Impact of assay design on test performance: lessons learned from 25-hydroxyvitamin D
Current automated immunoassays vary significantly in many aspects of their design. This study sought to establish if the theoretical advantages and disadvantages associated with different design formats of automated 25-hydroxyvitamin D (25-OHD) assays are translated into variations in assay performa...
Saved in:
Published in | Clinical chemistry and laboratory medicine Vol. 52; no. 11; pp. 1579 - 1587 |
---|---|
Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Germany
De Gruyter
01.11.2014
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Current automated immunoassays vary significantly in many aspects of their design. This study sought to establish if the theoretical advantages and disadvantages associated with different design formats of automated 25-hydroxyvitamin D (25-OHD) assays are translated into variations in assay performance in practice.
25-OHD was measured in 1236 samples using automated assays from Abbott, DiaSorin, Roche and Siemens. A subset of 362 samples had up to three liquid chromatography-tandem mass spectrometry 25-OHD analyses performed. 25-OHD
recovery, dilution recovery, human anti-animal antibody (HAAA) interference, 3-epi-25-OHD
cross-reactivity and precision of the automated assays were evaluated.
The assay that combined release of 25-OHD with analyte capture in a single step showed the most accurate 25-OHD
recovery and the best dilution recovery. The use of vitamin D binding protein (DBP) as the capture moiety was associated with 25-OHD
under-recovery, a trend consistent with 3-epi-25-OHD
cross-reactivity and immunity to HAAA interference. Assays using animal-derived antibodies did not show 3-epi-25-OHD
cross-reactivity but were variably susceptible to HAAA interference. Not combining 25-OHD release and capture in one step and use of biotin-streptavidin interaction for solid phase separation were features of the assays with inferior accuracy for diluted samples. The assays that used a backfill assay format showed the best precision at high concentrations but this design did not guarantee precision at low 25-OHD concentrations.
Variations in design among automated 25-OHD assays influence their performance characteristics. Consideration of the details of assay design is therefore important when selecting and validating new assays. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1434-6621 1437-4331 |
DOI: | 10.1515/cclm-2014-0111 |