Differential Impacts of Intravenous Iron Administration and Iron-Containing Phosphate Binders on Serum Intact Fibroblast Growth Factor 23 Levels

2019 ◽  
Vol 47 (Suppl. 2) ◽  
pp. 63-69 ◽  
Author(s):  
Hirokazu Honda ◽  
Kenji Tanaka ◽  
Tetsuo Michihata ◽  
Keigo Shibagaki ◽  
Toshitaka Yuza ◽  
...  

Aims: This study assessed the impact of iron administration on serum fibroblast growth factor 23 (FGF23) levels. Methods: Of 123 hemodialysis (HD) patients treated with erythropoiesis-stimulating agents, 22 received once-weekly intravenous iron and 17 received daily oral iron with iron-containing phosphate binders. Intact FGF23 and biomarkers of iron metabolism were measured from blood samples drawn before each HD session, at baseline and on days 3, 5, 7, and 14. Results: Phosphate levels did not differ among the 3 groups during the 14-day period. Ferritin levels were significantly increased in both iron treatment groups compared with the non-iron treatment group, but changes in transferrin saturation levels were similar in the intravenous iron and non-iron groups. However, intact FGF23 levels were continuously higher in the intravenous iron group than those in the other groups. Conclusion: Intravenous iron administration may influence intact FGF23 levels in HD patients independently of phosphate and iron metabolism.

PLoS ONE ◽  
2017 ◽  
Vol 12 (5) ◽  
pp. e0176984 ◽  
Author(s):  
Hirokazu Honda ◽  
Tetsuo Michihata ◽  
Kanji Shishido ◽  
Keiko Takahashi ◽  
Go Takahashi ◽  
...  

2019 ◽  
Vol 20 (3) ◽  
pp. 695 ◽  
Author(s):  
André Mansinho ◽  
Arlindo R. Ferreira ◽  
Sandra Casimiro ◽  
Irina Alho ◽  
Inês Vendrell ◽  
...  

The fibroblast growth factor (FGF) signaling pathway plays a key role in tumorigenesis and is recognized as a potential therapeutic target. In this study, the authors aimed to assess the impact of serum FGF23 levels in the prognosis of patients with cancer and bone metastases from solid tumors. A cohort of 112 patients with cancer and metastatic bone disease were treated with bone-targeted agents (BTA). Serum baseline FGF23 was quantified by ELISA and dichotomized in FGF23high and FGF23low groups. Additionally, the association between FGF23 and overall survival (OS) and time to skeletal-related events (TTSRE) was investigated. Baseline characteristics were balanced between groups, except for the median urinary N-terminal telopeptide (uNTX) level. After a median follow-up of 26.0 months, a median OS of 34.4 and 12.2 months was found in the FGF23low and FGF23high groups, respectively (multivariate HR 0.18, 95% CI 0.07–0.44, p = 0.001; univariate HR 0.27, p = 0.001). Additionally, TTSRE was significantly longer for patients with FGF23low (13.0 vs 2.0 months, p = 0.04). Overall, this study found that patients with FGF23low at baseline had longer OS and TTSRE. Further studies are warranted to define its role as a prognostic biomarker and in the use of drugs targeting the FGF axis.


2020 ◽  
Vol 9 (8) ◽  
pp. 2640
Author(s):  
Bernhard Bielesz ◽  
Thomas Reiter ◽  
Fabian Peter Hammerle ◽  
Wolfgang Winnicki ◽  
Marija Bojic ◽  
...  

Anemia in chronic kidney disease (CKD) is an almost universal complication of this condition. Fibroblast growth factor 23 (FGF23), a key-player in mineral metabolism, is reportedly associated with anemia and hemoglobin levels in non-dialysis CKD patients. Here, we sought to further characterize this association while taking into account the biologically active, intact fraction of FGF23, iron metabolism, and erythropoietin (EPO). Hemoglobin, EPO, iron, and mineral metabolism parameters, including both intact and c-terminal-FGF23 (iFGF23 and cFGF23, respectively) were measured cross-sectionally in 225 non-dialysis CKD patients (stage 1–5, median eGFR: 30 mL/min./1.73m2) not on erythropoiesis stimulating agents or intravenous iron therapy. Statistical analysis was performed by multiple linear regression. After adjustment for eGFR and other important confounders, only cFGF23 but not iFGF23 was significantly associated with hemoglobin levels and this association was largely accounted for by iron metabolism parameters. cFGF23 but not iFGF23 was also associated with mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV), again in dependence on iron metabolism parameters. Similarly, EPO concentrations were associated with cFGF23 but not iFGF23, but their contribution to the association of cFGF23 with hemoglobin levels was marginal. In pre-dialysis CKD patients, the observed association of FGF23 with hemoglobin seems to be restricted to cFGF23 and largely explained by the iron status.


2017 ◽  
Vol 44 (2) ◽  
pp. 122-128 ◽  
Author(s):  
Nicholas Carlson ◽  
Ole H. Mortensen ◽  
Mette Axelsen ◽  
Robert S. Pedersen ◽  
James G. Heaf

Introduction: Fibroblast growth factor (FGF23), sclerostin, osteocalcin, and osteoprotegerin are important factors that control mineral bone metabolism. End-stage renal disease is associated with the pronounced dysregulation of mineral bone metabolism; however, the impact and clearance of mineral bone metabolism factors during dialysis remain largely undescribed. Methods: In a cross-sectional study, 10 chronic hemodialysis patients were treated with hemodialysis for 8 h using a high-flux filter and a dialysate bath of 50% calculated total body water continuously recycled at a rate of 500 mL/min. Plasma and dialysate concentrations of FGF23, sclerostin, osteoprotegerin, and osteocalcin were measured at 1, 2, 4, 6, and 8 h permitting the estimation of dialysis clearance. Results: Clearance of FGF23 was 7.7 mL/min, of sclerostin was 7.6 mL/min, of osteoprotegerin was 1.2 mL/min, and of osteocalcin was 19.7 mL/min. Clearance of FGF23 was correlated to sclerostin and osteoprotegerin clearance and also to the ultrafiltration rate. Although, osteocalcin blood concentrations decreased during dialysis, they rebounded within 6 h. Overall, no significant changes in blood concentrations of the measure mineral bone metabolism factors were observed. Conclusions: The intradialytic clearance of osteocalcin, FGF23, sclerostin, and osteoprotegerin occurs; however, only clearance of FGF23 is directly correlated with the ultrafiltration rate. The effects of dialytic clearance on mineral bone metabolism are, however, uncertain and intradialytic plasma concentrations of the studied substrates remained largely unchanged.


2019 ◽  
Author(s):  
Ludmilla Bär ◽  
Philipp Hase ◽  
Michael Föller

AbstractSerine/threonine protein kinase C (PKC) is activated by diacylglycerol that is released from membrane lipids by phospholipase C in response to activation of G protein-coupled receptors or receptor tyrosine kinases. PKC isoforms are particularly relevant for proliferation and differentiation of cells including osteoblasts. Osteoblasts/osteocytes produce fibroblast growth factor 23 (FGF23), a hormone regulating renal phosphate and vitamin D handling. PKC activates NFκB, a transcription factor complex controlling FGF23 expression. Here, we analyzed the impact of PKC on FGF23 synthesis. Fgf23 expression was analyzed by qRT-PCR in UMR106 osteoblastlike cells and in IDG-SW3 osteocytes. Phorbol ester 12-O-tetradecanoylphorbol-13-acetate (PMA), a PKC activator, up-regulated Fgf23 expression. In contrast, PKC inhibitors calphostin C, Gö6976, sotrastaurin and ruboxistaurin supressed Fgf23 gene expression. NFκB inhibitor withaferin A abolished the stimulatory effect of PMA on Fgf23. PKC is a powerful regulator of FGF23 synthesis, an effect which is at least partly mediated by NFκB.


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