Multicenter comparison of analytical interferences of 25-OH vitamin D immunoassay and mass spectrometry methods by endogenous interferents and cross-reactivity with 3-epi-25-OH-vitamin D3

Joon Hee Lee; Jong Do Seo; Kyunghoon Lee; Eun Youn Roh; Yeo-Min Yun; Yong-Wha Lee; Sung-Eun Cho; Junghan Song

doi:10.1016/j.plabm.2023.e00347

Multicenter comparison of analytical interferences of 25-OH vitamin D immunoassay and mass spectrometry methods by endogenous interferents and cross-reactivity with 3-epi-25-OH-vitamin D₃

Pract Lab Med. 2023 Dec 12:38:e00347. doi: 10.1016/j.plabm.2023.e00347. eCollection 2024 Jan.

Authors

Joon Hee Lee^{1

2}, Jong Do Seo³, Kyunghoon Lee^{1

2}, Eun Youn Roh^{1

4}, Yeo-Min Yun³, Yong-Wha Lee⁵, Sung-Eun Cho⁶, Junghan Song^{1

2}

Affiliations

¹ Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, South Korea.
² Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
³ Department of Laboratory Medicine, Konkuk University School of Medicine, Seoul, South Korea.
⁴ Department of Laboratory Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, South Korea.
⁵ Department of Laboratory Medicine & Genetics, Soonchunhyang University Bucheon Hospital, Bucheon, South Korea.
⁶ Department of Endocrine Substance Analysis Center (ESAC), Green Cross Laboratories (GC Labs), Yongin, South Korea.

Abstract

Background: Vitamin D (vit-D) deficiency is highly prevalent in the Korean population, highlighting the need for accurate measurements. In this study, the interferences by endogenous and cross-reactive substances were compared between routine vit-D immunoassays and mass spectrometry (MS) methods.

Methods: Two MS methods and 4 immunoassays from different manufacturers (Abbott, Beckman Coulter, Roche, Siemens) were compared. Residual samples that were icteric, lipemic, hemolyzed, high in rheumatoid factor, from myeloma patients, or patients undergoing hemodialysis were collected. Also, 4 levels of National Institute of Standards and Technology (NIST) Standard Reference Material 972a, and 12 samples serially spiked with 3-epi-25-OH-D₃ were prepared.

Results: Significant interferences were observed in hemolytic (Roche), icteric (Beckman and Siemens) and lipemic samples (all 4 immunoassays). Level 4 NIST material and 3-epi-25-OH-D₃-spiked samples induced significant cross-reactivity, yielding higher total vit-D measurements in non-epimer-separating MS methods, and both the Beckman and Roche immunoassays.

Conclusion: Most observed interferences were consistent with manufacturers' claims, but overall improvement of immunoassay bias limits is required. Awareness of potential interference is important to increase the accuracy of vit-D measurements. Moreover, care is due when interpreting vit-D results of newborns, infants and less commonly, pregnant women, who are known to have physiologically high levels of the highly cross-reactive 3-epi-25-OH-D₃.

Keywords: 3-epi-25-OH-Vitamin D3; Analytical interference; Immunoassay; Mass spectrometry; Vitamin D.