No abstract

Objective: To evaluate the radiological characteristics of conglomerate masses using high-resolution computed tomography of the chest. Methods: From among the patients treated between 1986 and 2004 at the Antonio Pedro University Hospital, 75 patients with silicosis and massive fibrosis, most working in the field of sandblasting, were selected for study. These patients were submitted to a clinical evaluation, chest X-ray and high-resolution computed tomography of the chest. Results: In more than half of the patients with accelerated silicosis, the chest X-ray revealed large type B and C opacities, denoting the severity of the disease in those patients. In 1 case, a unilateral mass simulating lung cancer was observed. High-resolution computed tomography scans of the chest were acquired for 44 patients. In most cases (88.6%), the masses were located in the superior and posterior thirds of the lung. Common findings within the masses included air bronchograms (in 70.4%) and calcifications (in 63.6%). A history of tuberculosis was reported by 52% of the patients. Conclusion:In the vast majority of cases, the masses were bilateral, predominantly located in the superior and posterior regions of the lung, featuring air bronchograms and interposed calcifications. Concomitant calcification of the mediastinal and hilar lymph nodes was another common finding. Exposure to high concentrations of dust and having a history of tuberculosis were considered significant risk factors for the development of progressive massive fibrosis.

Silicosis is a disease caused by inhalation and deposition of crystalline silica that produces a fibrous tissue reaction. Bronchoalveolar lavage is a noninvasive technique that allows identifying particles, thus characterizing exposure to mineral dust. The aim of this work was to study bronchoalveolar lavage as a mean of estimating the amount of alveolar particles in different forms of silicosis. Bronchoalveolar lavage was carried out in 27 silicotic patients with simple (n = 12), complicated (n = 13), and acute (n = 2) forms of the disease and 7 healthy individuals as a control group. Macrophages were scored enumerating the percentage of cells with particles by polarizing light microscopy. Silicotic patients showed a marked increase in BAL cell particles compared to control population, however, relating simple to complicated silicosis, no significant difference was observed. In acute silicotic patients with massive silica dust exposure, more than 70% of BAL alveolar macrophages contained dust particles. When duration of exposure and retirement from work were evaluated, an inverse correlation between duration of exposure and the amount of alveolar dust, and a tendency to a smaller involvement on macrophages with the greater period of retirement from work were observed. These results suggest that particle analysis in BAL may be important in order to establish the nature and intensity of exposure.

The diagnosis of silicosis is based on the history of exposure to silica dust associated with the radiological alterations compatible with the disease. With the main objective of comparing the alterations found in the chest radiography to those of high resolution computed tomography 49 patients with silicosis were selected. These imaging methods were evaluated separately by three readers and the results summarized through the median of the readings. The following alterations were analysed: nodules, coalescences, large opacities, lynfadenopathy. The patients were male, at an average age of 47.1 years, the majority being sandblasters, with an average exposure time to dust of 15.3 years. When the chest radiography was compared to high resolution computed tomography the following alterations were observed: i) the high resolution computed tomography showed greater profusion of nodules in 19 cases; ii) the high resolution computed tomography detected isolated coalescence and large opacities in 28 cases, seven of them who were classified initially as having simple silicosis were later changed to the complicated form; iii) the high resolution computed tomography was superior in the evaluation of lynfadenopathy in 16 cases. So, from the 49 analysed patients the high resolution computed tomography was more sensitive than the chest radiography in the evaluation of the alterations studied in 38 (77,5%) cases. Other alterations such as cavities, pleural thickening and emphysema were also observed only by this method in 5 cases. In the last 6 (12,2%) cases the high resolution computed tomography did not add any data when compared to chest radiography, four of these showed the initial form of the disease.

A lavagem broncoalveolar é um procedimento simples e seguro, na avaliação das pneumopatias relacionadas à exposição a poeiras minerais. O objetivo do estudo foi caracterizar as subpopulações celulares no lavado broncoalveolar (LBA) de pacientes silicóticos. A lavagem broncoalveolar foi realizada em 26 trabalhadores com diferentes formas de silicose: forma simples (n = 12), complicada (n = 13) e um paciente com a forma aguda da doença. Como grupo controle, foram incluídos sete indivíduos sadios. Os pacientes com silicose apresentaram intensa pleocitose com predomínio de macrófagos alveolares e tendência à linfocitose. As subpopulações de linfócitos presentes no lavado broncoalveolar (LBA) dos indivíduos sadios apresentaram fenótipo de células maduras. A grande maioria era constituída por células CD2+TCR<FONT FACE=Symbol>ab</FONT> (87,3%) e somente 2,9% das células T apresentaram marcação CD2+TCR<FONT FACE=Symbol>gd</FONT>. A relação CD4/CD8 foi de 1,8, com poucas (16%) células T imaturas duplo-negativas CD4-CD8-. Em contraste, pacientes com silicose apresentaram redução acentuada das subpopulações dos linfócitos maduros CD2+CD4+, CD2+CD8+ e aumento marcante (47%) de células imaturas (DN) duplo-negativas (CD4-CD8-). Não foi observado aumento das células NK (CD56+). A análise do conteúdo protéico e a determinação da relação Ig/albumina permitiram caracterizar produção local de imunoglobulinas no microambiente pulmonar. Como não foi observado aumento percentual de plasmócitos e linfócitos B (CD19+) no LBA desses pacientes, é possível concluir que as células produtoras de imunoglobulinas estão possivelmente localizadas no interstício pulmonar. Estes resultados sugerem que, durante a evolução da silicose, ocorre o desenvolvimento de linfopoese extratímica e surgimento de órgão linfóide terciário, no microambiente pulmonar desses pacientes.