Oxalate quantification in hemodialysate to assess dialysis adequacy for primary hyperoxaluria.
BACKGROUND
Patients with primary hyperoxaluria (PH) overproduce oxalate which is eliminated via the kidneys. If end-stage kidney disease develops they are at high risk for systemic oxalosis, unless adequate oxalate is removed during hemodialysis (HD) to equal or exceed ongoing oxalate production. The purpose of this study was to validate a method to measure oxalate removal in this unique group of dialysis patients.


METHODS
Fourteen stable patients with a confirmed diagnosis of PH on HD were included in the study. Oxalate was measured serially in hemodialysate and plasma samples in order to calculate rates of oxalate removal. HD regimens were adjusted according to a given patient's historical oxalate production, amount of oxalate removal at dialysis, residual renal clearance of oxalate, and plasma oxalate levels.


RESULTS
After a typical session of HD, plasma oxalate was reduced by 78.4 ± 7.7%. Eight patients performed HD 6 times/week, 2 patients 5 times/week, and 3 patients 3 times/week. Combined oxalate removal by HD and the kidneys was sufficient to match or exceed endogenous oxalate production. After a median period of 9 months, pre-dialysis plasma oxalate was significantly lower than initially (75.1 ± 33.4 vs. 54.8 ± 46.6 mmol/l, p = 0.02).


CONCLUSIONS
This methodology can be used to individualize the dialysis prescription of PH patients to prevent oxalosis during the time they are maintained on HD and to reduce risk of oxalate injury to a transplanted kidney.
Nephrology and Hypertension Research, Mayo Clinic, Rochester, Minn., USA.
Xiaojing
X
Tang
Nikolay V
NV
Voskoboev
Stacie L
SL
Wannarka
Julie B
JB
Olson
Dawn S
DS
Milliner
John C
JC
Lieske
D000328:Adult; D005260:Female; D015312:Hemodialysis Solutions / Q000737:chemistry*; D006801:Humans; D006960:Hyperoxaluria, Primary / Q000097:blood / Q000628:therapy* / Q000652:urine; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy* / Q000652:urine; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D010070:Oxalates / Q000097:blood / Q000302:isolation & purification* / Q000652:urine; D006435:Renal Dialysis / Q000379:methods*; D013997:Time Factors; D055815:Young Adult
D015312:Hemodialysis Solutions; D010070:Oxalates