Evaluation of a method for measuring tissue non-specific alkaline phosphatase activity in healthy subjects.

BACKGROUND: Intestinal alkaline phosphatase (IAP) isozymes in the healthy human serum samples appears in two isoforms: normal-molecular-weight IAP (NIAP) and high-molecular-weight IAP (HIAP). We have demonstrated that the reference range for serum alkaline phosphatase (ALP) activity is higher in blood group B and O antigen secretors than in the tested other blood groups, for the appearance of these isoforms is depended on blood group B or O antigen secretors. METHODS: We assessed a diethanolamine-L-phenylalanine (DEA-Phe) method for measuring tissue non-specific alkaline phosphatase (TNAP). This assays the sum of liver alkaline phosphatase and bone alkaline phosphatase activities as determined by an inhibiting IAP activity method with Phe. We classified 420 healthy subjects into two groups, a group of subjects who had blood group B or O antigen secretors (n = 184) and a group of subjects who had other blood groups (n = 236). RESULTS: ALP activity was higher in the B or O secretor group than in the other group: 20.9% higher (P<0.001) by the N-methyl-D-glucamine method, 13.7% higher (P<0.002) by 2-amino-2-methyl-1-propanol method, and 9.6% higher (P<0.05) by the diethanolamine method, but there was no significant difference in TNAP activity between the two blood group when measured by the DEA-Phe method. CONCLUSIONS: These results of this study support the expectation that the DEA-Phe method would be specific for TNAP activity. In addition, the reference range for TNAP activity did not vary with the differences in the tested all blood groups.

[Estimation of blood-group-dependent hyperphosphatasemia in healthy subjects by agarose gel electrophoresis].

Intestinal alkaline phosphatase (IAP) isozymes in the healthy human sera appears in two isoforms: normal-molecular-weight IAP (NIAP) and high-molecular-weight IAP (HIAP). We have demonstrated that the reference range for ALP activity is higher in blood group B and O secretors than in the other blood groups, for the appearance of these isoforms is depended on blood group B or O secretors. We currently reported that blood groups dependent hyperphosphatasemia in healthy subjects only appeared in blood group B or O secretors. In the present paper, we examined estimation of blood groups dependent hyperphosphatasemia in healthy subjects by use of agarose gel electrophoresis. We classified 104 healthy subjects with the B or O secretors into two groups of blood groups dependent hyperphosphatasemia (n = 5) and normal ALP activity (n = 99). The mean HIAP percentage in blood groups dependent hyperphosphatasemia group (18.5%) was higher than that in normal ALP activity group (9.9%). These results suggested that blood groups dependent hyperphosphatasemia in healthy subjects can be estimated from the HIAP levels by agarose gel electrophoresis.

[Incidence and characteristics of intestinal hyperphosphatasemia in healthy subjects].

We recently reported that two intestinal alkaline phosphatase (IAP) isoforms, high molecular mass IAP (HIAP) and normal molecular mass IAP (NIAP), appear in healthy serum with our Triton-PAGE method for determination of ALP isozymes. In addition, HIAP is chiefly present in blood group B or O secretors, and a large amount of NIAP is secreted into the circulation in blood group B or O secretors. In the present paper, we examined incidences and characteristics of intestinal hyperphosphatasemia in healthy subjects and blood groups dependent hyperphosphatasemia. We classified 273 healthy women into two groups of blood group B or O secretors (n = 105) and other blood groups (n = 168). Intestinal hyperphosphatasemia in healthy subjects only appeared in sera of B or O blood group secretors, and incidence of intestinal hyperphosphatasemia was 26.6% (28/105). In addition, blood groups dependent hyperphosphatasemia, more than 350 U/l of ALP activity, was 21.4% (6/28) of intestinal hyperphosphatasemia in healthy subjects, and 5.7% (6/105) of blood group B or O secretors. These results suggested that blood groups dependent hyperphosphatasemia in healthy subjects was closely related to the HIAP and NIAP levels.

The effect of different buffers and amounts of intestinal alkaline phosphatase isoforms on total alkaline phosphatase activity.

BACKGROUND: The transphosphorylating accepter buffers (2-amino-2-methyl-1-propanol, AMP; N-methyl-D-glucamine, MEG; diethanolamine, DEA and 2-ethylaminoethanol, EAE) have been widely used for the measurement of serum total alkaline phosphatase activity (ALP) in clinical laboratories, and the individual isozyme are activated differently by respective buffers. MATERIALS AND METHODS: We examined the activity of serum ALP using four buffers with levels of both high molecular weight intestinal alkaline phosphatase (HIAP) and normal molecular weight intestinal alkaline phosphatase (NIAP). We classified 80 healthy subjects into two groups of blood group B or O secretors (n=36) and other blood groups (n=44). RESULTS: The mean ALP activities at fasting in blood group B or O secretors from AMP, MEG, DEA and EAE methods were 15.5%, 24.0%, 11.0% and 22.1% higher than those in other blood groups, respectively. The reference ranges of ALP activity at fasting with the AMP method in blood group B or O secretors and other blood groups were 63.5+/-17.4 U/l (mean+/-S.D.) and 55.0+/-14.5 U/l (mean+/-S.D.), respectively. The difference between the reference ranges of ALP activity in blood group B or O secretors and other blood groups was statistically significant (p<0.01). HIAP and NIAP in serum at fasting only appeared in blood group B or O secretors, and the activities of HIAP and NIAP were 4.7+/-3.4 U/l (mean+/-S.D.) and 2.2+/-1.2 U/l (mean+/-S.D.), respectively. The activity of ALP-(HIAP+NIAP) in blood group B or O secretors was 56.6+/-15.1 U/l (mean+/-S.D.), and this reference range was approximately the same as the ALP activity (55.0+/-14.5 U/l) of other blood groups. The same results were observed with MEG, DEA and EAE methods. CONCLUSIONS: These results suggested that the differences in ALP activity in blood group B or O secretors and other blood groups were closely related to the HIAP and NIAP levels.