Proteome profile of peritoneal effluents in children on glucose- or icodextrin-based peritoneal dialysis.
BACKGROUND
We compared the proteome profile of peritoneal effluents obtained with icodextrin (Ico) or glucose (Glu) in paediatric patients and defined the oxido-redox status of proteins.


METHODS
Sixteen patients underwent two 14-h daytime dwells performed on subsequent days with 7.5% Ico and 3.86% Glu solutions. Protein composition was analysed by two-dimensional electrophoresis and mass spectrometry; oxidized products were evaluated by cyanine labelling.


RESULTS
Peritoneal transport kinetics of β2-microglobulin and cystatin C was linear for both solutions, but was significantly higher with Ico than with Glu, suggesting a better efficiency for these molecules. There was a linear correlation between total protein removal during Ico and Glu dialysis in the same patient, suggesting that it is a function of peritoneal membrane characteristics. The ratio between proteins removed by Ico and by Glu solutions was higher at low removal rate. Image gel analysis revealed 1064 and 774 spots, respectively, in Ico and Glu solutions; 524 were common, and 314 were higher in Ico than Glu effluents. Analysis of protein oxido-redox status showed a greater amount of oxidized albumin in Ico dialysate that was correlated with lower serum levels.


CONCLUSIONS
Our results indicate a better efficiency of Ico in removing small proteins. Removal of big proteins and their oxidized isoforms reflects potentially opposite effects. The long-term clinical consequences of removing also potentially important molecules are to be defined.
Bruschi
Maurizio
M
Renal Child's Foundation, Genoa, Italy. mauriziobruschi@yahoo.it
Candiano
Giovanni
G
Santucci
Laura
L
Petretto
Andrea
A
Mangraviti
Salvatore
S
Canepa
Alberto
A
Perri
Katia
K
Ghiggeri
Gian Marco
GM
Verrina
Enrico
E
D000293:Adolescent; D015415:Biomarkers / Q000378:metabolism*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015314:Dialysis Solutions / Q000494:pharmacology; D015180:Electrophoresis, Gel, Two-Dimensional; D005936:Glucans / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D000077607:Icodextrin; D010530:Peritoneal Dialysis; D010537:Peritoneum / Q000378:metabolism*; D020543:Proteome / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013549:Sweetening Agents / Q000494:pharmacology
D015415:Biomarkers; D015314:Dialysis Solutions; D005936:Glucans; D020543:Proteome; D013549:Sweetening Agents; D000077607:Icodextrin; D005947:Glucose