A WHO Reference Reagent for the Serum Transferrin Receptor (sTfR): international collaborative study to evaluate a recombinant soluble transferrin receptor preparation

Autor: Giles Sharp, Richard Ellis, Alan Heath, Susan J. Thorpe, James D. Cook, Mark Worwood
Rok vydání: 2010
Předmět:
Zdroj: cclm. 48:815-820
ISSN: 1437-4331
1434-6621
DOI: 10.1515/cclm.2010.167
Popis: Background: The usefulness of serum transferrin receptor (sTfR) as a marker of iron deficiency is limited by lack of standardization of commercial immunoassays for sTfR. An international collaborative study was performed to evaluate a lyophilized preparation of recombinant soluble transferrin receptor (rsTfR) for its suitability to serve as a World Health Organization (WHO) Reference Reagent to standardize immunoassays for sTfR. Methods: The concentration of pure rsTfR was determined from the A280 nm using the adjusted theoretical extinction coefficient and molecular weight calculated from its sequence, before dilution and lyophilization in a sTfR-depleted serum matrix. Six manufacturers and a health protection laboratory assayed the candidate Reference Reagent, coded 07/202, along with three lyophilized serum samples, using commercial assays for sTfR. Results: Dose-response plots demonstrated acceptable overall parallelism between 07/202, manufacturers' in-house standards, and serum samples. However, there was poor agreement on the estimated (r)sTfR content of 07/202 and serum samples. Expressing the sTfR content of the serum samples relative to 07/202 markedly improved agreement between methods. Conclusions: Use of 07/202 would reduce inter-method variability. The preparation was established as the 1st WHO Reference Reagent for sTfR with assigned free rsTfR monomer values of 21.7 mg/L and 303 nmol/L (0.5 mL reconstitution). Clin Chem Lab Med 2010;48:815–20.
Databáze: OpenAIRE
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