitis obliterans syndrome; RAS: Restrictive allograft syndrome; CLAD: Chronic lung allograft dysfunction; CT: Computed tomography.