Glycated hemoglobin (HbA1c), which is measured in whole blood and not simultaneously with the other serum/plasma biomarkers on platform G.
Method(s): MALDI-TOF MS (1).
It is formed by non-enzymatically attachment of glucose to different amino groups of both 2 alpha and 2 beta chains of normal adult hemoglobin A (HbA). The relative amount of glucose bond to the N-terminal of the beta chain is measured as HbA1c. HbA1c is used to monitor long-term glycaemic control and treatment of diabetes.
Assessment of long-term glycemic control in diabetics.
Matrix: Whole blood.
Volume: Minimum volume is 20 µL, but 100 µL is optimal and allows reanalysis.
Preparation and stability: The blood sample must be put on ice, and frozen. HbA1c is stable for one week at 4-8C. At -70 °C, HbA1c is stable for many years and slightly increases if stored for more than one decade.
Reference values: 4-6%.
In diabetes patients values can range from 6.5 up to 14%.
Intraclass correlation coefficient (ICC): na.
1. Biroccio A, Urbani A, Massoud R, et al. (2005). A quantitative method for the analysis of glycated and glutathionylated hemoglobin by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Anal Biochem, 336(2):279-288.
2. Xu, A., Wang, Y., Li, J., Liu, G., Li, X., Chen, W. et al. (2019). Evaluation of MALDI-TOF MS for the measurement of glycated hemoglobin. Clin Chim Acta, 498, 154-160.