Alpha-1-Fetoprotein (AFP): international proficiency study with different test systems.

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Biochemical Analysis

Background:

• Proficiency testing is crucial for assessing the reliability of diagnostic assays.
• Alpha-fetoprotein (AFP) is a biomarker used in various clinical contexts, including cancer screening and monitoring.

Purpose of the Study:

• To evaluate the comparability and reliability of different commercial test systems for determining AFP concentrations.
• To identify potential sources of variation in AFP measurements across laboratories.

Main Methods:

• A proficiency study involving 25 laboratories over one year.
• Utilized liquid BIOREF-AFP control serum for routine internal quality control.
• Employed 8 different commercial test systems for AFP determination.

Main Results:

• Significant variations in AFP results were observed among participating laboratories.
• Deviations from the overall mean ranged from 0.1% to 26.1%, with most around 10%.
• Individual laboratory precision showed acceptable coefficients of variation, ranging from 13% to 16.1%.

Conclusions:

• Despite an international standard, AFP results exhibit inter-laboratory variability.
• Participation in external proficiency testing (ring studies) is recommended for all laboratories.
• Utilizing quality control sera independent of test kit manufacturers is advised for internal quality control.