BACKGROUND: The predictor for the result of calcitriol therapy would be useful in the clinical practice of secondary hyperparathyroidism. Fibroblast growth factor-23 (FGF-23) is a newly found circulating phosphaturic factor. Its circulating level is elevated in uremia. METHODS: Dialysis patients with plasma intact parathyroid hormone (iPTH) levels greater than 300 pg/mL were included in the study. Calcitriol was intravenously injected three times a week. The patients whose plasma iPTH levels dropped below 300 pg/mL within 24 weeks were defined as those who had been successfully treated. A sandwich enzyme-linked immunosorbent assay (ELISA) system that detects human FGF-23 was applied. RESULTS: Sixty-two patients were analyzed. The pretreatment FGF-23 levels were related to the iPTH levels, calcium x phosphate product levels, and history of active vitamin D therapy. The pretreatment FGF-23, iPTH, and calcium levels were lower in the patients who would be successfully treated with calcitriol. A logistic regression study revealed that the pretreatment iPTH and FGF-23 levels significantly affected the therapy results. Analyses using a receiver-operated curve revealed that FGF-23 was the best screening test for identifying patients with future refractory response to calcitriol therapy. The treatment would be successful in 88.2% of those with FGF-23 </=9860 ng/L and iPTH </=591 pg/mL, while it would be successful in only 4.2% of those with FGF-23 >9860 ng/L and iPTH >591 pg/mL. CONCLUSION: Pretreatment serum FGF-23 levels were a good indicator in predicting the response to calcitriol therapy. The measurement of serum FGF-23 levels, especially in combination with iPTH levels, is a promising laboratory examination for the clinical practice of secondary hyperparathyroidism.
BACKGROUND: The predictor for the result of calcitriol therapy would be useful in the clinical practice of secondary hyperparathyroidism. Fibroblast growth factor-23 (FGF-23) is a newly found circulating phosphaturic factor. Its circulating level is elevated in uremia. METHODS: Dialysis patients with plasma intact parathyroid hormone (iPTH) levels greater than 300 pg/mL were included in the study. Calcitriol was intravenously injected three times a week. The patients whose plasma iPTH levels dropped below 300 pg/mL within 24 weeks were defined as those who had been successfully treated. A sandwich enzyme-linked immunosorbent assay (ELISA) system that detects humanFGF-23 was applied. RESULTS: Sixty-two patients were analyzed. The pretreatment FGF-23 levels were related to the iPTH levels, calcium x phosphate product levels, and history of active vitamin D therapy. The pretreatment FGF-23, iPTH, and calcium levels were lower in the patients who would be successfully treated with calcitriol. A logistic regression study revealed that the pretreatment iPTH and FGF-23 levels significantly affected the therapy results. Analyses using a receiver-operated curve revealed that FGF-23 was the best screening test for identifying patients with future refractory response to calcitriol therapy. The treatment would be successful in 88.2% of those with FGF-23 </=9860 ng/L and iPTH </=591 pg/mL, while it would be successful in only 4.2% of those with FGF-23 >9860 ng/L and iPTH >591 pg/mL. CONCLUSION: Pretreatment serum FGF-23 levels were a good indicator in predicting the response to calcitriol therapy. The measurement of serum FGF-23 levels, especially in combination with iPTH levels, is a promising laboratory examination for the clinical practice of secondary hyperparathyroidism.
Authors: James B Wetmore; Shiguang Liu; Ron Krebill; Rochelle Menard; L Darryl Quarles Journal: Clin J Am Soc Nephrol Date: 2009-11-05 Impact factor: 8.237
Authors: Katherine Wesseling-Perry; Renata C Pereira; Hejing Wang; Robert M Elashoff; Shobha Sahney; Barbara Gales; Harald Jüppner; Isidro B Salusky Journal: J Clin Endocrinol Metab Date: 2008-12-02 Impact factor: 5.958