Wooden-Tip Electrospray Mass Spectrometry Characterization of Human Hemoglobin in Whole Blood Sample for Thalassemia Screening: A Pilot Study

Abstract

Traditional analytical methods for thalassemia screening are needed to process complicated and time-consuming sample pretreatment. In recent decades, ambient mass spectrometry (MS) approaches have been proven to be an effective analytical strategy for direct sample analysis. In this work, we applied ambient MS with wooden-tip electrospray ionization (WT-ESI) for the direct analysis of raw human blood samples that were pre-identified by gene detection. A total of 319 whole blood samples were investigated in this work, including 100 α-thalassemia carriers, 67 β-thalassemia carriers, and 152 control healthy samples. Only one microliter of raw blood sample was directly loaded onto the surface of the wooden tip, and then five microliters of organic solvent and a high voltage of +3.0 kV were applied onto the wooden tip to generate spray ionization. Multiply charged ions of human hemoglobin (Hb) were directly observed by WT-ESI-MS from raw blood samples. The signal ratios of Hb chains were used to characterize two main types of thalassemia (α and β types) and healthy control blood samples. Our results suggested that the ratios of charged ions to Hb chains being at +13 would be an indicator for β-thalassemia screening.

LC–MS/MS-Based Absolute Quantitation of Hemoglobin Subunits from Dried Blood Spots Reveals Novel Biomarkers for α-Thalassemia Silent Carriers

“…In silent α-thalassemia newborns and those who exhibit α-thalassemia traits, a slight increase in Hb Bart’s in the range of 1–2 and 5–6%, respectively, is noted . A screening approach for Hb Bart’s using immunochromatography yielded excellent outcomes in identifying α-thalassemia traits, but the method functioned poorly in the identification of silent α-thalassemia. , Recent developed mass spectrometry-based assays that detect different Hb subunits also demonstrated excellent performance in β-thalassemia carriers, but the poor performance was noted for the detection of the α-thalassemia trait and silent α-thalassemia. , The failure of existing phenotype-based and mass spectrometry-based screening strategies may be caused by the lack of markers and the limited resolution to correctly capture the subtle differences. We employed a liquid chromatography tandem mass spectrometry (LC–MS/MS) approach to address these issues.…”

“…15,16 Recent developed mass spectrometrybased assays that detect different Hb subunits also demonstrated excellent performance in β-thalassemia carriers, but the poor performance was noted for the detection of the αthalassemia trait and silent α-thalassemia. 17,18 The failure of existing phenotype-based and mass spectrometry-based screening strategies may be caused by the lack of markers and the limited resolution to correctly capture the subtle differences. We employed a liquid chromatography tandem mass spectrometry (LC−MS/MS) approach to address these issues.…”