IOPAMIDOL INTERFERENCE IN PROTEIN SEPARATION BY CAPILLARY ELECTROPHORESIS AND ITS CONNECTION TO RENAL FUNCTION

Introduction: Interferences in the electrophoretic proteinogram by capillary electrophoresis include the appearance of peaks with concentrations and electrophoretic mobilities, which could simulate the presence of a monoclonal component. Objectives: I n the light of an additional peak with inter alpha(2)-beta mobility by capillary electrophoresis (MINICAP (R)-Sebia), the aim was to identify the interferent and evaluate its connection to renal functionality. Methods: Serum samples that presented this interference over a period of one year were studied by proteinogram on solid support, electroimmunofixation and immunoelectrophoresis. The probable interferent was added in vitro to confirm its electrophoretic mobility. The impact of the interference correction with the "artifact removal" tool (Phoresis (R)-Sebia) and the correlation of the baseline peak concentration of the interferent with the estimation of the glomerular filtration rate (CKD-EPI) were evaluated. Results: The integration to the baseline of the peaks was 0.07-0.36 g/dL. No particularities were observed when performing the complementary studies. In all cases, the administration of lopamidol as a contrast medium was demonstrated, confirming its electrophoretic mobility due to its in vitro addition. Using the "artifact removal" tool, the basal levels of the fractions were recovered. The existence of a correlation between the concentration of the baseline peak of the interferent and the estimation of the glomerular filtration rate by CKD-EPI was shown (r=-0.534, p <0.0001). Conclusions: The interferent was identified as lopamidol and its connection to the decrease in the glomerular filtration rate was demonstrated.