Gastrointestinal complications in adult patients with cystic fibrosis

Cystic fibrosis (CF) is the most common autosomal recessive disease in the Caucasian population. The primary cellular defect, the reduced expression o f the cystic fibrosis transmembrane conductance regulator (CFTR), leading t o a chloride secretory defect, is present in all epithelial cells of endode rmal and mesodermal origin and has been described in sweat glands, the airw ay epithelium and the small intestine, the colon and rectum, including the pancreas. In the upper GI-tract the most troublesome complaints and symptoms originat ing from the esophagus are peptic esophagitis or esophageal varices. In the small intestinal wall, the clinical expression of CF largely depends on th e decreased secretion of fluid and chloride ions and the sticky mucous cove ring the enterocytes. Although CFTR expression in the colon is lower, the l arge intestine may be the site of several serious complications such as rec tal prolapse, distal intestinal obstruction (DIOS), and intussusception. in recent years an increase in colonic strictures after the use of high-dose pancreatic enzymes, has been increasingly reported. CF has also been report ed to be increasingly associated with a number of hepatic and/or biliary ab normalities? of which chronic cholestatic liver disease is by far the most relevant. Plugging of intrahepatic bile ducts with inspissated secretions i s thought to play a major role in the pathogenesis. It has been estimated t hat about 15% of cystic fibrosis patients reveal serum liver enzyme abnorma lities, but prevalence of liver involvement is likely to be higher. Oral bi le acid therapy is promising, but its long-term benefits in terms of surviv al and prevention of major complications by liver cirrhosis remain to be es tablished. Pancreatic dysfunction in cystic fibrosis (CF) is characterized by an insufficient pancreatic exocrine function. However, 10-15% of CF pati ents have pancreatic sufficiency and this status is genetically determined by one or two >>mild<< mutations in the CFTR.