Impact of FGF23 level on calcium and phosphorus levels in post-renal transplantation

Introduction: The level of fibroblast growth factor 23 (FGF23) may be considered as a prognostic factor for assessing renal function in regulating components of phosphate and vitamin D hemostasis. Objectives: The present study aimed to evaluate the prognostic value of FGF23 level to predict renal function after renal transplantation. Patients and Methods: Fifteen consecutive patients scheduled for renal transplantation. To assess renal function status, the MDRD formula and isotope scan were applied. The study endpoint was to assess the level of FGF23 and other factors involving calcium and phosphorus metabolism before and also 3 and 12 months after transplantation and also to determine role of FGF23 to predict postoperative renal function. Results: The mean level of FGF23 was 839.51 ± 694.56 ρg/mL at baseline that reduced to 44.31 ± 22.01 ρg/mL and 20.13 ± 36.50 ρg/mL, 3 and 12 months after initial assessment. The levels of FGF23 was significantly lower at 3 and 12 months after baseline (P = 0.01 and P = 0.02, respectively) with no difference in FGF23 level between the time points of 3 and 12 months after transplantation. Baseline level of FGF23 was found to be higher in the patients with higher glomerular filtration rate (GFR), in older patients, in males, in those patients with diabetic nephropathy, in those with acceptable renal function than in patients who suffered transplant rejection. Conclusion: The level of postoperative FGF23 is an important marker for secretion of phosphorus from kidneys emphasizing the central role of FGF23 marker to regulate calcium and phosphorus metabolism after a successful renal transplantation.