Pleural disorders

Indiana University School of Medicine Indianapolis, Indiana, U.S.A. 

Neutrophils are conspicuous by their absence. During the process of inflammation, a rapid transformation of the milieu in the pleural space occurs (8-10). The pleural mesothelium initiates a cascade of events that lead to the release of chemokines, the recruitment of phagocytic cells from the vascular compartment into the pleural space, and changes in pleural permeability that facilitate an organized series of events (8). 

In the present review, the role of chemokines in pleural disorders such as particulate-induced pleural disease, infectious disease, and malignant disease will be described. Besides pleural mesothelial cells, several other cells in the pleural space produce chemokines. Their role will be delineated. During treatment of diseases such as malignancy, pleurodesis agents such as talc are often instilled into the pleural space. Chemokine production during talc insufflation will be described. Importantly, chemokines have been identified to have multiple other immunologic and physiologic roles. In the pleural space, chemokines and chemokine receptors play an important role in repair of the denuded mesothelium. 

Marcel Dekker, Inc. 270 Madison Avenue, New YOTk, New York 10016 

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Additional research may help to develop therapeutic methods to interfere with the development of asbestos-induced lung and pleural disorders and to cause the disorders to regress once they are established. 

The Libby amphibole mineral, popularly known as tremolite asbestos, has been assigned a number of different names by scientists over the years (Meeker et al. 2001 Wylie and Verkouteren 2000) however, scientists agree that exposure to the mineral increased the risk of nonmalignant respiratory and pleural disorders, lung cancer, and mesothelioma in groups of people who worked in the now closed Libby mine and mill. These health problems are similar to those experienced by workers exposed to other types of asbestos before modem workplace air regulations were established. 

Exposure to any asbestos type (i.e., serpentine or amphibole) can increase the likelihood of lung cancer, mesothelioma, and nonmalignant lung and pleural disorders. 

Additional research may help to develop therapeutic methods to interfere with the development of nonmalignant lung and pleural disorders, and to cause the disorders to regress once they are established. Such research may include studies on the mechanism of asbestos-related disease to provide further understanding of how persistent production of reactive oxygen or nitrogen species and persistent inflammatory cellular responses precisely interact. 

It is abundantly clear that chemokines and chemokine receptors play a critical role in the pathogenesis of pleural disease. They are not only important in the development of pleural pathology, but play a role in normal homeostatic mechanisms as well as pleural repair processes. Chemokines are not only present in pleural fluids, but are expressed by multiple cell types present in the pleural space. Depending on the pleural disorder, they include pleural mesothelial cells, inflammatory cells including neutrophils and mononuclear cells, malignant cells that invade the pleural surface, and submesothellal cells such as pleural fibroblasts. That chemokines play a pivotal role in the process of development of pleural disease has been weU confirmed. Key pleural responses in diseases such as metastases or infection are mediated via chemokines. It remains to be seen if manipulation of local chemokine expression can modulate disease processes. 

CT Protocols for Imaging of Non-Malignant Asbestos-Related Pleural Disorders 233 References 235... 

The non-malignant forms of asbestos-related pleural disorders include pleural plaques, benign pleural effusion, and diffuse pleural thickening. Although circumscribed pleural plaques and diffuse pleural thickening are considered under this broad category of asbestos-related pleural fibrosis, these processes are distinct entities that are likely to involve different pathogenic mechanisms and have different clinical consequences (Schwartz 1991). 

Among asbestos-related pleural disorders, benign effusion is the most recent to come to our atten-... 

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