Characteristics of a two-site immunoradiometric assay for human skeletal alkaline phosphatase in serum.
This two-site IRMA includes specific monoclonal antibodies for measuring skeletal alkaline phosphatase (B-ALP) in human serum. Assay calibration is based on mass units (micrograms per liter) and was established with purified B-ALP from a human osteosarcoma cell line, SAOS-2. Precision studies demonstrated intra- and interassay CVs of 3-5% and 5-7%, respectively. Relative reactivity studies showed that the assay has a sevenfold preference for detecting B-ALP compared with the liver isoenzyme in serum. The normal reference interval for 478 healthy adults was 5-22 micrograms/L. Method comparison studies showed good correlation between this B-ALP assay (y) and commercially available electrophoretic methods (x) (y = 0.3540x + 20.5, R2 = 0.929) in a pagetic population. Temporal profiles for total ALP, this IRMA B-ALP assay, and B-ALP by electrophoresis in three pagetic patients were parallel. We conclude that this assay demonstrates good analytical performance and would be useful for the clinical assessment of metabolic bone disorders.
Panigrahi
K
K
Department of Pathology, University of Maryland, School of Medicine, Baltimore 21201.
Delmas
P D
PD
Singer
F
F
Ryan
W
W
Reiss
O
O
Fisher
R
R
Miller
P D
PD
Mizrahi
I
I
Darte
C
C
Kress
B C
BC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000097:blood* / Q000737:chemistry; D000596:Amino Acids / Q000032:analysis; D001842:Bone and Bones / Q000201:enzymology*; D004586:Electrophoresis; D004795:Enzyme Stability; D005260:Female; D006801:Humans; D015592:Immunoradiometric Assay / Q000379:methods* / Q000706:statistics & numerical data; D007527:Isoenzymes / Q000097:blood* / Q000737:chemistry; D008099:Liver / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D010001:Osteitis Deformans / Q000201:enzymology; D012516:Osteosarcoma; D012016:Reference Values; D012680:Sensitivity and Specificity; D014407:Tumor Cells, Cultured
D000596:Amino Acids; D007527:Isoenzymes; D000469:Alkaline Phosphatase