title: High background in Luminex® assay for HLA antibody screening: Interest of Adsorb Out™.
abstract: The Luminex® technology has become an integral component of clinical decision-making and diagnosis of transplanted organ rejection. Despite the superior sensibility of this technology, it is not completely problem free. We have observed in these bead-based assays that sera of some patients give a high negative control bead (NC) value which makes assessing HLA antibodies difficult. Treatment of sera by the Adsorb Out™ reagent may reduce the high background. In this study, we want to evaluate the effect of the Adsorb Out™ on the NC's MFI value by comparing treated and untreated patients' sera.
  
  
  
  HLA antibody screening was performed on 3011 sera. These sera came from patients awaiting and undergoing renal transplant from different Moroccan hospitals. The sera were analyzed using the standard protocol for Luminex® antibody screening. Sera with high NC's value has been pre-incubated by the Adsorb Out™, and analyzed on Luminex®.
  
  
  
  3% of studied samples have high NC's value. The Adsorb Out™ decreases the NC's value and brings it back to a normal range in 62.2% treated sera. It has no effect in 12.3%. The Adsorb Out™ effect depends only of NC's value, independently to age, storage date, sex and immunization.
  
  
  
  The Adsorb Out™ reagent has an important effect in decreasing NC value of sera. However, it has no effect in some patient's sera. In these cases we could try another treatment, as EDTA, DTT. The non-specific binding may be caused by multiple patient-specific factors, it would be important to search correlation between them and NC's values.
authors.affiliation: UPR d'immunologie, Faculté de médecine et de pharmacie de Rabat, Université Mohamed V, Rabat, Morocco. Electronic address: Asmae.zerrouki@um5s.net.ma.
authors.forename: Asmae
authors.initials: A
authors.lastname: Zerrouki
authors.affiliation: UPR d'immunologie, Faculté de médecine et de pharmacie de Rabat, Université Mohamed V, Rabat, Morocco; Service de transfusion sanguine et d'hémovigilance, Centre Hospitalier Ibn Sina, Rabat, Morocco.
authors.forename: Sanae
authors.initials: S
authors.lastname: Ouadghiri
authors.affiliation: UPR d'immunologie, Faculté de médecine et de pharmacie de Rabat, Université Mohamed V, Rabat, Morocco; Service de transfusion sanguine et d'hémovigilance, Centre Hospitalier Ibn Sina, Rabat, Morocco.
authors.forename: Nadia
authors.initials: N
authors.lastname: Benseffaj
authors.affiliation: Laboratoire de médecine sociale, Laboratoire d'épidémiologie et de recherche clinique, Faculté de médecine et de pharmacie de Rabat, Université Mohamed V, Rabat, Morocco.
authors.forename: Rachid
authors.initials: R
authors.lastname: Razine
authors.affiliation: UPR d'immunologie, Faculté de médecine et de pharmacie de Rabat, Université Mohamed V, Rabat, Morocco; Service de transfusion sanguine et d'hémovigilance, Centre Hospitalier Ibn Sina, Rabat, Morocco.
authors.forename: Malika
authors.initials: M
authors.lastname: Essakalli
mesh_terms: D000906:Antibodies / Q000378:metabolism*; D000066491:Clinical Decision-Making; D003951:Diagnostic Errors / Q000517:prevention & control*; D005260:Female; D006084:Graft Rejection / Q000175:diagnosis*; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D007164:Immunosorbents / Q000378:metabolism; D007202:Indicators and Reagents / Q000378:metabolism; D016030:Kidney Transplantation; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009018:Morocco; D012015:Reference Standards
chemical_list: D000906:Antibodies; D006680:HLA Antigens; D007164:Immunosorbents; D007202:Indicators and Reagents
keywords: Adsorb Out™; HLA antibodies; High negative control bead value; Luminex