Effect of Diabetes Mellitus on Sickle Hemoglobin Quantitation in Sickle Cell Trait.

OBJECTIVES

We evaluated the effect of diabetes on sickle hemoglobin (HbS) measurement on two common clinical hemoglobin separation platforms.

METHODS

We performed a method comparison between the Bio-Rad Variant II high-performance liquid chromatography (HPLC) and Sebia Capillarys 2 Flex Piercing capillary electrophoresis (CE) using clinical specimens from 38 patients without hemoglobin variants and 57 patients with sickle cell trait (AS) (HbA1c%, 4.1%-15.4%). We investigated the effect of intermethod Hb% differences on result interpretation by a panel of expert clinical observers.

RESULTS

In diabetic specimens, HPLC undermeasured HbS% up to 7.4% vs CE, due to S1c eluting closely with A0 in HPLC. This increased concern for underlying α-thalassemia in diabetic patients with AS based on HPLC results. HPLC P2% was linearly related to HbA1c% and can be a screen for diabetic AS samples.

CONCLUSIONS

Glycosylation can interfere with HbS% measurement by HPLC. Susceptible specimens should be identified and preferentially analyzed via CE.