Influence of Negative Interference of Pathological Bilirubin Levelson Assessment of Serum Creatinine Concentration

Overview

Background.
Negative interference of bilirubin with assessment of creatinine concentration is generally knownfrom the biochemical aspect. The objective of the presented work was to find the bilirubin level and creatinineconcentration where this phenomenon has actually a clinical impact.Methods and Results. In 200 samples selected at random the bilirubin and creatinine levels were examined bythe classical Jaffé method and a method where the effect of bilirubin is suppressed. After dividing the group into 8sub-groups by bilirubin and creatinine concentrations it was revealed that the interference plays a statisticallysignificant role (p < 0.01) already at total bilirubin concentrations above 70 mmol . l-1.In abnormal creatinine levelsthe interference is manifested only at bilirubin concentrations above 150 mmol . l-1(p < 0.001). The degree ofinterference in the whole group is directly proportional to the bilirubin level (r = 0.5497, p < 0.001).Conclusions. At bilirubin levels above 70 to 150 mmol . l-1its interference with assessment of the creatinineconcentration can be so significant that it must be taken into account when evaluating the patient’s renal function.

Key words:
bilirubin interference, assessment of creatinine, Jaffé’s kinetic method.