Proficiency Testing Program for Hb E (HBB: c.79G>A) Screening in Thailand Using Lyophilized Hb E Control Materials

Area of Science:

• Hematology
• Clinical Chemistry
• Public Health

Background:

• Hemoglobin E (Hb E) is prevalent in Thailand, necessitating reliable screening methods.
• The dichlorophenol-indophenol (DCIP) test and microcolumn chromatography are common Hb E screening techniques.
• A lack of proficiency testing (PT) programs for these methods poses a challenge to quality assurance.

Purpose of the Study:

• To evaluate the efficacy of lyophilized hemoglobin (Hb) control materials for an established PT program for Hb E screening.
• To assess the performance of laboratories using DCIP and microcolumn chromatography for Hb E screening.

Main Methods:

• Three cycles of proficiency testing were conducted between June 2018 and July 2019.
• Participants analyzed five types of lyophilized Hb control materials using their routine Hb E screening methods.
• Results from DCIP test and microcolumn chromatography users were compared.

Main Results:

• Participant numbers increased across the three PT cycles.
• Correct result reporting for the DCIP test showed a slight increase.
• Correct result reporting for microcolumn chromatography decreased significantly over the cycles.
• Lyophilized Hb control materials demonstrated effectiveness in the PT program.

Conclusions:

• Lyophilized Hb control materials are suitable for Hb E screening PT programs.
• Continuous quality improvement is needed, particularly for microcolumn chromatography skills.
• The PT program effectively monitors and supports Hb E screening laboratories.