Fibroblast growth factor 23 (FGF-23) and chronic kidney disease in children

Chronic kidney disease (CKD) in children is a complex medical and social problem in healthcare. One of the serious complications is mineral bone disorder (MBD), the pathogenesis of which is related to a new biomarker of bone origin - fibroblast growth factor 23 (FGF-23). The aim. To study the features of fibroblast growth factor 23 (FGF-23) in children with chronic kidney disease. Material and methods. A cross-sectional study was carried out on 73 children with CKD and 14 healthy children. Inclusion criteria: chronic kidney disease stage 1-5, written informed consent of the participants. The exclusion criteria: tubulopathy, infectious and inflammatory processes, oncological diseases, kidney transplant, condition after surgery, taking glucocorticosteroids, calcium and vitamin D drugs. We took fasting blood samples of participants and carried out an enzyme-linked immunosorbent assay in order determine the level of FGF-23 (Biomedica Medizinprodukte GmbH, Austria). The obtained data were analyzed using IBM SPSS, version 22 (New York, USA). Results and discussion. In healthy children, the median (Q1-Q3) level of FGF-23 in serum was 0.65 (0.22-0.98) pmol/l, in patients with stage 1 CKD it was 0.65 (0.22-1.08) pmol/l. At stage 2, the level of FGF-23 significantly increased in comparison with healthy individuals and with patients of stage 1, p≤0.05. Further, there is a gradual increase by stages, p≤0.05. Thus, in stage 3 patients, the median FGF-23 value was 1.9 (1.15-3.5) pmol/l, at stage 4 - 3.55 (2.48-6.35) pmol/l, at 5 stages - 14 (7.5-18.75) pmol/l. As a percentage, there were 7.1% of patients at the stage 1 with increased levels of phosphatonin, at stage 2 - 53.3%, at stage 3 - 69.2%, respectively. At stages 4 and 5, absolutely 100% of patients had high levels of FGF-23. At the same time, FGF-23 did not depend on gender, age, birth weight and type of renal replacement therapy at stage 5, p>0.05. Conclusions. Thus, in our study, we determined the features of changes FGF-23 in serum in children at various stages of CKD. The obtained results allow us to consider FGF-23 as a predictor of the clinical course of CKD. Keywords: fibroblast growth factor 23, phosphatonin, pediatric nephrology, chronic kidney disease, mineral-bone disorder.