Combined impact of mucosal damage and of cystic fibrosis on the small intestinal brush border enzyme activities.

In 61 cystic fibrosis (CF) patients, the small intestinal mucosa was studied at the time of diagnosis before starting therapy. In 19 out of 61 patients, partial villous atrophy on light microscopy and shortened villi on stereomicroscopic examination were seen. On the biopsy specimens, maltase, sucrase, lactase and alkaline phosphatase activities were studied. Comparison of the enzymatic activities in CF patients having damaged mucosa and a group of patients having similar mucosal lesions of unspecified origin (UTID), reveals a significantly more pronounced decrease of the alkaline phosphatase activity (p < 0.005) in the CF patients. This is in agreement with previous reported results in CF patients with normal mucosa. The abnormal mucosal findings could be due to the decreased neutralization of the gastric content delivered into the duodenum, the early inflammatory reaction present in the CF mucosa and/or to the impaired synthesis of membrane glycoproteins and enzymes secondary to the CFTR mutation.