Biological Variability of Plasma Intact and C-Terminal FGF23 Measurements
Edward R Smith, Michael M Cai, Lawrence P McMahon, Stephen G Holt
The Journal of Clinical Endocrinology & Metabolism | OXFORD UNIV PRESS INC | Published : 2012
CONTEXT: FGF23 measurement may have a role in the management of patients with chronic kidney disease (CKD). OBJECTIVE: Our objective was to study the biological variability of plasma intact FGF23 (iFGF23) and C-terminal FGF23 (cFGF23) concentrations. DESIGN: Plasma samples were taken from 12 healthy adults at multiple time points on 2 consecutive days to assess diurnal variability of FGF23 concentrations. Early-morning fasting and nonfasting samples were also taken over a 6-wk period to estimate components of biological variation. Samples from 170 volunteers were used to define reference intervals. FGF23 concentrations were measured by commercial ELISA. Western blotting was used to analyze F..View full abstract
We gratefully acknowledge the funding from the Sussex Kidney Unit and the Clinical Investigation and Research Unit, Brighton and Sussex University Hospitals, United Kingdom; the Department of Renal Medicine, Eastern Health Clinical School, Monash University, Australia; and an unrestricted research grant from Amgen.