PDF(Pubmed)
Abstract：
Hemoglobin A1c (HbA1c) refers to non-enzymatically glycated hemoglobin and reflects the patient\'s glycemic status over approximately 3 months. An elevated HbA1c over 6.5% National Glycohemoglobin Standardization Program (NGSP) (48 mmol/mol the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC)) can be used to diagnose diabetes mellitus. In our laboratory, HbA1c is determined by ion-exchange chromatography which has the advantage of detecting common Hb variants such as Hb S, C, E and D without adversely affecting the HbA1c determination. Certain homozygous or compound heterozygous hemoglobinopathies such as homozygous sickle disease and Hb SC disease can significantly lower the HbA1c by reducing red cell lifespan. Occasionally however, rare and mostly benign hemoglobinopathies can interfere with this technique resulting in an apparent elevation of HbA1c in an otherwise non-diabetic patient. In this report, we describe such a hemoglobinopathy termed Hb Wayne that resulted in a significant HbA1c elevation in a normoglycemic individual. HbA1c was determined by multiple methods including immunoassay, a modified capillary electrophoresis and an alternative ion-exchange system. These techniques yielded significantly lower A1c results, more in keeping with the patient\'s clinical background. The alternative ion-exchange system resulted in a low A1c that was qualified by warning flags on the chromatogram that indicated the result was not reportable. The hemoglobinopathy in question, Hb Wayne, is a frameshift mutation in the alpha globin gene that results in an extended alpha globin polypeptide that can form two variants Hb Wayne I and Wayne II. Hb Wayne is a clinically silent asymptomatic disorder with no hematologic consequences. The artifactual elevation of HbA1c is, in contrast, very significant because it may result in a misdiagnosis of diabetes mellitus leading to unnecessary treatment. In this report, we compare our findings with other descriptions of Hb Wayne in the literature and corroborate a number of previous observations and conclusions.
摘要：
血红蛋白A1c（HbA1c）是指非酶糖化血红蛋白，反映了患者在大约3个月内的血糖状态。超过6.5％的HbA1c升高国家糖化血红蛋白标准化计划（NGSP）（48mmol/mol国际临床化学和实验室医学联合会（IFCC））可用于诊断糖尿病。在我们的实验室里,HbA1c通过离子交换色谱法测定，该色谱法具有检测常见Hb变体如HbS的优势，C,E和D对HbA1c测定无不良影响。某些纯合或复合杂合血红蛋白病，例如纯合镰状病和HbSC病，可以通过减少红细胞寿命来显着降低HbA1c。然而，偶尔，罕见且大部分为良性血红蛋白病可干扰该技术,导致非糖尿病患者HbA1c明显升高.在这份报告中,我们描述了一种称为HbWayne的血红蛋白病,它导致血糖正常个体的HbA1c显著升高.HbA1c通过多种方法测定，包括免疫测定，改进的毛细管电泳和替代的离子交换系统。这些技术产生显著较低的A1c结果，更符合患者的临床背景。替代离子交换系统导致低A1c，色谱上的警告标志表明结果不可报告。有问题的血红蛋白病，HbWayne,是α珠蛋白基因中的移码突变,其导致可形成两个变体HbWayneI和WayneII的延伸α珠蛋白多肽。HbWayne是一种临床上无症状的无症状疾病，没有血液学后果。HbA1c的人为升高是，相比之下,非常重要，因为它可能导致糖尿病的误诊，导致不必要的治疗。在这份报告中,我们将我们的发现与文献中对HbWayne的其他描述进行了比较,并证实了之前的一些观察和结论.
