title: Anti-U-like as an alloantibody in S-s-U- and S-s-U+(var)  black people.
abstract: BACKGROUND
  S, s, and U antigens belong to the MNS system. They are carried by glycophorin B (GPB), encoded by GYPB. Black people with the low-prevalence S-s- phenotype, either U- or U+(var), can make a clinically significant anti-U. Anti-U-like, a cold immunoglobulin G autoantibody quite commonly observed in S-s+U+ black persons, was previously described to be nonreactive with ficin-, α-chymotrypsin-, and pronase-treated red blood cells (RBCs); nonreactive or weakly reactive with papain-treated RBCs; and reactive with trypsin-treated RBCs. Here we describe, in S-s- people from different molecular backgrounds, an alloantibody to a high-prevalence GPB antigen, which presents the same pattern of reactivity with proteases as autoanti-U-like.
  
  
  METHODS
  Four S-s- patients with an alloantibody to a high-prevalence GPB antigen were investigated by serologic and molecular methods.
  
  
  RESULTS
  An alloantibody was observed in two S-s-U-/Del GYPB, one S-s-U+(var)/GYPB(P2), and one S-s-U+(var)/GYPB(NY) patients. As this alloantibody showed the same pattern of reactivity with proteases as autoanti-U-like, we decided to name it "anti-U-like." Anti-U-like made by the two S-s-U- patients was reactive with the S-s-U+(var) RBCs of the two other patients.
  
  
  CONCLUSIONS
  S-s-U-/Del GYPB, S-s-U+(var)/GYPB(P2), and S-s-U+(var)/GYPB(NY) patients can make an alloanti-U-like. Anti-U-like made by S-s-U- people appears reactive with GYPB(P2) and GYPB(NY) RBCs, which both express a weak and partial U-like reactivity. We recommend transfusing S-s-U- RBCs in S-s-U- patients showing alloanti-U-like. Our study contributes to a better understanding of alloimmunization to GPB in black people and confirms importance of genotyping in S-s- patients, especially those with sickle cell disease to be frequently transfused.
authors: Centre National de Référence pour les Groupes Sanguins and the Unité de Biochimie et Génétique Moléculaire, Institut National de la Transfusion Sanguine, France. tpeyrard@ints.fr
authors: Thierry
authors: T
authors: Peyrard
authors: Yin
authors: Y
authors: Lam
authors: Carole
authors: C
authors: Saison
authors: Lionel
authors: L
authors: Arnaud
authors: Jérôme
authors: J
authors: Babinet
authors: Philippe
authors: P
authors: Rouger
authors: Philippe
authors: P
authors: Bierling
authors: Daniel
authors: D
authors: Janvier
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D044383:Black People / Q000235:genetics* / Q000706:statistics & numerical data; D005260:Female; D005838:Genotype; D006021:Glycophorins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006384:Hemagglutination; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D007518:Isoantibodies / Q000097:blood / Q000276:immunology*; D008951:MNSs Blood-Group System / Q000235:genetics* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011247:Pregnancy; D016036:Seroepidemiologic Studies; D055815:Young Adult
chemical_list: D001323:Autoantibodies; C409972:GYPA protein, human; C409973:GYPB protein, human; D006021:Glycophorins; D007074:Immunoglobulin G; D007518:Isoantibodies; D008951:MNSs Blood-Group System; C476165:anti-U-like antibody, human