Abstract

Objectives

Vitamin D-binding protein (VDBP), retinol-binding protein (RBP)4, and heat shock proteins (hsp) are markers of tubular function and apoptosis, accompanying chronic kidney disease (CKD) from its earliest stages. Fractional excretion of proteins with urine is a marker of tubular damage. The aim of study was to assess the usefulness of fractional excretion (FE) of VDBP, RBP4, HSF1 and Hsp27 as markers of tubular damage in the course of CKD.

Methods

The study group consisted of 70 children with CKD stages 1–5, treated conservatively, and 12 age-matched controls with normal kidney function. The serum and urine concentrations of VDBP, RBP4, HSF1 and Hsp27 were assessed by ELISA. The fractional excretion of analyzed parameters was calculated according to the formula: ([parameter urine concentration]?×?[creatinine serum concentration])?/?([parameter serum concentration]?×?[creatinine urine concentration])×100%.

Results

The FE values of all parameters exceeded 1% in CKD stage 2. However, the values of FE have raised significantly versus control group no sooner than CKD stage 2 (RBP4 and HSF1), stage 3 (VDBP) or stage 4 (Hsp27).

Conclusion

Fractional excretion of RBP4 and HSF1 with urine may become a valuable marker, assessing the damage of tubular cells in children with CKD.