icodextrin and maltotriose

An important number of patients dependent on renal dialysis prefer peritoneal dialysis to hemodialysis. In the case of peritoneal dialysis, the glucose polymer icodextrin is frequently added to the dialysis fluid as an osmotic agent, since this polymer is able to maintain an osmotic gradient across the peritoneal membrane longer than monomeric glucose, leading to a prolonged effective ultrafiltration time. It was previously shown that icodextrin is partly able to enter the blood via the lymphatic system, where hydrolysis to glucose oligomers such as maltose and maltotriose occurs. The presence of these oligomers in the blood appears to cause significant overestimations of the glucose values in several point-of-care (POC) glucose analyzers, with potentially dramatic consequences. This effect has been investigated for a series of POC glucose analyzers, both by analyzing the blood of peritoneal dialysis patients and by an in vitro investigation of the quantitative effects of maltose and maltotriose. In particular, POC analyzers utilizing the bacterially produced enzyme glucose dehydrogenase seem to lack glucose specificity.

Topics: Artifacts; Blood Chemical Analysis; Blood Glucose; Glucans; Glucose; Humans; Hydrolysis; Icodextrin; Maltose; Peritoneal Dialysis; Point-of-Care Systems; Reproducibility of Results; Trisaccharides

Glucose has been reported to interfere in the analysis of creatinine by the Jaffe method. The potential interference of icodextrin and its primary metabolites (maltose, maltotriose, maltotetraose) on creatinine measurements has not previously been addressed. We evaluated the potential interference of icodextrin and its metabolites at various concentrations using both the Jaffe and Creatinine Plus methods. Interference was determined in samples containing 0.6-20 mg/dL creatinine in saline solution or in plasma (n = 6), and in dialysate samples (n = 6) spiked with icodextrin, maltose, maltotriose, and maltotetraose at concentrations up to twofold the level found in plasma and dialysate from patients treated using icodextrin. Results confirm that no interference occurs when using either the colorimetric Jaffe method or the enzymatic Creatinine Plus method at levels up to 65 g/L icodextrin, 2 g/L maltose, 2 g/L maltotriose, and 1 g/L maltotetraose, levels representing worst-case clinical concentrations. In addition, our results confirm that comparable values can be obtained using either the Jaffe or the Creatinine Plus method for the analysis of creatinine in uremic plasma and in dialysate samples.

Topics: Creatinine; Dialysis Solutions; Glucans; Glucose; Humans; Icodextrin; Maltose; Oligosaccharides; Trisaccharides; Ultrafiltration

Topics: Blood Glucose; Dialysis Solutions; Glucans; Glucose; Glucose 1-Dehydrogenase; Glucose Dehydrogenases; Glucose Oxidase; Humans; Icodextrin; Maltose; Oligosaccharides; Trisaccharides