2019 Volume 62 Issue 1 Pages 31-36
A 57-year-old woman was found to have a high plasma glucose level at a health checkup and visited a diabetes clinic. Unexpectedly, she had a low hemoglobin A1c (HbA1c) of only 4.9 % on high-performance liquid chromatography (HPLC) (HA-8170; Arkray, Kyoto, Japan), while the blood glucose level was 295 mg/dL. High-quality HPLC revealed an extra peak, suggesting the presence of variant hemoglobin. The HbA1c level was 6.6 % when measured by an enzymatic assay. This patient was referred to our hospital with suspected variant hemoglobin but did not attend for one year due to pressure of work. At our initial examination, the postprandial (3 h) blood glucose level was 323 mg/dL, HbA1c (measured by enzymatic assay) was 12.1 %, glycoalbumin was 34.4 %, and urinary ketone bodies were positive. Accordingly, she was urgently hospitalized with a diagnosis of diabetic ketosis. An analysis of the globin gene revealed a heterozygous mutation, and we made a diagnosis of hemoglobin Montfermeil [β130 (H8) Tyr→Cys]. This is the first report to indicate that measurement of HbA1c by HPLC (HA-8170) can show false low values due to hemoglobin Montfermeil.
