Hematological analysis of anemic severity in beta thalassemia

Abstract

Beta thalassemia is an inherited blood disorder that affects synthesis of the beta chain in the production of haemogoblin, leading to the production of deficient RBCs (red blood cells) that cannot effectively transport oxygen. It is relatively widespread in parts of Asia, and Bangladesh is among the countries where this disorder is prevalent. Beta thalassemia patients require frequent transfusions of healthy blood throughout life in order to mitigate the symptoms, and can suffer from iron overload complications as a result. Transfusions of improperly selected blood can also worsen the condition by encouraging the patient's immune system to attack transplanted healthy RBCs, increasing the amount of transfusions a patient will need throughout life. Erythropoietin (EPO) acts as an erythropoietic protein. Higher-than-normal levels may indicate anemia and in severe cases of anemia, EPO levels in the blood may be a thousand times higher than normal. Serum ferritin is an useful monitoring tool for iron overload in thalassemia major. This study focused on comparing the serum erythropoietin and ferritin levels between Thalassemia patients grouped by the severity of their disease based on transfusion interval. Beta-thalassemia major or E/beta-thalassemia diagnosed patients were enrolled from Bangladesh Thalassemia Samity and Hospital for this study. Peripheral blood specimen was collected from study participants before blood transfusion. Complete Blood Count (CBC) analysis including hemoglobin, RBC, platelet, and reticulocyte counts as well as MCV, MCH and RDW was performed. Serum was separated from the blood specimen and serum erythropoietin and ferritin levels measured using ELISA. Statistical analysis of the obtained results revealed that the EPO level in severe group (irrespective of whether it is β-thalassemia major or E-beta thalassemia) patients was approximately 600 times higher than the control group whereas the less sever group has a concentration as high as 200 times than the healthy control group with a statistically significant difference (P<0.0001 and P<0.005, respectively). The data showed that serum EPO levels increased in all thalassemia patients despite repeated transfusion. A reason of this high EPO level can be resistance to endogenous EPO. Pro-inflammatory cytokines antagonize the action of EPO by exerting an inhibitory effect on erythroid progenitor cells and by disrupting iron metabolism. EPO resistance might also be caused by inflammation, which has a negative effect on EPO receptors. This study elucidates that the high EPO concentration is linked to anemic severity rather than type of thalassemic condition. Whether the endogenous EPO resistance is a contributing factor to this high magnitude of EPO needs further investigation.