Clinical interest in 25-OH Vitamin D has increased exponentially because of its usefulness in several pathologies, particularly in bone diseases. However, standardisation of assays remains a significant problem. Our laboratory has extensive experience in the development, evaluation and implementation of Vitamin D assays. With this background, we evaluated the performance of the novel Lumipulse® G 25-OH Vitamin D assay (Fujirebio), comparing results with a conventional assay (CLIA). This new assay is different from the current ones available on the market because it is the only method using a sandwich immunoassay instead of a competitive immunoassay approach and due to its unique VDBP release method (substitution instead of pretreatment method).
We tested randomly collected sera from 226 patients, covering the measuring range of 4-150 ng/mL. Both assays were compared using a proficiency panel of 20 samples (Labquality, Bioclin laboratory, Helsinki, Finland) that was quantified for 25-OH Vitamin D concentrations using Ghent University ID-LC/MS-MS (Reference Measurement Procedure). In addition, we compared the performance of the Lumipulse G and conventional CLIA assays with a VDSCP aligned LC-MS/MS in 20 routine samples.
The outcome of the evaluation was:
- Correlation between both commercial methods Liaison and Lumipulse G was high, with a correlation coefficient on 0.934 for all samples.
- The Lumipulse G 25-OH Vitamin D assay showed better correlation than the conventional CLIA assay with the LC/MS-MS reference method, being an accurate and precise automated tool for serum 25-OH Vitamin D measurements.
- The LUMIPULSE system was very easy to use and it demonstrated to be a very robust instrument, fulfilling the requirements for installation in clinical routine laboratories.
Laura Foj, Marina Parra and Xavier Filella
Department of Biochemistry and Molecular Genetics. Hospital Clínic, Barcelona