Monday, September 27, 2010 2:00 PM - American Society for ...

36-PRE-THINKING THE ROP TRAYS IN REGION 1.Maureen M. Miller, Tod V. Alberghini, Michael Rewinski, Trish Michalski, Laurine Bow. TransplantImmunology Laboratory, Hartford Hospital, Hartford, CT, USA.Aim: To understand the usefulness and cost of creating and exchanging serum trays within Region 1. In2010 CTOP stopped exchanging sera trays monthly with MAOB and switched to exchanging sera quarterlyfrom actively listed patients with a CPRA of greater than 50%. Do we need to share sera this often or canwe stop sharing sera all together?Methods: To expedite kidney allocation, Region 1 has agreed that each OPO lab must generate a list of thetop15 patients with a negative crossmatch for each deceased donor. The frequency of using exhange traydata was assessed by reviewing deceased donor kidney matches. All of the deceased donor kidney matchesin 2009 from CTOP and donors from MAOB from 10/1/09 until 3/31/10 were reviewed in UNET.Results: In 2009 CTOP had 36 deceased donor kidney matches. MAOB crossmatch results were neededfor the kidney allocation in 26/36 (72%) kidney matches. MAOB had 104 deceased donors with kidneymatches in the six months reviewed and only once (1%, 91% CPRA, patient subsquently transplanted withnegative flow crossmatch) was the exchange tray data used in kidney allocation. This data mimicks MAOBdata from 2007-2009 presented regionally. The cost of the exhange trays for CTOP is approximately $2500every six months. This does not take into account the cost to run the trays for each donor which wouldinclude additional tech time and reagents.Conclusions: The low usage of the CTOP exchange tray data by MAOB suggests that they could beeliminated to cut costs. However, since data from the MAOB trays were used by CTOP 72% of the time,there usage should be continued. The difference in effectiveness of exchange tray use is most likely due tovarying numbers of patients on the list, antigen assignment vairation and local organ acceptance criteria forECD and DCD donors.37-PUNACCEPTBLE ANTIGENS: HOW ARE THEY WORKING?Maureen M. Miller, Tod V. Alberghini, Michael Rewinski, Trish Michalski, Laurine Bow. TransplantImmunology Laboratory, Hartford Hospital, Hartford, CT, USA.Aim: Determine if unacceptable antigens listed in UNET predict patients who should have a negative Tand B cell crossmatch against a particular donor. In 2009 the unacceptable antigens were reviewed when apatient was listed in UNET and then twice a year. An antibody must be detected in two different samplesby two different detection methods to be listed in UNET as unacceptable.Methods: Deceased donor kidney matches from 2009 were analyzed. Patients with a CPRA of ≥10% in thetop 15 crossmatch results on each kidney match were reviewed. Patients from CTOP had T and B cellcytotoxic crossmatches performed primarily and T and B cell flow crossmatches as needed, based on ourlab’s policy. Patients from MAOB had only T cell cytotoxic crossmatch performed.Results: 36 deceased donor kidney matches were reviewed. Of the 540 total crossmatches for the top 15patients on each list, 135 (25%) were patients with a CPRA of ≥10%. 76 of these were patients listed withinCTOP and were evalutated further. 24/76 (32%) of the patients with CPRA >10% had a T and/or B cellpositive crossmatch. The CPRA ranged from 12-99%. 52/76 (68%) of the patients had a negativecrossmatch. Their CPRAs ranged from 10-94%. 8/24 (33%) of the patients with an unexpected positivecrossmatch had donor specific antibodies identified by only one antibody detection method. Many of theantibodies were identified by Gen-Probe Luminex ID assays but were not confirmed by either Gen-Probeor One Lambda Single Antigen assays. Another 8 (33%) had donor specific antibodies but did not havetheir unacceptable antigens updated in UNET. The remaining 8 unexpected positive crossmathces weremostly likely due to C,DP or low levels of antibodies, possibly IgM.Conclusions: Unacceptable antigens do aid in the kidney allocation process. Since they play such animportant role more frequent review is necessary to accurately report them to UNET.38-PSEROLOGIC SUBTYPES OF DQ7 SUGGESTED BY PRINCIPAL COMPONENT ANALYSIS OFSINGLE ANTIGEN SCREENING DATA.