\n"}" id="mwBA">
Desquamative interstitial pneumonia | |
---|---|
Other names | DIP |
Chest computerized tomography scan showing diffuse ground-glass opacities with air-bronchograms in the upper lobes and the left lower lobe. | |
Specialty | Pulmonology |
Desquamative interstitial pneumonia (DIP) is a type of idiopathic interstitial pneumonia featuring elevated numbers of macrophages within the alveoli of the lung. [1] DIP is a chronic disorder with an insidious onset. Its common symptoms include shortness of breath, coughing, fever, weakness, weight loss, and fatigue. In more severe cases, it may lead to respiratory failure, chest pain, digital clubbing, cyanosis, and hemoptysis. Asymptomatic cases are rare.
DIP is often linked to cigarette smoking, environmental or occupational exposure, systemic disorders, and infections. Environmental risk factors include diesel or fire smoke, asbestos, and other chemicals. DIP has also been associated with certain drugs like marijuana, sirolimus, macrolides, nitrofurantoin, tocainide, and sulfasalazine. Disorders, such as hepatitis C, cytomegalovirus, systemic lupus erythematosus, connective tissue disease, and rheumatoid arthritis, have also been tied to DIP.
Diagnosis often requires surgical biopsy, especially when imaging or other tests provide non-specific results. High-resolution computed tomography (HRCT) can help identify the features of DIP. Differential diagnosis includes non-specific interstitial pneumonia, pulmonary Langerhans cell histiocytosis, respiratory bronchiolitis-associated interstitial lung disease, and hypersensitivity pneumonia. DIP is primarily treated by quitting smoking, but it may not be enough in all cases. In moderate to severe cases, corticosteroids are used. Severe DIP can be treated with lung transplants, but recurrence is possible. DIP has a favorable prognosis, with a mortality rate of 6-28% and a survival rate of 68%-94%.
Desquamative interstitial pneumonia is a chronic disorder that often has an insidious onset. [2] The most common symptoms of DIP are shortness of breath, especially during exercise, and coughing. Non-specific symptoms such as fever, weakness, weight loss, and fatigue are common. Other symptoms include respiratory failure, chest pain, digital clubbing, cyanosis, and rarely hemoptysis. [3] Some people with DIP may be asymptomatic, although this is rare. [4] [5]
90% of desquamative interstitial pneumonia cases are linked to cigarette smoking. Other suggested causes of DIP include environmental or occupational exposure, systemic disorders and infections. [6] In many cases, no specific cause can be identified, and these are classified as idiopathic. [7]
Active or passive exposure to cigarette smoke is the most well-established risk factor for desquamative interstitial pneumonia. DIP has also been reported in those who do not smoke which indicates that there are other risk factors for DIP. [6]
Occupational exposure to diesel or fire smoke, asbestos, solder smoke, silica, beryllium, nylon filaments, wood dust, graphite, talc, copper dust, aluminum, and tungsten cobalt have been associated with DIP. [6] [8]
DIP has also been associated with certain drugs such as marijuana, sirolimus, macrolides, nitrofurantoin, tocainide, and sulfasalazine. [6]
Several other disorders have been linked to DIP. Infections such as hepatitis C [9] and cytomegalovirus [10] have been associated with DIP. Many systematic disorders such as systemic lupus erythematosus, [11] [12] connective tissue disease, [11] [13] and rheumatoid arthritis [14] have been connected to DIP. [15] [16]
Since laboratory testing, imaging, and bronchoalveolar lavage results are often non-specific, guidelines recommend surgical biopsy to diagnose desquamative interstitial pneumonia if high-resolution computed tomography does not reveal classic signs of interstitial pneumonia. [17] A definitive diagnosis of DIP relies on a lung biopsy. [18]
While some laboratory abnormalities have been reported in cases of DIP, biological analysis does not usually point toward any diagnosis. Chest X-rays often show non-specific findings or come back normal. [19] [20] Pulmonary function tests usually reveal a decrease in diffusion capacity and a restrictive pattern. [7]
Thoracic high-resolution computed tomography (HRCT) often shows signs of DIP, [17] however, HRCT has only been reported on in one study. HRCT shows a ground-glass appearance. [20]
The major hallmark of DIP is the presence of a large number of macrophages within the alveoli that are distributed throughout the pulmonary acini. These macrophages are rich in eosinophilic cytoplasm and frequently include a coarsely granular light-brown pigment. There are usually a few multinucleated large cells. The alveolar architecture is typically intact, however there is a modest chronic inflammatory infiltration inside the interstitium. A moderate quantity of eosinophils might also be present. Lymphoid aggregates can be present. [18]
The differential diagnosis for DIP includes non-specific interstitial pneumonia, pulmonary Langerhans cell histiocytosis, respiratory bronchiolitis-associated interstitial lung disease, and hypersensitivity pneumonia. [21]
The main treatment for DIP is quitting smoking. Sometimes smoking cessation is successful in managing DIP however in some cases this is not enough. Avoidance of other potential environmental factors is also advised. In those who are moderately to severely symptomatic and who have not responded to quitting smoking, corticosteroids are used. Cytotoxic and immunosuppressive drugs have been used for the treatment of DIP however there is not enough evidence on their usage. In cases of severe DIP lung transplants are an option however recurrence is still possible. [22] [16]
Desquamative interstitial pneumonia has a favourable prognosis and most patients improve with proper treatment. The mortality rate of DIP is between 6 and 28%. [22] The survival rate of DIP is estimated to be between 68% and 94%. Without treatment around 60% of patients get worse. Spontaneous recovery had also been reported. [16]
The prevalence of desquamative interstitial pneumonia is unknown, [6] but it most commonly affects people aged 40 to 60, [7] with males twice as likely to have it as females. [4] While DIP can sometimes progress rapidly, severe fibrosis is rare. [6]
Desquamative interstitial pneumonia was first defined by Averill Liebow et al. In 1965 Liebow described 18 patients with pulmonary lesions with large alveolar cell proliferation and desquamation. Liebow also noted that the walls of the patient's distal airways were thickened. [23] The name "desquamative interstitial pneumonia" originated from the assumption that the disease was caused by epithelial cell desquamation. [1] [4]
Pulmonary alveolar proteinosis (PAP) is a rare lung disorder characterized by an abnormal accumulation of surfactant-derived lipoprotein compounds within the alveoli of the lung. The accumulated substances interfere with the normal gas exchange and expansion of the lungs, ultimately leading to difficulty breathing and a predisposition to developing lung infections. The causes of PAP may be grouped into primary, secondary, and congenital causes, although the most common cause is a primary autoimmune condition in an individual.
Interstitial lung disease (ILD), or diffuse parenchymal lung disease (DPLD), is a group of respiratory diseases affecting the interstitium and space around the alveoli of the lungs. It concerns alveolar epithelium, pulmonary capillary endothelium, basement membrane, and perivascular and perilymphatic tissues. It may occur when an injury to the lungs triggers an abnormal healing response. Ordinarily, the body generates just the right amount of tissue to repair damage, but in interstitial lung disease, the repair process is disrupted, and the tissue around the air sacs (alveoli) becomes scarred and thickened. This makes it more difficult for oxygen to pass into the bloodstream. The disease presents itself with the following symptoms: shortness of breath, nonproductive coughing, fatigue, and weight loss, which tend to develop slowly, over several months. The average rate of survival for someone with this disease is between three and five years. The term ILD is used to distinguish these diseases from obstructive airways diseases.
Pulmonary fibrosis is a condition in which the lungs become scarred over time. Symptoms include shortness of breath, a dry cough, feeling tired, weight loss, and nail clubbing. Complications may include pulmonary hypertension, respiratory failure, pneumothorax, and lung cancer.
Hypersensitivity pneumonitis (HP) or extrinsic allergic alveolitis (EAA) is a syndrome caused by the repetitive inhalation of antigens from the environment in susceptible or sensitized people. Common antigens include molds, bacteria, bird droppings, bird feathers, agricultural dusts, bioaerosols and chemicals from paints or plastics. People affected by this type of lung inflammation (pneumonitis) are commonly exposed to the antigens by their occupations, hobbies, the environment and animals. The inhaled antigens produce a hypersensitivity immune reaction causing inflammation of the airspaces (alveoli) and small airways (bronchioles) within the lung. Hypersensitivity pneumonitis may eventually lead to interstitial lung disease.
Pneumonitis describes general inflammation of lung tissue. Possible causative agents include radiation therapy of the chest, exposure to medications used during chemo-therapy, the inhalation of debris, aspiration, herbicides or fluorocarbons and some systemic diseases. If unresolved, continued inflammation can result in irreparable damage such as pulmonary fibrosis.
Cryptogenic organizing pneumonia (COP), formerly known as bronchiolitis obliterans organizing pneumonia (BOOP), is an inflammation of the bronchioles (bronchiolitis) and surrounding tissue in the lungs. It is a form of idiopathic interstitial pneumonia.
Respiratory diseases, or lung diseases, are pathological conditions affecting the organs and tissues that make gas exchange difficult in air-breathing animals. They include conditions of the respiratory tract including the trachea, bronchi, bronchioles, alveoli, pleurae, pleural cavity, the nerves and muscles of respiration. Respiratory diseases range from mild and self-limiting, such as the common cold, influenza, and pharyngitis to life-threatening diseases such as bacterial pneumonia, pulmonary embolism, tuberculosis, acute asthma, lung cancer, and severe acute respiratory syndromes, such as COVID-19. Respiratory diseases can be classified in many different ways, including by the organ or tissue involved, by the type and pattern of associated signs and symptoms, or by the cause of the disease.
Bronchiolitis obliterans (BO), also known as obliterative bronchiolitis, constrictive bronchiolitis and popcorn lung, is a disease that results in obstruction of the smallest airways of the lungs (bronchioles) due to inflammation. Symptoms include a dry cough, shortness of breath, wheezing and feeling tired. These symptoms generally get worse over weeks to months. It is not related to cryptogenic organizing pneumonia, previously known as bronchiolitis obliterans organizing pneumonia.
Alveolar lung diseases, are a group of diseases that mainly affect the alveoli of the lungs.
Occupational lung diseases comprise a broad group of diseases, including occupational asthma, industrial bronchitis, chronic obstructive pulmonary disease (COPD), bronchiolitis obliterans, inhalation injury, interstitial lung diseases, infections, lung cancer and mesothelioma. These can be caused directly or due to immunological response to an exposure to a variety of dusts, chemicals, proteins or organisms. Occupational cases of interstitial lung disease may be misdiagnosed as COPD, idiopathic pulmonary fibrosis, or a myriad of other diseases; leading to a delay in identification of the causative agent.
Idiopathic pulmonary fibrosis (IPF) synonymous with cryptogenic fibrosing alveolitis is a rare, progressive illness of the respiratory system, characterized by the thickening and stiffening of lung tissue, associated with the formation of scar tissue. It is a type of chronic pulmonary fibrosis characterized by a progressive and irreversible decline in lung function.
Usual interstitial pneumonia (UIP) is a form of lung disease characterized by progressive scarring of both lungs. The scarring involves the pulmonary interstitium. UIP is thus classified as a form of interstitial lung disease.
High-resolution computed tomography (HRCT) is a type of computed tomography (CT) with specific techniques to enhance image resolution. It is used in the diagnosis of various health problems, though most commonly for lung disease, by assessing the lung parenchyma. On the other hand, HRCT of the temporal bone is used to diagnose various middle ear diseases such as otitis media, cholesteatoma, and evaluations after ear operations.
Idiopathic interstitial pneumonia (IIP), or noninfectious pneumonia are a class of diffuse lung diseases. These diseases typically affect the pulmonary interstitium, although some also have a component affecting the airways. There are seven recognized distinct subtypes of IIP.
Respiratory bronchiolitis is a lung disease associated with tobacco smoking. In pathology, it is defined by the presence of "smoker's macrophages". When manifesting significant clinical symptoms it is referred to as respiratory bronchiolitis interstitial lung disease (RB-ILD).
Rheumatoid lung disease is a disease of the lung associated with RA, rheumatoid arthritis. Rheumatoid lung disease is characterized by pleural effusion, pulmonary fibrosis, lung nodules and pulmonary hypertension. Common symptoms associated with the disease include shortness of breath, cough, chest pain and fever. It is estimated that about one quarter of people with rheumatoid arthritis develop this disease, which are more likely to develop among elderly men with a history of smoking.
Ground-glass opacity (GGO) is a finding seen on chest x-ray (radiograph) or computed tomography (CT) imaging of the lungs. It is typically defined as an area of hazy opacification (x-ray) or increased attenuation (CT) due to air displacement by fluid, airway collapse, fibrosis, or a neoplastic process. When a substance other than air fills an area of the lung it increases that area's density. On both x-ray and CT, this appears more grey or hazy as opposed to the normally dark-appearing lungs. Although it can sometimes be seen in normal lungs, common pathologic causes include infections, interstitial lung disease, and pulmonary edema.
Antisynthetase syndrome (ASS) is a multisystematic autoimmune disease associated with inflammatory myositis, interstitial lung disease, and antibodies directed against various synthetases of aminoacyl-transfer RNA. Other common symptoms include mechanic's hands, Raynaud's phenomenon, arthritis, and fever.
Flock worker's lung is an occupational lung disease caused by exposure to flock, small fibers that are glued to a backing in order to create a specific texture. People who work in flocking are at risk of inhaling small pieces of the flock fibers, which causes interstitial lung disease. The disease was initially described in 1998, when a group of workers at a flocking plant developed interstitial lung disease of unknown cause.
Averill Abraham Liebow was an international leader on the pathology of the lung. He is credited with the development of a classification system for lung disease. His observations resulted in the discovery of new diseases. Liebow was among the first scientists to enter Hiroshima, Japan, after the atomic bomb was dropped in 1945. Accounts of that experience were published in "Encounter With Disaster: A Medical Diary of Hiroshima" and "Medical Effects of the Atomic Bomb in Japan."