Techniques' Comparison and Report of the North Carolina Experience

Abstract

Controversy still exists as to the best laboratory method to use to screen newborns for sickle cell disease and other hemoglobinopathies. The proposed methods include hemoglobin electrophoresis, column chromatography, isoelectric focusing, and high performance liquid chromatography. There is also debate concerning the preferred method of sample collection. The proposed methods of sample collection include cord blood or blood obtained from the infant collected in a tube with anticoagulant or on filter paper. We compared hemoglobin electrophoresis patterns from infant blood samples collected in heparinized capillary tubes and on filter paper. This comparison was performed because hemoglobin electrophoresis of dried blood samples collected on filter paper has been advocated as a practical, reliable, and inexpensive method for mass screening programs, although the limitations of this technique have not been explored fully. We also summarize data from the North Carolina Newborn Hemoglobinopathy Screening Program, which relates to the advantages and limitations of hemoglobin electrophoresis from filter paper blood specimens. MATERIALS AND METHODS Specimens Four sets of specimens were used for this study: (1) specimens collected at Duke University Medical Center to compare hemoglobin electrophoresis patterns of hemolysates from filter paper and heparinized capillary tubes, (2) specimens collected by the North Carolina program for hemoglobinopathy screening, (3) specimens routinely collected at Duke University in heparinized capillary tubes for newborn hemoglobinopathy screening, and (4) samples for retesting to examine the error rate of the state program and to confirm screening results compatible with a hemoglobinopathy. Samples for Direct Comparison Between Filter Paper and Heparinized Specimens