Asbestos-related Pleural Plaques Research Articles

NELL-1 as a Target Antigen in Asbestosis Associated Membranous Nephropathy — A Case Report

An 80-year-old male with a history of prolonged asbestos exposure presented with 24-hour urine protein of 8 gm, and serum albumin of 1.7 gm/dl. Renal biopsy disclosed features of membranous nephropathy. Immunohistochemistry showed positivity for neural epidermal-like growth factor- like 1 (NELL1) (2+/3+). Further assessment uncovered an incidental finding of asbestos-related pleural plaques and left hemithorax volume loss on computed tomography (CT) chest, leading to a diagnosis of asbestosis. This case highlights the rare association between asbestosis and NELL-1 positive membranous nephropathy.

Expression of microRNAs in leukocytes and serum of asbestosis patients

BackgroundAlthough asbestos use is banned in many countries, long latency of asbestos-related diseases like pleural plaques or asbestosis mean it is still a public health issue. People suffering from these diseases have a higher risk of developing mesothelioma or lung cancer, which can progress quickly and aggressively. MicroRNAs were suggested as potential biomarkers in several diseases. However, in asbestosis, blood microRNAs are less explored. Since miR-32-5p, miR-143-3p, miR-145-5p, miR-146b-5p, miR-204-5p and miR-451a are involved in fibrotic processes and in cancer, expression of these microRNAs was analyzed in leukocytes and serum of asbestosis patients.MethodsMicroRNA expression was analyzed in leukocytes and serum of 36 patients (26 affected by pleural plaques and 10 by asbestosis) and 15 healthy controls by real-time RT-PCR. Additionally, data analyses were performed regarding disease severity based on ILO classification.ResultsMicroRNA miR-146b-5p was significantly down-regulated in leukocytes of patients suffering from pleural plaques with a large effect indicated by η2p = 0.150 and Cohen’s f = 0.42, a value of difference of 0.725 and a 95% confidence interval of 0.070–1.381. In patients suffering from asbestosis miR-146b-5p was not significantly regulated. However, data analyses considering disease severity only, revealed that miR-146b-5p was significantly down-regulated in leukocytes of mildly diseased patients compared to controls with a large effect indicated by η2p = 0.178 and Cohen’s f = 0.465, a value of difference of 0.848 and a 95% confidence interval of 0.097–1.599. Receiver operating characteristic (ROC) curve and an area under the ROC curve value of 0.757 for miR-146b-5p indicated acceptable discrimination ability between patients suffering from pleural plaques and healthy controls. Less microRNAs were detectable in serum than in leukocytes, showing no significant expression differences in all participants of this study. Moreover, miR-145-5p was regulated significantly differently in leukocytes and serum. An R2 value of 0.004 for miR-145-5p indicated no correlation in microRNA expression between leukocytes and serum.ConclusionLeukocytes seem more suitable than serum for microRNA analyses regarding disease and potentially cancer risk assessment of patients suffering from asbestos-related pleural plaques or asbestosis. Long-term studies may reveal whether down-regulation of miR-146b-5p in leukocytes might be an early indicator for an increased cancer risk.

Migrating pleural plaque in a patient with asbestos induced pleural disease: a case report

BackgroundHealth surveillance of formerly asbestos exposed individuals focus on early detection of asbestos related diseases, such as lung fibrosis (asbestosis), pleural plaques, mesothelioma and lung cancer in particular. One main concern is the early and clear identification of lesions with a high risk of malignant changes and their undelayed clinical work-up. False positive results may lead to unnecessary and often painful diagnostic interventions, which create high costs when applied to a large cohort and also may discredit the whole program. We describe an unusual presentation of a common lesion among asbestos exposed individuals, which has to our knowledge never been described before. Being aware of this pathological pathway may prevent inadequate clinical decisions with disadvantages for the patient. Underlying implications regarding health surveillance and the reading of CT-scans of the thorax are important for the management of formerly asbestos exposed individuals.Case presentationDuring follow-up of an asbestos exposed 72 year old former power plant worker with known pleural changes, a nodule located next to the left costophrenic angle was newly discovered on CT-scan. As the previous scan 1 year before did not show any changes in that area, a fast growing tumour was suspected and an immediate biopsy performed. The tissue showed the characteristics of a pleural plaque with no signs of malignancy. After carefully reviewing all previous radiographs a rounded opacity attached to the mediastinal pleura close to the oesophagus and slightly cranial to the position of the removed nodule could be discerned. That nodule had increased in size over several years and was no longer visible on the latest scan. It appeared that the originally slow growing plaque had migrated to the costophrenic angle some time before it was discovered in the latest scan thus imposing as a fast growing tumour.ConclusionsWe concluded that asbestos related pleural plaques can under special circumstances get separated from the pleura and migrate to another position in the pleural cavity. The case provides new insights in the development and properties of pleural lesions and may offer new options for the management of formerly asbestos exposed patients.

Pleural Plaques and Their Effect on Lung Function in Libby Vermiculite Miners

Multiple studies have investigated the relationship between asbestos-related pleural plaques (PPs) and lung function, with disparate and inconsistent results. Most use chest radiographs to identify PPs and simple spirometry to measure lung function. High-resolution CT (HRCT) scanning improves the accuracy of PP identification. Complete pulmonary function tests (PFTs), including spirometry, lung volumes, and diffusing capacity of the lung for carbon monoxide, provide a more definitive assessment of lung function. The goal of this study was to determine, using HRCT scanning and complete PFTs, the effect of PPs on lung function in Libby vermiculite miners. The results of HRCT scanning and complete PFTs performed between January 2000 and August 2012 were obtained from the medical records of 166 Libby vermiculite miners. Multivariate regression analyses with Tukey multivariate adjustment were used to assess statistical associations between the presence of PPs and lung function. Adjustments were made for age, BMI, smoking history, duration of employment, and years since last occupational asbestos exposure. Nearly 90% of miners (n = 149) had evidence of PPs on HRCT scan. No significant differences in spirometry results, lung volumes, or diffusing capacity of the lung for carbon monoxide were found between miners with PPs alone and miners with normal HRCT scans. Miners with both interstitial fibrosis and the presence of PPs had a significantly decreased total lung capacity in comparison with miners with normal HRCT scans (P = .02). Age, cumulative smoking history, and BMI were significant covariates that contributed to abnormal lung function. Asbestos-related PPs alone have no significant effect on lung function in Libby vermiculite miners.

Asbestos-related pleural plaques

An 85-year-old man with type 2 diabetes mellitus presented to our clinic with the chief complaints of dry cough and dyspnea on exertion for several months. The oxygen saturation under ambient room air was 92%. Upon physical examination, the patient looked ill and appeared with rapid, shallow breathing pattern. Fine, end-inspiratory crackles were auscultated at bilateral basal lungs. Chest radiography (Figure 1a) and computed tomography (CT) (Figure 1b) showed calcified pleural plaques, mostly distributed along …

Do asbestos-related pleural plaques on HRCT scans cause restrictive impairment in the absence of pulmonary fibrosis?

BackgroundIt is uncertain whether isolated pleural plaques cause functional impairment.ObjectiveTo analyse the relationship between isolated pleural plaques confirmed by CT scanning and lung function in subjects with occupational exposure to...

Pleural Plaque Profiles on the Chest Radiographs and CT Scans of Asbestos-exposed Japanese Construction Workers

Pleural plaques are asymptomatic focal thickenings of the pleura and considered the hallmark of asbestos exposure. However, it is often difficult to detect pleural plaques on chest x-rays (CXR). In a retrospective study, using chest CT scans of 140 Japanese asbestos-exposed construction workers who have probable or definite findings of pleural plaque on CXR; firstly, we proposed plaque morphology-based classification for CXR findings, and then we examined if those classified findings could be confirmed as pleural plaques on CT scans. Our morphology-based classification of pleural plaque findings included nine types. The percentages of confirmed pleural plaques on CT scans by type (number of confirmed pleural plaque on CT/number of observed on CXR) were 93% (40/43) for straight, 89% (56/63) for diamond, 88% (7/8) for double, 83% (19/23) for tapered medially, 80% (20/25) for parallel, 77% (23/30) for crescent, 79% (11/14) for tenting, 72% (18/25) for tapered-laterally (long type), and 0% (0/9) for tapered-laterally (short type). When added to the ILO classification, morphology-based classification of CXR pleural plaque findings makes its detection easier and hence chest radiograph continues to be a suitable tool for screening asbestos-related pleural plaques based on its simplicity, low radiation exposure, wide availability and cost-effectiveness.

Clinical consequences of asbestos-related diffuse pleural thickening: A review

Asbestos-related diffuse pleural thickening (DPT), or extensive fibrosis of the visceral pleura secondary to asbestos exposure, is increasingly common due to the large number of workers previously exposed to asbestos. It may coexist with asbestos related pleural plaques but has a distinctly different pathology. The pathogenesis of this condition as distinct from pleural plaques is gradually becoming understood. Generation of reactive oxygen and nitrogen species, profibrotic cytokines and growth factors in response to asbestos is likely to play a role in the formation of a fibrinous intrapleural matrix. Benign asbestos related pleural effusions commonly antedate the development of diffuse pleural thickening. Environmental as well as occupational exposure to asbestos may also result in pleural fibrosis, particularly in geographic areas with naturally occurring asbestiform soil minerals. Pleural disorders may also occur after household exposure. High resolution computed tomography (CT) is more sensitive and specific than chest radiography for the diagnosis of diffuse pleural thickening, and several classification systems for asbestos-related disorders have been devised. Magnetic resonance imaging and fluorodeoxyglucose positron emission tomography (PET) scanning may be useful in distinguishing between DPT and malignant mesothelioma. DPT may be associated with symptoms such as dyspnoea and chest pain. It causes a restrictive defect on lung function and may rarely result in respiratory failure and death. Treatment is primarily supportive.

Mesothelin family proteins and diagnosis of mesothelioma: analytical evaluation of an automated immunoassay and preliminary clinical results

Studies have suggested that soluble mesothelin-related protein (SMRP) can be used as a serum marker of malignant mesothelioma. We assessed the analytical performance of the Mesomark (Fujirebio Diagnostic) two-step ELISA on an automated analyser and performed a preliminary clinical evaluation. The precision of the assay and the in vitro effect of interfering substances on SMRP concentrations were investigated. The serum marker was analysed in 109 healthy subjects never exposed to asbestos, 26 healthy subjects exposed to asbestos, 33 patients with asbestosis, 33 with asbestos-related pleural plaques, 10 with non-malignant pleural diseases, 30 with lung cancer and 24 with histological diagnosis of pleural mesothelioma. Using the International Mesothelioma Interest Group classification, there were nine stage IV, two stage III, four stage II and nine stage I patients. SMRP concentrations of 4.75, 11.0 and 14 nmol/mL showed a total imprecision of 3.5%, 3.1% and 3.8%. The detection limit was 0.035 nmol/mL; the mean SMRP concentration of 0.63 nmol/mL was associated with a coefficient of variation of 10%. There was no effect (p>0.05) of interfering substances. Serum samples from patients with established pleural mesothelioma had significantly higher (p<0.05) concentrations of SMRP than control healthy and patient groups. SMRP measured on automated systems could be useful for the diagnosis of mesothelioma in routine clinical practice.

Pleural small cell carcinoma in pre-existent asbestos related pleural disease

Extrapulmonary small cell carcinoma (SCC) is a very rare disease, and a primary pleural manifestation is extremely rare. A case of SCC of the pleura in a 66-year-old man with pre-existent asbestos-related pleural plaques is presented. This is the first case of pleural SCC in a patient with asbestos-induced pleural disease and the third reported case of a pleural SCC. The SCC developed in an area with pre-existent pleural thickening, underlining the need for careful analysis of alterations in the manifestation of pleural disease in patients with asbestos exposition.

Absence of Left-Sided Predominance in Asbestos-Related Pleural Plaques: A CT Study

Differences between the number and areas of pleural plaques in every hemithorax could not be expected a priori. However, previous studies based on chest radiographs reported an unexplained left-sided predominance. In this paper, a comparison of summed surfaces and location of plaques calculated from CT studies was performed. Thoracic CT scans from 40 adults with asbestos exposure and pleural plaques were analyzed. The surface area of every plaque was calculated, and summed areas were recorded separately for every hemithorax. The statistical analysis was performed with t-tests for paired samples. Emphasis was placed on measurement differences. The results show lack of significant predominance for any hemithorax. A total of 668 plaques (352 right and 316 left) were measured, with an average area (+/-SD) of 47.81+/-47.72 cm2 for the right plaques and 45.34+/-67.32 cm2 for the left. The mean of differences (left minus right areas) was -2.56+/-53.68 and slightly statistically different from zero (p=0.652). Left-sided predominance of asbestos-related pleural plaques is not supported by this study.

Clinical Pathology and Histology of Pleural Plaques

Pleural plaques are an indicator of asbestos-associated disease that can be diagnosed by radiological techniques, thoracoscopy and at autopsy. Typical, asbestos-related pleural plaques have to be distinguished from other pleural lesions, such as diffuse pleural fibrosis, localised pleural tumours, mesothelio ma and metastasis. Pleural plaques can be the only manifestation of an asbes tos-related disease or are found in combination with asbestosis, mesothelioma and lung cancer. The association with asbestos can be shown by identifying ferruginous (asbestos) bodies in the lungs of the patients. Patients do not always have a positive occupational history of asbestos exposure, since they may have been exposed to an occult or environmental source of asbestos. In these situations, pleural plaques may be the only macroscopic finding of an asbestos-related disease.

Clinical Pathology and Histology of Pleural Plaques

Pleural plaques are an indicator of asbestos-associated disease that can be diagnosed by radiological techniques, thoracoscopy and at autopsy. Typical, asbestos-related pleural plaques have to be distinguished from other pleural lesions, such as diffuse pleural fibrosis, localised pleural tumours, mesothelioma and metastasis. Pleural plaques can be the only manifestation of an asbestos- related disease or are found in combination with asbestosis, mesothelioma and lung cancer. The association with asbestos can be shown by identifying ferruginous (asbestos) bodies in the lungs of the patients. Patients do not always have a positive occupational history of asbestos exposure, since they may have been exposed to an occult or environmental source of asbestos. In these situations, pleural plaques may be the only macroscopic finding of an asbestos-related disease.

Asbestos-related pleural plaques and lung cancer : Weiss W. 3912 Netherfield Road, Philadelphia, PA 19129. Chest 1993;103:1854–9

Asbestos-related pleural plaques and lung cancer : Weiss W. 3912 Netherfield Road, Philadelphia, PA 19129. Chest 1993;103:1854–9

Is there an association between pleural plaques and lung cancer without asbestosis?

A recent review or meta-analysis of epidemiologic studies concluded that persons with asbestos-related pleural plaques do not have an increased risk of lung cancer in the absence of parenchymal asbestosis. The reviewer inferred that this conclusion provided indirect supportive evidence for the proposition that asbestosis is a necessary precursor of asbestos-related lung cancer. The objective of the present communication is to contest these claims. Finnish epidemiologic data and population statistics were used to estimate the apparent risk ratio of lung cancer associated with radiographic signs of pleural plaques. Power calculations were applied to compute the needed population sizes to demonstrate that the association is statistically significant. Unrealistically large population studies would be needed to observe the statistical relation between pleural plaques and lung cancer, quantitated as a risk ratio of 1.1, resulting from relatively low levels of environmental asbestos exposure. In realistic and valid epidemiologic studies on heavily exposed subpopulations, a two- or threefold risk can be identified. Uninformative studies should not be interpreted as providing suppressive evidence that pleural plaques are a noncausal risk indicator of lung cancer. Even for the null hypothesis, the inference that asbestosis is a necessary causal link between asbestos and lung cancer is illogical.

Review: Asbestos-related pleural plaques are not associated with the risk for lung cancer

Source Citation Weiss W. Asbestos-related pleural plaques and lung cancer. Chest. 1993 Jun;103:1854-9.

Association between asbestos-related pleural plaques and resting hyperventilation.

This study reports an association between pleural plaques and resting hyperventilation in a group of workers exposed to asbestos. Information on exposure level, pack-years of cigarette smoking, chest radiographs, ventilation parameters, single-breath diffusing lung capacity, and arterial gases were obtained for 344 workers. After the exclusion of 37 workers for isolated parenchymal fibrosis, combined pleuroparenchymal fibrosis, or diffuse pleural thickening, 55 subjects with isolated pleural plaques were evaluated against 252 no-plaque workers. A quantitative pleural score revealed mild pleural disease. Forty-four workers with plaques (80%) had hypocapnia induced by resting hyperventilation. The quantitative pleural score correlated significantly with the partial pressure of carbon dioxide in arterial blood (correlation coefficient = 0.7). A decrement in forced vital capacity was associated with plaques, whether controlled for age, smoking, and exposure or not. It was concluded that the resting hyperventilation observed in some asbestos-exposed subjects is related to the presence of mild pleural plaques and a restrictive disorder.

Asbestos related pleural plaques in retired boiler room workers.

Occupational disease is often underestimated and only a few formal reports have been published in Taiwan. This study reports of a group of workers with asbestos-induced-disease, pleural plaque in Taiwan. Pleural plaque is a marker of exposure to asbestos. The disease was found in chest radiographs of five boiler room workers in a sugar refining factory. The chest radiographs of 248 current workers in that plant were reviewed, and none of them was found to have pleural plaques. The storage of asbestos and the long-time use of mixed asbestos cement for insulation of the inner wall of the stove and pipes were found in the factory. The authors believe that the pleural plaques might be resulted from occupational exposure to asbestos. It is suggested that the use of asbestos should be prohibited, step by step, and regular follow-up of the workers with an asbestos exposure history is required.

The ultrasound appearance of asbestos-related pleural plaques

Twenty-five patients with a history of asbestos exposure and radiological evidence of pleural plaques were examined by ultrasound (US). Non-calcified pleural plaque appeared as a regular area of echo-poor tissue which was well defined adjacent to the diaphragm or lateral chest wall, and varied in thickness from 5 mm to 12 mm. Calcified plaques had echogenic and irregular anterior margins with acoustic shadowing beyond. They were associated with characteristic comet tail and straight line artefact.

Asbestos Exposure and Asbestos-related Pleural andParenchymal Disease: Associations with Immune Imbalance

The study hypothesis was that asbestos exposure and asbestos-related pleural plaques and interstitial disease are associated with (1) immune imbalances favoring helper-inducer T-cell subsets in blood and bronchoalveolar lavage (BAL) and (2) T-lymphocyte accumulation in BAL. One hundred twenty-two asbestos-exposed subsets (AES), including 27 nonsmokers (NS), were evaluated and compared with 10 unexposed normal subjects. Data were collected on medical, smoking, and occupational histories, physical examination, spirometry, lung volumes, single-breath DLCO, chest films read by a "B" reader, and T-lymphocyte characterization in blood and BAL using flow cytometry analysis of monoclonal-antibody-treated cells. On average, AES were 47 yr of age and had 23 yr of asbestos exposure. Fifty-eight (48%) had pleural thickening, and seven (6%) had profusion greater than or equal to 1/0. In blood, asbestos-exposed NS had lower total and percent CD8 and lower total CD3 than did normal subjects. In BAL, asbestos-exposed NS had higher total CD3 than did normal subjects. Among AES, increased asbestos exposure was associated with increased percent CD8 in BAL and decreases in both percent lymphocytes and total CD8 in blood. Increase in CD4/CD8 ratio in BAL were associated with pleural thickening. In those seven with profusion greater than or equal to 1/0, there was increased percent CD4 in blood and decreased percent CD8 in BAL. These results suggest immune imbalance favoring helper-inducer T-cell subsets in association with asbestos exposure systemically and with pleural plaques in BAL.(ABSTRACT TRUNCATED AT 250 WORDS)