title: Spurious hemoglobin Barts caused by bilirubin: a common interference mimicking an uncommon hemoglobinopathy.
abstract: High-performance liquid chromatography (HPLC) is replacing electrophoresis for identification of hemoglobin variants. Our objective was to identify unknown tall peaks with elution times and shapes of hemoglobin Barts found on hemoglobin chromatograms that could not be confirmed by alkaline and acid gel electrophoresis. Of 90 specimens identified with this peak, 86 were from patients with hemoglobin SS. Regression of the height of the unknown peaks to serum bilirubin concentrations, diminution of the unknown peaks by washing the specimens, and chromatographic similarity of a total bilirubin serum calibrator, a bilirubin proficiency testing specimen, and 3 patients' serum samples with markedly elevated bilirubin to hemoglobin Barts provide evidence the peak was bilirubin. We suggest exclusion of bilirubin before HPLC results are reported as consistent with hemoglobin Barts.
authors.affiliation: Department of Pathology, SUNY Downstate, and Kings County Hospital Center, Brooklyn, NY 11203, USA.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Howanitz
authors.forename: Tzvetan B
authors.initials: TB
authors.lastname: Kozarski
authors.forename: Joan H
authors.initials: JH
authors.lastname: Howanitz
authors.forename: Yeshpal S
authors.initials: YS
authors.lastname: Chauhan
mesh_terms: D000293:Adolescent; D000328:Adult; D001663:Bilirubin / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D004586:Electrophoresis; D006453:Hemoglobinopathies / Q000175:diagnosis*; D006454:Hemoglobins / Q000032:analysis* / Q000737:chemistry; D006455:Hemoglobins, Abnormal / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D008875:Middle Aged; D010641:Phenotype
chemical_list: D006454:Hemoglobins; D006455:Hemoglobins, Abnormal; C030448:hemoglobin Bart's; D001663:Bilirubin