Pollution exposure in the first 3 months post transplant is associated with lower baseline FEV₁ and higher CLAD risk

Background: Exposure to air pollution post-lung transplant has been shown to decrease graft and patient survival. This study examines the impact of air pollution exposure in the first 3 months post-transplant on baseline (i.e., highest) forced expiratory volume in 1 second (FEV₁) achieved and development of chronic lung allograft dysfunction (CLAD).

Methods: Double-lung transplant recipients (n = 82) were prospectively enrolled for comprehensive indoor and personal environmental monitoring at 6- and 12-week post transplant and followed for >4 years. Associations between clinical and exposure variables were investigated using an exposomics approach followed by analysis with a Cox proportional hazards model. Multivariable analyses were used to examine the impact of air pollution on baseline % predicted FEV₁ (defined as the average of the 2 highest values post transplant) and risk of CLAD.

Results: Multivariable analysis revealed a significant inverse relationship between personal black carbon (BC) levels and baseline % FEV₁. The multivariable model indicated that patients with higher-than-median exposure to BC (>350 ng/m³) attained a baseline % FEV₁ that was 8.8% lower than those with lower-than-median BC exposure (p = 0.019). Cox proportional hazards model analysis revealed that patients with high personal BC exposure had a 2.4 times higher hazard risk for CLAD than patients with low BC exposure (p = 0.045).

Conclusions: Higher personal BC levels during the first 3 months post-transplant decrease baseline FEV₁ and double the risk of CLAD. Strategies to reduce BC exposure early following a lung transplant may help improve lung function and long-term outcomes.