(P-IN-1) Detecting the Almost Undetected: Comparing Reactive Strength During Antibody Detection with Three Blood Bank Analyzers

Background/Case Studies: Staff shortages in transfusion services have resulted in increased reliance on automation. Instrumentation must effectively detect clinically significant, including weakly reactive antibodies to help prevent delayed hemolytic transfusion reactions. This is especially important for evanescent antibodies that may appear and disappear over time. Methodologies that enhance weak antibody detection can benefit less experienced techs. This study compares the reactivity of weakly reacting samples across 3 analyzers using 2 gel-based and 1 solid phase-based technology.

Study

Design/Methods: The study compared antibody detection during a week-long evaluation using 3 analyzers. Instruments included the current instrumentation: Erytra (Grifols, Sant Cugat del Vallès, Spain), recently validated Vision Swift (QuidelOrtho, San Diego, CA), and demo unit, Echo Lumena (Werfen, Norcross, GA). This study compared only weak reactive strength samples (2+ or less) on 1 or more analyzer, and how the strength compared to the other instrumentation. Positive samples included on-site Erytra samples & positive samples that were sourced from a Vision & Echo facility. Each facility included 4-8 random, currently specimens, without duplicating patients. Additional samples (8) were sent to broaden the antibody specificity, Validation Panel (Werfen, Norcross, GA).

Results/Findings: Similar results were obtained with strong reacting antibodies (7), which were the Validation Panel samples (giving a 3-4+ reactions by all 3 instruments). The study included 1 validation sample and 13 weak reacting patient positive antibody detection samples. This included anti-Jka (6), anti-E (4), anti-D (1), anti-K (1), anti-E/S (1) and anti-Fya (1). See Table 1. Based on this data: 11 of the 14 samples gave 1-2+ stronger reactivity with solid phase on the Echo Lumena (79%) vs Vision Swift and Erytra. The Vision Swift (43%) gave stronger reactions on 6 of the 14 samples than the Erytra. No weak antibody reacted more strongly with the Erytra than the Echo Lumena or Vision Swift, nor did any sample on Vision Swift react more strongly than the Echo.

Conclusions: Automation supports blood bank efficiency, but analyzer’s sensitivity is critical, especially for less experienced techs. This 3-instrument study demonstrated that the Echo Lumena/solid phase technology is significantly better at detecting weaker clinically significant antibodies titers (2+ or less) than seen on the gel technologies incorporated with the Vision Swift and Erytra instruments. The Vision Swift did demonstrate stronger reactivity (43%) over the gel technology on the Erytra. The Echo Lumena showed stronger reactivity (79%) for clinically significant antibodies, making it advantageous in settings with limited expertise to help ensure accurate detection, particularly for antibodies that fluctuate over time. Expanding this study with additional low titer samples would be insightful.