title: Carboxyhemoglobin levels as a predictor of risk for significant hyperbilirubinemia in African-American DAT(+) infants.
abstract: To compare the degree of hemolysis in a group of direct antiglobulin test (DAT) positive (pos) African-American (AA) infants as measured by carboxyhemoglobin corrected (COHbc) for carbon monoxide in ambient air to a similar group of DAT negative (neg) ABO incompatible infants and a group without blood group incompatibility. To determine if COHbc is a better predictor of significant hyperbilirubinemia than DAT status.
  
  
  
  A prospective study of 180 AA infants from the Well-Baby Nursery of an inner city community hospital, all of whose mothers were type O pos. Infants (60) were ABO incompatible DAT pos, 60 were ABO incompatible DAT neg and 60 were type O(+). Blood for COHbc was drawn at the time of the infants' initial bilirubin and the infants' precise percentile on the Bhutani nomogram was calculated.
  
  
  
  Mean COHbc of type O(+) infants was 0.76±0.21 and 0.78±0.24% for ABO incompatible DAT neg infants (P=0.63). Mean CoHbc for the ABO incompatible DAT pos infants was 1.03±0.41% (P<0.0001 compared with both type O and DAT neg infants). Optimal cutoff on the receiver operating characteristic curve for COHbc to determine the risk for being in the Bhutani curve high risk zone was COHbc >0.90% (area under the curve(AUC) 0.8113). This was similar to the AUC of the receiver operating characteristic curve using any titer strength of DAT pos as a cutoff (0.7960).
  
  
  
  Although not greatly superior to the titer strength of DAT pos, COHbc is useful in determining if the etiology of severe hyperbilirubinemia is a hemolytic process.
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Einstein Medical Center, Philadelphia, PA, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Schutzman
authors.affiliation: Department of Pediatrics, Michigan State University, Lansing, MI, USA.
authors.forename: E
authors.initials: E
authors.lastname: Gatien
authors.affiliation: Division of Neonatology, Saint Christopher's Hospital for Children, Philadelphia, PA, USA.
authors.forename: S
authors.initials: S
authors.lastname: Ajayi
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Wong
mesh_terms: D000017:ABO Blood-Group System / Q000032:analysis; D001741:Black or African American / Q000706:statistics & numerical data; D001663:Bilirubin / Q000097:blood; D001787:Blood Group Incompatibility / Q000175:diagnosis; D002263:Carboxyhemoglobin / Q000032:analysis*; D003298:Coombs Test / Q000379:methods*; D005260:Female; D006461:Hemolysis / Q000502:physiology*; D006801:Humans; D051556:Hyperbilirubinemia, Neonatal / Q000097:blood / Q000175:diagnosis / Q000208:ethnology / Q000209:etiology; D007231:Infant, Newborn; D008297:Male; D049451:Nomograms; D011446:Prospective Studies; D014481:United States / Q000453:epidemiology
chemical_list: D000017:ABO Blood-Group System; D002263:Carboxyhemoglobin; D001663:Bilirubin