Effect of sickle cell trait and B-Thalassemia minor on determinations of HbA1c by an immunoassay method

OBJECTIVE: Glycated hemoglobin determination is being used worldwide to monitor the efficiency of blood glucose control and to plan treatment in diabetes mellitus patients. Several methods are used for measuring glycated hemoglobin, but a possible interference by hemoglobin variants is a major concern. The use of immunoassay methods with glycated hemoglobin-specific antibodies is supposed to overcome this problem. We are evaluating the effect of the most prevalent hemoglobinopathies in the region (sickle trait hemoglobin and B-Thalassemia) on the immunoassay method used in determining glycated hemoglobin.

METHODS: Eighty-one whole blood sample hemolysates were tested for glycated hemoglobin using Beckman Synchron LX20 system, 37 of these normal adult hemoglobin represented 22 diabetic and 15 non-diabetic samples. Of the remaining 44 samples, 28 were from B-thalassemia minor and 16 from sickle-cell trait sickle trait hemoglobin patients, all non-diabetic. The samples were collected in ethylenediaminetetraacetic acid anticoagulant and analyzed immediately or stored at 4?C for not more than 2 days.

RESULTS: Sickle trait hemoglobin had no effect on glycated hemoglobin measurement by Synchron LX20 while B-thalassemia minor blood elevated the value of glycated hemoglobin to the range of diabetic cases.

CONCLUSION: Synchron LX20 glycated hemoglobin immunoassay method gave falsely high glycated hemoglobin results with B-thalassemia minor patient samples. Therefore, while interpreting the results of Synchron LX20 glycated hemoglobin, the patients history regarding hemoglobinopathies should be checked.