Evaluation of MALDI-TOF MS for the measurement of glycated hemoglobin

Abstract

Background: Glycated hemoglobin (Hemoglobin A_1c, HbA_1c) plays a key role in monitoring long-term blood glucose levels in diabetics mellitus. Therefore, it is of great importance to ensure test quality of HbA_1c methods.

Objectives: We aimed to evaluate analytical performances of a matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) system for the measurement of HbA_1c.

Methods: We assessed the analytical performances of the method including imprecision, accuracy, and linearity. In addition, comparison with Variant II Turbo 2.0 and Capillarys3 TERA, correlation between glycation rate of α and β globin as well as the influence of most frequent analytical interferences in HbA_1c assays were also investigated.

Results: As measurement of imprecision, within-run CVs and total CVs were lower than 1.6% and 2.4%, respectively. Discrepancy of test results (<0.2%) of IFCC value-assigned external quality control samples indicated a good accuracy of the method. The linearity was excellent with a correlation coefficient of 0.999. The QuanTOF results were well correlated with those obtained by Variant II Turbo 2.0 and Capillarys3 TERA. Good correlation between glycation rates of α and β globin were found. QuanTOF was not prone to common interferences including bilirubin, triglyceride, labile A_1c, and carbamylated hemoglobin. However, unacceptable positive bias was observed when the amount of HbF were greater than approximately 8.0% or in the presence of HbS.

Conclusions: QuanTOF perform well for the determination of HbA_1c and meet quality criteria requested for clinical use.

Keywords: Analytical performance; Glycation rate; HbA(1c); MALDI-TOF MS.