title: Relationship between Mean Fluorescence Intensity and C1q/C3d-fixing capacities of anti-HLA antibodies.
abstract: BACKGROUND
  Complement-binding assays are proposed to better stratify the risk of antibody-mediated rejection associated-graft failure. Despite promising clinical results, some have suggested that the MFI of anti-HLA antibodies may influence these tests.
  
  
  METHODS
  We investigated the impact of Abs MFI reduction, induced by plasmapheresis, on C1q- and C3d-binding assays. Sera provided from 7 sensitized kidney transplant patients were analyzed.
  
  
  RESULTS
  Four hundreds and thirty-three SABs were analyzed. Before plasmapheresis, when compared to C1q- SABs, C1q+ SABs had a higher median MFI [17397 (IQR: 14851-18794) vs. 2745 (IQR: 1125-6476), p<0.01]. SABs that remained C1q+ after plasmapheresis had a higher median MFI. Regarding the C3d assay, results were strictly comparable. MFI value was a powerful predictor of both C1q and C3d positivity [AUC 0.97 (CI95% 0.95-0.99) and 0.96, (CI95% 0.93-0.98), respectively].
  
  
  CONCLUSIONS
  Our data suggest that both C1q- and C3d-binding assays are intimately linked to the MFI of anti-HLA Abs.
authors.affiliation: Service de Néphrologie et Transplantation Rénale, Hôpital NORD, CHU de Saint-Etienne, Université Jean MONNET, 42055 Saint-Etienne cedex 02, France. Electronic address: claisse.guillaum@gmail.com.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Claisse
authors.affiliation: Laboratoire d'Immunologie, EFS Loire-Auvergne, 25 Boulevard Pasteur, 42100 Saint-Etienne, France. Electronic address: Lena.Absi@efs.sante.fr.
authors.forename: Lena
authors.initials: L
authors.lastname: Absi
authors.affiliation: GIMAP - EA3064, COMUE Université de Lyon, 42055 Saint-Etienne cedex 02, France; Laboratoire d'Immunologie, EFS Loire-Auvergne, 25 Boulevard Pasteur, 42100 Saint-Etienne, France. Electronic address: fabrice.cognasse@univ-st-etienne.fr.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Cognasse
authors.affiliation: Service de Néphrologie et Transplantation Rénale, Hôpital NORD, CHU de Saint-Etienne, Université Jean MONNET, 42055 Saint-Etienne cedex 02, France; GIMAP - EA3064, COMUE Université de Lyon, 42055 Saint-Etienne cedex 02, France. Electronic address: eric.alamartine@univ-st-etienne.fr.
authors.forename: Eric
authors.initials: E
authors.lastname: Alamartine
authors.affiliation: Service de Néphrologie et Transplantation Rénale, Hôpital NORD, CHU de Saint-Etienne, Université Jean MONNET, 42055 Saint-Etienne cedex 02, France; GIMAP - EA3064, COMUE Université de Lyon, 42055 Saint-Etienne cedex 02, France. Electronic address: christophe.mariat@univ-st-etienne.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Mariat
authors.affiliation: Service de Néphrologie et Transplantation Rénale, Hôpital NORD, CHU de Saint-Etienne, Université Jean MONNET, 42055 Saint-Etienne cedex 02, France; GIMAP - EA3064, COMUE Université de Lyon, 42055 Saint-Etienne cedex 02, France. Electronic address: nicolas.maillarda@gmail.com.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Maillard
mesh_terms: D000906:Antibodies / Q000378:metabolism; D000920:Antibody-Dependent Cell Cytotoxicity; D003167:Complement Activation; D015922:Complement C1q / Q000378:metabolism*; D015933:Complement C3d / Q000378:metabolism*; D006084:Graft Rejection / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology; D006650:Histocompatibility Testing / Q000379:methods*; D006801:Humans; D007114:Immunization; D007118:Immunoassay; D016030:Kidney Transplantation; D061848:Optical Imaging; D010956:Plasmapheresis; D011485:Protein Binding
chemical_list: D000906:Antibodies; D006680:HLA Antigens; D015922:Complement C1q; D015933:Complement C3d
keywords: C1q; C3d; LUMINEX; MFI; PROZONE