FGF23 in Acute Kidney Injury

Acute kidney injury (AKI) – also called acute renal failure –  occurs when the kidneys suddenly fail to function due to an injury medication, or an infection. It happens within a few hours or days and is usually accompanied with other medical conditions e.g. blood vessel blockage, diabetes, heart failure, kidney and liver disease, hospitalization (ICU) and other.

FGF23 in Acute Kidney Injury

Fibroblast growth factor 23 (FGF23) is a bone derived hormone that regulates renal phosphate excretion in the kidney. In kidney disease, when the function of the kidney declines, serum phosphate levels rise which subsequently leads to the secretion of FGF-23. High phosphate levels are also common in patients with acute kidney injury (AKI) (1).

FGF23 marker of adverse outcomes in acute kidney injury 

 Fibroblast growth factor 23 (FGF23) levels rise rapidly with acute kidney injury and are associated with the requirement for renal replacement therapy (1-4). FGF-23 levels also have prognostic utility as shown in a large study in over 1500 patients with AKI (3).

Most studies measuring elevated FGF23 levels in AKI patients are performed using FGF23 (C-terminal) assays, which detect intact and C-terminal FGF23. Although the results mirror an increase of FGF23 production they may not necessarily reflect the bioactivity of FGF23 (5).

Quantifying circulating FGF23 levels

Circulating FGF23 levels include the bioactive intact hormone (iFGF23) and the inactive N-terminal and C-terminal fragments. FGF23 can be measured with two commercially available assay types (6). The C-terminal FGF23 assay captures both intact and the c-terminal fragments of FGF23, which result after cleavage. The intact FGF23 assay utilizes antibodies that are located in the N-terminal and in the C-terminal region of the FGF23 hormone, thus capturing only biologically active intact FGF23.

Learn more:  FGF23 – an Overview

BIOMEDICA offers quality FGF23 assays for serum & plasma samples

 

FGF23 (c-terminal) ELISA, cat. no. BI-20702

FGF23 intact ELISA, cat no. BI-20700

 

• developed & manufactured by Biomedica , Austria
• fully validated
• numerous top journal citations

 

Literature

1. Fibroblast Growth Factor 23 and Klotho in AKI. Christov M, Neyra JA, Gupta S, Leaf DE. Semin Nephrol. 2019 Jan;39(1):57-75. doi: 10.1016/j.semnephrol.2018.10.005. PMID: 30606408. 
2. Fibroblast Growth Factor 23 Regulation and Acute Kidney Injury. Zhou W, Simic P, Rhee EP. Nephron. 2022;146(3):239-242. doi: 10.1159/000517734. Epub 2021 Jul 20. PMID: 34284404; PMCID: PMC8770696. 
3. Fibroblast growth factor 23 associates with death in critically ill patients. Leaf DE, Siew ED, Eisenga MF, Singh K, Mc Causland FR, Srivastava A, Ikizler TA, Ware LB, Ginde AA, Kellum JA, Palevsky PM, Wolf M, Waikar SS, Am Clin J Am Soc Nephrol. 2018. 13(4):531–41. 
4. FGF-23 levels in patients with AKI and risk of adverse outcomes. Leaf DE, Wolf M, Waikar SS, Chase H, Christov M, Cremers S, Stern L. Clin J Am Soc Nephrol. 2012. 7(8):1217-23. 
5. Fibroblast Growth Factor 23 and αKlotho in Acute Kidney Injury: Current Status in Diagnostic and Therapeutic Applications. Neyra JA, Hu MC, Moe OW. Nephron. 2020;144(12):665-672. doi: 10.1159/000509856. Epub 2020 Aug 25. PMID: 32841947; PMCID: PMC7708396. 
6. The Measurement and Interpretation of Fibroblast Growth Factor 23 (FGF23) Concentrations. Heijboer AC, Cavalier E. Calcif Tissue Int. 2023. 112(2):258-270.