High prevalence of elevated lead levels in pediatric dialysis patients.

BACKGROUND: After parents raised concerns about potential lead (Pb) contamination of calcium carbonate for treatment of hyperphosphatemia in chronic kidney disease (CKD), we measured blood Pb using high-resolution sector field inductively coupled mass spectrometry in a quality-assurance investigation of ten pediatric dialysis patients (nine on hemodialysis) and six patients before dialysis.

METHODS: We assessed the kidney function as cystatin C estimated glomerular filtration rate (eGFR), blood Pb levels, calcium carbonate dose, and standard laboratory parameters, as well as Pb levels in the dialysis feed water.

RESULTS: Mean blood Pb concentration in the 16 pediatric CKD patients was 21.1 ± 15.8 µg/l with a maximum of 58 µg/l, which was significantly higher than that of 467 apparently healthy controls (median 6.35 µg/l, interquartile range 4.47, 8.71) and comparable to that of ten adult peritoneal dialysis (PD) patients. Lead levels correlated with red blood cell distribution width, eGFR, and calcium carbonate dose. Pb in dialysate feed water was always <0.00018 mg/l, which is below the accepted limit for water for dialysis of 0.005 mg/l.

CONCLUSIONS: We found a high prevalence of elevated Pb levels in pediatric CKD patients that correlated with the calcium carbonate dose and GFR. Lead levels should be monitored in these patients.