No Effect of Anticoagulant on Hb A1c Analysis by the IFCC Reference Procedure

To the Editor:The use of glycohemoglobin (Hb A1c)1 as a diagnostic marker has been limited because of the lack of a standardized method. Hb A1c estimation with the commercially available instruments is based on different analytical and immunological principles that are method and reagent dependent. Consequently, several global initiatives have been taken toward optimizing and standardizing Hb A1c estimation. An IFCC working group carried out one such initiative, which is now considered the gold standard for Hb A1c measurement (1–4). This method is based on the proteolytic digestion of the N-terminal β chain of Hb A1c and Hb A, followed by chromatographic separation of the hexapeptides and quantification by either liquid chromatography–mass spectrometry or capillary electrophoresis with ultraviolet detection.Anticoagulants are used to prevent the coagulation of blood. The IFCC method uses EDTA as the anticoagulant. The effects of other anticoagulants have not been studied, however, although they are known …