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.
|2021||Cavalier E, Eastell R, Jørgensen NR, Makris K, Tournis S, Vasikaran S, Kanis JA, Cooper C, Pottel H, Morris HA; IFCC-IOF Committee for Bone Metabolism (C-BM). A multicenter study to evaluate harmonization of assays for -terminal telopeptides of type I collagen (ß-CTX): a report from the IFCC-IOF committee for bone metabolism (C-BM) [published correction appears in Calcif Tiss Int. June 2021;108(6):825-826]. Calcif Tiss Int. June 2021;108(6):785-797.|
|2020||Cavalier E, Lukas P, Bottani M, Aarsand AK, Ceriotti F, Coşkun A, Díaz-Garzón J, Fernàndez-Calle P, Guerra E, Locatelli M, Sandberg S, Carobene A; European Federation of Clinical Chemistry and Laboratory Medicine Working Group on Biological Variation; IOF-IFCC Committee on Bone Metabolism. European Biological Variation Study (EuBIVAS): within- and between-subject biological variation estimates of β-isomerized C-terminal telopeptide of type I collagen (β-CTX), N-terminal propeptide of type I collagen (PINP), osteocalcin, intact fibroblast growth factor 23 and uncarboxylated-unphosphorylated matrix-Gla protein: a cooperation between the EFLM Working Group on Biological Variation and the International Osteoporosis Foundation-International Federation of Clinical Chemistry Committee on Bone Metabolism. Osteoporos Int. August 2020;31(8):1461-1470.|