Seminars in respiratory and critical care medicine
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Semin Respir Crit Care Med · Oct 2012
ReviewAcute interstitial pneumonia (AIP): relationship to Hamman-Rich syndrome, diffuse alveolar damage (DAD), and acute respiratory distress syndrome (ARDS).
Acute interstitial pneumonia (AIP) is a term used for an idiopathic form of acute lung injury characterized clinically by acute respiratory failure with bilateral lung infiltrates and histologically by diffuse alveolar damage (DAD), a combination of findings previously known as the Hamman-Rich syndrome. This review aims to clarify the diagnostic criteria of AIP, its relationship with DAD and acute respiratory distress syndrome (ARDS), key etiologies that need to be excluded before making the diagnosis, and the salient clinical features. ⋯ The main differences between AIP and ARDS are that AIP requires a histologic diagnosis of DAD and exclusion of known etiologies. AIP should also be distinguished from "acute exacerbation of IPF," a condition in which acute lung injury (usually DAD) supervenes on underlying usual interstitial pneumonia (UIP)/idiopathic pulmonary fibrosis (IPF).
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Semin Respir Crit Care Med · Oct 2012
ReviewLymphocytic interstitial pneumonia and other benign lymphoid disorders.
Nonneoplastic pulmonary lymphoid disorders consist of a complex spectrum of diseases for pathologists and pulmonologists alike. Advances in our understanding of these disorders in recent years have led to revisions in the classification scheme. This review summarizes the clinicoradiological and pathological features of several benign pulmonary lymphoid disorders as well as the current knowledge regarding their pathogenesis. The disorders discussed include lymphocytic interstitial pneumonitis, follicular bronchiolitis, nodular lymphoid hyperplasia, inflammatory pseudotumor, Castleman disease, immunoglobulin G4-related disease in the lung, and posttransplant lymphoproliferative disease.
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Semin Respir Crit Care Med · Oct 2012
ReviewImmunopathology, diagnosis, and management of hypersensitivity pneumonitis.
Hypersensitivity pneumonitis (HP) is an inflammatory interstitial lung disease caused by a wide variety of organic particles and certain small-molecular weight chemical compounds that provoke an exaggerated immune response in susceptible individuals. The clinical manifestations are heterogeneous and have been classically described as acute, subacute and chronic. The chronic form has an insidious onset over a period of months or years, with progressive dyspnea and often evolves to fibrosis. ⋯ The cornerstone of therapy is antigen avoidance. Although clinical trials are scanty, corticosteroids are usually indicated based upon expert opinion. In this review we summarize the current evidence regarding the diagnostic criteria and therapeutic strategies as well as the immunopathological mechanisms putatively implicated in the development of the disease.
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Cigarette smoking is a recognized causative agent or precipitant of specific diffuse lung diseases characterized by bronchiolar and interstitial lung inflammation. Respiratory bronchiolitis-associated interstitial lung disease and pulmonary Langerhans cell histiocytosis are now considered smoking-induced diffuse lung diseases. Desquamative interstitial pneumonia is also recognized as a smoking-induced interstitial pneumonia in most cases. ⋯ The avoidance of primary and second-hand cigarette smoke is a critical component of management for patients afflicted with these smoking-induced diffuse lung diseases. The role of corticosteroids and other immunosuppressive treatments in the management of smoking-related interstitial lung diseases remains poorly defined and should be reserved for individuals with progressive disease despite smoking cessation. Understanding mechanisms by which tobacco induces diffuse lung pathology is critical in the pursuit of novel therapeutic approaches for these diseases.
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Semin Respir Crit Care Med · Oct 2012
Current status of idiopathic nonspecific interstitial pneumonia.
Pulmonary pathologists were aware of cases of idiopathic interstitial pneumonia (IIP) that morphologically did not fit Liebow's classification scheme. These cases were labeled as "cellular interstitial pneumonia" or "chronic interstitial pneumonia not otherwise specified." The term nonspecific interstitial pneumonia (NSIP) was first used in relation to a pattern of lung interstitial inflammation seen in association with human immunodeficiency virus (HIV) infection. In 1994 NSIP was used to indicate a group of subacute or chronic interstitial pneumonias characterized morphologically by interstitial inflammation or fibrosis or both, with preservation of the lung architecture and the absence of typical findings for any of the other main categories of IIP (mainly usual interstitial pneumonia, desquamative interstitial pneumonia, and bronchiolitis obliterans organizing pneumonia). ⋯ The prognosis is good compared with idiopathic pulmonary fibrosis (IPF), and therapeutic options include mainly corticosteroids and immunosuppressive agents. Recently a more precise definition of clinical profiles and radiographic findings of idiopathic NSIP allows consideration of less invasive diagnostic procedures (bronchoalveolar lavage, transbronchial lung biopsy). Better understanding of pathogenetic mechanisms might widen the therapeutic horizon giving a role to new therapeutic options in more severe cases.