BioBridge Global San Antonio, Texas, United States
Background/Case Studies: Accurate detection of Anti-A and Anti-B antibodies in pooled plasma is critical for ensuring the safety and quality of plasma-derived products. The ORTHO VISION® Swift testing platforms, utilizing ID-MTS Gel Cards, automates immunohematology testing to quantify Anti-A and Anti-B antibody titers. This study aimed to validate the specificity, analytical sensitivity, robustness, and interference resistance of the Anti-A and Anti-B assays for production pool samples, in accordance with ICH Q2(R2) guidelines.
Study
Design/Methods: Specificity was assessed by testing diluent and 30 pooled plasma samples for Anti-A and Anti-B antibodies, comparing results to previous known titers within ±2 serial dilutions. Analytical sensitivity was evaluated using WHO High Titer Anti-A and Anti-B standards (NIBSC code: 14/300) at dilutions of 1:32, 1:64, 1:128, 1:256, 1:512, and 0, with 5 replicates per dilution tested over 3 days. Probit analysis determined the limit of detection (LOD). Robustness was tested by preparing two aliquots at 1:64 dilution (3 dilutions above Anti-A LOD) and analyzing 20 replicates on two instruments (S/N: 70003052, 50002420). Interference was evaluated by spiking production pool samples with Anti-D at 0, 0.0285, and 0.285 IU/mL, testing three replicates per concentration. Geometric titer means and titer scores were calculated, with precision assessed within ±2 serial dilutions and %CV ≤20% (within-run) and ≤30% (intermediate).
Results/Findings: The assays demonstrated excellent specificity, with the diluent testing negative and all production pools within ±2 serial dilutions of reference titers. Analytical sensitivity analysis established LODs of 1:512 for Anti-A and 1:256 for Anti-B, with 15/15 valid positive results at these dilutions. Robustness was confirmed, as all replicates across two instruments tested positive, with geometric titer means of 8 (Anti-A) and ~4 (Anti-B) and %CV ≤20% within-run and ≤30% intermediate precision. Interference studies showed consistent detection of Anti-A (1:64) and Anti-B (1:32) across all Anti-D antibody concentrations up to 0.285 IU/mL, with no interference observed. One exception occurred due to sample preparation at 3 dilutions above Anti-A LOD instead of 3x LOD for both antibodies, but this did not impact fitness for use.
Conclusions: The Anti-A and Anti-B assays on the ORTHO VISION® Swift platform were successfully validated for production pool testing, demonstrating high specificity, sensitivity, robustness, and resistance to Anti-D antibody interference. These assays are suitable for quantifying Anti-A and Anti-B antibody titers in pooled plasma, supporting quality control of plasma fractionation processes.
