Developing a reference system for the IFCC standardization of HbA.

The importance of hemoglobin A (HbA) as an indicator of the presence of β-thalassemia was established many years ago. However, clinical application of recommended HbA cut off values is often hampered due to poor equivalence of HbA results among methods and laboratories. Thus, the IFCC standardization program for HbA was initiated in 2004 with the goal of achieving a complete reference system for this measurand. HbA standardization efforts are still in progress, including the development of a higher-order HbA reference measurement procedure and the preparation of a certified reference material in collaboration with the IRMM. Here, we review the past, present and future of HbA standardization and describe the current status of HbA testing.