2020 Volume 69 Issue 4 Pages 577-583
The alkaline phosphatase (ALP) activity test was converted from the JSCC method to the IFCC method on 1 April 2020. We conducted a basic evaluation of ALP activity using “L-type Wako ALP·IFCC” manufactured by Fujifilm-Wako. Parallel-run precision and reproducibility for all control materials were good with a C.V. below 1.4%. The detection limit determined from dilution linearity using 10 dilution series of high-activity ALP samples was 1,762 U/L. There was no interference by bilirubin F, bilirubin C, chyle or hemoglobin. The correlation between currently used reagents was good with the correlation factor r = 0.990, but the correlation factor for IFCC reagent result was 1/3 lower, as determined with the regression equation y = 0.344x + 0.58. ALP isozyme analyses of seven samples using “Quick Gel ALP” manufactured by Helena showed a small divergence from the regression line and indicated that the ALP5 fraction was dominant (over 57%). The normal ALP activity range was calculated as 34–106 U/L. The results indicate that L-type Wako ALP·IFCC reagent has sufficient performance for routine testing.
