Measurement of glycated hemoglobin (HbA1c) is a key-role laboratory test in the management of diabetic patients. Clinicians need reliable and accurate measurements, with negligible pre-analytical and post-analytical errors. Among the pre-analytical variables, the presence of hemoglobin variants is a challenge to the laboratorians: the purpose of this document is to give some practical advices on how to report HbA1c values in presence of hemoglobin variants. Reporting is quite simple if measurement are carried on by HPLC and other similar analytical methods, when the Hb variant is well separated and does not interfere with HbA or HbA1c, such as in case of heterozygosis for HbS, HbC, HbD and HbE. In case of homozygosis or double heterozygosis for such variants the HbA1c values should not to be reported. Unusual HbA1c values, typically 15% (142 mmol/mol), could indicate the presence of hemoglobin variants. In these cases other approaches to the retrospective evaluation of glycemic control, based on the measurement of the glycation of different proteins, such as albumin, should be followed. Copyright original
