Fibrose maciça progressiva em trabalhadores expostos à sílica: achados na tomografia computadorizada de alta resolução / Progressive massive fibrosis in silica-exposed workers: high-resolution computed tomography findings

OBJETIVO: Avaliar as características radiológicas das massas conglomeradas pela tomografia computadorizada de alta resolução de tórax. MÉTODOS: Foram selecionados 75 pacientes silicóticos, a maioria jateadores de areia, portadores de fibrose maciça progressiva, atendidos no Hospital Universitário Antônio Pedro entre 1986 e 2004. Os pacientes foram submetidos a avaliação clínica, radiografia simples de tórax e tomografia computadorizada de alta resolução. RESULTADOS: Mais da metade dos pacientes com silicose complicada mostrou na radiografia de tórax grandes opacidades dos tipos B e C, denotando a gravidade da doença nesses pacientes. Dos 75 casos, apenas um apresentou massa unilateral simulando câncer de pulmão. Quarenta e quatro pacientes realizaram tomografia computadorizada de alta resolução do tórax. As massas predominaram nos terços superiores e posteriores (88,6 por cento). Broncograma aéreo e calcificações no interior das massas foram observados em 70,4 por cento e 63,8 por cento dos casos, respectivamente. História de tuberculose foi relatada em 52 por cento dos pacientes estudados. CONCLUSÃO: Na grande maioria dos casos as massas eram bilaterais, predominando nas regiões póstero-superiores dos pulmões, com broncogramas aéreos e calcificações de permeio. Associação com calcificações linfonodais foi um achado freqüente. A exposição a elevadas concentrações de poeira e a tuberculose foram consideradas fatores de risco para o desenvolvimento da fibrose maciça progressiva.

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 percent), the masses were located in the superior and posterior thirds of the lung. Common findings within the masses included air bronchograms (in 70.4 percent) and calcifications (in 63.6 percent). A history of tuberculosis was reported by 52 percent 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.

Cell proliferation and interferon-gamma response to recombinant MBP-3, NarL, MT-10.3, and 16kDa Mycobacterium tuberculosis antigens in Brazilian tuberculosis patients

Human pulmonary tuberculosis (TB) is a worldwide public health problem. In resistant individuals, control of the infection mainly requires development of a Th1 cell immune response with production of cytokines, of which interferon-gamma (IFN-gamma)plays an important role. Several antigens from Mycobacterium tuberculosis complex has been described for use in vaccine development or for diagnostic purposes, however little evaluation has been done in endemic area for TB. The proliferative and IFN-gamma human T cell immune responses, to four recombinant proteins (MBP-3, NarL, MT-10.3, 16 kDa) and PPD, of 38 Brazilian TB patients (6 untreated and 32 treated) and 67 controls (38 positive and 29 negative tuberculin skin test - TST) were compared. The highest reactivity mean rate was obtained with PPD followed by 16 kDa in TB patients. While most of the patients (87 percent) and controls (> 64 percent) respond to the PPD, 16kDa was more specifically recognized (> 21 percent) although less sensitive (54 percent). When TB patients were divided according to treatment status, opposite to PPD, higher average level of IFN-gamma was induced by 16kDa in untreated (505 pg/ml) compared to treated TB patients and TST+ (269.8 pg/ml x 221.6pg/ml, respectively), although the difference was not significant. These data show that in contrast with the other recombinant proteins, the stimulatory potency of 16kDa to induce proliferative and INF-gamma response was more effective and is more recognized by active TB untreated patients, eliciting in control individuals a more selective immune response than PPD.