Quantitation of hemoglobins using Sebia Capillarys-2 capillary electrophoresis (CE) for A1c: Comparison to results using CE for hemoglobins

Background: Measurement of A1c using the Sebia Capillarys-2 capillary electrophoresis (A1c CE) involves relative quantitative measurements of peaks for hemoglobins A1c, A, A2. We examined correlation of A1c CE results with results of CE analysis for hemoglobins (Hb CE) for homozygous A and S-trait patients. We specifically examined whether abnormalities in A2 or the A/S ratio by A1c CE alone would reasonably be the basis for recommendation of red cell indices for evaluation of possible thalassemia. Methods: Selection of patients was from results for A1c CE, exhibiting either a normal pattern or a pattern consistent with S-trait. We then examined correlation of results of quantitation for A, S and A2 between A1c CE and Hb CE. Results: %A2 by A1c CE (y) had high correlation with %A2 by Hb CE (x): y = 0.88 x; r = 0.948. %A2 in S-trait patients was right-shifted in comparison to normals by 0.5%. For S-trait patients, the A/S ratio by A1c CE (y) had high correlation with the A/S ratio by Hb CE (x): y = 1.02 x; r = 0.995. Conclusions: Given high correlation of results between A1c CE and Hb CE, patent elevation of A2 by A1c CE for either normal or S-trait patients is a reasonable basis for recommendation of red cell indices for evaluation of possible beta thalassemia. For S-trait patients, patent abnormality in the A/S ratio by A1c CE is a reasonable basis for recommendation of red cell indices for evaluation of possible alpha or beta thalassemia.