Maria Chiam (Presenter)
Biocrates Life Sciences AGBiocrates
Bio: Maria Chiam leads Business Development activities for Biocrates on the West Coast USA.She works with research institutes, biotech and pharma to utilize targeted metabolomics approaches to discover and validate metabolic signatures across a multitude of disease areas. Before she joined Biocrates she worked in early phase clinical trial research and drug development servicing research institutions, Biotech companies and world wide Pharma Companies to design clinical trial protocols for successful patient outcomes. Ms Chiam earned her Bachelor of Pharmacy from Monash University, Melbourne, Australia.
Authorship: Maria Chiam (1), Hai Pham Tuan (1), Therese Koal (1), Manfred Rauh (2)
(1) Biocrates Life Sciences AG, Innsbruck, Austria, (2) Universitätsklinikum Erlangen, Germany
| Short Abstract Interest in bile acids has been growing since the discovery of their significance, hormone-like regulatory factors acting via nuclear-farnesoid-X receptor (FXR), and G-protein-coupled plasma-membrane bound receptors (TGR5). Therefore, simultaneous quantitation of individual bile acids is of highly interest in many diseases, life-style, and clinical-related questions e.g. in nutrition, use of antibiotics, gut microbiome, metabolic syndrome, type 2 diabetes, Alzheimer´s disease, NAFLD or other liver related diseases. Standardization is mandatory to develop bile acid related biomarkers and to bring it into clinical routine application. Here, we describe the world-wide first bile acid assay in standardized format and will present the inter-laboratory ring trial data, method comparison and discuss their clinical relevance. |
Long Abstract
Bile acids, which are produced in liver and stored in bile duct, can be found in peripheral blood circulation. They can be used for diagnostic purposes towards for example hepatobiliary diseases and disorders. The reference concentration levels of individual bile acids in published literature are, however, incomplete and sometime contradicting due to the lack of standardized measurements of absolute concentrations. We introduced an inter-laboratory comparison study of a newly developed and standardized method for individual bile acids quantitation. The HPLC-MSMS based assay in a kit format, covering 16 bile acids in human and 19 bile acids in mouse, has been used to determine the reference concentrations range of individual bile acids in healthy adults.
Method
16 laboratories in Europe and North America were invited to join the comparison study. 4 labs have been excluded due to contempt of technical requirements. The remaining 12 labs have different MS platforms coupled with either HPLC (2/3 of the participants) or UHPLC front-end. Each has received a Bile Acids Kit to set up the assay and sample preparation procedure in its own lab. A set of 9 samples (3 each of human plasma, human serum and mouse plasma and at 3 different concentration levels: endogenous, spiked low and spiked high) has been measured in 4 replicates for the comparison purposes in accuracy and precision. The acceptance criteria for a lab to pass the ring trial were set as follows: 80% of reported values have to have accuracies within 70-130% range and precisions of replicates (CV) lower than 30%.
Plasma samples of 155 healthy individuals have been measured using the Bile Acids Kit to determine the reference concentration values. Additionally, method comparison to an established LC-MS/MS bile acid assay in clinical routine (Erlangen) was performed.
Result
12 participating labs have passed the acceptance criteria. 94% of the overall reported values have the accuracy within the range of 70-130%. When stricter ranges of accuracy are considers, 79% of reported values were within 80-120% accuracy and 65% within 85-115% accuracy, respectively. The precision criteria of replicate measurements (CV < 30%) has been fulfilled by 99% of the reported values. The percentage of reported values with CV lower than 20%, 15% and 10% were 96%, 91% and 73%, respectively. The average CV of all measurements was 8.3%.
The range of total bile acids content is 0.48-11.82 µmol/L with a median and average concentration of 3.81 µmol/L and 4.32 µmol/L, respectively. The ratio of glycine conjugated bile acids over taurine conjugated bile acids ranges from 1.65 to 19.48 with a median and average of 8.25 and 8.29, respectively. Excellent LC-MS/MS inter-method comparision was obtained.
Conclusion
The inter-laboratory ring trial showed very high accuracy and precision of the measurements of individual bile acids in human and mouse plasma samples, and that across a wide variety of LC-MS/MS platforms and at different locations. This proved that the first world-wide Bile Acids Kit is well suited for the standardization in measuring the absolute concentrations of individual bile acids. Based on this Kit, first reference concentration range of bile acids in healthy adult plasma samples has been established. Clinical relevant interesting diseases and samples will be presented as well.
References & Acknowledgements:
none
| Description | Y/N | Source |
| Grants | no | |
| Salary | yes | Biocrates |
| Board Member | no | |
| Stock | no | |
| Expenses | no |
IP Royalty: no
| Planning to mention or discuss specific products or technology of the company(ies) listed above: | yes |