Seminars in respiratory and critical care medicine
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Sarcoidosis is a chronic granulomatous disorder characterized by an accumulation of T lymphocytes, macrophages, and immune-effector cells within affected organs. The pathogenesis of sarcoidosis involves a complex interplay between immune and nonimmune cells, with myriad cytokines and chemokines involved in the orchestration and evolution of the granulomatous/fibrotic process. ⋯ Genetic polymorphisms influence the susceptibility to sarcoidosis as well as the evolution/prognosis of the disease among patients with sarcoidosis. This article discusses the complex immunological events and immune effector cells that are critical to the induction, evolution, and resolution of the sarcoid granulomatous response.
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Semin Respir Crit Care Med · Aug 2010
The etiologic role of infectious antigens in sarcoidosis pathogenesis.
Sarcoidosis is a disease of unknown etiology, characterized pathologically by noncaseating granulomas that most commonly involve the lung, skin, lymph nodes, and eyes. Syndromes with similar pathological and immunologic features to sarcoidosis such as chronic beryllium disease, hypersensitivity pneumonitis, and tuberculosis illustrate that granulomatous diseases may or may not have an infectious etiology. Although the etiology of sarcoidosis remains unknown, recent molecular, genetic, and immunologic studies strengthen the association of sarcoidosis with infectious antigens. ⋯ Recent discoveries regarding MHC class II alleles provide additional insight regarding the role of microbial antigens in sarcoidosis pathogenesis. Although further investigation is warranted, the recent progress of independent laboratories, using complementary techniques, strengthens the role of microbial antigens in sarcoidosis pathogenesis. These studies lay a strong foundation toward identifying therapeutic targets.
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Supplemental oxygen therapy is commonly used in patients with advanced chronic obstructive pulmonary disease (COPD) and severe hypoxemia at rest. Use of oxygen in these patients is justified by studies showing a mortality benefit. ⋯ This article reviews the available studies of the use of supplemental oxygen in patients with less severe hypoxemia at rest during the day, hypoxemia occurring only at night, and hypoxemia occurring only with exercise. With the knowledge that studies in patients with advanced COPD and less severe hypoxemia are limited, recommendations are provided on oxygen use in these groups of patients.
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Severe chronic obstructive pulmonary disease (COPD) exacerbations requiring hospitalization are a major cause of morbidity and mortality. Recognition of the importance of COPD exacerbations has led to the knowledge that prevention of exacerbations and early treatment are important goals of COPD therapy. Preventive management of COPD aiming at reducing exacerbations complicated by hospital admissions includes vaccination, avoiding pollutant exposure, and, when indicated, long-term oxygen therapy. ⋯ Novel pharmacological therapy, which can prevent disease progression and exacerbations, is still needed. New self-management strategies such as a written action plan that helps patients recognize their exacerbation and promptly access treatment may have great potential. This needs to be evaluated in a properly designed randomized clinical trial before it becomes the standard of care for COPD patients.
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Semin Respir Crit Care Med · Jun 2010
ReviewThe potential value of biomarkers in diagnosis and staging of COPD and exacerbations.
There is an unmet need in the diagnosis, phenotyping, and staging of COPD that could potentially be fulfilled by a validated molecular biomarker. Many promising candidates have been investigated, and some have been shown to be useful in certain situations. However, to date there is no outstanding disease-specific biomarker for widespread clinical application for patients in the stable state. ⋯ Utilizing biomarkers in combinations may ultimately prove more useful. Airway-derived biomarkers and their relationships with outcome measures require further longitudinal study as well as refinement of sampling techniques to make them more broadly applicable. There is substantial ongoing investigation of many biomarkers that we are hopeful will advance the field for the benefit of our patients.