Immunoadsorption assay for bone alkaline phosphatase compared with wheat germ agglutinin precipitation assay in serum from (pre)pubertal girls.
The performance characteristics of two bone alkaline phosphatase (ALP; EC 3.1.3.1) assays, a wheat germ agglutinin (WGA) precipitation assay and a new immunoadsorption assay (IAA), were compared. The within- and between-run imprecision of the IAA (3.6-4.2% and 3.6-7.7%) was comparable with that of the WGA assay. The mean cross-reactivity with liver ALP appeared to be 4% in the WGA assay and 11% in the IAA. The reference ranges in a group of 155 healthy Caucasian (pre)pubertal schoolgirls were: 149-401 U/L (total ALP, 30 degrees C), 105-349 U/L (bone ALP, 30 degrees C, WGA assay), and 58-205 U/L (bone ALP, 25 degrees C, IAA). Comparison of the WGA assay (x) with the IAA (y) demonstrated a correlation coefficient of 0.95 [Deming regression equation: y = (0.56 +/- 0.01)x + (2.0 +/- 1.5); Sy[symbol: see text]x = 5.3 U/L]. Correlation studies of the WGA assay and the IAA results with total ALP demonstrated r = 0.98 and 0.96, respectively.
Bouman
A A
AA
Department of Clinical Chemistry, Free University Hospital, Amsterdam, The Netherlands. klinlab@azvu.nl
de Ridder
C M
CM
Nijhof
J H
JH
Netelenbos
J C
JC
Delemarre-vd Waal
H A
HA
D000469:Alkaline Phosphatase / Q000097:blood*; D001842:Bone and Bones / Q000201:enzymology*; D011232:Chemical Precipitation; D002648:Child; D005260:Female; D006801:Humans; D007163:Immunosorbent Techniques / Q000706:statistics & numerical data; D007527:Isoenzymes / Q000097:blood*; D008099:Liver / Q000201:enzymology; D012016:Reference Values; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D014909:Wheat Germ Agglutinins
D007527:Isoenzymes; D014909:Wheat Germ Agglutinins; D000469:Alkaline Phosphatase