Preliminary comparative study of HBA1c measurement by IEX-HPLC Bio-Rad in dried blood spot vs. whole venous blood

HBA1c testing is a health indicator for pre-diabetes identification or diabetes detection and follow-up. Simplifying collection and transport of blood samples for HBA1c measurement remains of great interest. Capillary dried blood spots (DBS) sampling has been proposed as a potential alternative to classical whole blood (WB) venipuncture, however, international analytical and clinical validation of DBS use is necessary before implementation. We aimed in the present study to assess the performance, clinical acceptability and analyte stability (at 20-25°C, +4°C, -20°C) of DBS sampling method compared to WB. The study enrolled 40 participants. Obtained WB were applied to Whatman 903 protein blotting paper. Prepared DBS samples were compared to WB samples kept in EDTA collection tubes using the Bio-Rad D-10 IEX-HPLC instrument. Statistical analysis was carried out using IBM SPSS Statistics 29.0.1.0 and NCSS v23-0-2 software programs. Agreement (LCCC = 0.982; limits of agreement M ± 1.96SD: -0.45; 0.48) and correlation (PCC = 0.990) between DBS and WB results were excellent. Also, repeatability (CV = 1.13) and clinical conformity (K = 0.80) of the values obtained on DBS were found to be highly satisfactory. Our results clearly showed that DBS sampling could be an efficient alternative to WB venipuncture for HBA1c measurement.