Problems associated with compatibility testing for patients with autoimmune hemolytic anemia

Area of Science:

• Transfusion Medicine
• Immunology
• Hematology

Background:

• Autoimmune hemolytic anemia (AIHA) complicates blood compatibility testing.
• Challenges arise in ABO/Rh typing and crossmatching due to autoantibodies.
• Warm type AIHA (WAIHA) and cold agglutinin syndrome (CAS) require distinct testing protocols.

Purpose of the Study:

• To outline strategies for overcoming compatibility testing issues in AIHA patients.
• To detail methods for accurate ABO/Rh typing and blood crossmatching in WAIHA and CAS.
• To ensure safe and effective blood transfusion practices for individuals with AIHA.

Main Methods:

• For WAIHA: Using non-potentiated reagents or removing IgG with chloroquine for Rh typing.
• For CAS: Employing prewarm techniques with 37°C washed RBCs and serum testing at 37°C.
• For CAS crossmatching: Utilizing saline or LISS-suspended RBCs exclusively at 37°C, avoiding albumin/enzyme methods.
• For WAIHA with pan-reactivity: Performing absorption studies to rule out alloantibodies.
• Identification and crossmatching of antigen-negative blood when alloantibodies are present.
• Considering autoantibody specificity for donor selection if compatible donors are available.

Main Results:

• False positive Rh typing in WAIHA can be mitigated by reagent choice or IgG removal.
• CAS typing and crossmatching are optimized using prewarm techniques and 37°C saline methods.
• Distinguishing autoantibodies from alloantibodies is crucial for WAIHA transfusion management.
• Prioritizing antigen-negative blood for alloantibodies over rare autoantibody-specific donors.

Conclusions:

• Tailored compatibility testing protocols are essential for AIHA patients.
• Accurate differentiation between autoantibodies and alloantibodies guides safe transfusion decisions.
• Adherence to specific temperature and reagent guidelines minimizes transfusion risks in AIHA.