title: C4d fixing, luminex binding antibodies - a new tool for prediction of graft failure after heart transplantation.
abstract: The standard method to detect pretransplant antibodies has been the complement dependent cytotoxicity (CDC) test of donor leukocytes. Solid phase assays to detect HLA antibodies in pretransplant serum reveal a greater number of sensitized patients, but their clinical impact is less certain. Here we have developed a method of detecting C4d fixing HLA antibodies on Luminex beads. Pretransplant serum from 565 cardiac transplant patients was retrospectively tested for the presence of HLA antibodies using CDC, HLA coated Luminex beads and C4d deposition on Luminex beads, and the results correlated with graft survival. Whereas 5/565 patients had CDC positive donor specific antibodies (DSA) before their transplant, this number was increased by 19 using Luminex beads. The 1-year survival of CDC -ve/Luminex +ve patients with DSA (n = 19) was 42% compared with 77% for CDC -ve/Luminex +ve without DSA (n = 39, p = 0.0039). Fixation of C4d (22/67 Luminex positive sera) had a negative effect on graft outcome; 1-year graft survival was, C4d +ve/DSA +ve (n = 11) 20%, C4d +ve/DSA -ve (n = 11) 91%, C4d -ve DSA +ve (n = 13) 54%, C4d -ve DSA -ve (n = 32) 75%, compared with 75% for antibody-negative patients (p = 0.0002). In conclusion, detection of Luminex +ve DSA in pretransplant serum provides a powerful negative predictor of graft survival, especially if they bind C4d.
authors.affiliation: Transplant Immunology, Harefield Hospital, Imperial College, Harefield, UK.
authors.forename: J D
authors.initials: JD
authors.lastname: Smith
authors.forename: I M
authors.initials: IM
authors.lastname: Hamour
authors.forename: N R
authors.initials: NR
authors.lastname: Banner
authors.forename: M L
authors.initials: ML
authors.lastname: Rose
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies / Q000032:analysis / Q000097:blood*; D015935:Complement C4b / Q000032:analysis / Q000276:immunology*; D003601:Cytotoxicity Tests, Immunologic; D005260:Female; D006084:Graft Rejection / Q000175:diagnosis / Q000276:immunology*; D006085:Graft Survival / Q000276:immunology; D006680:HLA Antigens / Q000276:immunology*; D016027:Heart Transplantation / Q000276:immunology*; D006801:Humans; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D015999:Multivariate Analysis; D010446:Peptide Fragments / Q000032:analysis / Q000276:immunology*; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D000906:Antibodies; D006680:HLA Antigens; D010446:Peptide Fragments; D015935:Complement C4b; C032261:complement C4d