[Clinical characteristics and follow-up analysis of 63 cases of silicosis complicated with cavity-pulmonary tuberculosis]

Objective: To investigate the clinical characteristics and prognosis of silicosis complicated with cavity-pulmonary tuberculosis. Methods: The clinical data of 63 patients with silicosis complicated with cavity-pulmonary tuberculosis (group A) and silicosis patients (group B) admitted to Yantaishan Hospital from July 2018 to July 2022 were collected and analyzed. Results: Patients in group A were all male, and the common symptoms were cough, expectoration, chest tightness, shortness of breath, and hemoptysis. CT cavity lesions involving the lung, often occurs in the lung after the tip section, after the back section and basal segment, thick-walled cavity, may be accompanied by satellite lesions, endobronchial spread focal, pneumothorax, pleural effusion, etc. 1225 cases of group B patients haemoptysis of 59 patients, cavity in 3 patients, haemoptysis and/or cavity rate was lower than that in group A, the difference was statistically significant (P<0.05) . In group A, CT reexamination 6-24 months after anti-tuberculosis treatment showed that 52 cases (82.5%) had cavity reduction/healing, 8 cases (12.7%) had recurrence, and 3 cases (4.8%) had damaged lung (2 died) . Conclusion: Silicosis patients with hemoptysis and/or CT in cavity should be more vigilant about combined tuberculosis, anti-tuberculosis treatment and/or dynamic CT follow-up helps laboratory diagnosis negative patients.

[Diffuse interstitial lung disease of possible occupational origin treated at the Navarra Health Service. Navarra, Spain, 2017-2022]

INTRODUCTION

Diffuse interstitial lung disease (ILD) describes a broad group of pulmonary inflammatory and fibrosis disorders. Asbestosis and silicosis are the main causes linked to occupational exposure. The aim of this study was to estimate the proportion of cases with possible occupational origin and describe their exposure, clinical, and occupational status.

METHOD

We conducted a retrospective longitudinal study of ILD cases between 2017 - 2022 at the University Hospital of Navarra was conducted. Information was supplemented with interviews of cases with possible occupational origin. The occupational proportion was calculated, labor and clinical characteristics analyzed, by statistical comparison of percentages and means.

RESULTS

Out of 1067 ILD cases, 56 had a possible occupational origin 5,2% (95% CI 3,9-6,6%). 36 (64,3%) corresponded to asbestosis, 15 (26,8%) to silicosis, and 5 (8,9%) to unspecified pneumoconiosis. The most frequent activities in silicosis were "stone cutting-carving" and in asbestosis "manufacture of iron products". The average age of asbestosis cases was higher than that of silicosis cases (78,2 vs. 67,3 years), as well as their clinical manifestation. Five cases (8,9%) had been recognized as occupational diseases.

CONCLUSIONS

The implementation of a computer tool in medical records has made it possible to estimate the magnitude and assess the evolution of occupational ILD treated in the Public Health Service. Economic activities reflect the economic risk structure of the region. However, there is a lack of recognition of these diseases as occupational illnesses and they represent a preventable burden of respiratory disease.

Lung cancer risk and occupational pulmonary fibrosis: systematic review and meta-analysis

BACKGROUND

Molecular pathways found to be important in pulmonary fibrosis are also involved in cancer pathogenesis, suggesting common pathways in the development of pulmonary fibrosis and lung cancer.

RESEARCH QUESTION

Is pulmonary fibrosis from exposure to occupational carcinogens an independent risk factor for lung cancer?

STUDY DESIGN AND METHODS

A comprehensive search of PubMed, Embase, Web of Science and Cochrane databases with over 100 search terms regarding occupational hazards causing pulmonary fibrosis was conducted. After screening and extraction, quality of evidence and eligibility criteria for meta-analysis were assessed. Meta-analysis was performed using a random-effects model.

RESULTS

52 studies were identified for systematic review. Meta-analysis of subgroups identified silicosis as a risk factor for lung cancer when investigating odds ratios for silicosis in autopsy studies (OR 1.47, 95% CI 1.13-1.90) and for lung cancer mortality in patients with silicosis (OR 3.21, 95% CI 2.67-3.87). Only considering studies with an adjustment for smoking as a confounder identified a significant increase in lung cancer risk (OR 1.58, 95% CI 1.34-1.87). However, due to a lack of studies including cumulative exposure, no adjustments could be included. In a qualitative review, no definitive conclusion could be reached for asbestosis and silicosis as independent risk factors for lung cancer, partly because the studies did not take cumulative exposure into account.

INTERPRETATION

This systematic review confirms the current knowledge regarding asbestosis and silicosis, indicating a higher risk of lung cancer in exposed individuals compared to exposed workers without fibrosis. These individuals should be monitored for lung cancer, especially when asbestosis or silicosis is present.

Clinical characteristics of systemic sclerosis patients with occupational silicosis

To explore the clinical characteristics of systemic sclerosis complicated with silicosis. The systemic sclerosis patients treated in the Guangxi Workers' Hospital and the People's Hospital of Guangxi Zhuang Autonomous Region from January 2000 to December 2020 were divided into the systemic sclerosis with silicosis group and the systemic sclerosis without silicosis group. Survival analysis was performed using Kaplan-Meier estimates the Cox proportional hazards model. A propensity score matching was applied in order to avoid the selection bias.Over the past 20 years, 72 systemic sclerosis patients with silicosis and 238 systemic sclerosis patients without silicosis were treated in the two hospitals. The systemic sclerosis patients with silicosis group had more males (P < 0.000),lower mean age at onset of SSc (P < 0.000), more frequent occurrence of weight loss (P = 0.028), smoking (P < 0.000), tuberculosis (P < 0.000), cardiac involvement (P < 0.000), ILD (P = 0.017), pulmonary hypertension (P = 0.024), elevated BNP (P < 0.000). With regards to the multivariate Cox regression analysis, silicosis was related with a higher overall mortality before (HR = 3.666, 95% CI = 1.440-11.234, p = 0.025) and after the propensity score matching analysis (HR = 2.817, 95% CI = 1.196-10.764, p = 0.014). Independent risk factors for overall mortality were Gangrene (HR = 3.003, 95% CI = 1.343-9.431), Cardiac involved (HR = 5.370, 95% CI = 1.910-15.472), Scl-70 (HR = 3.569, 95% CI = 1.333-10.869), Elevated BNP (HR = 2.135, 95% CI = 1.293-9.564).Concomitant silicosis worsens systemic sclerosis patients' prognoses. Gangrene, Scl-70, elevated BNP and cardiac involvement are independent risk factors for overall mortality. Key Points •Concomitant silicosis worsens SSc patients' prognoses. •For individuals with occupational exposure, close observation of the symptoms of SSc, early diagnosis, and interruption of exposure may improve the prognosis. •Gangrene, Scl-70, elevated BNP and cardiac involvement are independent risk factors for overall mortality.

Silicosis as an unusual cause of symptomatic cervical adenopathy

A case of symptomatic cervical adenopathy is reported as a presentation of silicosis. Silicosis is one of the most important occupational health diseases worldwide caused by the inhalation of airborne silica particles. The presence of thoracic adenopathies is a common clinical feature of silicosis, cervical silicotic adenopathies on the other hand are rare and unknown to most clinicians and can therefore lead to a differential diagnostic problem. Awareness of the clinical, radiological, and histological features is key for the diagnosis.

Association of family sequence similarity gene 13A gene polymorphism and interstitial lung disease susceptibility: A systematic review and meta-analysis

BACKGROUND

Among present reports, the T/G allelic variation at the rs2609255 locus of the family sequence similarity gene 13A (FAM13A) was considerable associated with susceptibility to interstitial lung diseases (ILDs). In this study, we summarized relevant studies and applied a meta-analysis to explore whether the polymorphism of rs2609255 site of the FAM13A gene can be utilized to predict susceptibility to idiopathic pulmonary fibrosis (IPF) patients or rheumatoid arthritis-associated interstitial lung disease (RA-ILD) or silicosis patients in different populations for the first time.

METHODS

We compared the frequency of G allele on rs2609255 site of FAM13A between the control subjects and IPF or RA-ILD or silicosis patients from different races by using meta-analysis. Nine studies were involved in this meta-analysis, including five IPF studies, two RA-ILD studies, and two silicosis studies, and containing 14 subgroups. We conducted separate meta-analyses for different races.

RESULTS

In all individuals, a substantial link between the G allele of the FAM13A rs2609255 polymorphism and IPF (OR: 1.47, 95% CI: 1.33-1.63, p < 0.00001) was indicated. After dividing by ethnicity, the G allele was illustrated to be considerable correlation with IPF in Asian (OR: 2.63, 95% CI: 1.81-3.81, p < 0.00001) and with RA-ILD individuals (OR: 3.27, 95% CI: 1.26-8.49, p = 0.01). Conversely, there was no correlation with the G allele and IPF in European individuals (OR: 1.27, 95% CI: 0.89-1.83, p = 0.13) or silicosis in Chinese individuals (OR: 1.20, 95% CI: 0.99-1.46, p = 0.07).

CONCLUSION

This is the first meta-analysis that provides evidence that the rs2609255 of FAM13A might increase susceptibility to RA-ILD, and IPF especially in Asian but not in European individuals, and not be correlated with silicosis in Chinese individuals, which indicated the differences in susceptibility to disease by race were noteworthy.

Exploring the Impact of Silicosis Incidence on Tuberculosis Mortality and Morbidity: A Multi-Country Study

INTRODUCTION

There are several risk factors attributed to tuberculosis (TB) mortality and morbidity. There are few studies and systematic reviews showing the association of silicosis and tuberculosis at a country level. Very limited studies have been conducted using multi-country data in studying the association of incidence of silicosis with TB mortality and morbidity. Hence, the aim of this research was to explore the association of incidence of silicosis and other important risk factors with TB mortality and morbidity using multi-country data.

METHODS

Data from 217 WHO region countries were utilized, sourcing TB-related statistics from the Institute of Health Metrics and Evaluation and additional risk factors from the Demographic and Health Survey, Global Burden of Disease, and World Bank for 2019. Regression analysis was conducted to examine the association between silicosis incidence and TB outcomes.

RESULTS

The study found an average silicosis incidence of 121.92 per 100,000 population. Additionally, 62.69% of the sample population are exposed to air pollution from solid fuel cooking. Sanitation access stands at an average of 59.67%. Regression outcomes indicate that while alcohol consumption's influence on TB is not statistically significant, a unit increase in silicosis incidence significantly elevates TB deaths (235.9, p = 0.005), YLL (9399.3, p = 0.011), and YLD (910.8, p = 0.002).

CONCLUSION

The burden of silicosis is found to be one of the important determinants of deaths, YLL, and YLD due to tuberculosis. Country-specific strategies to prevent and control silicosis is a need of the hour.

[Prevalence and risk factors of silicosis complicated with chronic obstructive pulmonary disease]

Objective: To explore the prevalence, clinical characteristics and risk factors of chronic obstructive pulmonary disease (COPD) in silicosis patients. Methods: In May 2021, a cross-sectional study was used to retrospectively include 329 silicosis patients first diagnosed in Beijing Chaoyang Hospital from January 1, 2007 to December 31, 2020. The demographic data, occupational history, chest imaging, pulmonary function and blood routine indicators of silicosis patients with COPD were analyzed, and the risk factors of silicosis with COPD were analyzed by multiple logistic regression. Results: There were 128 patients with silicosis complicated with COPD, and the overall prevalence rate was 38.9% (128/329) . Among them, 73.4% (94/128) were male and 33.6% (43/128) were heavy smokers; 33.6% (43/128) of patients were classified as gold 1, 37.5% (48/128) as gold 2, 25.0% (32/128) as gold 3, and 3.9% (5/128) as gold 4. Diagnostic age (OR=1.04, 95%CI=1.02~1.06, P<0.001) , cumulative smoking (OR=1.03, 95%CI=1.01~1.05, P=0.008) and silicosis stage III (OR=7.06, 95% CI=4.00-12.46, P<0.001) were risk factors for silicosis complicated with COPD. Conclusion: Diagnostic age, cumulative smoking volume and third stage of silicosis are the risk factors of silicosis patients with different degrees of COPD, which should be paid attention to in clinical treatment.

[The influencing factors of cognitive impairment in patients with silicosis]

Objective: To explore the influencing factors of cognitive impairment in patients with silicosis, and to analyze the effect of brain-derived neurotrophic factor (BDNF) on cognitive function. Methods: In March 2021, 484 silicosis patients from April 2018 to April 2020 were included in the study. The Montreal Cognitive Assessment Scale of Chinese version was used to evaluate their cognitive function, and they were divided into the cognitive impairment group (n=282) and the non cognitive impairment group (n=202) , another 30 healthy persons from body check were served as control group. The concentrations of BDNF were compared between the three groups. And the receiver operating characteristic (ROC) curve was drawed to analyze the value of BDNF in predicting cognitive impairment in silicosis patients. And the logistic regression analysis was used to explore the risk factors of cognitive impairment. Results: The incidence of cognitive impairment in silicosis patients was 58.26% (282/484) . The level of BDNF in the cognitive impairment group[ (10.32±2.11) mg/L] was significantly lower than that in the non cognitive impairment group[ (13.43±3.45) mg/L] (t=-12.27, P<0.001) . The results of ROC curve analysis showed that the area unde the curve of BDNF in predicting cognitive impairment of silicosis patients was 0.763 (95%CI: 0.613-0.874, P=0.024) , the cut off value was 10 mg/L, the sensitivity was 0.88, and the specificity was 0.84. Logistic regression analysis showed that the level of BDNF (≤10 mg/L) , age (≥65 years old) , course of disease (≥5 years) and diabetes mellitus were the risk factors of cognitive impairment in silicosis patients (OR=2.346, 95%CI: 1.654-3.103; OR=1.757, 95%CI: 1.214-1.998; OR=1.346, 95%CI: 1.112-1.564; OR=1.165, 95%CI: 1.102-1.542, P=0.001, 0.012, 0.027, 0.036) . Conclusion: BDNF may be one of the indicator to predict the risk of cognitive impairment in patients with silicosis.

Multisystem Amyloidosis in a Coal Miner with Silicosis: Is Exposure to Silica Dust a Cause of Amyloid Deposition?

The over-secretion of monoclonal immunoglobulin light chains by clonal B cells followed by the aggregation and extracellular deposition of fibrillar deposits are responsible forthe clinical course AL amyloidosis. It is well documented that silica significantly increases the number of immunoglobulin-secreting cells. In the present paper, we report on a coal miner with silicosis and fast progressing primary amyloidosis with predominantly heart, kidney, and lung manifestations. Severeheart failure due to myocardial hypertrophy resulted in the patient’s death. We conclude that long-term environmental silica exposure and silica deposition may contribute to the development of monoclonal gammopathy and amyloidosis due to chronic stimulus and the dysregulation of the immune system.

[Analysis of the pulmonary function characteristics and associated factors in silicosis patients with progressive massive fibrosis]

Objective: To investigate the characteristics of and associated risk factors for pulmonary dysfunction in silicosis patients with progressive massive fibrosis (PMF) . Methods: In-patients with PMF treated in the Department of Occupational Medicine and Toxicology in Beijing Chao-Yang Hospital, Capital Medical University from June 2014 to October 2020 were enrolled in this study. Based on their pulmonary ventilation function, the patients were divided into normal ventilation group, obstructive ventilation dysfunction group, restrictive ventilation dysfunction group, and mixed ventilation dysfunction group. The location and area of the large opacity and the grade of emphysema were evaluated by high-resolution CT (HRCT) of the chest. Based on the location, the large opacity was classified into central type, peripheral type, and mixed type. Results: A total of 115 silicosis patients with PMF were enrolled, with 85 (73.91%) having different types of pulmonary dysfunction, including 36 cases (31.30%) in the obstructive ventilation dysfunction group, 9 cases (7.83%) in the restrictive ventilation dysfunction group and 40 cases (34.78%) in the mixed ventilation dysfunction group. As for the location of the large opacity, 41 cases (35.65%) were central type, 52 cases (45.22%) were peripheral type, and 22 cases (19.13%) were mixed type. Logistic regression analysis showed that the central large opacity and grade 3-4 emphysema were risk factors for obstructive ventilation dysfunction (OR=52.179, 5.500, P<0.05) , class C large opacity was the risk factor for restrictive ventilation dysfunction (OR=33.146, P<0.05) , class B, class C large opacity and central large opacity were the risk factors for mixed ventilation dysfunction (OR=6.414, 11.561, 19.600, P<0.05) . Conclusion: In silicosis patients with PMF, the incidence rate of pulmonary ventilation dysfunction is higher, mainly obstructive and mixed ventilation dysfunction. The area and location of large opacity are associated with the incidence and types of pulmonary ventilation dysfunction.

Prevalence and clinical impact of systemic autoimmune rheumatic disease in patients with silicosis

BACKGROUND

Silicosis is associated with an increased risk of developing systemic autoimmune rheumatic disease (SARD). The prognostic implications of this association are poorly characterized. The aim of this study was to determine the prevalence of SARD and autoimmune markers in a cohort of patients with exposure to silica and assess their impact on prognosis.

METHOD

We performed a prospective observational study of all patients attending the dedicated silicosis clinic of our pulmonology unit between 2009 and December 2017. Diagnosis was confirmed by a rheumatologist according to Spanish Rheumatology Society criteria. Autoimmune markers, pulmonary function tests, radiological progression, visits to the emergency department and primary care center, and hospital admissions for respiratory causes, and mortality were analyzed.

RESULTS

Overall, 489 cases of silicosis and 95 cases of exposure were studied. In total, 54 (11.0%) patients with silicosis had SARD: 12 (2.4%) rheumatoid arthritis, 10 (2.0%) systemic lupus erythematosus, 10 (2.0%) systemic sclerosis, 3 (0.6%) Sjögren syndrome, 2 (0.4%) vasculitis associated with anti-neutrophil cytoplasmic antibodies (ANCA +), 6 (1.2%) psoriatic arthritis, 3 (0.6%) ankylosing spondylitis, and 8 (1.6%) other autoimmune diseases with no special features. The patients with SARD visited the emergency room more often (63.0% vs. 42.5%; p = 0.004), and progressed more rapidly (22.2 vs. 11.7%; p = 0.030).

CONCLUSIONS

The presence of systemic rheumatic autoimmune diseases involves radiological progression and a higher clinical impact.

Case Series: Hypercalcemia From Granulomatous Silicosis Developing After COVID-19 Infection

Hypercalcemia is one of the most commonly encountered laboratory abnormalities in clinical medicine. Various causes have been well established. However, it is likely that the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), may be a newly found cause of this frequent finding, especially amongst those with a history of cosmetic surgery, specifically by means of silicone injection. In this case series, we describe 2 patients presenting with symptomatic hypercalcemia likely from their prior silicone injections. Interestingly, each patient only developed symptoms of hypercalcemia following infection with SARS-CoV-2.

Sodium tanshinone IIA sulfonate attenuates silica-induced pulmonary fibrosis in rats via activation of the Nrf2 and thioredoxin system

Silicosis is characterized by pulmonary fibrosis due to long-term inhalation of silica particles. Although the cause of this serious disease is known, its pathogenesis remains unclear and there are currently no specific treatments. Recent studies have shown that the anti-oxidant transcription factor Nrf2 is expressed at reduced levels in fibrotic foci, which may be related to disease progression. However, the molecular mechanisms by which this might occur have yet to be elucidated. Sodium tanshinone IIA sulfonate (STS), an extract of Salvia miltiorrhiza, is used in traditional Chinese medicine in the treatment of coronary heart disease. STS has been shown to play a strong anti-oxidative role in various organs. Here, we employed a rat model to explore the effects of STS on oxidative stress and the progression of fibrosis in silicosis. STS significantly reduced collagen deposition in the lungs, thereby antagonising silicosis. Immunohistochemical and immunofluorescence staining showed that Nrf2 was differentially expressed in lung cells during silica induced fibrosis, and chromatin immunoprecipitation-sequencing experiments demonstrated that Nrf2 promoted the expression of the antioxidant proteins thioredoxin and thioredoxin reductase. Our results suggest that the anti-fibrotic effects of STS may be related to upregulation of Nrf2 nuclear expression, especially in fibrotic lesions, and the promotion of thioredoxin and thioredoxin reductase expression. Our findings may open up new avenues for the development of STS as a treatment for silicosis.

High incidence of radiation pneumonitis in lung cancer patients with chronic silicosis treated with radiotherapy

Silica is an independent risk factor for lung cancer in addition to smoking. Chronic silicosis is one of the most common and serious occupational diseases associated with poor prognosis. However, the role of radiotherapy is unclear in patients with chronic silicosis. We conducted a retrospective study to evaluate efficacy and safety in lung cancer patients with chronic silicosis, especially focusing on the incidence of radiation pneumonitis (RP). Lung cancer patients with chronic silicosis who had been treated with radiotherapy from 2005 to 2018 in our hospital were enrolled in this retrospective study. RP was graded according to the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. Of the 22 patients, ten (45.5%) developed RP ≥2. Two RP-related deaths (9.1%) occurred within 3 months after radiotherapy. Dosimetric factors V5, V10, V15, V20 and mean lung dose (MLD) were significantly higher in patients who had RP >2 (P < 0.05). The median overall survival times in patients with RP ≤2 and RP>2 were 11.5 months and 7.1 months, respectively. Radiotherapy is associated with excessive and fatal pulmonary toxicity in lung cancer patients with chronic silicosis.

Intranasal Flunisolide Suppresses Pathological Alterations Caused by Silica Particles in the Lungs of Mice

Silicosis is an occupational disease triggered by the inhalation of fine particles of crystalline silica and characterized by inflammation and scarring in the form of nodular lesions in the lungs. In spite of the therapeutic arsenal currently available, there is no specific treatment for the disease. Flunisolide is a potent corticosteroid shown to be effective for controlling chronic lung inflammatory diseases. In this study, the effect of flunisolide on silica-induced lung pathological changes in mice was investigated. Swiss-Webster mice were injected intranasally with silica particles and further treated with flunisolide from day 21 to 27 post-silica challenge. Lung function was assessed by whole body invasive plethysmography. Granuloma formation was evaluated morphometrically, collagen deposition by Picrus sirius staining and quantitated by Sircol. Chemokines and cytokines were evaluated using enzyme-linked immunosorbent assay. The sensitivity of lung fibroblasts was also examined in in vitro assays. Silica challenge led to increased leukocyte numbers (mononuclear cells and neutrophils) as well as production of the chemokine KC/CXCL-1 and the cytokines TNF-α and TGF-β in the bronchoalveolar lavage. These alterations paralleled to progressive granuloma formation, collagen deposition and impairment of lung function. Therapeutic administration of intranasal flunisolide inhibited granuloma and fibrotic responses, noted 28 days after silica challenge. The upregulation of MIP-1α/CCL-3 and MIP-2/CXCL-2 and the cytokines TNF-α and TGF-β, as well as deposition of collagen and airway hyper-reactivity to methacholine were shown to be clearly sensitive to flunisolide, as compared to silica-challenge untreated mice. Additionally, flunisolide effectively suppressed the responses of proliferation and MCP-1/CCL-2 production from IL-13 stimulated lung fibroblasts from silica- or saline-challenged mice. In conclusion, we report that intranasal treatment with the corticosteroid flunisolide showed protective properties on pathological features triggered by silica particles in mice, suggesting that the compound may constitute a promising strategy for the treatment of silicosis.

A Cohort Study of Workers Employed in a Refractory Brick Plant

A mortality study was carried out on a cohort of workers who were exposed to silica dust in a refractory brick plant. The cohort was divided into two groups: workers with and without silicosis, and their mortality was contrasted with the death rate of Genova from 1960 to 1979. Results show an increased risk for laryngeal tumors (3 obs., 0.44 exp., SMR = 682), nonmalignant respiratory disease (16 obs., 3.2 exp., SMR = 500), and cardiovascular diseases (19 obs., 11 exp., SMR = 173) among silicotics. The mortality rate for lung cancer showed an increase for the cohort of workers as a whole (11 obs., 6 exp., SMR = 183). The almost double overall mortality observed in silicotic subjects raises some doubts about the validity of other proportional mortality studies that showed no excesses for workers in these industries.

Lung Cancer Mortality in Tuscany from 1971 to 2010 and Its Connections with Silicosis: A Space-Cohort Analysis Based on Shared Models

Lung cancer mortality in Tuscany (Italy) for males, from 1971 and 2010, is investigated. A hierarchical Bayesian model for space-time disease mapping is introduced. Such a model belongs to the class of shared random effect models and exploits the birth-cohort as the relevant time dimension. It allows for highlighting common and specific patterns of risk for each birth-cohort. The results show that different birth-cohorts exhibit quite different spatial patterns, even if the socioeconomic status is taken into account. In fact, there were different occupational exposures before and after the Second World War. The birth-cohort 1930-35 exhibits high relative risks related to particular areas. This fact could be connected with occupational exposure to risk factors for silicosis, perhaps a prognostic status for lung cancer.

Percutaneous treatment for silicosis-induced pulmonary artery stenosis: A case report and review of the literature

BACKGROUND

Exposure to crystalline silica results in silicosis with initiation and progression of pulmonary fibrosis. The impaired lung parenchyma leads to pulmonary arterial hypertension and increased pressure in the right ventricle of the heart. Usually, the silicosis may be followed by enlargement of hilar lymphnodes, but silicosis-induced pulmonary artery stenosis with severe pulmonary hypertension is rare. Percutaneous pulmonary artery stenting and balloon angioplasty were performed to relieve stenosis and pulmonary hypertension.

METHODS

We report the case of a 52-year-old man who was admitted for persistent dyspnea for 2 years and progressive dyspnea for half a month. He had been a stonemason for 20 years. The computer tomography pulmonary angiography scan images showed partially fibrotic lungs with a disseminated nodular pattern and enlarged bilateral hilar and mediastinal lymphnodes. The echocardiogram and right heart catheterization confirmed the diagnosis of severe pulmonary arterial hypertension.

RESULTS

Pulmonary angiograms showed severe stenosis of the proximal upper right and lower left pulmonary artery. Moderate stenosis occured in a branch of the lower right pulmonary artery and a branch of the upper left pulmonary artery. A total of 2 stents and 4 balloons were used to relieve lesions. The final angiograms showed a significantly increased pulmonary artery caliber. The clinical symptom and 6-minute walk distance of the patient were much improved.

CONCLUSION

To our knowledge, this is the first reported case of percutaneous treatment for silicosis-induced pulmonary artery stenosis and pulmonary hypertension. The clinical symptom, 6-minute walking test, and vessel caliber at areas of stenosis improved significantly following stent implantation and balloon dilatation. However, the patient was followed up for a short period and long-term outcomes have not yet been sufficiently evaluated.

Occupational exposure to silica dust and risk of lung cancer: an updated meta-analysis of epidemiological studies

BACKGROUND

Crystalline silica is considered as one of the most common and serious occupational hazards to workers' health. Although its association with lung cancer has been studied for many decades, the conclusion remains somewhat controversial. Our objectives are to review and summarize the epidemiological evidence on the relationship between occupational silica exposure and risk of lung cancer and to provide an update on this major occupational health concern.

METHODS

Eligible studies up to 29 April 2016 were identified. Pooled effect estimates were calculated according to the reported outcome and the study design. Cohort, case control and proportional mortality studies were examined separately. Studies reporting results according to silicotic status were grouped together and analyzed. Due to the significant amount of heterogeneity expected, random effects models were implemented. Subgroup and meta-regression analyses (both univariate and multivariate) were performed in an attempt to explain heterogeneity. Studies which had adequate exposure characterization were selected to find out whether there was an exposure-response relationship between silica and lung cancer.

RESULTS

The risk of lung cancer was found to be elevated in both silicotics and non-silicotics. The pooled standardized mortality ratio (SMR) was 2.32 with a 95 % confidence interval (95 % CI) of 1.91-2.81 and 1.78 (95 % CI 1.07-2.96) respectively. The pooled standardized incidence ratio (SIR) was 2.49 (95 % CI 1.87-3.33) and 1.18 (95 % CI 0.86-1.62) respectively. Subgroup analysis showed that workers in the mining industry had the highest risk of lung cancer with a pooled SMR of 1.48 (95 % CI 1.18-1.86) and the weakest association was seen in potteries with a pooled SMR of 1.14 (95 % CI 1.05-1.23). A positive exposure-response relation was found between cumulative silica exposure and risk of lung cancer.

CONCLUSION

The results of our meta-analysis supported the carcinogenic role of silica on the lungs, which was more pronounced at higher levels of exposure, in the presence of silicosis and in the mining industry. Further research is needed to evaluate whether non-silicotics are truly at risk, whether a predisposing factor would explain this potential risk, and to determine the mechanism of carcinogenicity of silica in humans.

Silicosis and renal disease: insights from a case of IgA nephropathy

A 68-yr-old male, smoker, is admitted for proteinuria (2,800 mg/24 h) and reduced renal function (serum creatinine 2 mg/dl, GFR 35 ml/min). Renter, he started working 20-yr-old as a sandstone cave miner. Despite the high levels of silica dusts, he reported no mandatory use of airways protection devices during the first 25 yr of activity. No clinical or radiological signs of silicosis or pneumoconiosis where reported until the year of retirement (1997). Erythrocyte sedimentation rate (91 mm/h) and C reactive protein (35 mg/l) suggested a pro-inflammatory status. High serum IgA was found (465 mg/dl). A renal biopsy identified glomerular sclerosis with IgA deposition, signs of diffuse vasculitis and tubular atrophia suggesting a diagnosis of IgA nephropathy. Chest X-Rays showed emphysema and diffuse nodularity suggesting diagnosis of silicosis. Chest tomography was also positive for mild signs of silicosis with silicotic nodules and without honeycombing. IgA nephropathy is the most common type of glomerulonephritis worldwide. Several clues suggest a genetic or acquired abnormality of immune system as a trigger of the increased production of IgA. In our case report, simultaneous kidney and pulmonary disease could suggest same triggers (e.g. exposure to virus, bacteria or environmental agents) inducing IgA synthesis and pulmonary immune system activation.

An 11-year-old boy with silico-tuberculosis attributable to secondary exposure to sandstone mining in central India

Silicosis from secondary exposure is not often reported. This is the first such report of a child with possible silicosis attributable to secondary exposure to sandstone mining in India. Silicosis from secondary exposure has been reported in the gem polishing and slate pencil manufacturing industries in India; however, the stone-mining industry is severely under-researched. No preventive measures have been instituted in the stone-mining industry and children are exposed to respirable silica dust when their mothers take them to their work places. Poverty and lack of accessibility to modern medical facilities promote malnutrition and tuberculosis, two known co-morbid conditions. Stone mining, an export-oriented industry, produces billions of dollars of foreign currency every year. Although there is legislation to protect workers from exploitation, employers disregard the law and the state turns a blind eye by not implementing proper enforcement mechanisms. Silicosis from environmental exposure affects the entire community that lives in stone-mining areas.

[Study on tissue Doppler imaging in diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease]

OBJECTIVE

To investigate the value of tissue Doppler imaging (TDI) in the diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease.

METHODS

A total of 50 cases of silicosis complicated by chronic pulmonary heart disease in our hospital underwent conventional electrocardiography (ECG) and TDI. The detection rates for right ventricular hypertrophy by two methods were compared.

RESULTS

Of 50 cases of silicosis complicated by chronic pulmonary heart disease, 19 were diagnosed with right ventricular hypertrophy by ECG, with a detection rate of 38.0%; 29 were diagnosed with right ventricular hypertrophy by TDI, with a detection rate off 58.0%. Statistical analysis suggested that TDI leads to a significantly higher detection rate for right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease (χ² = 4.006, P = 0.036).

CONCLUSION

Both TDI and ECG can be used for detecting right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease, but the detection rate is higher when TDI is employed. In addition, ECG cannot directly reflect the increase in pulmonary artery pressure. Therefore, TDI is more suitable for the diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease and provides a strong diagnostic basis for the clinical treatment of silicosis complicated by pulmonary heart disease.

Joint effects of smoking and silicosis on diseases to the lungs

Smokers are subject to being more susceptible to the long-term effects of silica dust, whilst it remains unclear whether the joint effect of smoking and silicosis differs amongst diseases to the lungs; this study aims to address this knowledge gap. This was a historical cohort study comprised of 3202 silicotics in Hong Kong during 1981-2005 who were followed up till 31/12/2006. We estimated the standardized mortality ratio (SMR) in the smoking and never smoking silicotics using the mortality rates of male general population indiscriminately by smoking status, but these SMRs were regarded as biased. We adjusted these biased SMRs using "smoking adjustment factors (SAF)". We assessed the multiplicative interaction between smoking and silicosis using 'relative silicosis effect (RSE)' that was the ratio of SAF-corrected SMR of smoking silicotics to the never smokers. A RSE differs significantly from one implies the presence of multiplicative interaction. A significant excess SMR was observed for respiratory diseases (lung cancer, chronic obstructive pulmonary diseases [COPD], silicosis) and other diseases to the lungs (pulmonary heart disease, tuberculosis). All the 'biased-SMRs' in smokers were higher than those in never smokers, but the SAF-corrected SMRs became higher in never smokers. The RSE was 0.95 (95%CI: 0.37-3.55), 0.94 (95%CI: 0.42-2.60), and 0.81 (95%CI: 0.60-1.19) for lung cancer, COPD, and silicosis; whilst it was 1.21 (95%CI: 0.32-10.26) for tuberculosis and 1.02 (95%CI: 0.16-42.90) for pulmonary heart disease. This study firstly demonstrated the joint effect of smoking and silicosis may differ amongst diseases to the lungs, but power is limited.

[Optimization of cholecystectomy method in patients with professional diseases of respiratory organs]

Results of cholecystectomy performance were analyzed in 99 patients with a biliary calculous disease, the course of which have become complicated by cholecystitis occurrence, in 49 of them professional diseases of respiratory organs, including silicosis, antracosis, were registered. Estimating results of laparoscopic and open cholecystectomy, we have established, that carboperitoneum in laparoscopic cholecystectomy impacts negatively the course of early postoperative period, what manifests with hemodynamic and respiratory disorders. The level of fibronectin and endotelin--1 in the blood plasm directly depends on the respiratory disorders severity and may be applied as a test for respiratory dysfunction. The method of cholecystectomy in patients, suffering professional diseases of respiratory organs, must be selected, depending on severity of functional disorders of respiratory organs.

[Structure and dynamics of occupational lung diseases in workers of Moscow region under longstanding 50 years of observation]

The article covers data on occupational morbidity in Moscow region over last 50 years. Stable number of newly diagnosed occupational diseases was seen up to first half of 1990s. Afterwards, steady decrease in occupational morbidity is seen with closure of major industrial enterprises. Among occupational pulmonary diseases, dust fibrosis (pneumoconiosis--44%) prevail. Tuberculosis complication of silicosis decreased, additional general somatic concomitants (arterial hypertension, ischemic heart disease, malignancies) are more frequent. Prevalence of occupational bronchial asthma has increased 16 times vs. that in 1976.

[Observation on the effects of the treatment of sillicosis merger asthma]

OBJECTIVE

To investigate Salmeterol/Fluticasone Propionate and Totropiumi treatment of Sillicosis merger Asthma.

METHODS

30 patients with Sillicosis merger Asthma were randomly divided into group Salmeterol/Fluticasone Propionate( Single group) ( n=14) and group Salmeterol/Fluticasone Propionate and Totropiumi (Joint group) ( n= 16), patient in single group were only given Salmeterol/Fluticasone Propionate (50 f.Lg Bid) inhaling,and those in Joint group were given Salmeterol/Fluticasone Propionate (50 f.Lg Bid) and Totropiumi ( 18 f.Lg Qd) inhaling. The treatment was last for 6 months.Before the treatment,evaluation of the two groups of Sillicosis installment,determination their foungation lung function and ACT score .. After the cause of treatment, lung function FEV10/FVC(% ), FEV10 pred%, FEV10(ml), ACT score, the incidence of side effects of two groups were compared and analyzed.

RESULT

The two groups before the treatment of lung fuction and ACT score had no statistically significant difference. The two groups after treatment of lung fuction FEV10/FVC (% ),FEV10 pred%, ACT score obviously higher than before treatment (P<0.05), Joint group in FEV1/FVC(% ), ACT score significantly higher than in Single group (?<0.05), Joint group acute attack times(0.98±0.79)/time lower than Single group (2.10 ± 0.81 )/time (t=3.86,P<0.05). There were no significant side effect in two groups.

CONCLUSION

Salmeterol/Fluticasone Propionate or the combination of Salmeterol/Fluticasone Propionate and Totropiumi can improve lung function and clinical symptoms of patients with Sillicosis merger Asthma. It is also better that the combination of Salmeterol/Fluticasone Propionate and Totropiumi obviously improve clinical symptoms of patients and reduice acute attack times.

Erasmus syndrome: silicosis and systemic sclerosis

The silicosis is the pneumoconiosis more frequent, resulting from the inhalation of silica or silicates containing mineral dust, mainly characterized by irreversible lung fibrosis. It is associated with the development of other diseases, including pulmonary tuberculosis, lung cancer and autoimmune diseases. The connective tissue disease after exposure to silica occurs usually after 15 years of initial exposure.The Erasmus syndrome describes the association of systemic sclerosis following exposure to silica with or without silicosis. The authors report two cases of patients with diagnosis of silicosis who developed systemic sclerosis.

Laryngeal cancer and silica dust exposure: a systematic review and meta-analysis

BACKGROUND

Individual epidemiological studies generally lack the power to examine the association between silica exposure or silicosis and laryngeal cancer. We summarized pertinent evidence from published literature by using meta-analysis.

METHODS

A systematic literature search was performed to identify cohort and case-control studies, and the method of meta-analysis was used to combine standardized mortality ratios (SMRs) or standardized incidence ratios (SIRs) from cohort studies and odds ratios (ORs) from case-control studies.

RESULTS

A significantly increased risk of laryngeal cancer (pooled OR = 1.39, 95% confidence interval (95% CI): 1.17-1.67) among workers exposed to silica dust was observed by combining six case-control studies with adjustment for smoking and alcohol consumption. A similarly increased but statistically non-significant risk estimate was observed from cohort studies, with a pooled SMR of 1.38 (95% CI: 0.79-1.96) for silicosis cases; and a pooled SMR of 1.13 (95% CI: 0.82-1.45) and a pooled SIR of 1.50 (95% CI: 0.59-2.42) for workers with silica dust exposure.

CONCLUSION

This systematic review demonstrated a weak association between silica or silicosis and laryngeal cancer. Owing to the inherent limitations of the original studies, interpretation of the results of this meta-analysis should be cautious.

Silicosis mortality with respiratory tuberculosis in the United States, 1968-2006

The presence of tuberculosis (TB) in patients with silicosis increases mortality risk. To characterize silicosis-respiratory TB comortality in the United States, the authors used 1968-2006 National Center for Health Statistics multiple cause-of-death data for decedents aged ≥25 years. The authors calculated proportionate mortality ratios (PMRs) using available information on decedents' industries and occupations reported from 26 states from 1985 through 1999. Among 16,648 silicosis deaths, 2,278 (13.7%) had respiratory TB listed on the death certificate. Of silicosis-respiratory TB deaths, 1,666 decedents (73.1%) were aged ≥65 years, 2,255 (99.0%) were male, and 1,893 (83.1%) were white. Silicosis-respiratory TB deaths declined 99.5% during the study period (P < 0.001 for time-related trend), from 239.8 per year during 1968-1972 to 1.2 per year during 2002-2006, with no reported deaths in 2006. Silicosis-respiratory TB deaths reported from Pennsylvania (n = 525; 1.29 per million population), Ohio (n = 258; 0.81 per million), and West Virginia (n = 146; 2.35 per million) accounted for 40.8% of all such deaths in the United States. The highest PMR for silicosis-respiratory TB death was associated with the "miscellaneous nonmetallic mineral and stone products" industry (PMR = 73.7, 95% confidence interval: 33.8, 139.8). In the United States, 2006 marked the first year since 1968 with no silicosis-respiratory TB deaths. The substantial decline in silicosis-respiratory TB comortality probably reflects prevention and control measures for both diseases.

[A case of microscopic polyangiitis with silicosis]

A 76-year-old man was admitted to our hospital because of increasing size of lung nodules, while he was under observation for silicosis at another hospital. As the result of bronchoscopic biopsy, it was confirmed that they were silicotic nodules. However, he was hospitalized again about one month later due to left spontaneous pneumothorax. The pneumothorax improved immediately by persistent drainage of the thoracic cavity, but he developed a fever on day 9, and ground-glass opacities in both lungs also became exacerbated in spite of our administration of antibiotics. In addition, the level of MPO-ANCA increased markedly and multiple 3-10mm sized purpurae was seen on the right thigh on day 29. Skin biopsy specimens revealed infiltration of histiocytes and lymphocytes around medium-sized vessels in lower dermis. We diagnosed microscopic polyangiitis, then treated with steroid and immunosuppressive therapy. Fever and radiological findings improved significantly from the day after initiation of steroid administration. The patient was discharged on day 92 because of the improvement of his respiratory condition. We report a case of microscopic polyangiitis with silicosis, which markedly improved by steroid and immunosuppressive therapy.

Meta-analyses of published epidemiological studies, 1979-2006, point to open causal questions in silica-silicosis-lung cancer research

BACKGROUND AND OBJECTIVES

Following up on a previous meta-analysis of lung cancer risk in individuals without silicosis, we provide more detailed results of silica associated lung cancer risk in both silicotics and non-silicotics. The objective was to examine in depth whether current data allows to answer the pressing question "does silica cause lung cancer in the absence of silicosis"?

METHODS

We updated earlier meta-analyses of silicosis and lung cancer and compared the results with our 2009 meta-analysis of risks in individuals without silicosis. We performed fixed (FE) and random (RE) effects meta-analyses, calculated heterogeneity statistics, stratified the study material, performed sensitivity analyses with modified study results and meta-regressions to detect effect modification.

RESULTS

In silicotics, lung cancer risks were found to be doubled in 38 studies (FE: RR = 2.1; 95% CI = 2.0-2.3). In non-silicotics, eight studies without smoking adjustment suggested marginally elevated risks (FE: RR = 1.2; 95% CI = 1.1-1.3; RE: RR = 1.2; 95% CI =1.0-1.4) but three studies which were controlled for smoking showed null results (FE and RE: RR = 1.0; 95% CI = 0.8-1.3). Heterogeneity was substantial but could be linked to study characteristics, like sector of industry, and other second-level data in meta-regression. As no excess was observe dfor other smoking-related effects in studies ofllung cancer among non-silicotics, smoking was not considered to be an important confounder or modifier. CONCLUSIONn: Our meta-analyses further substantiate evidence of a strong association between silicosis and lung cancer. However, questions remain regarding lung cancer caused by silica in non-silicotics. Ideally, future investigations should consider the entire exposure-response range between silica exposure, silicosis development and lung cancer occurrence, and analyze data in terms of processes taking intermediate confounding into account.

The IARC Monographs on the carcinogenicity of crystalline silica

BACKGROUND

Through extensive review of the published literature, two independent expert panels convened by the International Agency for Research on Cancer (IARC) Monographs Programme have classified crystalline silica as carcinogenic to humans while amorphous silica was not classifiable as to its carcinogenicity in humans. The panel remarked that crystalline silica in the form of quartz or cristobalite dust causes lung cancer in humans.

OBJECTIVES

We discuss the literature and rationale used to support the IARC evaluations of silica.

METHODS

A critical review, with a focus on lung tumors, was conducted of the pertinent literature on the carcinogenic effects of crystalline silica in humans and experimental animals as well as supportive mechanistic evidence.

RESULTS

The strongest supportive evidence comes from pooled and meta-analyses that employed quantitative exposure assessment, focused on silicotics, accounted for potential confounding and demonstrated exposure-response trends. Consistency of the effect was observed despite some heterogeneity between individual studies. Tumor site concordance was observed with rodents and further supported by mechanistic data.

CONCLUSIONS

Several million workers worldwide are exposed to crystalline silica. Silicosis and lung cancer in these workers are completely preventable diseases. The IARC evaluations are critical to supporting public health interventions to protect persons at high-risk.

Association between lymph node silicosis and lung silicosis in 4,384 German uranium miners with lung cancer

This study investigates the association between lymph node-only and lung silicosis in uranium miners with lung cancer and exposure to quartz dust. Tissue slides of 4,384 German uranium miners with lung cancer were retrieved from an autopsy archive and reviewed by 3 pathologists regarding silicosis in the lungs and lymph nodes. Cumulative exposure to quartz dust was assessed with a quantitative job-exposure matrix. The occurrence of silicosis by site was investigated with regression models for exposure to quartz dust. Miners with lung silicosis had highest cumulative quartz exposure, followed by lymph node-only silicosis and no silicosis. At a cumulative quartz exposure of 40 mg/m(3) × years, the probability of lung silicosis was above 90% and the likelihood of lymph node-only silicosis and no silicosis do not differ anymore. The results support that lymph node silicosis can precede lung silicosis, at least in a proportion of subjects developing silicosis, and that lung silicosis strongly depends on the cumulative quartz dose.

Pericardial plaque: a unique complication of silicosis

The heart and the respiratory system are closely connected in such a way that disorders of one system would influence the function of the other. This unique case of silicosis complicated by corpulmonale associated with pericardial plaque formation in a young adult male is reported here due to an unknown complication of silicosis.