title: Comparison between enzyme-linked immunosorbent assay and cytotoxic cross-match procedures for detecting IgG anti-donor antibodies.
abstract: BACKGROUND
  Disadvantages inherent to complement-dependent cytotoxicity cross-match (CDC XM) methods are the requirements for complement and viable target cells, detection of antibodies (Abs) against non-HLA antigens, and subjective scoring. Cross-Stat (SangStat Medical Corp., Menlo Park, CA), a recently developed enzyme-linked immunosorbent assay XM procedure for the detection of IgG anti-donor HLA Abs, is theoretically devoid of these flaws.
  
  
  METHODS
  We compared results of Cross-Stat and our standard anti-human globulin (AHG)-enhanced CDC XM procedure on 524 sera from 230 transplant candidates, which were evaluated against 51 cadaveric donors.
  
  
  RESULTS
  There was a significant correlation between AHG-CDC IgG XM and Cross-Stat results (P<0.001). For false negative sera, repeat AHG-CDC IgG XMs were still positive after platelet absorption, indicating that the Abs present were either non-HLA Abs or anti-HLA class II. Flow cytometry testing of false positive sera usually (42/62) substantiated Cross-Stat results, indicating that the discrepancy with AHG-CDC IgG XM is caused by greater sensitivity of Cross-Stat. Relative to the AHG-CDC XM, the sensitivity of Cross-Stat was 100%, the specificity was 93%, the positive predictive value was 73%, and the negative predictive value was 100%. A technical shortcoming of the Cross-Stat assay is that the frequency of indeterminate samples in the assays was 15%. Among 49 Cross-Stat negative vs. 13 Cross-Stat positive primary cadaveric renal allograft recipients (all AHG-CDC IgG-XM negative), there was no statistical difference in overall graft survival.
  
  
  CONCLUSIONS
  Given the important theoretical advantages of enzyme-linked immunosorbent assay-based XM methods over the CDC XM, however, further testing of the clinical relevance of the Cross-Stat is warranted.
authors.affiliation: Division of Immunology and Organ Transplantation, University of Texas Health Science Center, Houston, USA.
authors.forename: B
authors.initials: B
authors.lastname: Susskind
authors.forename: R H
authors.initials: RH
authors.lastname: Kerman
authors.forename: R
authors.initials: R
authors.lastname: Nelson
authors.forename: J
authors.initials: J
authors.lastname: Gregory
authors.forename: T
authors.initials: T
authors.lastname: La
authors.forename: A
authors.initials: A
authors.lastname: Bayat
authors.forename: M
authors.initials: M
authors.lastname: Dang
authors.forename: C
authors.initials: C
authors.lastname: Van Buren
authors.forename: S
authors.initials: S
authors.lastname: Katz
authors.forename: B D
authors.initials: BD
authors.lastname: Kahan
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay; D006085:Graft Survival; D006650:Histocompatibility Testing / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D016030:Kidney Transplantation / Q000276:immunology*; D014019:Tissue Donors
chemical_list: D007074:Immunoglobulin G