Occupational Interstitial Lung Diseases

Progressive Pulmonary Fibrosis: Where Are We Now?

Interstitial lung diseases (ILDs) are a diverse collection of lung disorders sharing similar features, such as inflammation and fibrosis. The diagnosis and management of ILD require a multidisciplinary approach using clinical, radiological, and pathological evaluation. Progressive pulmonary fibrosis (PPF) is a distinct form of progressive and fibrotic disease, occurring in ILD cases other than in idiopathic pulmonary fibrosis (IPF). It is defined based on clinical symptoms, lung function, and chest imaging, regardless of the underlying condition. The progression to PPF must be monitored through a combination of pulmonary function tests (forced vital capacity [FVC] and diffusing capacity of the lung for carbon monoxide), an assessment of symptoms, and computed tomography scans, with regular follow-up. Although the precise mechanisms of PPF remain unclear, there is evidence of shared pathogenetic mechanisms with IPF, contributing to similar disease behavior and worse prognosis compared to non-PPF ILD. Pharmacological treatment of PPF includes immunomodulatory agents to reduce inflammation and the use of antifibrotics to target progressive fibrosis. Nintedanib, a known antifibrotic agent, was found to be effective in slowing IPF progression and reducing the annual rate of decline in FVC among patients with PPF compared to placebos. Nonpharmacological treatment, including pulmonary rehabilitation, supplemental oxygen therapy, and vaccination, also play important roles in the management of PPF, leading to comprehensive care for patients with ILD. Although there is currently no cure for PPF, there are treatments that can help slow the progression of the disease and improve quality of life.

Occupational interstitial lung diseases

Millions of workers are exposed to substances known to cause occupational interstitial lung diseases (ILDs), particularly in developing countries. However, the burden of the disease is likely to be underestimated due to under-recognition, under-reporting or both. The diagnosis of occupational ILD requires a high level of suspicion and a thorough occupational history, as occupational and non-occupational ILDs may be clinically, functionally and radiologically indistinguishable, leading to delayed diagnosis and inappropriate management. A potential occupational aetiology should always be considered in the differential diagnosis of ILD, as removal from the workplace exposure, with or without treatment, is a key therapeutic intervention and may lead to significant improvement. In this article, we provide an overview of the 'traditional' inorganic dust-related ILDs but also address idiopathic pulmonary fibrosis and the immunologically mediated chronic beryllium disease, sarcoidosis and hypersensitivity pneumonitis, with emphasis on the importance of surveillance and prevention for reducing the burden of these conditions. To this end, health-care professionals should be specifically trained about the importance of occupational exposures as a potential cause of ILD.

Pneumoconiosis: current status and future prospects

ABSTRACT

Pneumoconiosis refers to a spectrum of pulmonary diseases caused by inhalation of mineral dust, usually as the result of certain occupations. The main pathological features include chronic pulmonary inflammation and progressive pulmonary fibrosis, which can eventually lead to death caused by respiratory and/or heart failure. Pneumoconiosis is widespread globally, seriously threatening global public health. Its high incidence and mortality lie in improper occupational protection, and in the lack of early diagnostic methods and effective treatments. This article reviews the epidemiology, safeguard procedures, diagnosis, and treatment of pneumoconiosis, and summarizes recent research advances and future research prospects.

Informatics Approaches for Recognition, Management, and Prevention of Occupational Respiratory Disease

Computer and information systems can improve occupational respiratory disease prevention and surveillance by providing efficient resources for patients, workers, clinicians, and public health practitioners. Advances include interlinking electronic health records, autocoding surveillance data, clinical decision support systems, and social media applications for acquiring and disseminating information. Obstacles to advances include inflexible hierarchical coding schemes, inadequate occupational health electronic health record systems, and inadequate public focus on occupational respiratory disease. Potentially transformative approaches include machine learning, natural language processing, and improved ontologies.

Respiratory surveillance in mineral dust-exposed workers

Recently, there has been a worldwide resurgence in pneumoconiosis, or pulmonary fibrosis due to occupational mineral dust exposure. In Queensland, Australia, there has been a re-emergence of coal workers' pneumoconiosis and silicosis. Some coal mining communities have experienced a resurgence of progressive massive fibrosis in the USA and a worldwide epidemic is occurring of accelerated silicosis due to exposure to artificial stone.

These diseases are all preventable and should not be occurring in the 21st century. Best practice prevention includes reduction of exposure to mineral dusts or, ideally, prevention of exposure altogether. However, where dust exposure has occurred, respiratory surveillance can provide a strategy for early disease detection. It is important to identify early signs of occupational lung disease at a stage where intervention may be beneficial, though it must be acknowledged that progression may occur even after cessation of exposure to dusts. Respiratory surveillance should be distinguished from population screening and case finding, which are different methods used for disease investigation and control. Designing an ideal respiratory surveillance programme is challenging, as there is no single test that accurately identifies early disease. Several different respiratory disorders may occur related to the same exposure(s). Physicians organising and interpreting tests used in respiratory surveillance must be aware of the broad range of potential work-related respiratory conditions, complexities in diagnosis, and appropriate interpretation of the exposure history, as well as current management options. A working knowledge of the compensation and medicolegal avenues available to workers in individual jurisdictions is also useful.

Organising and interpreting respiratory surveillance for mineral dust-exposed workers requires specialist knowledge and understanding of the potential range of diseases, as well as a detailed occupational historyhttp://bit.ly/37KXSE4

Extended Mortality Follow-up of a Cohort of 25,460 Workers Exposed to Acrylonitrile

We extended the mortality follow-up of a cohort of 25,460 workers employed at 8 acrylonitrile (AN)-producing facilities in the United States by 21 years. Using 8,124 deaths and 1,023,922 person-years of follow-up, we evaluated the relationship between occupational AN exposure and death. Standardized mortality ratios (SMRs) based on deaths through December 31, 2011, were calculated. Work histories and monitoring data were used to develop quantitative estimates of AN exposure. Hazard ratios were estimated by Cox proportional hazards regression. All-cause mortality and death from total cancer were less than expected compared with the US population. We observed an excess of death due to mesothelioma (SMR = 2.24, 95% confidence interval (CI): 1.39, 3.42); no other SMRs were elevated overall. Cox regression analyses revealed an elevated risk of lung and bronchial cancer (n = 808 deaths; for >12.1 ppm-year vs. unexposed, hazard ratio (HR) = 1.43, 95% CI: 1.13, 1.81; P for trend = 0.05), lagged 10 years, that was robust in sensitivity analyses adjusted for smoking and co-exposures including asbestos. Death resulting from bladder cancer (for >2.56 ppm vs. unexposed, lagged 10-year HR = 2.96, 95% CI: 1.38, 6.34; P for trend = 0.02) and pneumonitis (for >3.12 ppm-year vs. unexposed, HR = 4.73, 95% CI: 1.42, 15.76; P for trend = 0.007) was also associated with AN exposure. We provide additional evidence of an association between AN exposure and lung cancer, as well as possible increased risk for death due to bladder cancer and pneumonitis.

Idiopathic pulmonary fibrosis: unmasking cryptogenic environmental factors

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease of unknown origin that is associated with high morbidity and mortality. In this perspective, we briefly review the current understanding of the pathophysiology of IPF and the importance of environmental triggers as a precipitant of disease. We discuss occult intrinsic and extrinsic environmental factors that affect the lung microenvironment and may contribute to the development and progression of disease. The clinical implications of this framework need to be further elucidated, because prompt identification and elimination of occult exposures may represent a novel treatment modality.

Interstitial Lung Disease and Pulmonary Fibrosis: A Practical Approach for General Medicine Physicians with Focus on the Medical History

Interstitial lung disease (ILD) and pulmonary fibrosis comprise a wide array of inflammatory and fibrotic lung diseases which are often confusing to general medicine and pulmonary physicians alike. In addition to the myriad of clinical and radiologic nomenclature used in ILD, histopathologic descriptors may be particularly confusing, and are often extrapolated to radiologic imaging patterns which may further add to the confusion. We propose that rather than focusing on precise histologic findings, focus should be on identifying an accurate etiology of ILD through a comprehensive and detailed medical history. Histopathologic patterns from lung biopsy should not be dismissed, but are often nonspecific, and overall treatment strategy and prognosis are likely to be determined more by the specific etiology of ILD rather than any particular histologic pattern. In this review, we outline a practical approach to common ILDs, highlight important aspects in obtaining an exposure history, clarify terminology and nomenclature, and discuss six common subgroups of ILD likely to be encountered by general medicine physicians in the inpatient or outpatient setting: Smoking-related, hypersensitivity pneumonitis, connective tissue disease-related, occupation-related, medication-induced, and idiopathic pulmonary fibrosis. Accurate diagnosis of these forms of ILD does require supplementing the medical history with results of the physical examination, autoimmune serologic testing, and chest radiographic imaging, but the importance of a comprehensive environmental, avocational, occupational, and medication-use history cannot be overstated and is likely the single most important factor responsible for achieving the best possible outcomes for patients.

Occupational lung diseases in Australia

Occupational exposures are an important determinant of respiratory health. International estimates note that about 15% of adult-onset asthma, 15% of chronic obstructive pulmonary disease and 10-30% of lung cancer may be attributable to hazardous occupational exposures. One-quarter of working asthmatics either have had their asthma caused by work or adversely affected by workplace conditions. Recently, cases of historical occupational lung diseases have been noted to occur with new exposures, such as cases of silicosis in workers fabricating kitchen benchtops from artificial stone products. Identification of an occupational cause of a lung disease can be difficult and requires maintaining a high index of suspicion. When an occupational lung disease is identified, this may facilitate a cure and help to protect coworkers. Currently, very little information is collected regarding actual cases of occupational lung diseases in Australia. Most assumptions about many occupational lung diseases are based on extrapolation from overseas data. This lack of information is a major impediment to development of targeted interventions and timely identification of new hazardous exposures. All employers, governments and health care providers in Australia have a responsibility to ensure that the highest possible standards are in place to protect workers' respiratory health.