Cigarette-related cadmium and environmental pollution exposure are reflected in airway ultrafine particle content

Abstract

IntroductionParticulate matter (PM) and cigarette-related cadmium exposure increases inflammation and smokers' susceptibility to developing lung diseases. The majority of inhaled metals are attached to the surface of ultrafine particles (UFPs). A low inhaled UFP content in exhaled breath condensate (EBC) reflects a high inflammatory status of airways.MethodsEBC was collected from 58 COPD patients and 40 healthy smokers and nonsmokers. Participants underwent spirometry, diffusion capacity, EBC and blood sampling. Environmental pollution data were collected from monitoring stations. UFPs were measured in EBC and serum, and cadmium content was quantified.ResultsSubjects with low UFP concentrations in EBC (<0.18×108·mL−1) had been exposed to higher long-term PM2.5 levels versus subjects with high UFP concentrations in EBC (>0.18×108·mL−1) (21.9 µg·m−3versus 17.4 µg·m−3, p≤0.001). Long-term PM2.5 exposure levels correlated negatively with UFP concentrations in EBC and positively with UFP concentrations in serum (r=−0.54, p≤0.001 and r=0.23, p=0.04, respectively). Healthy smokers had higher cadmium levels in EBC versus healthy nonsmokers and COPD patients (25.2 ppm versus 23.7 ppm and 23.3 ppm, p=0.02 and p=0.002, respectively). Subjects with low UFP concentrations in EBC also had low cadmium levels in EBC versus subjects with high UFP levels (22.8 ppm versus 24.2 ppm, p=0.004)ConclusionsLow UFP concentration in EBC is an indicator of high-level PM exposure. High cadmium levels in EBC among smokers and the association between cadmium and UFP content in EBC among COPD patients indicate cadmium lung toxicity.

Biomarkers of the relationship of particulate matter exposure with the progression of chronic respiratory diseases

“…In addition, a low UFP level in EBC was an independent predictor of frequent exacerbations (OR = 3.6, 95% CI 1.06–7.97; p = 0.04). Therefore, a low UFP level in EBC has potential as a biomarker of COPD exacerbation and high PM exposure [ 37 ].…”

“…The characteristics of the included studies are listed in Table 3. Three studies [36][37][38] had a high risk of bias in the possibility of target group comparisons domain, and another [38] in the confounders domain. One study [39] had a high risk of bias in the exposure measurement domain, and another [38] in the outcome domain (Fig.…”

Biomarkers of particulate matter exposure in patients with chronic obstructive pulmonary disease: a systematic review

“…Instead, in this review, we summarized the possible role of biomarkers linked to COPD according to four representative types of biological plausibility in patients with COPD exposed to PM through a qualitative review. Among 22 studies, six were found to be relevant regarding biomarkers exploring oxidative stress ( 22 - 24 , 37 - 39 ); one study investigated the roles of innate and adaptive immune systems ( 25 ); and 17 studies investigated genetic regulation ( 26 - 32 , 34 - 36 , 38 - 42 ) and epigenetic regulation of inflammation ( 27 , 43 ).…”

“…In addition, various other biomarkers, such as tumor necrosis factor α (TNFα) ( 28 , 33 , 34 , 41 ), circulating vascular cell adhesion molecule-1 (sVCAM-1) ( 26 , 29 , 30 ), fibrinogen ( 41 ), hepatocyte growth factor ( 41 ), ultrafine particle concentration in exhaled breath ( 42 ), and exhaled hydrogen sulfide ( 36 ).…”

Trajectory of inhaled cadmium ultrafine particles in smokers

“…The findings of low UFP concentrations in EBC and high UFP concentrations in the serum of COPD patients compared with healthy controls serve to support our hypothesis. 5 The concept that UFP translocate to circulation was first proposed by the findings of a murine model in which the induction of lung inflammation resulted in a shift of the UFP pattern towards larger particles, a process which can be explained by translocation of smaller particles thorough inflamed epithelium. 6 In order to further investigate the trajectory of…”