Bronchiectasis has both congenital and acquired causes, with the latter more frequent.
Acquired causes
Acquired Immune Deficiency Syndrome (AIDS) is the leading cause of bronchiectasis, especially in children. AIDS predisposes patients to a variety of pulmonary ailments, such as pneumonia and other opportunistic infections.Tuberculosis is another major cause. Endobronchial tuberculosis commonly leads to bronchiectasis, either from bronchial stenosis or secondary traction from fibrosis.
Bronchiectasis can sometimes be an unusual complication of inflammatory bowel disease, especially ulcerative colitis. It can occur in Crohn's disease as well, but does so less frequently. Bronchiectasis in this situation usually stems from various allergic responses to inhaled fungus spores.
Recent evidence has shown an increased risk of bronchiectasis in patients with rheumatoid arthritis who smoke. One study stated a tenfold increased prevalence of the disease in this cohort. Still, it is unclear as to whether or not cigarette smoke is a specific primary cause of bronchiectasis.
Other acquired causes of bronchiectasis involving environmental exposures include respiratory infections, obstructions, inhalation and aspiration of ammonia and other toxic gases, pulmonary aspiration, alcoholism, heroin (drug use), various allergies , and allergic bronchopulmonary aspergillosis.
Congenital causes
Kartagener syndrome, which affects the mobility of cilia in the lungs, aids in the development of the disease. Another common genetic cause is cystic fibrosis, in which a small number of patients develop severe localized bronchiectasis. Young's syndrome, which is clinically similar to cystic fibrosis, is thought to significantly contribute to the development of bronchiectasis. This is due to the occurrence of chronic, [http://www.biology-online.org/dictionary/Sinopulmonary sinopulmonary] infections. Patients with alpha 1-antitrypsin deficiency have been found to be particularly susceptible to bronchiectasis, for unknown reasons. Other less-common congenital causes include primary immunodeficiencies, due to the weakened or nonexistent immune system response to severe, recurrent infections that commonly affect the lung.Adapted from the Wikipedia article Bronchiectasis, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki
