Patients that are sensitized, who have panel reactive antibodies (PRAs) > 20%, comprise a disproportionate and increasing cluster on the wait list (33%), and have to wait longer to receive a transplant than non-sensitized patients. By 36 months on the wait list, 10% died before receiving a transplant. Those who do receive transplants require desensitization. The current desensitization protocols include anti-CD20 monoclonal antibody to remove B cells, a proteasome inhibitor to eliminate plasma cells and plasma exchange and/or intravenous immunoglobulin (IVIG) to remove pre-formed donor specific antibodies (DSA). The success of these protocols can be measured using single antigen bead (SAB) luminex technology. These desensitization protocols have been shown to significantly decrease mean fluorescence intensity (MFI). Desensitization protocols typically are more effective in removing antibodies that recognize HLA Class I molecules than those that recognize HLA Class II molecules. Unfortunately, even after pre-conditioning, sensitized patients are more likely to develop antibody mediated rejection (ABMR) than patients that do not have donor specific antibodies prior to transplant. Currently, serum levels of DSA are measured after desensitization, but not donor specific B cells (DSB). It is possible that B cells and/or plasma cells remain after treatment. Donor specific B cells, upon transplant and the accompanying exposure to antigen, can be re-stimulated to both produce antibody and also to develop into plasma cells which produce antibody. Therefore, potentially a better means of determining whether desensitization has been successful would be to look at both the DSA level using SAB technology as described above and to look at DSB to determine if these cells have been adequately cleared by the desensitization protocol.