Determination of the elimination half-life of fibroblast growth factor-23.
BACKGROUND
Tumor-induced osteomalacia (TIO) is a rare paraneoplastic disease caused by mesenchymal tumors that secrete fibroblast growth factor-23 (FGF-23), a newly-described vitamin D and phosphate-regulating hormone. Surgical removal of the tumor, the ectopic source of circulating FGF-23, offers the opportunity to determine the elimination half-life of FGF-23.


OBJECTIVE
The aim of the study was to determine the elimination half-life of FGF-23.


METHODS
The tumors were removed from three patients with TIO, and serum samples were taken every 30 min for up to 72 h after the operation. FGF-23 was measured by both a C-terminal/intact assay and an intact assay, and the elimination half-life was determined by one phase exponential decay methodology.


METHODS
The Mark O. Hatfield Clinical Research Center of the National Institutes of Health, a tertiary referral clinical research center, was the setting for the study.


RESULTS
The elimination life of FGF-23 as determined by C-terminal/intact and intact assays was 46 +/- 12 and 58 +/- 34 min, respectively.


CONCLUSIONS
The plasma half-life of serum FGF-23 is in the range of 46-58 min.
Khosravi
Azarmindokht
A
Skeletal Clinical Studies Unit, Craniofacial and Skeletal Diseases Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4320, USA.
Cutler
Carolee M
CM
Kelly
Marilyn H
MH
Chang
Richard
R
Royal
Richard E
RE
Sherry
Richard M
RM
Wodajo
Felasfa M
FM
Fedarko
Neal S
NS
Collins
Michael T
MT
D000328:Adult; D001859:Bone Neoplasms / Q000097:blood / Q000150:complications / Q000378:metabolism / Q000601:surgery; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010018:Osteomalacia / Q000097:blood / Q000209:etiology*; D010257:Paraneoplastic Syndromes / Q000097:blood / Q000150:complications*; D011184:Postoperative Period; D012983:Soft Tissue Neoplasms / Q000097:blood* / Q000150:complications* / Q000378:metabolism / Q000601:surgery; D013997:Time Factors
C000717427:FGF23 protein, human; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23