Performance Characteristics of the New Fully-Automated LC-MS/MS Total Vitamin D Assay on the CascadionTM SM Clinical Analyzer Marta Kozak (Presenter) Thermo Fisher Scientific

Authors: Bernardino Gutierrez (1), Mindy Gao (2), Justin Sturgess (3), Pratima Kayathi (4), Jasmine Villanueva (5), Marta Kozak (6)
Thermo Fisher Scientific, Fremont, California

The Cascadion Analyzer is an easy to use, random-access analytical platform implementing LC-MS/MS technology. Performance of the Vitamin D assay for the quantitation of 25-hydroxy Vitamin D3 and 25-hydroxy Vitamin D2 in human serum and plasma was evaluated according to CLSI guidelines. NIST standard reference materials and CDC certified serum samples were analyzed to evaluate accuracy. Precision, accuracy, linearity, limit of quantitation, absence epimer interference, and method robustness met accepted laboratory criteria. Sixteen types of collection tubes were qualified. A calibration curve stability of 2 weeks was demonstrated. A reference range was established using the US population.

Introduction

The Cascadion SM Clinical Analyzer was developed to provide an easy-to-use, random-access analyzer implementing Liquid Chromatography and Mass Spectrometry (LC-MS/MS) technology. The Vitamin D assay on the Cascadion SM Clinical Analyzer measures the levels of 25-hydroxy Vitamin D3 (VitD3) and 25-hydroxy Vitamin D2 (VitD2) in human serum and plasma. Patient samples, reagents, calibrators, and controls are loaded onto the instrument; the analyzer then separates Vitamin D from the epi-isomers chromatographically, and a triple quadrupole mass spectrometer quantitates the analytes. Results are generated at a throughput of 25 samples/hour.

Methods

The performance of the Cascadion SM 25-Hydroxy Vitamin D assay on the Cascadion Analyzer was characterized following CLSI guidelines.

Results

The obtained limits of quantitation were 3.4 ng/mL and analytical measurement ranges were from 3.4 ng/mL to 132 ng/mL for VitD2 and VitD3. Precision data was collected over 20 days and %CV results were less than 10% for samples ranging from 7.30 ng/mL to 84.37 ng/mL for total Vitamin D. Method comparison was performed by analyzing 117 CDC certified serum samples and the regression analysis showed a correlation coefficient (R) of 0.9969 and average % bias of 1.6% and 3.7% for VitD2 and VitD3, respectively. Analyte recoveries in patient serum samples spiked at concentrations of 30-70 ng/mL were 93.0-108.9% and 94.1-109.9% for VitD2 and VitD3, respectively. Carry-over was tested at a level of 200ng/mL; no carry-over was found. Forty-seven (47) compounds were tested for interference: Vitamin D metabolites, endogenous compounds, and over-the-counter medications. No interferences greater than 10% to Vitamin D levels were detected at interference concentrations specified by CLSI guidelines or predicate devices. Seven (7) types of serum collection tubes and 9 types of plasma collection tubes were evaluated and found to provide acceptable samples. Equivalency between serum and plasma samples was demonstrated in the same study.

The reference range of 7.96-53.09 ng/mL was established using a US population of male and female adults of diverse ethnic and racial background. Three (3) distinct climatic regions in different weather seasons were included in this study of 414 samples.

Stability of the calibration curve was measured by accuracy of QC samples; calibration was stable for fourteen (14) days.

Conclusions & Discussion

The performance study demonstrated that Cascadion SM Clinical Analyzer, developed for routine laboratory use, delivers 25-hydroxy Vitamin D results which meet or exceed accepted laboratory criteria for data quality.

Product not 510(k) cleared and not yet available for sale in the U.S.