Tube and column agglutination technology for autocontrol testing

Area of Science:

• Transfusion Medicine
• Immunology
• Clinical Pathology

Background:

• Positive autocontrol results in blood group serology can indicate alloimmunization or autoantibodies.
• Column agglutination technology (CAT) offers increased sensitivity compared to traditional methods.
• Variability in positive autocontrol rates between different CAT systems necessitates further study.

Purpose of the Study:

• To investigate the incidence and significance of positive autocontrols using the ID Micro Typing System (gel) and Gamma ReACT (ReACT) column agglutination technologies.
• To compare the frequency of positive autocontrols between gel, ReACT, and conventional tube methods.
• To evaluate the clinical relevance of positive autocontrols, especially when direct antiglobulin test (DAT) is negative.

Main Methods:

• Prospective study of 1021 patient and 95 donor samples.
• Autocontrol testing performed using ID Micro Typing System (gel), Gamma ReACT, and low-ionic-strength solution (LISS) tube methods.
• Direct antiglobulin test (DAT) performed via tube method, with elution studies as needed.

Main Results:

• A 7.74% incidence of positive autocontrols was observed in patient samples.
• The gel test showed the highest frequency of positive autocontrols (91.13% of positive cases), followed by ReACT (26.58%) and tube method (34.18%).
• Of 79 positive autocontrols, 44 had a negative DAT, and only one sample with a positive DAT had a clinically significant antibody (anti-D).

Conclusions:

• Column agglutination techniques, especially the gel method, exhibit higher sensitivity for detecting positive autocontrols than the conventional tube method.
• Significant differences exist in the frequency of positive autocontrols between ReACT and gel systems.
• Further investigation into the clinical significance of positive autocontrols in CAT, particularly when the tube method is also positive, is recommended.