IFCC primary reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 °C. Part 9: Reference procedure for the measurement of catalytic concentration of alkaline phosphatase

Abstract

This paper is the ninth in a series dealing with reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 °C and the certification of reference preparations. Other parts deal with: Part 1. The concept of reference procedures for the measurement of catalytic activity concentrations of enzymes; Part 2. Reference procedure for the measurement of catalytic concentration of creatine kinase; Part 3. Reference procedure for the measurement of catalytic concentration of lactate dehydrogenase; Part 4. Reference procedure for the measurement of catalytic concentration of alanine aminotransferase; Part 5. Reference procedure for the measurement of catalytic concentration of aspartate aminotransferase; Part 6. Reference procedure for the measurement of catalytic concentration of γ-glutamyltransferase; Part 7. Certification of four reference materials for the determination of enzymatic activity of γ-glutamyltransferase, lactate dehydrogenase, alanine aminotransferase and creatine kinase at 37 °C; Part 8. Reference procedure for the measurement of catalytic concentration of α-amylase. The procedure described here is derived from the previously described 30 °C IFCC reference method. Differences are tabulated and commented on in Appendix 1.

Progress and impact of enzyme measurement standardization

“…In the last 14 years, the IFCC has recommended RMPs for seven enzymes [12][13][14][15][16][17][18], which are now listed in the database of the Joint Committee on Traceability in Laboratory Medicine (JCTLM) [19]. Few enzyme reference materials (ERM) are also listed (for aspartate aminotransferase [AST], γ-glutamyltranspeptidase [γGT], and α-amylase [AMY]), whereas reproduction and characterization of new ERMs for alanine aminotransferase (ALT), creatine kinase (CK) and lactate dehydrogenase (LDH) are ongoing [20].…”

“…The introduction of enzyme reference measurement systems to provide traceable patient results have therefore been followed by the definition of traceable reference intervals to provide more congruent and effective information to clinicians. In particular, traceable reference intervals have been established for AST, ALT, γGT, LDH, CK, alkaline phosphatase (ALP), and AMY first in Caucasian adults and afterwards in Asian individuals [17,18,[22][23][24][25][26]. Table 1 reports a synopsis of traceable reference intervals for enzymes obtained in European and Asian subjects.…”

BCL11A gene DNA methylation contributes to the risk of type 2 diabetes in males

“…Plasma levels of TG and TC were measured using an enzymatic end point assay (29). Concentrations of ALT and blood glucose were measured using the International Federation of Clinical Chemistry reference measurement systems (30) and the glucose oxidase and peroxidase assay (31), respectively. UA levels were measured with a CX77 Analyzer (Beckman Coulter, Inc., Fullerton, CA, USA).…”

Standards for Reporting Enzyme Data: The STRENDA Consortium: What it aims to do and why it should be helpful

“…The IFCC has produced "several primary reference procedures" for the assay of such enzymes (see, e.g. Schumann et al, 2011), which provide complete assay details. Other researchers have a greater freedom to select assay conditions that they find convenient.…”

“…For example acetylthiocholine is frequently used to assay acetylcholinesterase (EC 3.1.1.7) because the thiocholine produced can be readily detected by reaction with sulfydryl reagent 5, 5 0 -dithiobis-2-nitrobenzoate (Nbs 2 ) releasing a yellow coloured compound whose formation can be followed spectrophotometrically at 412 nm (Ellman et al, 1961). Other examples include the use of 4-nitrophenyl phosphate to assay alkaline phosphatase (EC 3.1.3.1) (Schumann et al, 2011). The use of synthetic dyes as electron acceptors in oxidoreductase assays has been common and in some cases the physiological acceptor remains unknown.…”