Comparison of two hemolysis procedures prior to an automated HbA(1c) immunoassay

Hemoglobin A(1c) (HbA(1c)) is widely accepted as the most important biological parameter reflecting glycemic control in diabetic patients. Its measurement in clinical chemistry necessitates the use of reliable and robust methods. We studied here the influence of two hemolysis procedures on an automated HbA(1c) immunoassay using the Mira Plus analyzer.

Whole blood was hemolyzed either manually, using an external manual procedure, or automatically on-board the analyzer. The results of imprecision studies showed comparable performance of both procedures, coefficients of variation (CVs) being slightly higher with the automated procedure (2.2-2.7% versus 1.7-2.1% in within-run experiments, and 2.4-3.5% versus 2.1-3.0% in between-run experiments). Comparison of results in 100 fresh samples showed acceptable correlation between the two procedures (r(2) = 0.94, y = 0.98x+0.43). Sedimentation of whole blood in sample tubes prior to automatic hemolysis did not alter the results.

These data demonstrate that both procedures are suitable for routine use, with a higher practicability of the automated one. However, the values are not directly comparable, pointing out the critical role of every analytical step and the need for standardization and strict quality control of HbA(1c) assays.