Prevalence and Clinical Significance of Intestinal Alkaline Phosphatase in Healthy Adults

Cho, Sung Ran; Huh, Ji Young; Park, Il Joong; Rheem, Insoo

Abstract

BACKGROUND
Intestinal alkaline phosphatase (ALP) is more prevalent in individuals of blood group B or O secretors and increases after a meal, especially, high-fat diet. The purpose of this study was to evaluate the prevalence and clinical significance of intestinal ALP in the sera of healthy adults. METHODS: Whole blood specimens were obtained from 42 healthy adults after fasting for at least 8 hours, and again at 2 hours after a regular meal. ALP was measured by TBA-200FR and analyzed for isoenzymes by Helena REP system. We also tested their ABO blood groups using GENEDIA anti-A and anti-B sera. RESULTS: The levels of fasting ALP, postprandial ALP, and the difference between the fasting and postprandial ALP (ALP difference) were 57.6+/-20.8 (12-111) IU/L, 62.3+/-17.4 (27-120) IU/L, and 4.6+/-15.4 (-8~63) IU/L, respectively. Delta (delta) ALP was 27.6+/-86.3 (-11.4~312.5)%. Among the 42 subjects, 6 were blood group A, 16 group B, 10 group AB, and 10 group O. Intestinal isoenzyme of ALP was detected in two subjects, both of whom were blood group O. The differences in fasting ALP, postprandial ALP, ALP difference, and delta ALP between ABO blood groups were statistically not significant. CONCLUSIONS: Intestinal ALP was detected in 5% of healthy adults, especially, in 20% of blood group O. Intestinal ALP has been known to be of no specific clinical significance. However, when ALP is measured in a non-fasting sample, the presence of intestinal ALP could result in an abnormally high ALP and subsequent unnecessary tests. Therefore, it is recommended that ALP should be measured only after fasting.