Cryptogenic organizing pneumonia: A rare extra-intestinal manifestation of Crohn's disease

Dear Sir, Cryptogenic organizing pneumonia (COP), formerly known as bronchiolitis obliterans organizing pneumonia, is a subacute pulmonary illness characterized by buds of granulation tissue in the bronchioles and alveolar ducts with extension of organization to the alveoli.1,2 It is an exceptionally rare extraintestinal manifestation of Crohn's disease (CD). The shared antigen theory may account for inflammation of both organ systems: decreased IgA secretion from mononuclear cells causes increased permeability to antigens such as bacteria, digestive enzymes and dietary antigens. The common embryonic origin of the GI tract and the bronchial tree from the primitive foregut results in susceptibility of both systems to these antigen.3 …