Journal article

Publication year: 2020

Pages: 1731-1739

Journal: Clinical Chemistry and Laboratory Medicine

Volume number: 58

Issue number: 10

ISSN: 1434-6621

eISSN: 1437-4331

DOI Link: https://doi.org/10.1515/cclm-2020-0318

Publisher: De Gruyter

Abstract: 

Objectives: Our recent survey of 44 mass spectrometry laboratories across 17 countries identified variation in internal standard (IS) choice for the measurement of serum/ plasma 17 alpha-hydroxyprogesterone (17OHP) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The choice of IS may contribute to inter-method variations. This study evaluated the effect of two common isotopically labeled IS on the quantification of 17OHP by LC-MS/MS.

Methods: Three collaborating LC-MS/MS laboratories from Asia, Europe and Australia, who routinely measure serum 17OHP, compared two IS, (1) IsoSciences carbon-13 labeled 17OHP-[2,3,4-C-1(3)3], and (2) IsoSciences deuterated 17OHP-[2,2,4,6,6,21,21,21-H-2]. This was performed as part of their routine patient runs using their respective laboratory standard operating procedure.

Results: The three laboratories measured 99, 89, 95 independent samples, respectively (up to 100 nmol/L) using the C-13-and H-2-labeled IS. The slopes of the Passing-Bablok regression ranged 0.98-1.00 (all 95% confidence interval [CI] estimates included the line of identity), and intercept of <0.1 nmol/L. Average percentage differences of -0.04% to -5.4% were observed between the two IS materials, which were less than the optimal bias specification of 7% determined by biological variation, indicating no clinically significant difference. The results of 12 Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP) proficiency samples (1-40 nmol/L) measured by the laboratories were all within the RCPAQAP analytical performance specifications for both IS.

Conclusions: Overall, the comparison between the results of C-13- and H-2-labeled IS for 17OHP showed good agreement, and show no clinically significant bias when incorporated into the LC-MS/MS methods employed in the collaborating laboratories.

Harvard Citation style: Loh, T., Ho, C., Hartmann, M., Zakaria, R., Lo, C., van den Berg, S., et al. (2020) Influence of isotopically labeled internal standards on quantification of serum/plasma 17α-hydroxyprogesterone (17OHP) by liquid chromatography mass spectrometry, Clinical Chemistry and Laboratory Medicine, 58(10), pp. 1731-1739. https://doi.org/10.1515/cclm-2020-0318

APA Citation style: Loh, T., Ho, C., Hartmann, M., Zakaria, R., Lo, C., van den Berg, S., de Rijke, Y., Cooke, B., Hoad, K., Graham, P., Davies, S., Mackay, L., Wudy, S., & Greaves, R. (2020). Influence of isotopically labeled internal standards on quantification of serum/plasma 17α-hydroxyprogesterone (17OHP) by liquid chromatography mass spectrometry. Clinical Chemistry and Laboratory Medicine. 58(10), 1731-1739. https://doi.org/10.1515/cclm-2020-0318