The computed tomographic appearances in chronic berylliosis

Imaging of Occupational Lung Disease

Occupational lung diseases span a variety of pulmonary disorders caused by inhalation of dusts or chemical antigens in a vocational setting. Included in these are the classic mineral pneumoconioses of silicosis, coal worker's pneumoconiosis, and asbestos-related diseases as well as many immune-mediated and airway-centric diseases, and new and emerging disorders. Although some of these have characteristic imaging appearances, a multidisciplinary approach with focus on occupational exposure history is essential to proper diagnosis.

An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease

RATIONALE

Beryllium continues to have a wide range of industrial applications. Exposure to beryllium can lead to sensitization (BeS) and chronic beryllium disease (CBD).

OBJECTIVES

The purpose of this statement is to increase awareness and knowledge about beryllium exposure, BeS, and CBD.

METHODS

Evidence was identified by a search of MEDLINE. The committee then summarized the evidence, drew conclusions, and described their approach to diagnosis and management.

MAIN RESULTS

The beryllium lymphocyte proliferation test is the cornerstone of both medical surveillance and the diagnosis of BeS and CBD. A confirmed abnormal beryllium lymphocyte proliferation test without evidence of lung disease is diagnostic of BeS. BeS with evidence of a granulomatous inflammatory response in the lung is diagnostic of CBD. The determinants of progression from BeS to CBD are uncertain, but higher exposures and the presence of a genetic variant in the HLA-DP β chain appear to increase the risk. Periodic evaluation of affected individuals can detect disease progression (from BeS to CBD, or from mild CBD to more severe CBD). Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline.

CONCLUSIONS

Medical surveillance in workplaces that use beryllium-containing materials can identify individuals with BeS and at-risk groups of workers, which can help prioritize efforts to reduce inhalational and dermal exposures.

Advances in the diagnosis and treatment of sarcoidosis

This manuscript outlines recent advances in the diagnosis and treatment of sarcoidosis. The diagnosis of sarcoidosis can occasionally be made on clinical grounds without a confirmatory biopsy when very specific clinical findings are present. Otherwise, the diagnosis requires histologic evidence of granulomatous inflammation, exclusion of alternative causes, and evidence of systemic disease. Because there is no available diagnostic test for sarcoidosis, the diagnosis is never completely secure. Instruments have been developed to establish the presence of sarcoidosis in a second organ and hence establish the systemic nature of the disease. Corticosteroids remain the drug of choice for the treatment of sarcoidosis. Additional sarcoidosis medications are most commonly used as corticosteroid-sparing agents. Recent clinical sarcoidosis drug trials have exposed important issues that may confound trial results, including selecting patients with active disease, identifying study drug effects in patients receiving concomitant corticosteroids, and establishing proper study endpoints.

Chronic beryllium disease: computed tomographic findings

Chronic beryllium disease is a rare multisystem granulomatous disease predominantly involving the lungs and resulting from an immunologic response to long-term occupational exposure. Computed tomography of the chest reveals important lung parenchymal and mediastinal findings and plays an important role in the diagnosis and follow-up assessment of patients with chronic beryllium disease. Its significance lies in the exact localization and evaluation of the extent of lesions. We present an overview of the subject and a pictorial review of the spectrum of computed tomographic features of beryllium disease.

Immunology of chronic beryllium disease

PURPOSE OF REVIEW

This review discusses the immunology of chronic beryllium disease. It addresses the importance of the interaction between class II molecules and the T cells that recognize beryllium, along with the subsequent immune response that results in sensitization and disease, and genetic factors leading to variation in this response.

RECENT FINDINGS

HLA-DPB1 with a glutamic acid at amino acid position 69 (Glu69) confers increased risk of beryllium sensitization and is not specific for chronic beryllium disease. The degree of negative surface charge of the molecule may increase risk of chronic beryllium disease but not sensitization. In the absence of Glu69, HLA-DRB1 alleles may function in beryllium presentation, increasing the risk of chronic beryllium disease. The T-cell response as assessed by the beryllium lymphocyte proliferation test is dependent on central memory T-cells, while Th1 cytokine secretion leading to granulomatous inflammation and chronic beryllium disease is dependent on the activity of effector memory T cells. Polymorphisms in cytokine genes, such as the TGF-beta1 gene, also affect the risk of chronic beryllium disease and more severe disease.

SUMMARY

The current diagnostic criteria for sensitization and chronic beryllium disease rely on the beryllium lymphocyte proliferation test. By understanding the novel immunologic mechanisms and genetic factors associated with sensitization and chronic beryllium disease, we may improve our ability to detect beryllium health effects with new diagnostics, and hopefully refine therapies for disease.

The diagnosis of sarcoidosis

The diagnosis of sarcoidosis can never be assured: sarcoidosis is a diagnosis of exclusion and this cannot be accomplished with complete confidence. The diagnosis requires clinicoradiographic findings compatible with the diagnosis, histologic confirmation of granulomatous inflammation, exclusion of known causes of granulomatous disease, and evidence of disease in at least two organs. The end result of this diagnostic evaluation for sarcoidosis is neither a definitive diagnosis nor an exclusion of the diagnosis, but rather a statistical likelihood of the disease.

Pneumoconiosis: comparison of imaging and pathologic findings

Pneumoconiosis may be classified as either fibrotic or nonfibrotic, according to the presence or absence of fibrosis. Silicosis, coal worker pneumoconiosis, asbestosis, berylliosis, and talcosis are examples of fibrotic pneumoconiosis. Siderosis, stannosis, and baritosis are nonfibrotic forms of pneumoconiosis that result from inhalation of iron oxide, tin oxide, and barium sulfate particles, respectively. In an individual who has a history of exposure to silica or coal dust, a finding of nodular or reticulonodular lesions at chest radiography or small nodules with a perilymphatic distribution at thin-section computed tomography (CT), with or without eggshell calcifications, is suggestive of silicosis or coal worker pneumoconiosis. Magnetic resonance imaging is helpful for distinguishing between progressive massive fibrosis and lung cancer. CT and histopathologic findings in asbestosis are similar to those in idiopathic pulmonary fibrosis, but the presence of asbestos bodies in histopathologic specimens is specific for the diagnosis of asbestosis. Giant cell interstitial pneumonia due to exposure to hard metals is classified as a fibrotic form of pneumoconiosis and appears on CT images as mixed ground-glass opacities and reticulation. Berylliosis simulates pulmonary sarcoidosis on CT images. CT findings in talcosis include small centrilobular and subpleural nodules or heterogeneous conglomerate masses that contain foci of high attenuation indicating talc deposition. Siderosis is nonfibrotic and is indicated by a CT finding of poorly defined centrilobular nodules or ground-glass opacities.

Bérylliose pulmonaire chronique (2e partie)

INTRODUCTION

Chronic beryllium disease (CBD) is an occupational lung disease caused by the inhalation of beryllium dust, fumes or metallic salts.

CURRENT DATA

Beryllium affects the lungs via particles deposited in the pulmonary alveoli. These are ingested by alveolar macrophages which act as antigen presenting cells to CD4+ T lymphocytes. T lymphocytes proliferate in response to beryllium antigens and combined with macrophages produce numerous epithelioid granulomas with the release of inflammatory cytokines (IFNgamma, IL-2, TNFalpha and IL6) and growth factors. Beryllium induces macrophage apoptosis which reduces its clearance from the lung which in turn contributes to the host's continual re-exposure and thus a chronic granulomatous disorder. Pulmonary granulomatous inflammation is the primary manifestation of CBD, but the disease occasionally involves other organs such as the liver, spleen, lymph nodes and bone marrow. The clinical, radiological, and histopathological features of CBD can be difficult to distinguish from sarcoidosis. The Beryllium lymphocyte proliferation test (BeLPT) demonstrates a beryllium specific immune response, confirms the diagnosis of CBD, and excludes sarcoidosis.

CONCLUSIONS AND PERSPECTIVES

CBD provides a human model of pulmonary granulomatous disease produced by an occupational exposure, occurring more frequently in those with a genetic pre-disposition. It can be differentiated from sarcoidosis by specific immunological testing.

Ground-glass computed tomography pattern in chronic beryllium disease: pathologic substratum and evolution

Five cases of chronic beryllium disease with predominant or isolated diffuse ground-glass lung opacities on computed tomography are reported with correlation to lung pathology. The ground-glass attenuation was either homogeneous and isolated (n = 1) or patchy and clearly predominant (n = 4) over linear and nodular opacities. In 4 cases, histologic samples showed a prominent diffuse involvement of the alveolar-capillary walls by florid granulomas. Evolution under corticosteroid was remarkable by the appearance of small-sized cysts in 3 cases.

Imaging of nonmalignant occupational lung disease

The radiologist plays an important partnership role in detecting presymptomatic disease in those at risk for occupational lung disease, contributing to the specificity of the diagnosis and recognizing sentinel events. Medicolegal roles for imaging include confirming the presence of a morphologic abnormality compatible with occupational lung disease, identifying other potential causes for disability, and determining the morphologic extent of disease. This article describes and illustrates the imaging appearance of a wide range of occupational lung diseases.

High-resolution CT in the evaluation of occupational and environmental disease

The most common of the pneumoconioses are silicosis, CWP, and asbestosis. The former two are characterized by the presence of small nodular opacities predominantly distributed in the upper zones of the lung. The small nodular opacities are classified into two patterns on HRCT: (1) ill-defined fine branching lines and (2) well-defined discrete nodules. Asbestosis demonstrates thickened interlobular and intralobular lines, subpleural dot-like or curvilinear opacities, and honeycombing on HRCT, predominantly distributed in the bases of the lungs. Although HRCT findings of other pneumoconioses are variable and nonspecific, there are predominant and characteristic findings for each type of pneumoconiosis. HRCT is useful in achieving more accurate categorization of the parenchymal changes in each type of pneumoconiosis.

CT of noninfectious granulomatous lung disease

Noninfectious granulomatous diseases of the lung consist of a diverse group of disorders that logically can be subdivided into those with and without associated vasculitis. This article reviews the epidemiologic, clinical, pathologic, and radiologic features of sarcoidosis, hypersensitivity pneumonitis, berylliosis, and the five entities traditionally classified as pulmonary angiitis and granulomatosis.