Lung and pleural fibrosis in asbestos-exposed workers: a risk factor for pneumonia mortality

TRPM7 restrains plasmin activity and promotes transforming growth factor-β1 signaling in primary human lung fibroblasts

Sustained exposure of the lung to various environmental or occupational toxins may eventually lead to pulmonary fibrosis, a devastating disease with no cure. Pulmonary fibrosis is characterized by excessive deposition of extracellular matrix (ECM) proteins such as fibronectin and collagens. The peptidase plasmin degrades the ECM, but protein levels of the plasmin activator inhibitor-1 (PAI-1) are increased in fibrotic lung tissue, thereby dampening plasmin activity. Transforming growth factor-β1 (TGF-β1)-induced activation of SMAD transcription factors promotes ECM deposition by enhancing collagen, fibronectin and PAI-1 levels in pulmonary fibroblasts. Hence, counteracting TGF-β1-induced signaling is a promising approach for the therapy of pulmonary fibrosis. Transient receptor potential cation channel subfamily M Member 7 (TRPM7) supports TGF-β1-promoted SMAD signaling in T-lymphocytes and the progression of fibrosis in kidney and heart. Thus, we investigated possible effects of TRPM7 on plasmin activity, ECM levels and TGF-β1 signaling in primary human pulmonary fibroblasts (pHPF). We found that two structurally unrelated TRPM7 blockers enhanced plasmin activity and reduced fibronectin or PAI-1 protein levels in pHPF under basal conditions. Further, TRPM7 blockade strongly inhibited fibronectin and collagen deposition induced by sustained TGF-β1 stimulation. In line with these data, inhibition of TRPM7 activity diminished TGF-β1-triggered phosphorylation of SMAD-2, SMAD-3/4-dependent reporter activation and PAI-1 mRNA levels. Overall, we uncover TRPM7 as a novel supporter of TGF-β1 signaling in pHPF and propose TRPM7 blockers as new candidates to control excessive ECM levels under pathophysiological conditions conducive to pulmonary fibrosis.

Non-Malignant Respiratory Illnesses in Association with Occupational Exposure to Asbestos and Other Insulating Materials: Findings from the Alberta Insulator Cohort

Many insulating materials are used in construction, although few have been reported to cause non-malignant respiratory illnesses. We aimed to investigate associations between exposures to insulating materials and non-malignant respiratory illnesses in insulators. In this cross-sectional study, 990 insulators (45 ± 14 years) were screened from 2011-2017 in Alberta. All participants underwent pulmonary function tests and chest radiography. Demographics, work history, and history of chest infections were obtained through questionnaires. Chronic obstructive pulmonary disease (COPD) was diagnosed according to established guidelines. Associations between exposures and respiratory illnesses were assessed by modified Poisson regression. Of those screened, 875 (88%) were males. 457 (46%) participants reported having ≥ 1 chest infection in the past 3 years, while 156 (16%) were diagnosed with COPD. In multivariate models, all materials (asbestos, calcium silicate, carbon fibers, fiberglass, and refractory ceramic fibers) except aerogels and mineral fibers were associated with recurrent chest infections (prevalence ratio [PR] range: 1.18-1.42). Only asbestos was associated with COPD (PR: 1.44; 95% confidence interval [CI]: 1.01, 2.05). Therefore, occupational exposure to insulating materials was associated with non-malignant respiratory illnesses, specifically, recurrent chest infections and COPD. Longitudinal studies are urgently needed to assess the risk of exposure to these newly implemented insulation materials.

Role of chest computed tomography in prevention of occupational respiratory disease: review of recent literature

This review provides an update on literature published over the past 5 years that is relevant to using chest computed tomography (CT) as a tool for preventing occupational respiratory disease. An important area of investigation has been in the use of low-dose CT (LDCT) to screen asbestos-exposed populations for lung cancer. Two recent systematic reviews have reached conclusions in support of screening. Based on the limited evidence that is currently available, the Finnish Institute of Occupational Health has recommended LDCT screening in asbestos-exposed individuals if their personal combination of risk factors yields a risk for lung cancer equal to that needed for entry into the National Lung Screening Trial. It has also recommended further research, such as to document the optimal frequency of screening and the effectiveness of screening. Recent literature continues to support high-resolution CT (HRCT) as being more sensitive than chest radiography in detecting pneumoconiosis. However, there are insufficient data to determine the effectiveness of HRCT screening in improving individual outcomes if used in screening for pneumoconiosis and its routine use for this purpose cannot be recommended. However, if HRCT is used to evaluate populations, recent literature shows that the International Classification of HRCT for Occupational and Environmental Respiratory Diseases provides an important tool for reproducible evaluation and recording of findings. HRCT is an important tool for individual patient management and recent literature has documented that chest HRCT findings are significantly associated with outcomes such as pulmonary function and mortality.

[Pneumococcal vaccine recommendations in chronic respiratory diseases]

Community-acquired pneumonia is an acute respiratory infectious disease which has an incidence of 3-8 cases/1,000 inhabitants, and increases with age and comorbidities. The pneumococcus is the organism most frequently involved in community-acquired pneumonia in the adult (30-35%). Around 40% of patients with community-acquired pneumonia require hospital admission, and around 10% need to be admitted to an intensive care unit. The most serious forms of pneumococcal infection include invasive pneumococcal disease (IPD), which covers cases of bacteremia (associated or not to pneumonia), meningitis, pleuritis, arthritis, primary peritonitis and pericarditis. Currently, the biggest problem with the pneumococcus is the emergence of resistance to antimicrobial agents, and its high morbimortality, despite the use of appropriate antibiotics and proper medical treatment. Certain underlying medical conditions increase the risk of IPD and its complications, especially, from the respiratory diseases point of view, smoking and chronic respiratory diseases. Pneumococcal disease, according to the WHO, is the first preventable cause of death worldwide in children and adults. Among the strategies to prevent IPD is vaccination. WHO considers that its universal introduction and implementation against pneumococcus is essential and a priority in all countries. There are currently 2 pneumococcal vaccines for adults: the 23 serotypes polysaccharide and conjugate 13 serotypes. The scientific societies represented here have worked to develop some recommendations, based on the current scientific evidence, regarding the pneumococcal vaccination in the immunocompetent adult with chronic respiratory disease and smokers at risk of suffering from IPD.

Asbestosis: Past voices from the Mumbai factory floor

Background:

Asbestos′s production, processing, and consumption is on very high scale in India and it is increasing, and so do the related diseases. Asbestosis is such a disease which causes progressive respiratory disability.

Aim:

To find out perceptions and thinking about this disease and its risk among the patients which will help in constructing an effective community-based prevention and rehabilitation program.

Materials and Methods:

It was a community-based, qualitative study using a semi-structured interview schedule with 17 asbestosis patients from Mumbai, disgnosed by specialist with pulmonary function test and X-rays as per International Labour Organisation′s recommandations.

Results:

The risk percived by the patients is very less and attitude toward the illness is bengine as there is no clear understanding about the causation. The prolong latent period appears to be the main cause. It suggests a need of very strong program for prevention of asbestosis with the incorporation of worker awareness and eduaction for safety. The socio-economical status and educational levels of the workers make this floating population more vulnarable for manipulation by the corporates.

Conclusion:

Apart from the radical step of ban on asbestos, there is a need of community-based sustainable, affordable, and accessible rehabilitation program with a component of palliative care which will consider the different needs of this marginalized group. The need for such a program is intense as the number of asbestisis patients will keep on increasing till 30 to 40 years of asbestos ban.