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Inhalation Toxicology Aug 2020Silicosis is a lung disease of fibrotic nature resulting from the inhalation and deposition of dust containing crystalline silica. Subjects exposed to the same...
BACKGROUND
Silicosis is a lung disease of fibrotic nature resulting from the inhalation and deposition of dust containing crystalline silica. Subjects exposed to the same environmental factors may show distinct radiological manifestations, and since silicosis is known as a multifactorial disease, it is plausible that individual genetic susceptibility may play a role in the pathology. This review of the literature aims to provide an assessment of the present data on the genetic association studies in silicosis and describe the genes that potentially might influence silicosis susceptibility in silica-exposed individuals.
METHODS
We accessed the database of PubMed for articles published in English about interindividual genetic susceptibility to silicosis using terms related to the subject matter.
RESULTS
Following the evaluation process, 28 studies were included in this systematic review, including 23 original studies and 5 meta-analyses.
CONCLUSIONS
Regardless of the advances in the knowledge of the importance of gene variations in silicosis, more studies need to be performed, in particular, special polygenic and genome-wide investigations.
Topics: Cytokines; Genetic Predisposition to Disease; Humans; Inhalation Exposure; Silicon Dioxide; Silicosis
PubMed: 33006295
DOI: 10.1080/08958378.2020.1825569 -
BMJ (Clinical Research Ed.) Mar 2020To determine the annual rate of tuberculosis development after a positive tuberculin skin test (TST) or interferon-gamma release assay result (IGRA), or both, among... (Meta-Analysis)
Meta-Analysis
Absolute risk of tuberculosis among untreated populations with a positive tuberculin skin test or interferon-gamma release assay result: systematic review and meta-analysis.
OBJECTIVE
To determine the annual rate of tuberculosis development after a positive tuberculin skin test (TST) or interferon-gamma release assay result (IGRA), or both, among untreated populations with characteristics believed to increase the risk of tuberculosis (at risk populations).
DESIGN
Systematic review and meta-analysis.
DATA SOURCES
Embase, Medline, and Cochrane Controlled Register of Trials from 1 January 1990 to 17 May 2019, for studies in humans published in English or French. Reference lists were reviewed.
ELIGIBILITY CRITERIA AND DATA ANALYSIS
Retrospective or prospective cohorts and randomised trials that included at least 10 untreated participants who tested positive to tuberculosis antigens (contained in TST or IGRA, or both) followed for at least 12 months. Following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and meta-analyses of observational studies in epidemiology (MOOSE) guidelines, two reviewers independently extracted study data and assessed quality using a modified quality assessment of diagnostic accuracy studies (QUADAS-2) tool. Data were pooled using random effects generalised linear mixed models.
MAIN OUTCOME MEASURES
The primary outcome was tuberculosis incidence per 1000 person years among untreated participants who tested positive (TST or IGRA, or both) in different at risk subgroups. Secondary outcomes were the cumulative incidence of tuberculosis and incidence rate ratios among participants with a positive test result for latent tuberculosis infection compared with those with a negative test result in at risk subgroups.
RESULTS
122 of 5166 identified studies were included. In three general population studies, the incidence of tuberculosis among 33 811 participants with a TST induration of ≥10 mm was 0.3 (95% confidence interval 0.1 to 1.1) per 1000 person years. Among 116 197 positive test results for latent tuberculosis infection in 19 different at risk populations, incidence rates were consistently higher than those in the general population. Among all types of tuberculosis contacts, the incidence of tuberculosis was 17.0 (95% confidence interval 12.9 to 22.4) per 1000 person years for participants with a positive IGRA result and 8.4 (5.6 to 12.6) per 1000 person years for participants with a positive TST result of ≥5 mm. Among people living with HIV, the incidence of tuberculosis was 16.9 (10.5 to 27.3) for participants with a positive IGRA result and 27.1 (15.0 to 49.0) for participants with a positive TST result of ≥5 mm. Rates were also high for immigrants, people with silicosis or requiring dialysis, transplant recipients, and prisoners. Incidence rate ratios among test positive versus test negative participants were significantly greater than 1.0 in almost all risk groups, for all tests.
CONCLUSIONS
The incidence of tuberculosis is substantial in numerous at risk populations after a positive TST or IGRA result. The information from this review should help inform clinical decisions to test and treat for latent tuberculosis infection.
STUDY REGISTRATION
PROSPERO CRD42019136608.
Topics: Comorbidity; Disease Progression; HIV Infections; Humans; Immunocompromised Host; Incidence; Interferon-gamma Release Tests; Latent Tuberculosis; Risk Factors; Tuberculin Test
PubMed: 32156698
DOI: 10.1136/bmj.m549 -
International Journal of Environmental... Feb 2019Silicosis is a progressive fibrotic lung disease that is caused by the inhalation of respirable crystalline silica. Due to its high silica content, artificial stone (AS)...
Silicosis is a progressive fibrotic lung disease that is caused by the inhalation of respirable crystalline silica. Due to its high silica content, artificial stone (AS) can become a possible source of hazardous dust exposure for workers that are employed in the manufacturing, finishing, and installing of AS countertops. Therefore, the aim of this review was to verify the association between AS derived silica exposure and silicosis development, and also then define the pathological characteristics of the disease in relation to specific work practices and preventive and protective measures that were adopted in the workplace. A systematic review of articles available on Pubmed, Scopus, and Isi Web of Knowledge databases was performed. Although the characteristics of AS-associated silicosis were comparable to those that were reported for the disease in traditional silica exposure settings, some critical issues emerged concerning the general lack of suitable strategies for assessing/managing silica risks in these innovative occupational fields. Further research that is designed to assess the hazardous properties of AS dusts, levels of exposure in workplaces, and the effectiveness of protective equipment appears to be needed to increase awareness concerning AS risks and induce employers, employees, and all factory figures that are engaged in prevention to take action to define/adopt proper measures to protect the health of exposed workers.
Topics: Construction Materials; Dust; Humans; Occupational Exposure; Pulmonary Fibrosis; Silicon Dioxide; Silicosis; Workplace
PubMed: 30781462
DOI: 10.3390/ijerph16040568 -
Bioscience Reports Feb 2019Studies investigating association between tumor necrosis factor (TNF) gene polymorphisms and silicosis susceptibility report conflicting results. The aim of this... (Meta-Analysis)
Meta-Analysis
Studies investigating association between tumor necrosis factor (TNF) gene polymorphisms and silicosis susceptibility report conflicting results. The aim of this meta-analysis was to assess association between TNF gene polymorphisms and silicosis susceptibility. A systematic literature search was conducted to find relevant studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the strength of association. Finally, a total of 12 articles, involving 1990 silicosis patients and 1898 healthy controls were included in the meta-analysis. Overall, meta-analysis revealed a significant association between the TNF -308A allele and silicosis (OR = 1.348, 95%CI = 1.156-1.570, <0.001). A significant association of AA+AG genotype of the TNF -308 A/G polymorphism with susceptibility to silicosis was also found (OR = 1.466, 95%CI = 1.226-1.753, <0.001). After stratification by ethnicity, significant associations were detected under the genetic models (A allele and AA+AG genotype) for TNF -308A/G polymorphisms in the Asian population (<0.05). Similarly, meta-analysis of the TNF -238A/G polymorphism revealed the same pattern as that shown by meta-analysis of TNF -308A/G. The meta-analysis suggests that the TNF -308A/G and -238A/G polymorphisms are associated with susceptibility to silicosis, especially in Asians.
Topics: Asian People; Genetic Predisposition to Disease; Humans; Odds Ratio; Polymorphism, Genetic; Silicosis; Tumor Necrosis Factor-alpha
PubMed: 30643011
DOI: 10.1042/BSR20181896 -
Oncotarget May 2017Cell therapy holds the most promising for acute and chronic deleterious respiratory diseases. However, the safety and tolerance for lung disorders are controversy. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Cell therapy holds the most promising for acute and chronic deleterious respiratory diseases. However, the safety and tolerance for lung disorders are controversy.
METHODS
We undertook a systematic review and meta-analyses of all 23 clinical studies of cell therapy. The outcomes were odds ratio (OR), risk difference (RD), Peto OR, relative risk, and mean difference of serious adverse events.
RESULTS
342 systemic infusions and 57 bronchial instillations (204 recipients) of cells were analyzed for acute respiratory distress syndrome (ARDS), bronchopulmonary dysplasia, pulmonary arterial hypertension, silicosis, sarcoidosis, extensively drug-resistant tuberculosis, chronic obstructive pulmonary diseases (COPD), and idiopathic pulmonary fibrosis. The frequency of death in adults from any causes was 71 and 177 per 1,000 for cell therapy and controls, respectively, with an OR of 0.31 (95% CI: 0.03, 3.76) and RD of -0.22 (95% CI: -0.53, 0.09). No significant difference was found for ARDS and COPD. The frequency of deaths and non-fatal serious adverse events of 17 open studies were similar to those of randomized controlled trials. Moreover, serious adverse events of allogenic cells were greater than autologous preparations, as shown by frequency, OR and RD.
CONCLUSIONS
We conclude that either infusion or instillation of mesenchymal stem stromal or progenitor cells are well tolerated without serious adverse events causally related to cell treatment. Cell therapy has not been associated with significant changes in spirometry, immune function, cardiovascular activity, and the quality of life.
Topics: Cell- and Tissue-Based Therapy; Clinical Trials as Topic; Humans; Mesenchymal Stem Cells; Odds Ratio; Respiratory Tract Diseases; Treatment Outcome
PubMed: 28430622
DOI: 10.18632/oncotarget.15426 -
International Archives of Occupational... Oct 2017While occupational exposure to respirable silica is known to lead to lung disease, most notably silicosis, its association with chronic kidney disease is unclear. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
While occupational exposure to respirable silica is known to lead to lung disease, most notably silicosis, its association with chronic kidney disease is unclear.
OBJECTIVES
This review explores the association between occupational exposure to respirable silica and chronic non-malignant renal disease such as glomerulonephritis. The evidence has been collected and compiled. Possible sources of bias are thoroughly discussed.
METHODS
Cohort studies with silica exposure and case-control studies of renal disease were searched in PubMed until January 2015. Two authors independently abstracted data; any disagreement was resolved by consulting a third reviewer. A meta-analysis was performed to evaluate the association to silica exposure.
RESULTS
A total of 23 cohort and four case-control studies were included in the analysis. The meta-analysis of cohort studies yielded elevated overall SMRs for renal disease. Some studies, however, included dose-response analyses, most of which did not show a positive trend. The approaches and results of the case-control studies were very heterogeneous.
CONCLUSIONS
While the studies of cohorts exposed to silica found elevated SMRs for renal disease, no clear evidence of a dose-response relationship emerged. The elevated risk may be attributed to diagnostic and methodological issues. In order to permit a reliable estimation of a possible causal link, exposed cohorts should be monitored for renal disease, as the information from mortality studies is hardly reliable in this field.
Topics: Case-Control Studies; Cohort Studies; Dose-Response Relationship, Drug; Glomerulonephritis; Humans; Inhalation Exposure; Occupational Diseases; Occupational Exposure; Renal Insufficiency, Chronic; Risk Assessment; Silicon Dioxide
PubMed: 28409224
DOI: 10.1007/s00420-017-1219-x -
The Cochrane Database of Systematic... Nov 2015Non-malignant dust-related respiratory diseases, such as asbestosis and silicosis, are similar to other chronic respiratory diseases and may be characterised by... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Non-malignant dust-related respiratory diseases, such as asbestosis and silicosis, are similar to other chronic respiratory diseases and may be characterised by breathlessness, reduced exercise capacity and reduced health-related quality of life. Some non-malignant dust-related respiratory diseases are a global health issue and very few treatment options, including pharmacological, are available. Therefore, examining the role of exercise training is particularly important to determine whether exercise training is an effective treatment option in non-malignant dust-related respiratory diseases.
OBJECTIVES
To assess the effects of exercise training for people with non-malignant dust-related respiratory diseases compared with control, placebo or another non-exercise intervention on exercise capacity, health-related quality of life and levels of physical activity.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE/PubMed, EMBASE, CINAHL, PEDro and AMED (all searched from inception until February 2015), national and international clinical trial registries, reference lists of relevant papers and we contacted experts in the field for identification of suitable studies.
SELECTION CRITERIA
We included only randomised controlled trials (RCTs) that compared exercise training of at least four weeks duration with no exercise training, placebo or another non-exercise intervention.
DATA COLLECTION AND ANALYSIS
We used standard methodological procedures expected by Cochrane. Two review authors independently assessed study eligibility and risk of bias, and extracted data. We employed the GRADE approach to assess the overall quality of evidence for each outcome and to interpret findings. We synthesized study results using a random-effects model based on the assessment of heterogeneity. We conducted subgroup analyses on participants with dust-related interstitial lung diseases (ILDs) and participants with asbestos related pleural disease (ARPD).
MAIN RESULTS
Two RCTs including a combined total of 40 participants (35 from one study and five from a second study) met the inclusion criteria. Twenty-one participants were randomised to the exercise training group and 19 participants were randomised to the control group. The included studies evaluated the effects of exercise training compared to a control group of no exercise training in people with dust-related ILDs and ARPD. The exercise training programme in both studies was in an outpatient setting for an eight-week period. The risk of bias was low in both studies. There were no reported adverse events of exercise training. Following exercise training, six-minute walk distance (6MWD) increased with a mean difference (MD) of 53.81 metres (m) (95% CI 34.36 to 73.26 m). Improvements were also seen in the domains of health-related quality of life: Chronic Respiratory Disease Questionnaire (CRQ) Dyspnoea domain (MD 2.58, 95% CI 0.72 to 4.44); CRQ Fatigue domain (MD 1.00, 95% CI 0.11 to 1.89); CRQ Emotional Function domain (MD 2.61, 95% CI 0.74 to 4.49); and CRQ Mastery domain (MD 1.51, 95% CI 0.29 to 2.72). Improvements in exercise capacity and health-related quality of life were also evident six months following the intervention period: 6MWD (MD 52.68 m, 95% CI 27.43 to 77.93 m); CRQ Dyspnoea domain (MD 3.03, 95% CI 1.41 to 4.66); CRQ Emotional Function domain (MD 5.57, 95% CI 2.34 to 8.81); and CRQ Mastery domain (MD 2.66, 95% CI 1.08 to 4.23). Exercise training did not result in improvements in the Modified Medical Research Council (MMRC) dyspnoea scale immediately following exercise training or six months following exercise training. The improvements following exercise training were similar in a subgroup of participants with dust-related ILDs and in a subgroup of participants with ARPD compared to the control group, with no statistically significant differences in treatment effects between the subgroups.
AUTHORS' CONCLUSIONS
The evidence examining exercise training in people with non-malignant dust-related respiratory diseases is of very low quality. This is due to imprecision in the results from the small number of trials and the small number of participants, the indirectness of evidence due to a paucity of information on disease severity and the data from one study being from a subgroup of participants, and inconsistency from high heterogeneity in some results. Therefore, although the review findings indicate that an exercise training programme is effective in improving exercise capacity and health-related quality of life in the short-term and at six months follow-up, we remain unsure of these findings due to the very low quality evidence. Larger, high quality trials are needed to determine the strength of these findings.
Topics: Aged; Aged, 80 and over; Asbestosis; Dust; Exercise Tolerance; Health Status; Humans; Male; Middle Aged; Physical Conditioning, Human; Pneumoconiosis; Quality of Life; Randomized Controlled Trials as Topic; Respiration Disorders; Time Factors
PubMed: 26544672
DOI: 10.1002/14651858.CD009385.pub2 -
The Cochrane Database of Systematic... Jul 2013Preventing active tuberculosis (TB) from developing in people with latent tuberculosis infection (LTBI) is important for global TB control. Isoniazid (INH) for six to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Preventing active tuberculosis (TB) from developing in people with latent tuberculosis infection (LTBI) is important for global TB control. Isoniazid (INH) for six to nine months has 60% to 90% protective efficacy, but the treatment period is long, liver toxicity is a problem, and completion rates outside trials are only around 50%. Rifampicin or rifamycin-combination treatments are shorter and may result in higher completion rates.
OBJECTIVES
To compare the effects of rifampicin monotherapy or rifamycin-combination therapy versus INH monotherapy for preventing active TB in HIV-negative people at risk of developing active TB.
SEARCH METHODS
We searched the Cochrane Infectious Disease Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; LILACS; clinical trials registries; regional databases; conference proceedings; and references, without language restrictions to December 2012; and contacted experts for relevant published, unpublished and ongoing trials.
SELECTION CRITERIA
Randomized controlled trials (RCTs) of HIV-negative adults and children at risk of active TB treated with rifampicin, or rifamycin-combination therapy with or without INH (any dose or duration), compared with INH for six to nine months.
DATA COLLECTION AND ANALYSIS
At least two authors independently screened and selected trials, assessed risk of bias, and extracted data. We sought clarifications from trial authors. We pooled relative risks (RRs) with their 95% confidence intervals (CIs), using a random-effects model if heterogeneity was significant. We assessed overall evidence quality using the GRADE approach.
MAIN RESULTS
Ten trials are included, enrolling 10,717 adults and children, mostly HIV-negative (2% HIV-positive), with a follow-up period ranging from two to five years. Rifampicin (three/four months) vs. INH (six months)Five trials published between 1992 to 2012 compared these regimens, and one small 1992 trial in adults with silicosis did not detect a difference in the occurrence of TB over five years of follow up (one trial, 312 participants; very low quality evidence). However, more people in these trials completed the shorter course (RR 1.19, 95% CI 1.01 to 1.30; five trials, 1768 participants; moderate quality evidence). Treatment-limiting adverse events were not significantly different (four trials, 1674 participants; very low quality evidence), but rifampicin caused less hepatotoxicity (RR 0.12, 95% CI 0.05 to 0.30; four trials, 1674 participants; moderate quality evidence). Rifampicin plus INH (three months) vs. INH (six months)The 1992 silicosis trial did not detect a difference between people receiving rifampicin plus INH compared to INH alone for occurrence of active TB (one trial, 328 participants; very low quality evidence). Adherence was similar in this and a 1998 trial in people without silicosis (two trials, 524 participants; high quality evidence). No difference was detected for treatment-limiting adverse events (two trials, 536 participants; low quality evidence), or hepatotoxicity (two trials, 536 participants; low quality evidence). Rifampicin plus pyrazinamide (two months) vs. INH (six months)Three small trials published in 1994, 2003, and 2005 compared these two regimens, and two reported a low occurrence of active TB, with no statistically significant differences between treatment regimens (two trials, 176 participants; very low quality evidence) though, apart from one child from the 1994 trial, these data on active TB were from the 2003 trial in adults with silicosis. Adherence with both regimens was low with no statistically significant differences (four trials, 700 participants; very low quality evidence). However, people receiving rifampicin plus pyrazinamide had more treatment-limiting adverse events (RR 3.61, 95% CI 1.82 to 7.19; two trials, 368 participants; high quality evidence), and hepatotoxicity (RR 4.59, 95% 2.14 to 9.85; three trials, 540 participants; moderate quality evidence). Weekly, directly-observed rifapentine plus INH (three months) vs. daily, self-administered INH (nine months)A large trial conducted from 2001 to 2008 among close contacts of TB in the USA, Canada, Brazil and Spain found directly observed weekly treatment to be non-inferior to nine months self-administered INH for the incidence of active TB (0.2% vs 0.4%, RR 0.44, 95% CI 0.18 to 1.07, one trial, 7731 participants; moderate quality evidence). The directly-observed, shorter regimen had higher treatment completion (82% vs 69%, RR 1.19, 95% CI 1.16 to 1.22, moderate quality evidence), and less hepatotoxicity (0.4% versus 2.4%; RR 0.16, 95% CI 0.10 to 0.27; high quality evidence), though treatment-limiting adverse events were more frequent (4.9% versus 3.7%; RR 1.32, 95% CI 1.07 to 1.64 moderate quality evidence)
AUTHORS' CONCLUSIONS
Trials to date of shortened prophylactic regimens using rifampicin alone have not demonstrated higher rates of active TB when compared to longer regimens with INH. Treatment completion is probably higher and adverse events may be fewer with shorter rifampicin regimens. Shortened regimens of rifampicin with INH may offer no advantage over longer INH regimens. Rifampicin combined with pyrazinamide is associated with more adverse events. A weekly regimen of rifapentine plus INH has higher completion rates, and less liver toxicity, though treatment discontinuation due to adverse events is probably more likely than with INH.
Topics: Adult; Antibiotics, Antitubercular; Child; Directly Observed Therapy; Drug Administration Schedule; HIV Seronegativity; Humans; Isoniazid; Latent Tuberculosis; Randomized Controlled Trials as Topic; Rifabutin; Rifampin; Tuberculosis, Pulmonary
PubMed: 23828580
DOI: 10.1002/14651858.CD007545.pub2 -
American Journal of Industrial Medicine Aug 2012Individual epidemiological studies generally lack the power to examine the association between silica exposure or silicosis and laryngeal cancer. We summarized pertinent... (Meta-Analysis)
Meta-Analysis Review
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.
Topics: Air Pollutants, Occupational; Dust; Humans; Laryngeal Neoplasms; Occupational Diseases; Occupational Exposure; Odds Ratio; Silicon Dioxide; Silicosis
PubMed: 22457229
DOI: 10.1002/ajim.22037 -
Cancer Causes & Control : CCC Aug 2009To examine the association between occupational exposure to silica and lung cancer from a systematic review (and meta-analysis) of the epidemiologic literature, with... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To examine the association between occupational exposure to silica and lung cancer from a systematic review (and meta-analysis) of the epidemiologic literature, with special reference to the methodological quality of observational studies.
METHODS
We searched Medline, Toxline, BIOSIS, and Embase (1966-December 2007) for original articles published in any language. Observational studies (cohort and case-control studies) were selected if they reported the result of dose-response analyses relating lung cancer to occupational exposure to silica after appropriate adjustment for smoking.
RESULTS
Ten studies (4 cohort studies and 6 case-control studies) met the inclusion criteria of the meta-analysis, nine of which contributing to the main analysis (dose-response analysis, no lag time). We found increasing risk of lung cancer with increasing cumulative exposure to silica, with heterogeneity across studies however. Posthoc analyses identified a set of seven more homogeneous studies. Their meta-analysis resulted in a dose-response curve that was not different from that obtained in the main analysis.
CONCLUSION
Silica is a lung carcinogen. This increased risk is particularly apparent when the cumulative exposure to silica is well beyond that resulting from exposure to the recommended limit concentration for a prolonged period of time.
Topics: Carcinogens; Case-Control Studies; Cohort Studies; Dose-Response Relationship, Drug; Epidemiologic Studies; Humans; Lung Neoplasms; Occupational Exposure; Risk Factors; Silicon Dioxide; Silicosis; Smoking
PubMed: 19184475
DOI: 10.1007/s10552-009-9296-0