Abstract
The ALP activities measured by the JSCC transferable method were significantly different depending on the ABO blood groups of the specimen used, between A·B types and B·O types (P<0.001). On the contrary, when a multiple comparison test was performed using the activities obtained by a modified JSCC transferable method in the presence of L-phenylalanine, no significant difference was observed regardless of the ABO blood groups.
We determ ined that the value inhibited by the assay using L-phenylalanine was small intestine-type ALP (SI-ALP) activity.
Maximu m likelihood estimation was applied for determination of the reference intervals not only in the total ALP activities of the JSCC transferable method, but also in the SI-ALP activities. The reference intervals for the total ALP activity were 110 to 340U/l (median: 201U/l) for A and AB types, and 153 to 379U/l(median: 239U/l) for B and O types. The reference intervals of SI-ALP activity were 1 to 16 U/l (median: 4U/l) for A and AB types, and 2 to 73 U/l ( median: 21U/l) for B and O types.
There was a linear regression line (y=1.003x-1.4, r=0.998, r; correlation coefficient) for the ALP activities between the IFCC transferable method (x) and the modified JSCC transferable conversion method (y). Thus, as long as a suitable calibrator is available, activity in the converted method was compatible with the IFCC method's value. The inhibition assay presented in this paper is a useful tool for obtaining the activity of the IFCC transferable method.
