An association of particulate air pollution and traffic exposure with mortality after lung transplantation in Europe

Abstract

Air pollution from road traffic is a serious health risk, especially for susceptible individuals. Single-centre studies showed an association with chronic lung allograft dysfunction (CLAD) and survival after lung transplantation, but there are no large studies.13 lung transplant centres in 10 European countries created a cohort of 5707 patients. For each patient, we quantified residential particulate matter with aerodynamic diameter ≤10 µm (PM) by land use regression models, and the traffic exposure by quantifying total road length within buffer zones around the home addresses of patients and distance to a major road or freeway.After correction for macrolide use, we found associations between air pollution variables and CLAD/mortality. Given the important interaction with macrolides, we stratified according to macrolide use. No associations were observed in 2151 patients taking macrolides. However, in 3556 patients not taking macrolides, mortality was associated with PM (hazard ratio 1.081, 95% CI 1.000-1.167); similarly, CLAD and mortality were associated with road lengths in buffers of 200-1000 and 100-500 m, respectively (hazard ratio 1.085- 1.130). Sensitivity analyses for various possible confounders confirmed the robustness of these associations.Long-term residential air pollution and traffic exposure were associated with CLAD and survival after lung transplantation, but only in patients not taking macrolides.

Chronic effects of air pollution on lung function after lung transplantation in the Systems prediction of Chronic Lung Allograft Dysfunction (SysCLAD) study

“…In LTRs, higher short-term exposure to PM increased the risk for lymphocytic bronchiolitis, which was associated with further development of BOS, and increased airway neutrophilic inflammation [27]. Our findings expand results from a recent observational study indicating that the deleterious effects of air pollution in LTRs might be modified by macrolides [16]. The anti-inflammatory effects of the macrolides could explain this observation.…”

“…Intraclass correlation coefficients (ICC) were estimated for each exposure window to quantify the within-subject variability of the air pollutant exposure over time. We stratified the analysis on the use of macrolides to attempt to replicate the findings from a previous study indicating that macrolides might prevent the deleterious effects of air pollution on LTRs [16]. We further assessed the association considering the 6-month average levels of air pollutants after each lung function test.…”

“…The Canadian study did not detect any significant association between CLAD occurrence and mean annual concentrations of particulate matter with an aerodynamic cut-off of 2.5 µm (PM2.5), ozone (O 3 ) and nitrogen dioxide (NO 2 ) estimated at the residential address using nearby fixed-site monitoring stations [14]. Recent results ( presented in an abstract) from a study based on 13 European centres indicated that the incidence of CLAD and mortality were significantly associated with particulate matter with an aerodynamic cut-off of 10 µm (PM10) exposure estimated at the residential address, only in patients not taking macrolide antibiotics [16]. None of these studies directly addressed the effect of exposure to air pollutants on lung function level, considered as a continuous parameter.…”

Should we be concerned about air quality as a contributor to poor outcomes in lung transplant recipients?

“…Attention to such factors may provide meaningful nonpharmacological approaches to improving outcomes. Two articles [6,7] in this issue of the European Respiratory Journal assess the association between ambient air pollution exposures and prognosis following lung transplantation. Taken together, these papers support the hypothesis that living in areas with higher outdoor concentrations of particulate matter air pollution and of traffic-related air pollutants lead to worse outcomes in lung transplant recipients.…”

“…RUTTENS et al [7] analysed CLAD mortality in 5707 patients from 13 European transplant centres, and found increased risk with higher residential estimated particulate matter concentrations and with living near major roads. Interestingly, both showed decreased risk for these effects among the group of transplant recipients taking macrolides.…”