A roadmap for the standardization of hemoglobin A₂

Area of Science:

• Clinical Chemistry
• Hematology
• Laboratory Medicine

Background:

• Standardizing laboratory tests, such as hemoglobin A2 (HbA2) measurement, is a lengthy process.
• HbA2 is a critical marker for diagnosing beta-thalassemia and related conditions.
• The IFCC standardization project for HbA2 began in 2004, requiring over 15 years to establish reference procedures and materials.

Purpose of the Study:

• To describe process indicators for assuring the validity and longevity of HbA2 measurement standardization.
• To evaluate the effectiveness of standardization efforts through inter-method studies and quality assessment schemes.

Main Methods:

• Developing process indicators for standardization.
• Conducting inter-method studies comparing different HbA2 analytical techniques.
• Analyzing yearly distributions of HbA2 measurements from selected laboratories.
• Establishing External Quality Assessment Schemes.

Main Results:

• Preliminary data show stable median yearly HbA2 values over time but significant differences between analytical methods.
• Capillary electrophoresis yielded significantly lower HbA2 results compared to HPLC in 2 out of 3 observed years.

Conclusions:

• Significant progress has been made towards standardizing HbA2 measurement globally.
• Further steps are necessary to achieve worldwide standardization of HbA2 testing.