SENSITIVITY OF COLUMN AGGLUTINATION TECHNOLOGY IN DETECTING UNEXPECTED RED-CELL ANTIBODIES

This study was conducted to compare a new microtube column agglutination technology (CAT) with a previously described tube saline-indirect antiglobulin test (SIAT) with carefully defined performance in the detection of unexpected antibodies. On testing 117 sera from fresh and frozen stock containing antibodies detectable by SIAT, CAT failed to detect two examples of weak anti-K. All other discrepancies between the two techniques involved antibodies generally regarded as clinically insignificant. Titration studies with anti-D (concentration approximately 10 ng/ml) and 23 other antibodies, and studies with 10 weak antibodies of various blood group systems, showed the two techniques to be of similar sensitivity. Equivocal CAT results requiring repeated testing were found in 4.1% of specimens tested. We conclude that the CAT method adequately meets our requirements in sensitivity of detection of unexpected antibodies in pre-transfusion testing and offers opportunities for savings in technical staff time.