Fibroblast Growth Factor 23 (FGF23) is an Early Specific Marker in the Diagnosis and Staging of Chronic Kidney Disease (CKD) in Human

Objective: To evaluate the clinical utility of serum FGF23 as an early specific biomarker in the diagnosis and progression of chronic kidney disease (CKD) patients.

Methods: A number of 120 male patients with CKD who were classified according to the eGFR into four stages (n=30 for each stage), in addition to 30 healthy control men were included.

Results: Patients in stage 2 of CKD did not show any significant difference in serum levels of urea and creatinine, and lactate dehydrogenase (LDH) activity. With the progression of CKD from stage 3 to stage 5, there were linear increases in the serum urea and creatinine levels, and LDH activity. There was a significant decrease in serum albumin and a significant elevation in creatine kinase in all CKD stages. There was a significant decrease in serum Ca2+ level in stages 2-4. Only patients in CKD stage 5 showed a significant elevation in serum phosphorus level. There were significant elevations in serum aminotransferases, C-reactive protein, and parathyroid hormone levels in stages 4 and 5. Serum testosterone level was significantly reduced in stages 3 and 4 as compared to control. With the progression of CKD stages from stage 2 to 5, there were linear significant elevations in serum TNF-a and FGF23 levels.

Conclusions: FGF23 was the most sensitive indicator in the early diagnosis and staging of CKD. Other biomarkers were elevated in the late stages in addition to their low specificity. Therefore, FGF23 could be used in the diagnosis and prognosis of CKD patients.