Interference with hemoglobin A(1C) determination by the hemoglobin variant Shelby.
Hemoglobin variant carrier status was found in a 46-year-old African American man following detection of a falsely elevated hemoglobin A1c (HbA1c) by ionexchange high-performance liquid chromatography (HPLC, VARIANT A1c, Bio-Rad Laboratories, Hercules, CA). Additional analysis of the hemoglobin variant using the Beta Thal Short program (Bio-Rad) revealed an unknown peak with a retention time of 4.84 minutes and a proportion of 26.3%. No mass shift in alpha-globin or beta-globin proteins was observed by mass spectrometry. DNA sequencing revealed a missense mutation in 1 beta-globin allele corresponding to the hemoglobin Shelby trait. The patient was asymptomatic with a normal hemoglobin value of 13.6 g/dL (136 g/L) but had increased target cells on a peripheral blood smear. An alternative method for HbA1c determination using boronate-affinity HPLC provided a value of 3.9% (0.04; reference range, 4.0%-6.9% [0.04-0.07]), more consistent with the patient's recent blood glucose values in the normal range.
Scuderi
Richard T
RT
The Department of Pathology, University of California San Diego, La Jolla, CA, USA.
Griffin
Terrance L
TL
Mehta
Shruti P
SP
Herold
David A
DA
Fitzgerald
Robert L
RL
D001786:Blood Glucose; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D005914:Globins / Q000235:genetics; D006442:Glycated Hemoglobin / Q000032:analysis*; D006452:Hemoglobinometry; D006455:Hemoglobins, Abnormal; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D019300:Medical Errors; D008875:Middle Aged; D020125:Mutation, Missense
D001786:Blood Glucose; D005914:Globins; D006442:Glycated Hemoglobin; D006455:Hemoglobins, Abnormal; C044398:hemoglobin Shelby