New tubular injury markers in children with a solitary functioning kidney

Abstract

Background

The present study aimed to assess whether the urinary profiles of the lysosomal exoglycosidases N‑acetyl‑β‑hexosaminidase (HEX) and its isoenzymes A (HEX A) and B (HEX B), α-fucosidase (FUC), β-galactosidase (GAL), α-mannosidase (MAN), and β- glucuronidase (GLU) are useful biomarkers of tubular dysfunction in children with a solitary functioning kidney (SFK).

Methods

We measured the urinary activity of HEX, its isoenzymes HEX A, HEX B, and FUC, GAL, MAN, and GLU in 52 patients with SFK. Patients were subdivided into two groups: congenital SFK (cSFK)—unilateral renal agenesis and acquired SFK (aSFK)—unilateral nephrectomy. The reference group (RG) contained 60 healthy sex- and age-matched children.

Results

Urinary activity of all exoglycosidases in SFK was significantly higher than in RG ( p < 0.05). There were no differences in exoglycosidase activity between cSFK and aSFK ( p > 0.05). HEX and its isoenzymes HEX A and HEX B correlated negatively with estimated glomerular filtration rate (eGFR), and all estimated parameters correlated positively with albumin/creatinine ratio ( p < 0.001).

Conclusion

Urinary activity of HEX, its isoenzymes HEX A and HEX B, and FUC, GAL, MAN, and GLU is elevated in children with SFK. Long-term follow-up studies in larger groups of children with SFK may help us to better understand their clinical significance.