Diagnostic significance of determination of serum alkaline phosphatase intestinal isoenzyme activity in coeliac sprue in childhood.

In a group of 26 child patients with coeliac sprue verified by clinical tests and biopsy, we observed a significant change in the proportion of the intestinal alkaline phosphatase isoenzyme in the serum in correlation to a gluten-free therapeutic diet. In untreated patients, in the active phase of the disease, intestinal AP isoenzyme activity rises in the serum and falls in the intestinal mucosa. In our experience, the change in activity is reversible within 3--5 days of instituting adequate treatment, i.e. a gluten-free diet. No such activity changes were observed in children with other forms of malabsorption syndrome (hepatogenic, pancreatogenic) or in the children in the control group. This test was found to be a suitable and sensitive method for indirect determination of the response of the intestinal mucosa to treatment in children with coeliac sprue.