Possible baseline lung allograft dysfunction within the first year defines a high-risk and potentially reversible state after lung transplantation

Background Baseline lung allograft dysfunction (BLAD) has been associated with impaired long-term outcomes. However, BLAD within the first post-transplant year represents a potentially dynamic state. Aim This is the first study evaluating a provisional Possible BLAD state, investigating risk factors and evolution to normal baseline lung function or confirmed BLAD. Methods Possible BLAD was defined as failure to reach baseline FEV1 and FVC≥lower limit of normal (LLN) within the first post-transplant year. Association of Possible BLAD and BLAD with allograft failure was investigated using multivariate time-dependent cox regression analysis. Results Among lung allograft recipients in the Munich Lung Transplant cohort, Possible BLAD occurred in a substantial share of lung allograft recipients. Possible BLAD was independently associated with a markedly increased risk of allograft failure (HR 4.76, 95% CI 2.73–8.29). Patients who recovered from Possible BLAD to normal baseline lung function, had similar survival compared to lung allograft recipients directly reaching normal baseline lung function. A four-item clinical score at timepoint of first spirometry predicted recovery from possible BLAD (AUC 0.83 for DLTX, AUC 0.88 for SLTX recipients). Conclusion Possible BLAD is associated with a markedly increased risk of mortality. A share of patients with Possible BLAD may recover to normal baseline lung function, while others progress to BLAD. Possible BLAD characterization improves early risk stratification and might provide further insight into modifiable mechanisms underlying impaired allograft performance.