Discrepancy between Vitamin D Total Immunoassays due to Various Cross-reactivities.
10.11005/jbm.2015.22.3.107
- Author:
Jun Hyung LEE
1
;
Jee Hye CHOI
;
Oh Joo KWEON
;
Ae Ja PARK
Author Information
1. Department of Laboratory Medicine, Chung-Ang University College of Medicine, Seoul, Korea. ajcp@cau.ac.kr
- Publication Type:Original Article
- Keywords:
Cross reactions;
Immunoassay;
Reference standards;
Vitamin D
- MeSH:
Cross Reactions;
Delivery of Health Care;
Immunoassay*;
Reference Values;
Vitamin D*;
Vitamins*
- From:Journal of Bone Metabolism
2015;22(3):107-112
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: The purpose of this study was to find out the cause of discrepancy between various automated immunoassays for 25-hydroxy-vitamin D (25-[OH]D). METHODS: National Institute of Standards & Technology Standard Reference Material (SRM) 972a is SRM for 25-(OH)D and consists of 4 vials of frozen serum with different concentrations of 25-(OH)D. Each concentration was measured 6 times in 3 different immunoassays: ADVIA Vitamin D Total assay (Siemens Healthcare, Erlangen, Germany), ARCHITECT 25-(OH)D (Abbott Laboratories, Abbott Park, IL, USA), and COBAS Vitamin D Total assay (Roche Diagnostics, Basel, Switzerland). RESULTS: When using the certified reference values of SRM 972a as it is, discarding the cross-reactivity of each immunoassay, for ADVIA, the coefficient of determination (R2) as a score of regression analysis was 0.8995 and maximal difference between measured value and certified reference value was 3.6 ng/mL in level 3. The R2 and maximal differences of ARCHITECT were 0.5377 and 6.9 ng/mL, respectively, in level 4. Those of COBAS were 0.3674 and 22.3 ng/mL, respectively, in level 4. When considering cross-reactivities of each immunoassays to various 25-(OH)D metabolites, the ADVIA had R2 and maximal difference of 0.9254 and 3.3 ng/mL, respectively, in level 3. For ARCHITECT, the R2 and maximal differences were 0.7602 and 5.1 ng/mL, respectively, in level 1. Those of COBAS were 0.9284 and 4.9 ng/mL, respectively, in level 1. CONCLUSIONS: The cause of discrepancies between vitamin D immunoassays was mainly on the difference in cross-reactivities to various vitamin D metabolites. The discrepancies can be considerably decreased by considering cross-reactivities of each immunoassay.
