[Evaluation of HbA1c using different methods in haemoglobin variant, Hb J-Bangkok].

A 31-year-old Japanese man with haemoglobin variant, Hb J-Bangkok [beta56 (D7) Gly-->Asp], was found by discrepant values between HbA1c and glycated-albumin. We measured HbA1c using three different methods, HPLC, enzyme assay and turbidimetric immunoassay. HbA1c value measured by HPLC was much lower than those by others. Furthermore, we estimated calculated glyco-haemoglobin value measured by high-resolution HPLC, revealing that HbA1c values measured by enzyme assay and turbidimetric immunoassay were comparable with calculated value. When measuring HbA1c value in haemoglobin variant, Hb J Bangkok, enzyme assay and turbidimetric immunoassay are useful methods.