A RADIOLABELED ANTIGLOBULIN-TEST FOR CROSSMATCHING PLATELET TRANSFUSIONS

  • 1 January 1983
    • journal article
    • research article
    • Vol. 61  (2) , 238-242
Abstract
Despite the use of HLA-matched platelets for alloimmunized recipients, transfusion failures occur. To reduce these failures, the use of a radiolabeled antiglobulin technique for platelet crossmatching was investigated. The principle of the test is that of an indirect Coombs test using 125I labeled goat anti-human IgG. Incompatibility is determined by calculating a radioactivity antiglobulin test (RAGT) index. Using this technique, 89 crossmatches were performed on 19 leukemic or aplastic patients who were refractory to random donor platelets and receiving varying degrees of HLA-matched platelets. Effectiveness of the transfusion was assessed from the posttransfusion corrected platelet count increment (CCI) determined at 1 and 20 h. When the RAGT index was 1.9 or less, the mean CCI at 1 h was 17,570 .+-. 7003/cu mm, n = 55. When the RAGT index was 2.0 or greater, the mean CCI was 4237 .+-. 4100/cu mm, n = 34. At 20 h when the RAGT index was 1.9 or less, the mean CCI was 8722 .+-. 3143/cu mm, n = 33, and when the index was 2.0 or greater, the mean CCI was 571 .+-. 1286/cu mm, n = 23. Using this technique, 1 false negative resulted. Nine positive crossmatches with good increments at 1 h were found; at 20 h, the survival of these units was zero. This method is apparently a useful adjunct in the selection of platelets in the refractory patient.