Effect of Club cell secretory proteins on the association of tobacco smoke and PAH co-exposure with lung function decline: A longitudinal observation of Chinese coke oven workers

Impact of metals exposure on lung function and serum club cell secretory protein among schoolchildren: A mixture and mediation analysis

Particulate matter (PM) and its harmful components are significant contributors to respiratory diseases and impaired lung function, especially in children. Club cell secretory protein (CC16) is a maker of lung epithelium or club cell injuries. To date, the relationship between metals related with PM and CC16 and lung function impairment has been overlooked in children. We enrolled 603 schoolchildren exposed to different levels of PM in China. We found per doubling increase, urinary thallium, and iron was associated with a 3.42 % (95 % CI: 0.01, 6.72) and 3.09 % (95 % CI: 0.55, 5.56) decrease of serum CC16, respectively, whereas urinary cadmium was associated with a 4.74 % (95 % CI: 1.29, 8.31) increase of serum CC16. The Bayesian kernel machine regression (BKMR) model confirmed these associations and showed a potential synergistic interaction between thallium and cadmium. Urinary metal mixtures were associated with lower CC16 when they were below the 35th percentile compared with their median. Serum CC16 mediated 11.47 % (95 % CI: 0.06, 45.00) of the association between urinary thallium and FEV1/FVC decline. The inverted U-shaped association with CC16 and the mediation role of CC16 on associations with lung function provide insight into the mechanisms underlying lung injury induced by metals related with PM.

Plasma nicotine and its metabolite as biomarkers of tobacco exposure and their relevance to pulmonary nodule

Aim: Explore the optimal cut-off values for plasma nicotine and its metabolites in assessing smoking status and quantify the association between individual tobacco exposure and pulmonary nodules (PNs).Materials & methods: A total of 2245 plasma samples were included for the determination of nicotine (Nic), cotinine (Cot) and trans-3'-hydroxycotinine (OHCot) concentrations. The receiver operating characteristic curve was used to determine the optimal biomarkers reflecting smoking status. Binary logistic regression, restricted cubic spline and generalized linear model were used to analyze the association of nicotine and its metabolites with PNs. Quantile g-computation was used to investigate the mixed effects between them.Results: Cot was found to be the best biomarker of self-reported active-passive smoking, with optimal thresholds of 9.06 and 1.26 ng/ml, respectively. Except for OHCot, increased concentrations of Cot, Nic, total nicotine equivalent (TNE2) and TNE3 were significantly positively associated with the risk of PNs, whereas nicotine metabolite ratio presented a negative association. The mixed effects of OHCot, Cot and Nic were associated with PNs, with an odds ratio of 1.17 and a 95% CI of 1.05-1.30.Conclusion: Nicotine and its metabolites as potential biomarkers of tobacco exposure were significantly associated with PNs.

Prospective Study on the Association Between Blood Heavy Metal Levels and Pulmonary Function in University Students from a Medical College in Shandong Province, China

Background

This study aimed to examine the blood concentrations of selected heavy metals, their corresponding pulmonary functions, and their interrelationship with university students.

Methods

This prospective study, conducted from September 2019 to September 2020, encompassed 593 university students. Participants completed self-administered questionnaires regarding demographic factors and underwent lung function testing and blood mercury analysis at two distinct intervals: an initial assessment and a follow-up examination. Pulmonary function was assessed using Forced Vital Capacity, Forced Expiratory Volume in one second, and Peak Expiratory Flow. The blood concentrations of various heavy metals were determined through inductively coupled plasma mass spectrometry.

Results

Notable disparities in pulmonary function emerged among university students when categorized by gender, Body Mass Index, physical activity, and seafood consumption frequency, all showing statistical significance (p<0.05). Blood levels of Pb, Mn, Co, and Ni exhibited diverse patterns and extents of correlation with pulmonary function (p<0.05 in each instance). Specifically, a positive correlation was observed with blood Pb levels, while Mn, Co, and Ni levels were inversely correlated with pulmonary function (p<0.01 for both observations).

Conclusion

This study uncovered significant and complex relationships between the blood concentrations of individual heavy metals and pulmonary function in university students. These findings highlight the need for further research to elucidate these associations in greater detail.

Club Cells-A Guardian against Occupational Hazards

Club cells have a distinct role in the epithelial repair and defense mechanisms of the lung. After exposure to environmental pollutants, during chronic exposure, the secretion of club cells secretory protein (CCSP) decreases. Exposure to occupational hazards certainly has a role in a large number of interstitial lung diseases. According to the American Thoracic Society and the European Respiratory Society, around 40% of the all interstitial lung disease is attributed to occupational hazards. Some of them are very well characterized (pneumoconiosis, hypersensitivity pneumonitis), whereas others are consequences of acute exposure (e.g., paraquat) or persistent exposure (e.g., isocyanate). The category of vapors, gases, dusts, and fumes (VGDF) has been proven to produce subclinical modifications. The inflammation and altered repair process resulting from the exposure to occupational respiratory hazards create vicious loops of cooperation between epithelial cells, mesenchymal cells, innate defense mechanisms, and immune cells. The secretions of club cells modulate the communication between macrophages, epithelial cells, and fibroblasts mitigating the inflammation and/or reducing the fibrotic process. In this review, we describe the mechanisms by which club cells contribute to the development of interstitial lung diseases and the potential role for club cells as biomarkers for occupational-related fibrosis.

Risk factors of pulmonary arterial hypertension in patients with systemic lupus erythematosus: A meta-analysis

OBJECTIVE

To determine the risk factors of pulmonary arterial hypertension (PAH) related to systemic lupus erythematosus (SLE) through systematic reviews and meta-analyses.

METHODS

We undertook electronic search strategies using Medline via PubMed, Embase, Web of Science, and Cochrane Library up to April 11, 2023. Study selection and data extraction were performed by 2 authors independently. We made risk of bias judgments based on the Newcastle-Ottawa Scale (NOS). Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated to estimate the overall effect sizes of potential risk factors for PAH in SLE patients. Univariate and multivariate meta-regression models were used to assess the independent effects of each risk factor on PAH. Sensitivity analyses were also conducted to explore potential sources of heterogeneity.

RESULTS

A total of 19 articles were included in this meta-analysis, and the results showed that gender (female) [RR = 1.04, 95% CI (1.02, 1.06), p = .0001], interstitial lung disease [RR = 4.36, 95% CI (2.42, 7.85), p = .0001], alopecia [RR = 1.39, 95% CI (1.06, 1.83), p = .017], Raynaud's phenomenon [RR = 1.83, 95% CI (1.41, 2.37), p = .0001], systemic hypertension [RR = 1.30, 95% CI (1.07, 1.58), p = .007], serositis [RR = 2.29, 95% CI (1.89, 2.77), p = .0001], pericardial effusion [RR = 3.33, 95% CI (2.20, 5.05), p = .0001], anti-RNP [RR = 1.86, 95% CI (1.19, 2.91), p = .006], anti-SSA [RR = 1.28, 95% CI (1.01, 1.62), p = .041], anti-SSB [RR = 1.38, 95% CI (1.19, 1.60), p = .0001], anti-U1RNP [RR = 1.58, 95% CI (1.07, 2.34), p = .023], thrombocytopenia [RR = 1.38, 95% CI (1.14, 1.68), p = .001], and current smokers [RR = 2.20, 95% CI (1.19, 4.06), p = .012] were all risk factors for PAH related to SLE.

CONCLUSION

PAH is a serious complication of SLE. Since prognosis of SLE patients after the occurrence of PAH is poor, routine examination should be conducted for SLE patients with PAH risk factors.