Alphafetoprotein in the Dutch External Quality Assurance programme: a need for improvement

Area of Science:

• Clinical Chemistry
• Tumor Marker Analysis
• Laboratory Medicine

Background:

• Elevated alphafetoprotein (AFP) is a significant tumor marker.
• Variations in AFP assay methods can lead to differing results, even with international standardization.
• Assessing analytical performance across different AFP measurement methods is crucial.

Purpose of the Study:

• To evaluate the analytical performance of various alphafetoprotein (AFP) immunoassay methods.
• To identify method-specific biases and assess compliance with analytical performance criteria.

Main Methods:

• Analysis of annual AFP survey data from 65-75 Dutch laboratories (2005-2010).
• External Quality Assurance program data from the SKML/Binding Analysis.
• Comparison of method biases against the all-laboratory trimmed mean and assessment against the Fraser criterion.

Main Results:

• Elecsys/Modular (36%) and Immulite 2000/2500 (29%) were the most common AFP assay methods.
• Average method biases ranged up to 15% positive and 12% negative.
• Over 70% of Immulite/Elecsys users met the Fraser criterion, while over 50% of users of other methods did not.

Conclusions:

• Method bias persists in alphafetoprotein (AFP) immunoassays, despite calibration to the same international standard.
• Certain AFP assay methods demonstrate insufficient analytical performance, potentially affecting clinical interpretation.