The effect of elevated fetal hemoglobin on hemoglobin A1c results

Hemoglobin A(1c) (HbA(1c)) is an important indicator of risk for complications in patients with diabetes mellitus. Elevated fetal hemoglobin (HbF) levels have been reported to interfere with results of some HbA(1c) methods, but it has generally been assumed that HbA(1c) results from boronate-affinity methods are not affected by elevated HbF levels. None of the previous studies used the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference method as the comparative HbA, method. We, therefore, measured HbA(1c), in samples with normal and elevated HbF levels by several common assay methods and compared the results with those of the IFCC reference method. HbF levels of more than 20% artificially lowered HbA(1c). results from the Primus CLC 3301385 (Primus Diagnostics, Kansas City, MO), Siemens DCA2000 (Siemens Healthcare Diagnostics, Tarrytown, NY), and Tosoh 2.2+ (Tosoh Bioscience, South San Francisco, CA), but not the Bio-Rad Variant H (Bio-Rad Laboratories, Hercules, CA) and Tosoh G7. Physicians and laboratory professionals need to be aware of potential interference from elevated HbF levels that could affect HbA(1c) results, including those from boronate-affinity methods.