TY - JOUR
T1 - Plasma calcium oxalate supersaturation in children with primary hyperoxaluria and end-stage renal failure
AU - Hoppe, Bernd
AU - Kemper, Markus J.
AU - Bökenkamp, Arend
AU - Portale, Anthony A.
AU - Cohn, Richard A.
AU - Langman, Craig B.
N1 - Funding Information: This work was supported in part by a grant of the Deutsche Forschungsgemeinschaft (Ho 1272/4-1) and a grant from the McNulty Foundation to the Bone and Mineral Research Fund at Children’s Memorial Hospital. We thank the nurses of the dialysis units at the participating hospitals for their outstanding support.
PY - 1999
Y1 - 1999
N2 - Plasma calcium oxalate supersaturation in children with primary' hyperoxaluria and end-stage renal failure. Background. Children with primary hyperoxaluria type 1 (PH 1) are at great risk to develop systemic oxalosis in endstage renal disease (ESRD), as endogenous oxalate production exceeds oxalate removal by dialytic therapy. As oxalate accumulates, calcium oxalate (CaOx) tissue deposition occurs. Children with other causes of ESRD, however, are not prone to CaOx deposition despite elevated plasma oxalate (P(ox)) levels. Methods. Our study objective was to examine the potential mechanisms for these observations. We measured P(ox), sulfate, citrate, and calculated CaOx saturation (β(Ca,Ox)) in 7 children with ESRD caused by PH 1 and in 33 children with nonPH-related ESRD. Maintenance hemodialysis (HD) was performed in 6 PH 1 and 22 non-PH patients: Pre- and post-HD levels were analyzed at this point and were repeated twice within 12 months in 5 PH1 and 14 non-PH patients. Samples were obtained only once in 12 patients (one PH 1) on peritoneal dialysis (PD). After liver-kidney or kidney transplantation, plasma levels were measured repetitively. Results. The mean P(Ox) was higher in PH 1 (125.7 ± 17.9 μol/liter) than in non-PH patients (44.2 ± 3.3 μol/liter, P < 10-4). All other determined anions did not differ between the two groups, β(CaOx) was higher in PH 1 (4.71 ± 0.69 relative units) compared with non-PH children (1.56 ± 0.12 units, P < 10-4). P(Ox) and β(CaOx) were correlated in both the PH 1 (r = 0.98, P < 2 X 10-4) and the non-PH group (r = 0.98, P < 10-4). P(Ox) and β(CaOx) remained stable over time in the non-PH children, whereas an insignificant decline was observed in PHI patients after six months of more aggressive dialysis, β(CaOx) was supersaturated (more than 1) in all PH 1 and in 25 out of 33 non-PH patients. Post-HD β(CaOx) remained more than 1 in all PH 1, but in only 2 out of 22 non-PH patients. In non-PH children, P(Ox) and β(CaOx) decreased to normal within three weeks after successful kidney transplantation, whereas the levels still remained elevated seven months after combined liver-kidney transplantation in two PH 1 patients. Conclusion. Systemic oxalosis in PH 1 children with ESRD is due to higher P(Ox) and β(CaOx) levels. As β(CaOx) remained supersaturated in PH 1 even after aggressive HD, oxalate accumulation increases, and CaOx tissue deposition occurs. Therefore, sufficient reduction of P(Ox) and β(CaOx) is crucial in PH 1 and might only be achieved by early, preemptive, combined liver-kidney transplantation or liver transplantation alone.
AB - Plasma calcium oxalate supersaturation in children with primary' hyperoxaluria and end-stage renal failure. Background. Children with primary hyperoxaluria type 1 (PH 1) are at great risk to develop systemic oxalosis in endstage renal disease (ESRD), as endogenous oxalate production exceeds oxalate removal by dialytic therapy. As oxalate accumulates, calcium oxalate (CaOx) tissue deposition occurs. Children with other causes of ESRD, however, are not prone to CaOx deposition despite elevated plasma oxalate (P(ox)) levels. Methods. Our study objective was to examine the potential mechanisms for these observations. We measured P(ox), sulfate, citrate, and calculated CaOx saturation (β(Ca,Ox)) in 7 children with ESRD caused by PH 1 and in 33 children with nonPH-related ESRD. Maintenance hemodialysis (HD) was performed in 6 PH 1 and 22 non-PH patients: Pre- and post-HD levels were analyzed at this point and were repeated twice within 12 months in 5 PH1 and 14 non-PH patients. Samples were obtained only once in 12 patients (one PH 1) on peritoneal dialysis (PD). After liver-kidney or kidney transplantation, plasma levels were measured repetitively. Results. The mean P(Ox) was higher in PH 1 (125.7 ± 17.9 μol/liter) than in non-PH patients (44.2 ± 3.3 μol/liter, P < 10-4). All other determined anions did not differ between the two groups, β(CaOx) was higher in PH 1 (4.71 ± 0.69 relative units) compared with non-PH children (1.56 ± 0.12 units, P < 10-4). P(Ox) and β(CaOx) were correlated in both the PH 1 (r = 0.98, P < 2 X 10-4) and the non-PH group (r = 0.98, P < 10-4). P(Ox) and β(CaOx) remained stable over time in the non-PH children, whereas an insignificant decline was observed in PHI patients after six months of more aggressive dialysis, β(CaOx) was supersaturated (more than 1) in all PH 1 and in 25 out of 33 non-PH patients. Post-HD β(CaOx) remained more than 1 in all PH 1, but in only 2 out of 22 non-PH patients. In non-PH children, P(Ox) and β(CaOx) decreased to normal within three weeks after successful kidney transplantation, whereas the levels still remained elevated seven months after combined liver-kidney transplantation in two PH 1 patients. Conclusion. Systemic oxalosis in PH 1 children with ESRD is due to higher P(Ox) and β(CaOx) levels. As β(CaOx) remained supersaturated in PH 1 even after aggressive HD, oxalate accumulation increases, and CaOx tissue deposition occurs. Therefore, sufficient reduction of P(Ox) and β(CaOx) is crucial in PH 1 and might only be achieved by early, preemptive, combined liver-kidney transplantation or liver transplantation alone.
KW - Crystal deposition
KW - Liver
KW - Oxalosis
KW - Renal replacement therapy
KW - Solid organ transplantation
UR - http://www.scopus.com/inward/record.url?scp=0033059461&partnerID=8YFLogxK
U2 - https://doi.org/10.1046/j.1523-1755.1999.00546.x
DO - https://doi.org/10.1046/j.1523-1755.1999.00546.x
M3 - Article
C2 - 10411702
SN - 0085-2538
VL - 56
SP - 268
EP - 274
JO - Kidney International
JF - Kidney International
IS - 1
ER -