Studies on the platelet radioactive anti-immunoglobulin test.

A platelet radioactive antiimmunoglobulin test (PRAT) has recently been introduced. In the present report, a detailed analysis the influence of varying test conditions (i.e. efficiency of iodination of anti-IgG, cell number, degree of sensitization of platelets, times and temperatures of incubation, frequency of washings) on the results of this technique is presented. A standard procedure based on these findings is outlined. It is shown that the PRAT is two to four times more sensitive than platelet complement fixation for the detection of HLA antibodies.