Bilirubin quantitation with lipemic plasma.

Area of Science:

• Clinical Chemistry
• Biochemistry
• Laboratory Medicine

Background:

• Accurate measurement of bilirubin (BR) is crucial for diagnosing and monitoring various medical conditions.
• Lipemia, a condition of abnormal lipid levels in the blood, can interfere with spectrophotometric assays, including BR estimation.
• Existing methods for BR determination may yield inaccurate results in the presence of lipemia.

Purpose of the Study:

• To evaluate the reliability of bilirubin estimation in lipemic plasma.
• To assess the performance of the A-O bilirubinometer in the presence of lipemia.
• To develop a method for correcting bilirubin measurements affected by lipemia.

Main Methods:

• Bilirubin (BR) levels were measured in lipemic plasma using the diazo method and the A-O bilirubinometer.
• Theoretical BR values were used as a reference for comparison.
• Regression analysis was performed to correlate the percent error in BR estimation with triglyceride (TG) concentrations.

Main Results:

• The diazo method for BR estimation showed variable and unreliable results in the presence of lipemia.
• The A-O bilirubinometer consistently underestimated BR levels in lipemic plasma compared to theoretical values.
• A linear relationship was observed between the percent error in BR estimation and TG concentrations.

Conclusions:

• The diazo method is not suitable for accurate BR determination in lipemic plasma.
• The A-O bilirubinometer provides lower BR values in lipemic samples.
• A correction factor derived from regression analysis can be applied to adjust BR measurements in lipemic plasma (5-25 mg/dl) when the degree of lipemia is known.