Labile hemoglobin A1c: A factor affecting the estimation of glycated hemoglobin

Abstract

Labile hemoglobin A1c (also known as pre-HbA1c or LA1c or pre-glycohemoglobin) an unstable form, is a Schiff base formed during non-enzymatic glycation of hemoglobin. The concentration of labile fraction varies with acute change in plasma glucose level. Labile hemoglobin A1c fraction cannot be separated from the stable ketoamine fraction by most of the methods available for estimation of glycated hemoglobin (HbA1c). Though ion-exchange HPLC (high pressure liquid chromatography) method can separate the labile HbA1c fraction, but in some situation abnormally high level of this fraction may serve as a pre-analytical error interfering in estimation of glycated hemoglobin. By focusing on the hemoglobin chromatogram, reporting of this pre-analytical error can be minimized in HPLC method.

Keywords

• Diabetes,Glycated hemoglobin,HPLC,Labile hemoglobin

References

1. 1. Bunn HF, Haney DN, Kamin S, Gabbay KH, Gallop PM. The biosynthesis of human hemoglobin A1c: Slow glycosylation of hemoglobin in vivo. J Clin Invest. 1976;57:16529. 2. John WG. Effect of Schiff base (labile fraction) on the measurement of glycated hemoglobin by affinity chromatography. Clin Chem. 1984; 30: 1111-2. 3. Goldstein DE, Peth SB, England JD, et al., Effects of acute changes in blood glucose on HbA1c. Diabetes. 1980; 29: 623-8. 4. The Diabetes Control and Complications Trial Research Group. The effect of intensive treatment of diabetes on the development and progression of long term complications in insulin dependent diabetes mellitus. N Eng J Med. 1993;329: 977 – 86.
2. 5. Chandalia HB, Krishnaswamy PR. Glycated hemoglobin. Curr Scie. 2002; 83: 1522 – 32. 6. Kaiser P, Akerboom T, Molnar P, Reinauer H. Modified HPLC-Electrospray Ionization/ Mass Spectrometry Method for HbA1c Based on IFCC Reference Measurement Procedure. Clin Chem. 2008; 54:6 1018–22. 7. Bannon P, Joly JG, Lessard F, Lepage R. Comparison of three methods for the elimination of the labile fraction of the HbA1c. Clin Biochem. 1985; 18: 114 – 7. 8. Yatscoff RW, Tevaarwerk GJM, Clarson CL, Warnock LM. Interference of fetal hemoglobin and labile glycosylated hemoglobin with measurements of glycosylated hemoglobin. Clin Chem. 1983; 29: 543 – 5. 9. Corbe-Guillard E, Jaisson S, Pileire C, Gillery P. Labile hemoglobin A1c: unexpected indicator of preanalytical contraindications. Clin Chem. 2011; 57: 340-6.