An antibody screening test based on the antiglobulin gel technique, pooled test cells, and plasma

The recently introduced gel technique offers significantly advances compared to traditional tube tests. The purpose of the present study was to design an antibody screening test based on the gel technique, pooled cells, and plasma and to evaluate this test by comparison with a conventional spin-tube indirect antiglobulin test (IAT) combined with a two-stage papain technique. Pilot studies were performed to establish optimal parameters during the design phase, and finally 5,446 consecutive samples were screened for irregular antibodies by the gel technique in parallel with routine techniques. Irregular erythrocyte antibodies were detected in 151 samples, and the gel technique proved equal or superior to the tube test in the detection of all antibodies except 'enzyme-only' anti-E and anti-Lea. We conclude from this study that screening for unexpected antibodies using the gel IAT in our set-up, which includes: (1) omission of enzyme technique; (2) the use of stabilized (EDTA) plasma instead of serum as test material in order to facilitate automation; and (3) pooling 2 by 2 of 4 test cells (to make the gel technique price competitive), is a fast, reliable and sensitive procedure that maintains transfusion safety and compares favourably with our previous routine of saline IAT combined with a two-stage papain technique.