External quality assessment in molecular immunohematology: the INSTAND proficiency test program

Area of Science:

• Molecular immunohematology
• Transfusion medicine
• Clinical pathology

Background:

• Genotyping for red blood cell (RBC), platelet (PLT), and granulocyte antigens is a critical tool for transfusion medicine and blood banks.
• External quality assessments (EQAs) are essential for establishing laboratory test proficiency and clinical application.
• Limited EQAs are available for molecular immunohematology.

Purpose of the Study:

• To analyze participation and pass rates in an established EQA for RBC, PLT, and granulocyte antigens.
• To evaluate the trends in molecular immunohematology testing performance over time.

Main Methods:

• Analysis of participation and pass rates in INSTAND's EQA Number 235 Immunohematology A (molecular diagnostic) from Fall 2006 to Fall 2012.
• Tracking of participant numbers, system participation (RBC, PLT, granulocytes), and allele detection rates.
• Assessment of pass rates for specific antigen systems, including RHD and ABO.

Main Results:

• Participant numbers increased steadily, with over 60 institutions utilizing the EQA annually.
• High participation rates were observed for RBC (approx. 80%) and PLT (approx. 68%) systems, with lower participation in granulocyte systems (approx. 22%).
• Pass rates generally exceeded 93%, with exceptions for RHD (82%) and granulocytes (85%); pass rates showed minor changes over 6.5 years, with an increase for granulocytes and a decrease for ABO.

Conclusions:

• The INSTAND proficiency testing program is widely adopted, particularly in Central Europe, for molecular immunohematology EQAs.
• Participating laboratories demonstrate high technical standards and consistent pass rates.
• Despite high performance, there has been limited improvement in pass rates for molecular immunohematology testing since the program's inception in 2006.