Background:
Because of the limitation in the specificity of serum bilirubin measurement by conventional method, the true concentration of bilirubin have not been known with any great certitude. Certain compounds, especially indican and propranolol present
in
uremic patients are known to interfere with bilirubin measurement. Indican and propranolol metabolites interfere with the bilirubin measurement especially in uremic patients. This study was carried out in order to compare diazo method and
bilirubin
oxidase method in uremic patients
Methods:
Total serum bilirubin was measured for uremic patients, 45 and control group, 89 which were nonuremic patients including hepatobiliary disease, gastiritis and gastirc ulcer, etc, by diazo method and bilirubin oxidase method respectively. In
diazo
method, diazo reagent was 2.5-dichloroanylline diazonium salt(T-Bil-S reagent, Japan) and absorbance was read at 546 nm by Hitachi 747R(Hitachi, Japan). In bilirubin oxidase method, T-Bil-VE reagent(Japan) was used as bilirubin oxidase and
absorbance
was read at 450nm by Hitachi 747R(Hitachi, Japan) within 5 minutes after adding the first and seceond regent in control group but gradually increased with time in uremic patients group. In uremic patients group, there was a significant difference
between total bilirubin values by diazo method and that by bilirubin oxidase method (P<0.05). And their values were 0.96±0.36 (M±SD) mg/dl and 0.31±0.10 mg/dl, respectively. In control group, there was no significant difference between total
bilirubin values by diazo method and that by bilirubin oxidase method (p≥0.05). and their vallues were 1.63±3.50 (M±SD) mg/dl and 1.48±2.70 mg/dl, respectively. In control group, correlation coefficient among total bilirubin obtained by diazo
method
and bilirubin oxiadse method was 0.96.
Conclusions:
Total bilirubin levels measured by diazo method using 2.5-dichloroanylline diazonium as diazo reagent were falsely high in uremic patients group. Therefore bilirubin oxidase methods is preferable to diazo method in uremic patients for total
bilirubin measurment.
|