Ericson Bagatin

Asbestos-related disease: progression of parenchymal abnormalities on high-resolution CT.

Purpose To evaluate the changes over time in the pattern and extent of parenchymal abnormalities in asbestos-exposed workers after cessation of exposure and to compare 3 proposed semiquantitative methods with a careful side-by-side comparison of the initial and the follow-up computed tomography (CT) images. Materials and Methods The study included 52 male asbestos workers (mean age±SD, 62.2 y±8.2) who had baseline high-resolution CT after cessation of exposure and follow-up CT 3 to 5 years later. Two independent thoracic radiologists quantified the findings according to the scoring systems proposed by Huuskonen, Gamsu, and Sette and then did a side-by-side comparison of the 2 sets of scans without awareness of the dates of the CT scans. Results There was no difference in the prevalence of the 2 most common parenchymal abnormalities (centrilobular small dotlike or branching opacities and interstitial lines) between the initial and follow-up CT scans. Honeycombing (20%) and traction bronchiectasis and bronchiolectasis (50%) were seen more commonly on the follow-up CT than on the initial examination (10% and 33%, respectively) (P=0.01). Increased extent of parenchymal abnormalities was evident on side-by-side comparison in 42 (81%) patients but resulted in an increase in score in at least 1 semiquantitative system in only 16 (31%) patients (all P>0.01, signed test). Conclusions The majority of patients with previous asbestos exposure show evidence of progression of disease on CT at 3 to 5 years follow-up but this progression is usually not detected by the 3 proposed semiquantitative scoring schemes.

Differences between remaining ability and loss of capacity in maximum aerobic impairment.

In the evaluation of exercise intolerance of patients with respiratory diseases the American Medical Association (AMA) and the American Thoracic Society (ATS) have proposed similar classification for rating aerobic impairment using maximum oxygen uptake (VO2max) normalized for total body weight (ml min-1 kg-1). However, subjects with the same VO2max weight-corrected values may have considerably different losses of aerobic performance (VO2max expressed as % predicted). We have proposed a new, specific method for rating loss of aerobic capacity (VO2max, % predicted) and we have compared the two classifications in a prospective study involving 75 silicotic claimants. Logistic regression analysis showed that the disagreement between rating systems (higher dysfunction by the AMA/ATS classification) was associated with age > 50 years (P < 0.005) and overweight (P = 0.04). Interestingly, clinical (dyspnea score) and spirometric (FEV1) normality were only associated with the VO2max, % predicted, normal values (P < 0.01); therefore, in older and obese subjects the AMA/ATS classification tended to overestimate the aerobic dysfunction. We conclude that in the evaluation of aerobic impairment in patients with respiratory diseases, the loss of aerobic capacity (VO2max, % predicted) should be used instead of the traditional method (remaining aerobic ability, VO2max, in ml min-1 kg-1).

Pleural plaques in asbestos-exposed workers: reproducibility of a new high-resolution CT visual semiquantitative measurement method.

Objective To assess the reproducibility of a new high-resolution computed tomography (CT) visual semiquantitative method for pleural plaques in asbestos-exposed workers. Material and Methods We performed thin-section CT in 752 chrysotile asbestos mining workers and ex-workers. Institutional review board approval and signed written informed consent from subjects were obtained. Two readers independently evaluated the 752 CT scans and identified 57 workers (mean age±SD, 61.8 years±8.1; range, 37 to 81 years) who had pleural plaques and no other pleural or parenchymal abnormality. Three independent radiologists then quantified the plaque burden in these 57 workers using a scoring system based on the evaluation of the maximum thickness of parietal pleural plaques and percentage of parietal pleural surface involvement. We also calculated the proportion between the number of CT slices with diaphragmatic plaques and the total number of slices in which the diaphragm was seen (pdiaph). The intraobserver and interobserver agreements were analyzed using weighted Kappa coefficient. Results Interobserver agreements were good for the pleural plaque score (k=0.61, 0.75, and 0.79) and ranged from good (k=0.61) to excellent (k=0.86) for the pdiaph. Intraobserver agreements ranged from good to excellent for the pleural plaque score (k=0.79 and 1.00) and for the pdiaph (k=0.79 and 0.93). Conclusion The method proposed for high-resolution CT pleural plaque quantification in asbestos-exposed workers has a high reproducibility.

Lung diffusing capacity relates better to short‐term progression on HRCT abnormalities than spirometry in mild asbestosis

BACKGROUND Pulmonary function tests (PFT), particularly spirometry and lung diffusing capacity for carbon monoxide (DL(CO) ), have been considered useful methods for the detection of the progression of interstitial asbestos abnormalities as indicated by high-resolution computed tomography (HRCT). However, it is currently unknown which of these two tests correlates best with anatomical changes over time. METHODS In this study, we contrasted longitudinal changes (3-9 years follow-up) in PFTs at rest and during exercise with interstitial abnormalities evaluated by HRCT in 63 ex-workers with mild-to-moderate asbestosis. RESULTS At baseline, patients presented with low-grade asbestosis (Huuskonen classes I-II), and most PFT results were within the limits of normality. In the follow-up, most subjects had normal spirometry, static lung volumes and arterial blood gases. In contrast, frequency of DL(CO) abnormalities almost doubled (P < 0.05). Twenty-three (36.5%) subjects increased the interstitial marks on HRCT. These had significantly larger declines in DL(CO) compared to patients who remained stable (0.88 vs. 0.31 ml/min/mm Hg/year and 3.5 vs. 1.2%/year, respectively; P < 0.05). In contrast, no between-group differences were found for the other functional tests, including spirometry (P > 0.05). CONCLUSIONS These data demonstrate that the functional consequences of progression of HRCT abnormalities in mild-to-moderate asbestosis are better reflected by decrements in DL(CO) than by spirometric changes. These results might have important practical implications for medico-legal evaluation of this patient population.

Doença pulmonar obstrutiva crônica ocupacional

Occupational chronic obstructive pulmonary disease, despite having been widely discussed for nearly half a century, is still rarely addressed in Brazil. Various studies, especially those that were population-based, have revealed the relationship between occupational exposure to aerosols and impairment of the airways. This chapter aims to remind physicians of the diagnosis of occupational chronic obstructive pulmonary disease by presenting a succinct review of the literature on the theme, which should be incorporated into the Global Initiative for Chronic Obstructive Lung Disease, in terms of the scope of the diagnostic basis as well as in terms of the questionnaire specific for the disease. Collecting detailed work histories and characterizing exposure to inhaled agents known to have deleterious effects on the respiratory system will surely result in improved approaches to making diagnoses and prognoses of this disease, as well as contributing to its greater control.Occupational chronic obstructive pulmonary disease, despite having been widely discussed for nearly half a century, is still rarely addressed in Brazil. Various studies, especially those that were population-based, have revealed the relationship between occupational exposure to aerosols and impairment of the airways. This chapter aims to remind physicians of the diagnosis of occupational chronic obstructive pulmonary disease by presenting a succinct review of the literature on the theme, which should be incorporated into the Global Initiative for Chronic Obstructive Lung Disease, in terms of the scope of the diagnostic basis as well as in terms of the questionnaire specific for the disease. Collecting detailed work histories and characterizing exposure to inhaled agents known to have deleterious effects on the respiratory system will surely result in improved approaches to making diagnoses and prognoses of this disease, as well as contributing to its greater control.

Mesotelioma maligno de pleura com associação etiológica a asbesto: a propósito de três casos clínicos

O mesotelioma maligno de pleura (MM) e tumor de ocorrencia rara em nosso meio e tem-se mostrado, quando em elevada incidencia, relacionado a exposicao pregressa a asbesto ou amianto nas series descritas em outros paises. OBJETIVO. A partir de casos clinicos atendidos no Hospital de Clinicas da Unicamp, procurou-se evidenciar tal associacao epidemiologica, visando alertar profissionais medicos quanto a possivel elevacao da incidencia de tal tumor nesta decada e, futuramente, por caracteristicas proprias da historia natural desse tipo de tumor. METODOS. Sao descritos tres casos de MM de pleura ocorridos na regiao de Campinas, SP, num periodo de dois anos, dos pontos de vista clinico, laboratoriais complementares e anatomopatologico, incluindo minuciosa investigacao anamnesica ocupacional e ambiental. RESULTADOS. Todos os casos foram confirmados do ponto de vista anatomopatologico, incluindo microscopia eletronica, como casos de MM. Os tres casos mostraram relacao epidemiologica, comprovada por meio de historia ocupacional, com exposicao a asbesto no passado. Um dos casos teve exposicao ocupacional pregressa de curta duracao (cerca de um ano); outro teve exposicao domestica a partir de asbesto trazido do ambiente de trabalho por seu pai, durante sua infância, e o terceiro caso com contaminacao ocupacional indireta. CONCLUSAO. A ocorrencia de MM de pleura relacionada a exposicao a asbesto, no passado, parece ser realidade em nosso meio, como mostram estes tres casos clinicos. Destaca-se a necessidade da anamnese ocupacional e ambiental detalhadas na abordagem desses casos, alertando-se para maior atencao no diagnostico dos tumores primarios da pleura e do peritonio, nos proximos anos, em funcao de provavel aparecimento de novos casos relacionados a exposicao a asbesto pregressa, tendo em vista o intervalo de tempo entre o inicio da manipulacao do asbesto em nosso pais e o aparecimento destes primeiros casos coincidir com o tempo de latencia medio esperado para a ocorrencia de MM. Destacam-se, ainda, as necessidades de definicao precisa de criterios diagnosticos, para esse tipo de tumor, e criacao de registro centralizado de casos.

Genetic polymorphisms and surface expression of CTLA-4 and PD-1 on T cells of silica-exposed workers

Exposure to silica dust has been examined as a possible risk factor for autoimmune diseases, including scleroderma, rheumatoid arthritis and systemic lupus erythematosus. Since CTLA-4 [CD152] and PD-1 [CD279] are important for the maintenance of peripheral tolerance by regulating T cell responsiveness, we evaluated the expression of these molecules on the surface of CD4 and CD8 T cells, as well as single nucleotide polymorphisms (SNP) in CTLA-4 and PDCD1 genes, of 70 silica-exposed workers and 30 non-exposed, age-, ethnically- and sex-matched controls. Expression of CTLA-4 was significantly (P<0.05) reduced in CD4 T cells of exposed individuals [median=0.1% and interquartile range, IQR 0.0-0.1% (exposed), median=0.20%, IQR 0.0-0.4% (control)]. Also the expression of PD-1 was significantly (P<0.0001) reduced in both CD4 [median=0.9%, IQR 0.4-2.3% (exposed), median=5.7%, IQR 1.4-13.3% (control)] and CD8 T cells [median=0.9%, IQR 0.3-1.9% (exposed), median=5.0%, IQR 3.4-8.9% (control)]. The study of polymorphisms demonstrated a lower frequency of the A allele in the analysis of the PD1.3 SNP in the exposed group, which might be associated with the lower expression of PD-1 on the surface of CD4 T cells. Our findings provide evidence for the association of silica exposure and the maintenance of self-tolerance, i.e., the susceptibility to autoimmune disorders.

Laboratory animals and respiratory allergies: The prevalence of allergies among laboratory animal workers and the need for prophylaxis

OBJECTIVE: Subjects exposed to laboratory animals are at a heightened risk of developing respiratory and allergic diseases. These diseases can be prevented by simple measures such as the use of personal protective equipment. We report here the primary findings of the Laboratory Animals and Respiratory Allergies Study regarding the prevalence of allergic diseases among laboratory animal workers, the routine use of preventive measures in laboratories and animal facilities, and the need for prevention programs. METHODS: Animal handlers and non-animal handlers from 2 Brazilian universities (University of São Paulo and State University of Campinas) answered specific questionnaires to assess work conditions and symptoms. These subjects also underwent spirometry, a bronchial challenge test with mannitol, and skin prick tests for 11 common allergens and 5 occupational allergens (rat, mouse, guinea pig, hamster, and rabbit). RESULTS: Four hundred fifty-five animal handlers (32±10 years old [mean±SD], 209 men) and 387 non-animal handlers (33±11 years old, 121 men) were evaluated. Sensitization to occupational allergens was higher among animal handlers (16%) than non-animal handlers (3%, p<0.01). Accessibility to personal protective equipment was measured at 85% (median, considering 73 workplaces of the animal handler group). Nineteen percent of the animal handlers indicated that they wear a respirator at all times while handling animals or working in the animal room, and only 25% of the animal handlers had received an orientation about animal-induced allergies, asthma, or rhinitis. CONCLUSION: In conclusion, our data indicate that preventive programs are necessary. We suggest providing individual advice to workers associated with institutional programs to promote a safer work environment.

Study of risk factors for atopic sensitization, asthma, and bronchial hyperresponsiveness in animal laboratory workers

Study of risk factors for atopic sensitization, asthma, and bronchial hyperresponsiveness in animal laboratory workers: Christian Silva Simoneti, et al. Department of Medicine, Medical School of Ribeirão Preto, University of São Paulo, Brazil

Relationship between induced sputum cytology and inflammatory status with lung structural and functional abnormalities in asbestosis

BACKGROUND Asbestosis is associated with lung cellular and immunological abnormalities. Induced sputum cytology and local and systemic markers of inflammation may be helpful to characterize disease status and progression in these patients. METHODS Thirty-nine ex-workers with asbestosis on high-resolution CT (HRCT) and 21 non-exposed controls were evaluated. Sputum cytology and IL-8 in serum and sputum were related to lung function impairment. RESULTS Subjects with asbestosis had reduced sputum cellularity but higher macrophage/neutrophil ratio and % macrophage as compared with controls. Sputum and serum IL-8 were also higher in patients with asbestosis (P < 0.05). In addition, evidence of lung architectural distorption on HRCT was associated with increased levels of serum IL-8. Interestingly, absolute macrophage number was negatively correlated with total lung capacity (r = -0.40; P = 0.04) and serum IL-8 to lung diffusing capacity (r = -0.45; P = 0.01). CONCLUSIONS Occupationally exposed subjects with asbestosis on HRCT have cytologic abnormalities in induced sputum and increased local and systemic pro-inflammatory status which are correlated to functional impairment.