Comparative Study of Tube and Gel Techniques for Compatibility Testing and Antibody Identification

The gel test based on column agglutination technology is replacing the conventional cross match in blood bank settings. The present study aims at evaluating the advantage of using gel test in compatibility testing over the tube technique and finding out the incidence and the nature of alloantibodies in the recipients whose cross match was incompatible. A study of 69,148 consecutive, unselected cross matches was conducted at Department of Transfusion Medicine, Apollo Hospital, New Delhi. In this study LISS/Coombs cards based on Gel technique was compared with Conventional tube technique. Antibody screening was carried out on samples giving incompatible cross match results to know the incidence and type of alloantibodies, using the ID-DiaCell screening panel. The antibody screen, antibody identification was carried out using ID-DiaPanel, an 11 cell identification panel. 398 (0.57%) incompatible cross matches using both techniques at all phases were encountered in 86 recipients. A total of 385(96.73%) units were incompatible by LISS/ Coombs on gel technique, while 197(49.5%) were incompatible by tube AHG method. In 2 of the patients, 13 units were found to be incompatible only in the Immediate spin saline RT tube cross match and compatible by coombs cross matches in tube as well as by gel technique. Out of these 86 recipients, antibody screening was positive in 61(70.9%) cases. LISS/ Coombs Gel technique picked up more cases of cross match incompatibility as compared to tube technique which shows distinct advantage and superiority of the LISS/Coombs Gel technique over tube technique for routine use in the blood bank.