title: Hemolysis and hyperbilirubinemia in antiglobulin positive, direct ABO blood group heterospecific neonates.
abstract: OBJECTIVE
  We quantified hemolysis and determined the incidence of hyperbilirubinemia in neonates who were direct antiglobulin titer (DAT)-positive, ABO heterospecific, and compared variables among O-A and O-B subgroups.
  
  
  METHODS
  Plasma total bilirubin (PTB) was determined before the neonates were discharged from the hospital and more frequently when clinically warranted, in neonates who were DAT positive with blood group A or B and with mothers who had blood group O. Heme catabolism (and therefore bilirubin production) was indexed by blood carboxyhemoglobin corrected for inspired carbon monoxide (COHbc). Hyperbilirubinemia was defined as any PTB concentration >95th percentile on the hour-of-life-specific bilirubin nomogram.
  
  
  RESULTS
  Of 164 neonates, 111 were O-A and 53 O-B. Overall, hyperbilirubinemia developed 85 neonates (51.8%), and it tended to be more prevalent in the O-B neonates than O-A neonates (62.3% versus 46.8%; P = .053). Hyperbilirubinemia developed in more O-B newborns than O-A newborns at <24 hours (93.9% versus 48.1%; P< .0001). COHbc values were globally higher than our previously published newborn values. Babies in whom hyperbilirubinemia developed had higher COHbc values than the already high values of babies who were non-hyperbilirubinemic, and O-B newborns tended to have higher values than their O-A counterparts.
  
  
  CONCLUSIONS
  DAT-positive, ABO heterospecificity is associated with increased hemolysis and a high incidence of neonatal hyperbilirubinemia. O-B heterospecificity tends to confer even higher risk than O-A counterparts.
authors.affiliation: Department of Neonatology, Shaare Zedek Medical Center, Jerusalem, Israel; Faculty of Medicine, The Hebrew University, Jerusalem, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Kaplan
authors.forename: Cathy
authors.initials: C
authors.lastname: Hammerman
authors.forename: Hendrik J
authors.initials: HJ
authors.lastname: Vreman
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wong
authors.forename: David K
authors.initials: DK
authors.lastname: Stevenson
mesh_terms: D000017:ABO Blood-Group System / Q000097:blood*; D000888:Antibodies, Anti-Idiotypic / Q000097:blood*; D005260:Female; D006461:Hemolysis; D006801:Humans; D051556:Hyperbilirubinemia, Neonatal / Q000097:blood* / Q000150:complications* / Q000453:epidemiology; D015994:Incidence; D007231:Infant, Newborn; D008297:Male
chemical_list: D000017:ABO Blood-Group System; D000888:Antibodies, Anti-Idiotypic