Causes
Cigarette smoking is the cause of most cases of emphysema. Tobacco smoke damages the lungs' alveoli, the tiny air sacs through which inhaled oxygen is transferred to the bloodstream and carbon dioxide is passed back to the lungs to be exhaled. The lungs become less elastic and breathing becomes increasingly difficult. The genetic form of emphysema occurs earlier in life (worsened by, but not dependent upon cigarette smoking). It is caused by a rare genetic deficiency of the protein alpha1-antitrypsin. In the absence of antitrypsin, which normally functions to protect the lungs from damage, the walls of the alveoli are attacked by chemicals released in alveoli in response to tobacco smoke and air pollutants.
Treatment
Emphysematous lung damage is irreversible. Its progression can be slowed by giving up smoking. Treatment is aimed at increasing the functional capacity of the lungs and may include bronchodilators, administration of supplemental oxygen, or lung transplantation. Surgical removal of affected lung tissue (lung volume reduction surgery), aimed at allowing healthy areas of the lung room to function, is being studied for its effectiveness and safety. The genetic form is treated with supplemental antitrypsin administered by infusion or by a gene therapy technique that uses T cells (special immune cells that identify diseased or deformed cells) to deliver it to the desired cell sites.
Licensed from Columbia University Press
Abnormal distension of the lungs with air, usually associated with cigarette smoking and chronic bronchitis. Elastic tissue degenerates, severely interfering with exhalation. Capillary walls disappear, leaving lung tissue dry and pale. The walls of the pulmonary alveoli (see pulmonary alveolus) break down, so the lung fills with pools of air. Symptoms include severe breathlessness, weight loss, bluish skin, chest tightness, and wheezing. In bullous emphysema, the alveoli form large air cysts that may rupture, causing lung collapse (see atelectasis), or require surgery. Emphysema is irreversible; it normally continues to progress even after the cessation of smoking and may lead to death. Seealso pulmonary heart disease.
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