Interference of Thalassemias on Hemoglobin A1c Measurement by Ion-Exchange High-Performance Liquid Chromatography Method Tosoh HLC-723 G8

Abstract

The presence of hemoglobinopathies could interfere with some assays for Hemoglobin A1c (HbA1c) measurement; therefore, the effect of thalassemia on ion-exchange high-performance liquid chromatography (IEHPLC) method Tosoh HLC-723 G8 (Tosoh G8) was evaluated. A total of 43 normal controls and 101 thalassemia patients were quantified by Premier Hb9210 and Tosoh G8 (variant-mode) systems. At the same time, 7 normal controls and 8 thalassemia patients were confirmed by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference method for verification. For normal controls, the HbA1c values of Tosoh G8 system (y) showed great correlation and agreement with those from Premier Hb9210 (x) (y = 0.9688x + 0.2151, r = 0.9951; mean difference 0.02 ± 0.30%), and no significant relative bias above 7% was observed; the HbA1c values obtained by Tosoh G8 were consistent with the IFCC targets (relative bias < ± 6%) in all of the samples. However, for thalassemia, the correlation between Tosoh G8 (y) and Premier Hb9210 (x) became relatively low (y = 0.8079x + 1.2897, r = 0.7780); the HbA1c values of 91.1% of the samples (92/101) obtained by Tosoh G8 were higher than those by Premier Hb9210 (mean difference 0.33 ± 0.48%) and a significant positive bias above 7% was noticed in 43.3% (45/101) thalassemia patients; when compared with the IFCC targets, the 87.5% (7/8) relative bias was > ± 6%. Thalassemia could directly affect the measurement of HbA1c using the IE-HPLC method Tosoh G8 and the clinical laboratorial staff should pay close attention.