Fluorescence Immunoassay versus HPLC: Two Approaches for HbA1c Measurement, Same Reliability?

Objective: To compare the analytical performance of two HbA1c measurement methods: high-performance liquid chromatography (HPLC) using the Turbo Variant II system (Bio-Rad), considered the reference method, and fluorescence immunoassay using the STANDARD F200 system (SD Biosensor).
Methods: Fifty-five EDTA-anticoagulated whole blood samples were analyzed using both techniques. Results were compared using Bland-Altman analysis and Passing-Bablok regression to assess agreement and correlation between the two methods.
Results: The mean HbA1c values were 7.461 ± 2.037% for HPLC and 7.740 ± 2.021% for the STANDARD F200. Bland-Altman analysis showed a mean bias of 0.279%, with limits of agreement ranging from -0.248% to 0.804%. Passing-Bablok regression yielded the equation Y = 0.9837X + 0.3999 with a high correlation coefficient (r = 0.991, p < 0.001).
Conclusion: Both methods demonstrated good correlation and satisfactory agreement, with a slight overestimation of values by the STANDARD F200. Given its faster processing time and greater accessibility, the STANDARD F200 represents a reliable alternative to HPLC, particularly in settings requiring rapid screening or with limited resources.