Background: The primary work-related lung disease in Brazil is silicosis. Its pathogenic agent is the dust of crystalline free silica (SiO2; silicon dioxide). The inflammatory process of silicosis is not yet well understood. Objective: To analyze, through immunologic laboratory evaluation, including nonspecific and specific immunity, the profile of IgG, IgM, IgA, C3, C4 and autoantibodies in the serum of workers, with or without silicosis, exposed to silica. Methods: Fifty-eight male workers were studied. All had been exposed to silica. Immunologic, radiologic and functional evaluations were made. The immunoglobulins IgG, IgA, and IgM, the complement system components C3 and C4, and the autoantibodies were assessed. Results: Chest X-rays were normal in 20 of the 58 workers and compatible with silicosis in 38. Among the 38 who were positive, IgG values were, on average, higher than in the group with normal X-rays (p < 0.05). There were no significant differences in average values of IgA, IgM, C3 or C4 (p > 0.05). The percentage of autoantibody positivity was higher in the silicosis group than in the group with normal X-rays. Conclusion: The increased levels of IgG in patients with silicosis constitutes an important discovery. It may represent continuity of the granulomatous reaction, even when the individual is no longer being exposed to silica. However, further studies are necessary in order to increase understanding of the mechanism involved in the silicosis immunologic process.

Keywords: Lung diseases. Silicosis. Occupational diseases. Immunoglobulins

Silica is one of the main occupational agents associated with lung cancer. It is classified by the International Agency for Research on Cancer (IARC) as a Group 1 substance, i.e., carcinogenic for humans, since 1996. The objective of this paper is to report two cases of workers previously exposed to silica who developed lung cancer, seen in an out-patient clinic, focusing on important points of the current literature on the subject.

Objective: Silicosis is a pneumoconiosis characterized by fibrosis of the lung parenchyma caused by inhalation of silica particles. Genetic factors might play a role in the severity silicosis. We sought to evaluate the influence of polymorphisms in the ACE, FAS, FASLG, NOS2, IL1RN, FAM13A, TGFB1, and TNF genes on the severity of silicosis. Methods: Nine polymorphisms were genotyped by PCR in a sample of 143 patients with silicosis in the state of Rio de Janeiro, Brazil. Results: Fifty-seven patients (40%) were classified as having simple silicosis and 86 (60%) were classified as having complicated silicosis. The TT genotype of rs1800469 in the TGFB1 gene showed a protective effect for complicated silicosis (OR = 0.35; 95% CI, 0.14-0.92; p = 0.028) when compared with the other two genotypes (CC+CT). The polymorphic T allele of rs763110 in the FASLG gene (OR = 0.56; 95% CI, 0.31-0.99; p = 0.047), as well as a dominant model for the T allele (TT+CT: OR = 0.37; 95% CI, 0.15-0.96; p = 0.037), also showed a protective effect. When patients with simple silicosis despite having been exposed to silica for a longer time (> 44,229 hours) were compared with patients with complicated silicosis despite having been exposed to silica for a shorter time, the T allele of rs763110 in the FASLG gene (OR = 0.20; 95% CI, 0.08-0.48; p < 0.0001), as well as dominant and recessive models (OR = 0.06; 95% CI, 0.00-0.49; p = 0.01 and OR = 0.22; 95% CI, 0.06-0.77; p = 0.014, respectively), showed a protective effect against the severity of silicosis. Conclusions: It appears that rs1800469 polymorphisms in the TGFB1 gene and rs763110 polymorphisms in the FASLG gene are involved in the severity of silicosis. Given the lack of studies relating genetic polymorphisms to the severity of silicosis, these results should be replicated in other populations.

Keywords: Silicosis; Polymorphism, genetic; Genetic association studies; Cytokines.

Objective: Tuberculosis (TB) is an infectious disease caused by the bacillus Mycobacterium tuberculosis, which was recognized by the World Health Organization (WHO) as a global epidemic in 1993. TB is the leading infectious disease associated with silicosis, with studies showing an increased risk when compared to healthy individuals. We conducted an association study to evaluate the influence of polymorphisms in the ACE, FAM13A, FAS, FASLG, IL1RN, NOS2, TGFB1, and TNF genes on TB susceptibility. Methods: Nine polymorphisms were genotyped using Polymerase Chain Reaction (PCR) in a sample of 143 patients with silicosis in Rio de Janeiro (RJ), Brazil. Results: Seventy (49%) patients had a confirmed prior diagnosis of TB, of whom 25 (35.7%) had simple silicosis and 45 (64.3%) had complicated silicosis. The TG genotype of rs2609255 in FAM13A showed a protective effect against TB (OR=0.46; 95% CI: 0.22-0.98; p=0.040) compared to the GG genotype, and also when compared to the two combined homozygous genotypes (TT+GG) (OR=0.43; 95% CI: 0.20-0.90; p=0.024). Logistic regression analysis, including independent clinical variables, confirmed the protective effect of the TG genotype. Conclusion: This study suggests that the rs2609255 polymorphism in FAM13A may play a role in TB risk among patients with silicosis. Given the limited research on genetic polymorphisms and TB susceptibility in silicosis patients, further studies are needed to validate these findings.

Keywords: silicosis, tuberculosis, genetic polymorphisms, genetic association studies, cytokines.

Introduction: Silicosis is the most prevalent pneumoconiosis in Brazil, with most of the registered cases occurring in the State of Minas Gerais. Although it is a preventable disease, silicosis is still epidemic in some areas. Objective: To describe the profile of workers seen at the Clinics Hospital of the Federal University of Minas Gerais. Patients and methods: 300 medical records of silica-exposed workers in different occupations, seen between 1989-2000, were reviewed. Clinical and occupational information, radiographic and spirometric data were analyzed. Statistical methods included univariate analyses with chi-square and t tests. Results and conclusion: The mean age of the exposed patients was 51 years, with mean exposure duration of 15.6 years. 126/300 (42%) were radiologically classified as cases of silicosis. Increasing grades of profusion were associated with lower spirometric indices and more frequent associations with tuberculosis and chronic airflow limitation. Most of the workers were regularly registered employees and the main occupational activity was mining, accounting for the exposure of 197 (66%) workers. Non-registered workers presented more severe radiological grades of silicosis, suggesting, possibly, worse conditions of silica exposure in this group of workers.

The authors report the case of a 7-year-old girl, with a history of recurrent respiratory infections since five months of age. Immunological evaluation at four years of age revealed a normal level of total serum immunoglobulins, but a deficient humoral response to Streptococcus pneumoniae. Although having all normal IgG subclasses, the patient had inadequate antibody levels to all serotypes tested (1, 3, 5, 6, 9, and 14). Concurrent radiological evaluation showed diffuse atelectasis and bronchiectasis. Patient was started on IVIG, and subsequent chest CT scan revealed resolution of the above-mentioned lesions. To prevent irreversible damage to lung parenchyma, due to recurrent lower respiratory infections, it is important to identify immunocompromised individuals and treat them accordingly.

Keywords: Immunologic deficiency syndromes. Streptococcus pneumoniae.

Objective: Silicosis is a pneumoconiosis characterized by fibrosis of the lung parenchyma caused by the inhalation of silica particles. Silica dust inhalation is associated with inflammation and induction of oxidative stress in the lungs. This oxidative stress affects telomeres, which are short tandem DNA repeats that cap the end of linear chromosomes. We aimed to determine whether telomere length (TL) correlates with silicosis or severity of silicosis in silica-exposed workers in Brazil. Methods: We included 200 men in southeastern Brazil: 100 with silicosis and 100 who had not been exposed to silica. We extracted DNA from buccal cells and assessed TL by multiplex quantitative polymerase chain reaction. Results: The median TL was significantly shorter in the patients with silicosis than in the unexposed controls (p < 0.0001), although it did not differ between the patients with simple silicosis and those with complicated silicosis (p = 0.961). We also found that, in patients with silicosis, TL was influenced by smoking (p = 0.034) and by a history of personal protective equipment use in the workplace (p = 0.002). Conclusions: Silica exposure appears to have an impact on TL, which was found to be shorter in patients with silicosis than in unexposed controls. Further studies are needed in order to confirm the impact that oxidative stress caused by silica inhalation has on telomeres.

Keywords: Silicosis; Oxidative stress; Inflammation; Telomere.

Objective: To determine the prevalence and duration of social security benefit (SSB) claims granted to registered workers with asthma in Brazil by the Brazilian National Institute of Social Security in 2008. Methods: This was a retrospective, descriptive study, based on information obtained from the Brazilian Unified Benefit System database, on the number of SSB claims granted to registered workers with asthma in 2008. The reference population was the monthly mean number of workers registered in the Brazilian Social Registry Database in 2008. The variables studied were type of economic activity, gender, age, and type/duration of the SSB allowance. The relationship between work and asthma was evaluated by the prevalence ratio (PR) between work-related and non-work-related SSB claims for asthma. Results: In 2008, 2,483 SSB claims were granted for asthma, with a prevalence of 7.5 claims per 100,000 registered workers. The prevalence was higher among females than among males (PR = 2.1 between the sexes). Workers  40 years of age were 2.5 times more likely to be granted an SSB allowance for asthma than were younger workers. The prevalence was highest among workers engaged in the following types of economic activity: sewage, wood and wood product manufacturing, and furniture manufacturing (78.8, 22.4, and 22.2 claims/100,000 registered workers, respectively). The median (interquartile range) duration of SSB claims for asthma was 49 (28-87) days. Conclusions: Asthma is a major cause of sick leave, and its etiology has a strong occupational component. This has a major impact on employers, employees, and the social security system. Being female, being  40 years of age, and working in the areas of sewage, wood and wood product manufacturing, and furniture manufacturing increase the chance of sick leave due to asthma.

Keywords: Asthma; Social security; Prevalence; Occupational exposure; Occupational health.

Background: Dyspnea is a symptom that is difficult to evaluate, especially in occupational diseases. Objective: To evaluate the relationship between chronic dyspnea, in its varying degrees of severity, and the functional repercussions for dysfunction or incapacitation in former workers with asbestosis. Method: A total of 40 former workers diagnosed with asbestosis were evaluated. Dyspnea scores were determined using the modified Medical Research Council scale, the 1984 and 1993 American Medical Association scales, and the Baseline Dyspnea Index. Spirometry, measurement of diffusion capacity for carbon monoxide and cardiopulmonary exercise tests (incremental and submaximal) were also performed. Results: Based on scores obtained using the Medical Research Council and 1984 American Medical Association scales, respectively, 72.5% and 67.5% of the subjects were classified as dyspneic, compared with 37.5% and 31.6%, respectively, using the 1993 American Medical Association and Baseline Dyspnea Index scales. There was greater concordance between the Medical Research Council and 1993 American Medical Association scales, as well as between the 1984 and 1993 American Medical Association scales, when the categories of "absent" and "mild" were grouped. No significant relation was found between dyspnea, as determined by each of the scales, and functional abnormalities - either at rest or during exercise. Conclusion: In individuals with asbestosis, the degree of concordance among the available dyspnea scales varies significantly. There is a real need for dyspnea indices that evaluate respiratory dysfunction at rest and during exercise.

Keywords: Asbestosis/diagnosis. Dyspnea/physiopathology. Spirometry/methods.

Objective: To describe the sociodemographic and clinical characteristics of individuals exposed to smoking or biomass smoke and followed at primary health care (PHC) centers across three states in Brazil. Methods: This was a cross-sectional multicenter study including patients followed at any of four PHC centers in Brazil. Patients = 35 years of age who were smokers or former smokers, or were exposed to biomass smoke were included, the exception being those with physical/mental disabilities and those who were pregnant. Face-to-face assessments included a questionnaire assessing clinical and sociodemographic characteristics, as well as the COPD Assessment Test (CAT) and the modified Medical Research Council (mMRC) dyspnea scale. Results: Of a total of 737 patients, 56.3% were female and 64.2% were White, with a mean age of 57.7 ± 11.8 years. Most (54.4%) had < 9 years of schooling, 50.2% had low socioeconomic status, and 71.5% were overweight/obese. Smokers accounted for 43.4% of the study sample, whereas 15.0% had no direct exposure to cigarette smoke. Common symptoms included cough, in 37.3%; wheezing, in 33.8%; and phlegm, in 27.4%. Most (75.1%) of the study participants had mMRC dyspnea scale scores of 0 or 1. CAT scores were 0-10, in 40.2%; 11-20, in 44.6%; 21-30, in 14.1%; and 31-40, in 1.1%. Binary logistic regression showed that sex and age significantly impacted mMRC dyspnea scale predictions, whereas BMI and socioeconomic status influenced CAT predictions. Common comorbidities included hypertension, in 51.3%; depression, in 27.4%; and diabetes, in 24.3%. No association was found between hypertension and obesity or smoking, or between diabetes and obesity or smoking. Conclusions: PHC patients with risk factors such as smoking and exposure to biomass smoke have a high comorbidity burden, with over half experiencing mild to moderate quality-of-life impacts. This study emphasizes the need for targeted preventive measures in PHC settings.

Keywords: Smoking; Risk factors; Biomass; Primary health care.

Objective: Various studies of emphysema involve long-term exposure of animals to cigarette smoke, focusing on the cell type involved in the protease/antiprotease imbalance and on extracellular matrix degradation. In emphysema, increased expression of metalloproteinases is associated with cytokines, and evidence suggests that the matrix metalloproteinase-12 (MMP-12) plays an important role. Our objective was to investigate tissue inhibitor of metalloproteinase-2 (TIMP-2), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) detection by immunohistochemical methods in mouse lung. Methods: Male C57BL/6 mice were exposed 3 times a day to the smoke of 3 cigarettes over a period of 10, 20, 30 or 60 days in an inhalation chamber (groups CS10, CS20, CS30 and CS60, respectively). Controls were exposed to the same conditions in room air. Results: A progressive increase in the number of alveolar macrophages was observed in the bronchoalveolar lavage fluid of the exposed mice. The mean linear intercept, an indicator of alveolar destruction, was greater in all exposed groups when compared to control group. In the CS10, CS20 and CS30 mice, the immunohistochemical index (II) for MMP-12 increased in parallel with a decrease in II for TIMP-2 in the CS10, CS20 and CS30 mice. The II for the cytokines TNF-α and IL-6 was greater in all exposed groups than in the control group. Emphysema, with changes in volume density of collagen and elastic fibers, was observed in the CS60 group. Conclusions: These findings suggest that cigarette smoke induces emphysema with major participation of TNF-α and IL-6 without participation of neutrophils.

Keywords: Macrophages, alveolar; Emphysema; Tissue inhibitor of metalloproteinase-2; Interleukin-6.

The prevalence of respiratory symptoms in populations at risk or in populations not at risk is an indirect indicator of acute and chronic respiratory diseases, with a high grade of confidence from an epidemiological point of view. In order to contribute to this, the authors carried out a prevalence study among workers with occupational exposure to silica dust in a marble plant. The authors selected workers who worked with hard granite stone, slate and marble. Workers were submitted to a standardized questionnaire and 84 people were studied. All were male, mean age was (± SD) 26.2 (± 7.4 years), and had had short time of exposure to dust (52 workers worked less than 5 years in the marble industry). Thirty-four were smokers (10.0 (± 2.3) pack years), 9 former smokers, and 41 non-smokers. Twenty-four had cough, 30 sputum, 1 dyspnea grade III, 5 wheezing. Thirty-eight presented at least one of the studied respiratory symptoms and 9 presented chronic bronchitis. The lung function evaluated in 82 workers through spirometry was normal in 78 of the cases and an obstructive pattern was detected in 4 of them. A significant statistical association between chronic bronchitis and exposure time to stone dust was found (OR = 5.37; 95% CI = 1.01-28.74). However, that association was lost after other factors, such as cigarette smoking and age, were evaluated (OR = 1.21; 95% CI = 0.12-11.93). The association between smoking and bronchitis (OR = 14.18; 95% CI = 1.80-111.62) remained marginally significant even after controlling exposure time to stone dust and age (OR = 6.34; 95% CI = 0.76-52.94). Results suggest that among the marble industry workers studied, the prevalence of chronic bronchitis is more strongly associated to smoking to with exposure time to stone dust.

Objective: To report the cases of four patients with bronchiolitis caused by exposure to artificial butter flavoring at a cookie factory in Brazil. Methods: We described the clinical, tomographic, and spirometric findings in the four patients, as well as the lung biopsy findings in one of the patients. Results: All four patients were young male nonsmokers and developed persistent airflow obstruction (reduced FEV1/FVC ratio and FEV1 at 25-44% of predicted) after 1-3 years of exposure to diacetyl, without the use of personal protective equipment, at a cookie factory. The HRCT findings were indicative of bronchiolitis. In one patient, the surgical lung biopsy revealed bronchiolitis obliterans accompanied by giant cells. Conclusions: Bronchiolitis resulting from exposure to artificial flavoring agents should be included in the differential diagnosis of airflow obstruction in workers in Brazil.

Keywords: Diacetyl; Flavoring agents; Bronchiolitis.

Objective: To determine the prevalence of smoking, as well as its association with sociodemographic factors, alcohol consumption, and stress levels, among industrial workers in Brazil. Methods: This was a nationwide survey, conducted in 24 capitals in Brazil through the application of a pre-tested questionnaire. The response to the question "What is your smoking status?" was the outcome variable. To determine the associations, we performed Poisson regression analyses in which the inputs were blocks of variables: block 1 (age and marital status); block 2 (level of education and gross family income); block 3 (geographic region); and block 4 (alcohol consumption and stress level). All analyses were stratified by gender. Results: The sample consisted of 47,328 workers ≥ 18 years of age, of whom 14,577 (30.8%) were women. The prevalence of smoking was 13.0% (15.2% in men and 7.9% in women). Advancing age, alcohol consumption, and a high stress level were positively associated with smoking. A lower risk of smoking was associated with being married, having a higher level of education, and living in the northeastern region of the country (versus the southern region). Conclusions: The prevalence of smoking was greater in men than in women. Alcohol consumption and high stress levels appear to promote smoking.

Keywords: Tobacco use disorder/epidemiology; Tobacco smoking; Occupational health; Industry; Brazil.

Objective: To identify respiratory symptoms and evaluate lung function in mine workers. Methods: This was a cross-sectional observational study involving production sector workers of a pyrochlore mining company. The subjects completed the British Medical Research Council questionnaire, which is designed to evaluate respiratory symptoms, occupational exposure factors, and smoking status. In addition, they underwent pulmonary function tests with a portable spirometer. Results: The study involved 147 workers (all male). The mean age was 41.37 ± 8.71 years, and the mean duration of occupational exposure was 12.26 ± 7.09 years. We found that 33 (22.44%) of the workers had respiratory symptoms and that 26 (17.69%) showed abnormalities in the spirometry results. However, we found that the spirometry results did not correlate significantly with the presence of respiratory symptoms or with the duration of occupational exposure. Conclusions: The frequencies of respiratory symptoms and spirometric changes were low when compared with those reported in other studies involving occupational exposure to dust. No significant associations were observed between respiratory symptoms and spirometry results.

Keywords: Spirometry; Mining; Niobium; Occupational exposure.

Objective: To evaluate COVID-19 knowledge, attitudes, and practices among health care workers (HCWs) practicing in Latin American countries during the first surge of the COVID-19 pandemic. Methods: This was a multinational cross-sectional survey study, using an online self-administered questionnaire. The final version of the questionnaire comprised 40 questions, organized in five sections: demographic and professional characteristics; COVID-19 knowledge; attitudes toward COVID-19; COVID-19 practices; and institutional resources. Results: The study involved 251 HCWs from 19 Latin American countries who agreed to participate. In our sample, 77% of HCWs participated in some sort of institutional training on COVID-19, and 43% had a low COVID-19 knowledge score. COVID-19 knowledge was associated with the type of health center (public/private), availability of institutional training, and sources of information about COVID-19. Concerns about not providing adequate care were reported by 60% of the participants. The most commonly used ventilatory strategies were protective mechanical ventilation, alveolar recruitment maneuvers, and prone positioning, and the use of drugs to treat COVID-19 was mainly based on institutional protocols. Conclusions: In this multinational study in Latin America, almost half of HCWs had a low COVID-19 knowledge score, and the level of knowledge was associated with the type of institution, participation in institutional training, and information sources. HCWs considered that COVID-19 was very relevant, and more than half were concerned about not providing adequate care to patients.

Keywords: COVID-19; Health knowledge, attitude, practice; Health personnel; Latin America.

Objective: To estimate the frequency of interstitial lung disease in a group of patients with progressive systemic sclerosis, and to describe the clinical, functional and radiological characteristics of the patients studied. Methods: Fifty-eight patients diagnosed with progressive systemic sclerosis were submitted to high-resolution computed tomography of the chest, pulmonary function tests and a blood test for anti-Scl 70 antibodies. Comparisons were drawn between patients with interstitial lung disease and those without. Logistic regression with multivariate analysis was used to identify factors predictive of interstitial lung disease. Results: Of the 58 patients evaluated, 51.7% presented interstitial lung disease on high-resolution computerized tomography scans. Dyspnea and cough were the most common symptoms (seen in 65.5% and 39.7%, respectively). Bronchiolectasis and honeycombing were the most common tomographic abnormalities (observed in 83.3% and 80%, respectively). When compared to individuals without interstitial lung disease, patients with the condition had a comparable frequency of pulmonary and extrapulmonary symptoms but presented progressive systemic sclerosis of longer duration, a higher frequency of crackling rales, higher rates of anti-Scl 70 positivity, lower vital capacity and reduced total lung capacity. Only forced vital capacity < 80% was found to be a predictor of interstitial lung disease. Conclusion: Interstitial lung disease was common in this group of patients with progressive systemic sclerosis. No correlation with symptoms was found, although interstitial lung disease was found to correlate with crackling rales and with anti-Scl 70 positivity. Nevertheless, only reduced forced vital capacity was found to be predictive of interstitial lung disease.