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

This study was conducted to compare a new microtube column agglutinati on technology (CAT) with a previously described tube saline-indirect a ntiglobulin test (SIAT) with carefully defined performance in the dete ction of unexpected antibodies. On testing 117 sera from fresh and fro zen stock containing antibodies detectable by SIAT, CAT failed to dete ct two examples of weak anti-K. All other discrepancies between the tw o techniques involved antibodies generally regarded as clinically insi gnificant. 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 si milar sensitivity. Equivocal CAT results requiring repeated testing we re found in 4.1% of specimens tested. We conclude that the CAT method adequately meets our requirements in sensitivity of detection of unexp ected antibodies in pre-transfusion testing and offers opportunities f or savings in technical staff time.