[Gastrointestinal complications of adult patients with cystic fibrosis]

Abstract

Cystic fibrosis (CF) is the most common autosomal recessive disease in the Caucasian population. The primary cellular defect, the reduced expression of the cystic fibrosis transmembrane conductance regulator (CFTR), leading to a chloride secretory defect, is present in all epithelial cells of endodermal and mesodermal origin and has been described in sweat glands, the airway epithelium and the small intestine, the colon and rectum, including the pancreas. In the upper GI-tract the most troublesome complaints and symptoms originating from the esophagus are peptic esophagitis or esophageal varices. In the small intestinal wall, the clinical expression of CF largely depends on the decreased secretion of fluid and chloride ions and the sticky mucous covering the enterocytes. Although CFTR expression in the colon is lower, the large intestine may be the site of several serious complications such as rectal 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 reported to be increasingly associated with a number of hepatic and/or biliary abnormalities, of which chronic cholestatic liver disease is by far the most relevant. Plugging of intrahepatic bile ducts with inspissated secretions is thought to play a major role in the pathogenesis. It has been estimated that about 15% of cystic fibrosis patients reveal serum liver enzyme abnormalities, but prevalence of liver involvement is likely to be higher. Oral bile acid therapy is promising, but its long-term benefits in terms of survival and prevention of major complications by liver cirrhosis remain to be established. Pancreatic dysfunction in cystic fibrosis (CF) is characterized by an insufficient pancreatic exocrine function. However, 10-15% of CF patients have pancreatic sufficiency and this status is genetically determined by one or two "mild" mutations in the CFTR.