Quality of interpretative commenting on common clinical chemistry results in the Asia-Pacific region and Africa

10.1515/CCLM.2009.225Clinical Chemistry and Laboratory Medicine478963-970CCLM

Butyrylcholinesterase K variant and Alzheimer's disease

This study attempted to corroborate findings on the association between butyrylcholinesterase K variant and Alzheimer’s disease. This was performed on an autopsy-confirmed series of patients with Alzheimer’s disease and controls. The butyrylcholinesterase K variant was found to be of increased allele frequency in patients with sporadic Alzheimer’s disease. When related to APOE ɛ4 typing the association was specific but not sensitive for the diagnosis of Alzheimer’s disease

Recommendations on the measurement and the clinical use of vitamin D metabolites and vitamin D binding protein – A position paper from the IFCC Committee on bone metabolism

Vitamin D, an important hormone with a central role in calcium and phosphate homeostasis, is required for bone and muscle development as well as preservation of musculoskeletal function. The most abundant vitamin D metabolite is 25-hydroxyvitamin D [25(OH)D], which is currently considered the best marker to evaluate overall vitamin D status. 25(OH)D is therefore the most commonly measured metabolite in clinical practice. However, several other metabolites, although not broadly measured, are useful in certain clinical situations. Vitamin D and all its metabolites are circulating in blood bound to vitamin D binding protein, (VDBP). This highly polymorphic protein is not only the major transport protein which, along with albumin, binds over 99% of the circulating vitamin D metabolites, but also participates in the transport of the 25(OH)D into the cell via a megalin/cubilin complex. The accurate measurement of 25(OH)D has proved a difficult task. Although a reference method and standardization program are available for 25(OH)D, the other vitamin D metabolites still lack this. Interpretation of results, creation of clinical supplementation, and generation of therapeutic guidelines require not only accurate measurements of vitamin D metabolites, but also the accurate measurements of several other “molecules” related with bone metabolism. IFCC understood this priority and a committee has been established with the task to support and continue the standardization processes of vitamin D metabolites along with other bone-related biomarkers. In this review, we present the position of this IFCC Committee on Bone Metabolism on the latest developments concerning the measurement and standardization of vitamin D metabolites and its binding protein, as well as clinical indications for their measurement and interpretation of the results. © 2021 Elsevier B.V

Harmonization of commercial assays for PINP; the way forward

Summary: International Federation of Clinical Chemistry and Laboratory Medicine and The International Osteoporosis Foundation Joint Committee on Bone Metabolism believes that the harmonization of PINP assays is an achievable and practical goal. Introduction: In order to examine the agreement between current commercial assays, a multi-center study was performed for PINP in serum and plasma. Methods: The automated methods for PINP (Roche Cobas and IDS iSYS) gave similar results. A significant proportional bias was observed between the two automated assays and the Orion radioimmunoassay (RIA) for PINP. Results: Results from other published studies comparing PINP values among these three assays broadly support our findings. Taken together, these results confirm that harmonized PINP measurements exist between the two automated assays (Roche Cobas and IDS iSYS) when the eGFR is > 30 mL/min/1.73m2, but a significant bias exists between the Orion RIA and the two automated assays. Conclusion: Therefore, in subjects with normal renal function, PINP results reported by the Roche Cobas and IDS iSYS assays are similar and may be used interchangeably, and similar reference intervals and treatment targets could be applied for the two automated assays. Harmonization between the automated assays and the RIA is potentially possible with the use of common calibrators and the development of a reference method for PINP. This should also help ensure that any new commercial assay developed in the future will attain similar results. IOF and IFCC are committed to working together towards this goal with the cooperation of the reagent manufacturing industry. © 2020, International Osteoporosis Foundation and National Osteoporosis Foundation