Does decreasing the incubation period used in the antibody screen affect its sensitivity?

Pre-transfusion testing (PTT) encompasses a set of mandatory laboratory tests performed before red blood cell transfusion. The antibody screen, one component of PTT, commonly includes a 10-20 min incubation. The primary aim of this study was to determine if this period can be reduced when using current immunohematology methodologies.

Antibody screens were performed on reagent samples using Glass or Gel-based column agglutination technologies (CAT) and a solid phase red cell adherence (SPRCA) assay, with incubation periods of 1, 5, 10 and 15 min, and 20 min (SPRCA assay only). For each method, the shortest period producing a minimum of a 1+ reaction with all reagent samples was considered optimal. The sensitivity of each assay using the optimal period was calculated after performing antibody screens on 100 patient samples.

It was demonstrated that the incubation period in the SPRCA and Glass CAT systems can be reduced to 5 and 10 min, respectively, while achieving high assay sensitivity (98.9% in both). The incubation period in the Gel CAT system cannot be reduced from 15 min. Significant association between titre and reaction strength was observed for all three screening methods (p < 0.001 for both CAT methods, p = 0.041 for SPRCA). This study demonstrates that the incubation period used in the antibody screen can be reduced when using systems employing the Glass CAT and SPRCA methods, without affecting assay sensitivity. If confirmed, it could result in faster completion of PTT.