Micro-column affinity test and gel test: comparative study of two techniques for red cell antibody screening

Area of Science:

• Transfusion Medicine
• Immunology
• Clinical Pathology

Background:

• Routine red blood cell antibody screening is crucial for safe blood transfusions.
• Evaluating new serological techniques is essential for improving laboratory diagnostics.

Purpose of the Study:

• To comparatively evaluate the performance of the gel test (ID Micro Typing) and the micro-column affinity test (MCAT, Cellbind Screen) for red blood cell antibody screening and identification.
• To assess sensitivity, specificity, and antibody detection capabilities under routine laboratory conditions.

Main Methods:

• Parallel testing of 3,000 patient serum samples using both gel test and MCAT.
• Utilized standardized test cells, low-ionic-strength-saline indirect antiglobulin test (gel), and protein G affinity technique (MCAT).
• Performed titration studies on detected antibodies and known specificities to compare antibody strength.

Main Results:

• A total of 154 antibodies were detected (5.1%); 149 by gel test, 147 by MCAT.
• Overall sensitivity and specificity were comparable: Gel test (96.8% sensitivity, 96.5% specificity) and MCAT (95.5% sensitivity, 97.2% specificity).
• Titration scores showed no significant overall difference, though MCAT excelled for anti-Fy(a) and anti-Kell, while the gel test was better for anti-Lu(a).

Conclusions:

• The micro-column affinity test (MCAT) is as sensitive as the gel indirect antiglobulin test for screening unexpected red blood cell antibodies.
• Both systems demonstrate comparable sensitivity and specificity.
• The gel test may offer superior detection of certain antibody types, specifically IgM antibodies.