Generation and characterization of human δ-globin-specific monoclonal antibodies

The human δ-globin chain, unique to the hemoglobin A2 (HbA2) heterotetramer, is important for the evaluation of hemoglobinopathy. However, there are no well-defined antibodies specific for the δ-globin chain, a fact that is attributed a striking similarity (93%) in amino acid sequence between δ-globin and β-globin of the hemoglobin A (HbA). In this study, two monoclonal antibodies (mAbs) against the δ-globin chain were generated and designated as 2H4 and 1H11. These antibodies were specific to HbA2 and do not cross-react with HbA and HbF (fetal hemoglobin). Moreover, the expression of HbA2 in fetal liver and mature erythrocytes was determined using these two mAbs. In addition to being useful tools for research or diagnosis, these antibodies could be valuable for development of rapid and effective antibody-based immunoassays of HbA2 expression in erythroid cells and non-erythroid tissue.