USE OF IGM MONOCLONAL REAGENTS LICENSED FOR TUBE TESTS IN COLUMN AGGLUTINATION TECHNOLOGY

BACKGROUND: Red cell (RBC) phenotyping using column agglutination tech nology (GAT) is currently limited by the reagents formulated in the sy stem. To overcome this limitation, it was investigated whether monoclo nal IgM reagents licensed for use with tube tests produced valid resul ts with CAT. STUDY DESIGN AND METHODS: Commercial CAT, does not contai n antisera, was used to evaluate Procedures A (40 mu L of reagent and 10 mu L of 4% RBCs) and B (50 mu L of reagent and 50 mu L of 0.8% RBCs ) with or without incubation at room temperature. In Study 1, reagents were tested to determine whether potentiators inhibit the passage of antigen-negative RBCs through the column. In Study 2, CAT sensitivity was measured by the use of potency titrations to define a procedure fo r each reagent that matched or exceeded that of the tube method. In St udy 3, the specificity of each reagent was determined in parallel with the CAT and tube tests. Typing of 1644 samples was performed. RESULTS : Study 1: Free passage was obtained with all reagents. Study 2: Immed iate-spin methods using CAT produced the same results as the tube meth od. Study 3: With 8048 comparisons made, discrepant results were found in 32 transfused patients and in 6 cord blood samples, mainly with Le wis reagents. With comparison of CAT and the standard tube method, com plete agreement was obtained with Kell reagents, 99.9-percent agreemen t with Kidd reagents, and 98.9-percent and 99.4-percent agreement with Lewis reagents. CONCLUSION: Most examined reagents seem suitable for use with CAT.