Falskt högt HbA1c pga fetalt Hba
Från South Med J. 2000:93(1):62-64.

   Spurious Elevation of Hemoglobin A1c by Hereditary Persistence of Fetal Hemoglobin Leonard E. Egede, MD, Eugene Obah, MD, Teresa Lorch, MD, Tatania Oussova, MD. Internal Medicine Residency Program, Greater Baltimore Medical Center, Baltimore, Md. Our patient did not meet the revised 1997 American Diabetes Association criteria for the diagnosis of type 2 DM, even though she had carried the diagnosis for years. Serum fructosamine level, blood glucose levels, and results of glucose tolerance tests were normal, giving evidence of a spurious elevation of HbA1c.

    We believe this spurious HbA1c elevation was due to the heterozygous trait of HPFH. On the basis of our case and review of the literature, we recommend the following: (1) HbA1c should not be used as a screening tool in patients without formally diagnosed type 2 diabetes according to the current American Diabetes Association criteria until a universal standard for interlaboratory calibration being developed by the American Association of Clinical Chemistry becomes available [7,8].

    (2) High HbA1c levels should not be the only basis for treatment. Values should be correlated with the clinical picture and home-monitored blood glucose values [6]. (3) In situations where HbA1c levels do not correlate with home or fasting blood glucose levels, the presence of abnormal hemoglobins should be considered if ion-exchange elution is the method used for determining HbA1c [5]. (4)

    Laboratories should specify the method used for determining HbA1c whenever it is reported. Laboratories that use the electrophoretic method should periodically assess the prevalence of HbF in their population and if the prevalence is >2%, they should consider alternative methods as proposed by Cox et al.[5]

    We alert physicians and allied health care professionals to this potentially significant problem in the diagnosis and management of DM, particularly in the wake of the Diabetes Complications and Control Trial when strict glycemic control monitored by HbA1c is considered optimal care.

    We recommend the serum fructosamine test as a cost-effective adjunct in assessment of glycemic control, especially in diabetic patients with abnormal hemoglobins.


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