Fibroblast growth factor 23 and α-Klotho serum concentration did not differ between children with autosomal dominant polycystic kidney disease and healthy controls

Introduction
Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited monogenous kidney disease that can also be seen in children. One of the indicators of changes in metabolism in ADPKD children according to the novel knowledge are fibroblast growth factor 23 (FGF-23) and -Klotho protein.

Aim
To observe whether children who suffer from ADPKD whilst preserving normal kidney function (eGFR > 90 ml/min/1.73 m²) have any changes in the concentration of FGF-23 and Klotho protein along with the growth of renal volume.

Material and methods
The study was a cross-sectional analysis of 70 children aged from 1 to 18.8 years. FGF-23 and Klotho were measured by the ELISA tests. Clinical and laboratory analysis comprised the following: ultrasound measurement of the total kidney volume (TKV), eGFR calculation, serum calcium, phosphate, and urinary albumin excretion.

Results
Serum concentration of FGF-23 did not differ between children suffering from ADPKD and the control group (27.77 pg/ml vs. 24.15 pg/ml; p = 0.96). -Klotho concentrations were also similar (1650 pg/ml vs. 1440 pg/ml; p = 0.14) between both groups. Klotho correlated significantly with FGF-23 (Rs = 0.55; p = 0.000002) and eGFR (Rs = 0.25; p = 0.039566). No significant relation was detected between FGF-23 or Klotho concentration and albumin excretion, TKV, age, or anthropometric measures.

Conclusions
FGF-23 and -Klotho concentration did not differ significantly between children suffering from ADPKD and the control group.