Plasma microRNA-451 as a novel hemolytic marker for β⁰-thalassemia/HbE disease

In Southeast Asia, particularly in Thailand, β⁰-thalassemia/hemoglobin E (HbE) disease is a common hereditary hematological disease. It is associated with pathophysiological processes, such as the intramedullary destruction of immature erythroid cells and peripheral hemolysis of mature red blood cells. MicroRNA (miR) sequences, which are short non-coding RNA that regulate gene expression in a suppressive manner, serve a crucial role in human erythropoiesis. In the present study, the plasma levels of the erythroid-expressed miRNAs, miR-451 and miR-155, were analyzed in 23 patients with β⁰-thalassemia/HbE and 16 control subjects. Reverse transcription-quantitative polymerase chain reaction analysis revealed signifcantly higher levels of plasma miR-451 and miR-155 in β⁰-thalassemia/HbE patients when compared to the control subjects. Notably, among the β⁰-thalassemia/HbE patients, a signifcant increase in miR-451 levels was detected in severe cases when compared with mild cases. The levels of plasma miR-451 correlated with reticulocyte and platelet counts. The results suggest that increased plasma miR-451 levels may be associated with the degree of hemolysis and accelerated erythropoiesis in β⁰-thalassemia/HbE patients. In conclusion, miR-451 may represent a relevant biomarker for pathological erythropoiesis associated with β⁰-thalassemia/HbE.