European Journal of Biomedical and Pharmaceutical Sciences

INTERFERING EFFECT OF BILIRUBIN ON THE MEASUREMENT OF ALKALINE PHOSPHATASE ACTIVITY

Noha A. Darag* and Nassr E. Mohamed

ABSTRACT

Introduction: Analytical interference is the systematic error of measurement caused by a sample component which does not by itself produce a signal in the measuring system. Objective: This study was designed to evaluate whether the high concentration of bilirubin is able to interfere the determination of alkaline phosphatase (ALP). Methods: Clinical tests evaluating the interfering substance of bilirubin on the determination of ALP were conducted based upon the Clinical and Laboratory Standards Institute (CLSI) document EP7-A2, the most recent guideline on interference testing approved in 2005. Results: The interference judgment is made by comparing the observed systemic error (bias) with the amount of error that is allowable for the test. There is no interfering effects of bilirubin at this cocentration on the determination of different ALP concentrations. Conclusion: We need high concentration of bilirubin to detect the interfering effects can cause false measurement of ALP levels, probably interfering with the clinical prognosis of liver diseases.

Keywords: Alkaline phosphatase, bilirubin, interference.