A retrospective assessment of the clinical value of jejunal disaccharidase analysis.

BACKGROUND

The measurement of jejunal disaccharidases is used by several gastroenterologists when investigating suspected small-bowel disease. The clinical value of this analysis is assessed.

METHOD

The histology and disaccharidase results in 1585 jejunal biopsy specimens were reviewed retrospectively.

RESULTS

Disaccharidase and histology results concurred in most cases (72%). However, disaccharidases were an insensitive indicator of small-bowel disease: low levels were found in only 65% of coeliac patients with villous atrophy, 15% of patients with giardiasis, and 6% of patients with villous atrophy associated with non-coeliac histology. Low disaccharidase levels were sometimes found in patients with normal histology (1.6%) and when biopsy specimens were unwittingly taken from non-jejunal sites (1.4%). Isolated low lactase activities were found in 3.2%. Usually this finding was not clinically relevant because patients had no symptoms of lactose intolerance (38%), had another diagnosis that responded to appropriate treatment (8%), or had no response to a low-lactose diet (14%). In 16 patients sucrase activities were markedly low, and this investigation proved central to the diagnosis of sucrase-alpha-dextrinase deficiency, which was subsequently confirmed in 9.

CONCLUSION

Jejunal disaccharidases are clinically useful only in the diagnosis of sucrase-alpha-dextrinase deficiency. We recommend that their measurement be reserved for the investigation of patients suspected of having this condition.