New insights into the sensitivity of Immulab reagent red blood cells compared to Bio-Rad, Grifols and QuidelOrtho.

Objective: Antibody screening and identification facilitates the issue of antigen-negative blood for patients with alloantibodies to red blood cell (RBC) antigens, thereby maximizing blood safety and the survival of transfused donor cells. The sensitivity and specificity of reagent red blood cells (RRBCs) used in pre-transfusion testing varies between manufacturers. This Phase II study aimed to build on a previously published Phase I study comparing the analytical performance of four manufacturers' RRBCs in column agglutination technology (CAT). A total of 231 patient samples with a negative indirect antiglobulin test (IAT) results were tested using Immulab, Bio-Rad, Grifols, and QuidelOrtho RRBCs. Phase II results were pooled with Phase I results to provide more accurate calculations of the RRBC analytical performance.

Results: The sensitivity of the RRBCs used in the combined studies was 94.52% (95%CI 86.56-98.49%) for Bio-Rad, 81.48% (95%CI 71.30-89.25%) for Grifols, and 95.71% (95%CI 87.98-99.11%) for QuidelOrtho RRBCs. The sensitivity of Immulab RRBCs were stratified based on performance in the three CAT platforms: 100%, 95%CI 95.07-100.00% in Bio-Rad CAT, 100%, 95%CI 95.55-100.00% in Grifols CAT and 100%, 95%CI 94.87-100.00% in QuidelOrtho CAT.

Conclusions: Immulab 0.8% RRBCs showed greater sensitivities and NPVs than the equivalent Bio-Rad, Grifols, and QuidelOrtho RRBCs in Bio-Rad, Grifols, and QuidelOrtho CAT, respectively. These differences may have implications in clinical pre-transfusion settings.