Riscontro occasionale di una condizione emolitica mediante la determinazione di HbA1c in elettroforesi capillare
Casual finding of a hemolytic condition through the determination of HbA1c by capillary electrophoresis

AUTORI

ABSTRACT

Casual finding of a hemolytic condition through the determination of HbA1c by capillary electrophoresis

HbA1c is a major hemoglobin characterized by nonenzymatic binding of glucose to the N-terminal valine residue of the hemoglobin β-chain, which reflects average glucose levels during the erythrocyte lifespan. This test has been recommended for diabetes monitoring and even for diagnosis, as well as in assessing the risk for chronic complications in diabetic patients. Therefore, an accurate measurement of HbA1c is extremely important. However, the reliability of HbA1c is impaired in certain clinical conditions, such as hemolytic anemia, blood transfusion, renal disease, and pregnancy, that increase the erythrocyte turnover or reduce its lifespan. We report the case of a 38-years-old woman with previous history of high fasting plasma glucose level who underwent routine laboratory assessment. The analysis of HbA1c by capillary electrophoresis (CE) showed an atypical profile with a clear presence of abnormal hemoglobin that did not allow to obtain a reliable result for HbA1c. The same sample analyzed by HPLC showed, the presence of an abnormal Hb and obtained a different result for HbA1c. Subsequently, the analysis of hemoglobin fractions in CE (using Hemoglobin kit- Sebia) confirmed an atypical profile with the presence of an abnormal hemoglobin peak (27.3%) in the “zone Z15” and low HbA2 (0.5%). The molecular investigation of the globin genes highlighted the presence of three mutations of the α-genes compatible with HbH disease. The HbH disease is responsible for a hemolytic condition that is associated with reduced erythrocyte survival, making it impossible to use HbA1c for diagnosis and monitoring the glycemic status in this patient. The use of separative technologies, such as CE and HPLC, has been useful to detect a thalassemic defect, which must be reported to allow correct diagnostic conclusions. In this condition, the introduction of alternative biomarkers like glycated albumin (GA) is thought to be more reliable than HbA1c, since GA values are not influenced by the modifications of the erythrocyte lifespan.

BIBLIOGRAFIA