Clusterin as a New Marker of Kidney Injury in Children Undergoing Allogeneic Hematopoietic Stem Cell Transplantation—A Pilot Study

Abstract

Background and aims: The markers of renal damage defining subclinical AKI are not widely used in children undergoing allogeneic hematopoietic stem cell transplantation (alloHSCT). The aim of the study was to evaluate serum and urinary clusterin as indices of kidney injury after alloHSCT in relation to damage (kidney injury molecule (KIM)-1) and functional (cystatin C) markers. Material and methods: Serum and urinary clusterin, KIM-1 and cystatin C concentrations were assessed by ELISA in 27 children before alloHSCT, 24 h, 1, 2, 3 and 4 weeks after alloHSCT and in controls. Results: All parameters were significantly higher in HSCT patients compared to controls even before the transplantation. The serum concentrations increased after HSCT and this rising trend was kept until the third (clusterin) or 4th (KIM-1, cystatin C) week. Urinary clusterin and KIM-1 were elevated until the third week and then decreased yet remained higher than before HSCT. Urinary cystatin C has risen from the second week after HSCT and decreased after the third week but was still higher than before alloHSCT. Conclusions: The features of kidney injury are present even before alloHSCT. Clusterin seems useful in the assessment of subclinical AKI and may become a new early marker of sublethal kidney injury in children.

Current Concepts of Pediatric Acute Kidney Injury—Are We Ready to Translate Them into Everyday Practice?

“…Of note, the percentage of children with increased eGFR values was the highest among those who have undergone HSCT for oncological reasons. Moreover, urinary concentrations of tubular damage markers in these patients were significantly higher than in the age-matched healthy controls, even before HSCT, and rose after the procedure [ 41 ]. These observations suggested that children undergoing HSCT most probably approach this procedure with already diminished renal functional reserve.…”

The Impact of Allogeneic Hematopoietic Stem Cell Transplantation on Kidney Function in Children—A Single Center Experience

“…Irrespective of the background, in practice, any potential sign of kidney injury during this early period would have been masked if serum creatinine had been the only marker evaluated. The hypothesis on possible renal injury in this early period was partly confirmed by our preliminary study assessing various indices in the early post-transplantation period [ 18 ].…”

“…Summarizing, the presented results give way to strong suggestion that an additional method of renal function assessment (especially in the early period after alloHSCT) is needed for this particular group of patients. Probably, the use of renal damage markers will become obligatory, but their role in pediatric HSCT is yet to be established [ 17 , 18 ].…”

“…The existence of such discrepancies triggers the search for new markers of early kidney injury in this population [ 17 ]. Our previous study in children undergoing allogeneic hematopoietic stem cell transplantation (alloHSCT) concerned the assessment of classical markers of kidney function (serum creatinine, cystatin C) in confrontation with known (urinary kidney injury molecule (KIM)-1) and new (urinary clusterin) damage markers [ 18 ]. The urinary concentrations of examined indices showed elevation already before alloHSCT when serum creatinine was normal.…”

“…The urinary concentrations of examined indices showed elevation already before alloHSCT when serum creatinine was normal. Moreover, this elevation of damage markers continued, or was even aggravated, just after transplantation, and persisted until the 2nd–4th week [ 18 ].…”