title: Adsorption of autoantibodies in the presence of LISS to detect alloantibodies underlying warm autoantibodies.
abstract: BACKGROUND
  The safe transfusion of patients with warm autoimmune hemolytic anemia requires an efficient and time-saving assay to detect alloantibodies underlying autoantibodies. Methods used include RBCs treated with ZZAP reagent, proteolytic enzyme, or untreated RBCs in the presence of PEG. We propose a method using LISS, which presents some advantages over previous methods.
  
  
  METHODS
  We evaluated the effectiveness of autoantibody adsorption with papain-treated and untreated RBCs in the presence of LISS for removal of autoantibodies, without affecting alloantibodies.
  
  
  RESULTS
  One-hundred twenty sera containing autoantibodies were adsorbed with our routine method, which uses papain-treated allogeneic RBCs. Seven-hundred twenty adsorptions (mean, 6 per sample) and 21,600 minutes (mean, 180 min per sample) were required to remove autoantibodies. Fifty sera were adsorbed with our routine method that uses papain-treated allogeneic RBCs in the presence of LISS. The number of adsorptions and the completion time were, respectively, 144 (mean, 2.9 per sample) and 2,880 minutes (mean, 57.6 min per sample). Twenty sera were evaluated with untreated autologous RBCs, in the presence of LISS; 58 adsorptions (mean, 2.9) and 1,160 minutes (mean, 58 min per sample) were required. Three adsorptions with antigen-negative allogeneic RBCs were performed on 8 sera containing alloantibodies with weak reactivity (anti-K [1], anti-D [1], anti-Fya[2], anti-S [2], anti-E [1], and anti-Jka[1]). Alloantibodies were detected with the LISS procedure with papain-treated and untreated RBCs and the routine papain method. Alloantibodies with weak reactivity, tested against the same antibody-detection RBCs, remained unchanged following adsorption of 5 sera. An anti-S, with very weak reactivity, was no longer detected, and an anti-Jka became weaker (1+), regardless of the procedure used. One anti-D became weaker only with the LISS adsorption method.
  
  
  CONCLUSIONS
  Autoantibodies can be adsorbed more efficiently in the presence of LISS.
authors.affiliation: Etablissement Français du Sang Alpes Méditerranée, 149, Boulevard Baille, 13005 Marseille, France. jacques.chiaroni@efs.sante.fr
authors.forename: Jacques
authors.initials: J
authors.lastname: Chiaroni
authors.forename: Mohammed
authors.initials: M
authors.lastname: Touinssi
authors.forename: Magali
authors.initials: M
authors.lastname: Mazet
authors.forename: Philippe
authors.initials: P
authors.lastname: De Micco
authors.forename: Virginie
authors.initials: V
authors.lastname: Ferrera
mesh_terms: D001323:Autoantibodies; D004912:Erythrocytes / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D007163:Immunosorbent Techniques / Q000592:standards; D007518:Isoantibodies / Q000032:analysis* / Q000276:immunology; D010206:Papain / Q000494:pharmacology; D012189:Retrospective Studies
chemical_list: D001323:Autoantibodies; D007518:Isoantibodies; D010206:Papain