A 70-year-old male with a history of type 2 diabetes mellitus (T2DM) presented to an outpatient laboratory for routine venipuncture to evaluate glycemic management and cardiovascular disease risk.
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Nicole J. Mathewson, Lauren N. Pearson, and Kelly Doyle
A 70-year-old male with a history of type 2 diabetes mellitus (T2DM) presented to an outpatient laboratory for routine venipuncture to evaluate glycemic management and cardiovascular disease risk. The patient arrived at the laboratory alert, with no apparent distress. Hemoglobin A1c (Hb A1c) testing was performed along with a lipid panel for routine screening of lipid disorders. The lipid panel results demonstrated mixed hyperlipidemia, showing increased triglycerides and decreased HDL cholesterol. The Hb A1c analysis by capillary electrophoresis (CE) on the Sebia CAPILLARYS 3 TERA instrument resulted with a flag for an atypical profile in the electropherogram and no Hb A1c value was reported. Prior Hb A1c measurements throughout the past year demonstrated Hb A1c concentrations ≥6.5%, consistent with his diagnosis of T2DM, and revealed a downward trend in the Hb A1c concentration. The patient was not receiving medical treatment or medications known to affect red blood cells or Hb A1c measurement. The inconclusive Hb A1c result was repeated with a different instrument and another sample from the patient, collected at a different phlebotomy location, showed similar inconclusive results as the previous specimen. Compared to typical hemoglobin and Hb A1c migration patterns, this patient’s specimens resulted in unusual shifts in hemoglobin peak migration times as observed upon close review of the electropherogram, suggesting a potential analytical interference of the Hb A1c measurement.