title: Reassessment of T Lymphocytes Crossmatches Results Prediction With Luminex Class I Single Antigen Flow Beads Assay.
abstract: In virtual crossmatch (XM) strategies, a correct anticipation of XM results is required for appropriately allocating organs. We reassessed the ability to predict T lymphocyte flow cytometry and complement dependent cytotoxicity XM results with the mean fluorescence intensity (MFI) in Luminex class I single antigen flow beads (SAFB) assay, after correction of complement interference and exclusion of antidenatured HLA antibodies.
  
  
  
  Among 432 XM with T lymphocytes (T-XM), 407 were analyzed after exclusion of antidenatured HLA antibodies. Only ethylenediaminetetraacetic acid-treated serum MFI was considered. Only 1 cellular target HLA antigen for the serum was expressed in 238 cases, 209 and 29 being heterozygous and homozygous for this antigen, respectively. For the remaining 169 cases, at least 2 antigens were recognized. Single antigen flow bead MFI thresholds allowing XM positivity to be predicted were calculated with receiver operating characteristic curves.
  
  
  
  T-XM results were tightly associated with SAFB MFI values. Anti-HLA-A and anti-HLA-B antibodies behaved similarly. Prediction and sensitivity SAFB MFI thresholds were determined, respectively, assessing the highest sensitivity/specificity ratio and at least 95% sensitivity for predicting T-XM positivity. Both were slightly lower for HLA-B than for HLA-A, whereas anti-HLA-Cw antibodies induced random XM results. Both thresholds were only slightly diminished for homozygous and for multiple HLA targets, considering the immunodominant, but not the sum, of antibodies MFI.
  
  
  
  Antibodies against HLA-A, -B, or -Cw behave differently. A homozygous HLA target does not trigger a twice higher XM positivity. Multiple antibodies are better evaluated through the immunodominant DSA MFI than through the sum of DSA MFI.
authors.affiliation: 1 Laboratoire d'Immunologie et Immunogénétique, Hôpital Pellegrin, CHU de Bordeaux, Bordeaux, France. 2 UMR 5164 CNRS, Université Bordeaux Segalen, Bordeaux, France. 3 One Lambda, Inc., Canoga Park, CA. 4 Service de Néphrologie, Transplantation, Dialyse, Hôpital Pellegrin, CHU de Bordeaux, Bordeaux, France.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Visentin
authors.forename: Thomas
authors.initials: T
authors.lastname: Bachelet
authors.forename: Cécile
authors.initials: C
authors.lastname: Borg
authors.forename: Nicolas
authors.initials: N
authors.lastname: Franchini
authors.forename: Thoa
authors.initials: T
authors.lastname: Nong
authors.forename: Jar-How
authors.initials: JH
authors.lastname: Lee
authors.forename: Lionel
authors.initials: L
authors.lastname: Couzi
authors.forename: Pierre
authors.initials: P
authors.lastname: Merville
authors.forename: Gwendaline
authors.initials: G
authors.lastname: Guidicelli
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Taupin
mesh_terms: D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D006680:HLA Antigens / Q000097:blood / Q000235:genetics / Q000276:immunology*; D006579:Heterozygote; D006648:Histocompatibility; D006650:Histocompatibility Testing / Q000379:methods*; D006720:Homozygote; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D016030:Kidney Transplantation / Q000009:adverse effects / Q000379:methods*; D011237:Predictive Value of Tests; D012372:ROC Curve; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D015415:Biomarkers; D006680:HLA Antigens; D007518:Isoantibodies