Hb Ube-2 in a Diabetic Case with an Abnormally Low HbA1C Value.

Abstract

A 69-year-old male diabetic patient had an abnormally low HbAlc value of 2.8% , which was inconsistent with his elevated fasting plasma glucose of 8.2 mmol//. Hb analysis disclosed that the abnormal Hb was Hb Ube-2 [oc68 (E17) Asn -+ Asp] and it accounted for 21.5% of the total Hb. Since the glycated abnormal Hb emerged at the same position as did HbF on high performance liquid chromatography, the HbAlc value was falsely low. The present case demonstrates that Hb Ube-2 is one of the abnormal Hbs in which caution should be exercised when monitoring diabetic control. (Internal Medicine 38: 800-803, 1999)

Two Cases in which an Abnormal Hemoglobin (Hb Kamakura) was Identified on the Basis of an Abnormally Low Glycohemoglobin Levels

“…The major peak of the abnormal Hb might even overlap with HbAic giving rise to an erroneously high HbAic level, thereby causing determination errors. Thus, both abnormally low HbAic levels, as in our cases (7)(8)(9), and abnormally high HbAic levels (10) have been reported in the past. In such cases of abnormal hemoglobin levels, the true levels can be obtained by immuneturbidimetry, except for variants with N-terminal substitution of the P globin chain.…”

A Japanese Family with Congenital Erythrocytosis Caused by Haemoglobin Bethesda

“…The presence of a Hb variant may be diagnosed in the course of the determination of HbA1c, by unexpectedly low or high HbA1c levels, as in the case of Hb Hiroshima. Therefore, particular care must be taken in daily medical practice due to deviations between the HbA1c values and actual blood sugar levels (15)(16)(17)(18). While the present patient had high levels of HbA1c, his fasting blood sugar was concurrently high and the patient's HbA1c levels were mostly normalised after initiating oral medication for diabetes, leading to good glycaemic control.…”

Haemoglobin variants may cause significant differences in haemoglobin A1c as measured by high-performance liquid chromatography and enzymatic methods in diabetic patients: a cross-sectional study

“…These mutations have been previously reported. 21–23 However, we could not utilize a β-thalassemia program (Variant II analyzer, Bio Rad Laboratories, Munich, Germany) to screen for β-thalassemia minor. 7 This system does not exist in Japan because β-thalassemia is very rare in the Japanese population, and most patients not only present anaemia but other clinical symptoms as well.…”