Evaluating Dried Blood Spot and Dried Blood Matrix as Alternatives to Venipuncture for Diagnosing Haemoglobinopathies in Adults: A Mass Spectrometric Approach

Microsampling techniques such as dried blood spot (DBS) and dried blood matrix (DBM) offer several advantages over venipuncture sampling techniques, including ease of collection, reduced sample volume, improved sample stability and simplified transportation. In this study, mass spectrometry, a highly sensitive analytical instrument capable of handling small sample volumes, was used to compare venipuncture, DBS and DBM sampling methods for the detection of haemoglobin variants-HbS, HbE and HbD-Punjab-and thalassemia in adults. Anonymised leftover K2-EDTA venipuncture blood samples were used, including 10 samples each of normal, HbS trait/disease, HbE trait, HbD trait and α-thalassemia (HbH), as well as eight samples of β-thalassemia. Three biomarker ratios-S/β for HbS, α/β for α-thalassemia (HbH) and δ/β (%) for β-thalassemia-were analyzed. All the sampling techniques successfully distinguished sickle cell trait from sickle cell disease, β-thalassemia trait from β-thalassemia major and detected HbE and HbD-Punjab traits. There were no statistically significant differences between sampling techniques in the qualitative detection of HbS and HbD-Punjab variants. However, HbE variant, α/β and δ/β (%) values were altered in DBS and DBM when compared with venipuncture blood. Statistical evaluation necessitates the need for matrix-matched reference ranges for quantitative thalassemia analysis. Triple quadrupole mass spectrometry provides a unified platform for analysing blood samples using diverse sampling techniques, minimising logistical challenges and enabling efficient, accurate high-throughput screening for haemoglobinopathies in clinical, population-wide and resource-limited settings.