Background: Our reference adsorption procedure is to autoadsorb serum with ZZAP-pretreated patients' red cells (RBCs), although it is time-consuming. The aim of this study was to evaluate the use of polyethylene glycol (PEG) for performing autologous adsorption procedures without pretreatment of patients' RBCs.
Study design and methods: Equal volumes of patient's plasma, patient's RBCs, and PEG were mixed. This mixture was incubated for 15 minutes at 37 degrees C, and the adsorbed plasma-PEG mixture was immediately harvested to proceed to the antiglobulin test with anti-immunoglobulin G. The ZZAP-adsorption procedure was performed in our reference laboratory.
Results: Thirty-one samples were detected with warm autoantibodies in pretransfusion testing. A total number of 58 autologous adsorption procedures were performed with PEG in 870 minutes (mean, 28 min) and alloantibodies were detected in 4 (13%) cases (anti-E in 2 cases and anti-E + K in 2 cases). Our reference laboratory performed a total number of 61 adsorption procedures with ZZAP in 3660 minutes (mean, 118 min) and detected the same alloantibodies specificities.
Conclusion: The PEG autologous adsorption procedure is an efficient method of enhancing autoantibody adsorption and alloantibody detection and decreasing the labor-intensive testing required by the presence of serum warm autoantibodies in pretransfusion samples.