Markers of ineffective erythropoiesis in non-transfusion dependent β-thalassaemia

@#Non-transfused β-thalassaemia patients develop complications related to unsuppressed ineffective erythropoiesis (IE). Serum markers of IE would be useful for risk stratification and monitoring treatment. We studied βthalassaemia trait (β-TT) and non-transfusion-dependent βthalassaemia (β-NTDT) patients. Serum erythropoietin (EPO) and soluble transferrin receptor (sTfR) were correlated against markers of clinical severity (haemoglobin, LDH, retics, bilirubin, spleen size) and iron overload (ferritin, hepcidin, and MRI-T2* in NTDT patients). Eleven β-NTDT and nine β-TT subjects were studied. βNTDT patients had significantly higher markers of haemolysis and iron overload. In β-NTDT, liver iron ranged from mild to severe, but no cardiac loading was seen. EPO and sTfR were higher in patients with β-NTDT than β-TT, and correlated significantly with each other (ρ=0.630, p=0.003). Both markers were negatively correlated with haemoglobin (sTfR ρ=-0.540, p=0.014; EPO ρ=-0.807, p<0.001, and positively correlated with spleen size (sTfR ρ=0.783, p<0.001; EPO ρ=0.654, p=0.002) and markers of iron overload. There was a strong correlation between ferritin and hepcidin (ρ=0.720, p<0.001), and a relatively lower increment of hepcidin for the degree of iron overload in βNTDT compared to β-TT. EPO and sTfR appear to be reliable markers of erythropoiesis in non-transfused β-thalassaemia and correlate well with markers of disease severity. Their role in managing patients, predicting complications, and monitoring response to treatments aimed at reducing IE should be explored.

Beta Thalassemia Major: Overview of Molecular Etiology, Pathophysiology, Current and Novel Therapeutic Approaches

Major beta thalassemia is a severe form of thalassemia caused by the alteration of two beta globin genes resulting in a defective synthesis of hemoglobin. It is characterized by chronic severe anemia, ineffective erythropoiesis (IE) and iron overload. However although the thransfusion and chelation assosciated constitute the basis of the traitement curently recommended, they do not allow always to control the iron overload induced by pathology and repeated transfusions. Hematopoietic stem cell transplantation (HSCT) has proven to be a definitive treatment for beta thalassemia. However, this procedure is confronted to immunological complications and the small nomber of histocompatible donors. In the face of these therapeutic blocks, much research has been undertaken in recent years leading to the development of a number of promising therapeutic strategies in order to reduce the constraints linked to current chronic treatments, and to move towards an access to healing for all patients. Among other three approaches are envisaged and are in the experimental phase: Gene therapy to restore globin chain imbalance, Improve ineffective erythropoiesis and Improve iron dysregulation. In this article we give a view on the pathophysiology, clinical manifestations, genetic origin of beta-thalassaemia major. The second part presents the therapeutic arsenal currently used, and its limits leading to therapeutic impasse. The last part explores the scientific tracks that present a real therapeutic potential in ?-Thalassemia.

Serum Soluble Transferrin Receptor Concentration as a Biomarker of Erythropoietic Activity: Surrogate Marker of Adequate Transfusion in Adult Beta-Thalassaemia Intermedia Patients

Management of Beta (β)-thalassaemia intermedia in contrast to β-thalassaemia major patients has no clear guidelines as to indicators of adequate transfusion. Regular blood transfusion suppresses bone marrow erythropoietic activity. Serum soluble transferrin receptor (sTfR) concentration is a marker for erythropoietic activity, with increased sTfR being associated with functional iron defi ciency and increased erythropoietic activity. This study aimed to determine the use of sTfR as an indicator of adequate transfusion in adult β-thalassaemia intermedia patients. A cross-sectional study was conducted at Hospital Ampang, Malaysia, for six months. Patient group included six β-thalassaemia intermedia and 34 HbE-β-thalassaemia transfused patients. None of the patients were on regular monthly blood transfusions as in β-thalassaemia major. The control group comprised of 16 healthy subjects with normal haematological parameters. Haemoglobin (Hb) analysis, sTfR and ferritin assays were performed. Hb and HbA percentages (%) were found to be signifi cantly lower in patients compared to the controls, while HbE%, HbF%, sTfR and ferritin were signifi cantly higher in patients. An inverse relationship was found in the controls between HbF% with Hb (r = -0.515, p < 0.05) and HbA% (r = -0.534, p < 0.05). In patients, sTfR showed an inverse relationship with HbA% (r = -0.618, p = 0.000) and a positive correlation with HbE% (r = 0.418, p = 0.007) and HbF% (r = 0.469, p = 0.002). Multivariate analysis showed that HbA% (r = 2.875, p = 0.048), HbE% (r = 2.872, p = 0.020) and HbF% (r = 2.436, p = 0.013) best predicted sTfR independently in patients. Thus, sTfR is a useful marker for erythropoiesis. The elevated sTfR in these patients indicate that the transfusion regimen used was inadequate to suppress ineffective erythropoiesis. Hb levels may not be the best target for monitoring transfusion treatment in β-thalassaemia intermedia patients, but the use of sTfR is helpful in individualising transfusion regimens.

Hidrops fetal no inmune por anemia diseritropoyética congénita / Nonimmune hydrops fetalis by congenital dyserythropoietic anaemia

La anemia diseritropoyética congénita se engloba dentro de un grupo raro y heterogéneo de trastornos eritrocitarios caracterizados por eritropoyesis ineficaz, anemia megaloblástica, hemosiderosis secundaria e hidrops fetal. Presentamos el caso de un feto de 20 semanas con hidrops como consecuencia de una anemia fetal intensa por eritropoyesis ineficaz. Ante el hallazgo de hidrops fetal no inmune es fundamental un diagnóstico etiológico precoz para ofrecer a la pareja las alternativas terapéuticas más adecuadas.

Congenital dyserythropoietic anemia is a rare group of heterogeneous disorders characterized by ineffective erythropoiesis, megaloblastic anemia, secondary hemosiderosis and fetal hydrops. We report a case of a 20 week old fetus with hydrops as a consequence of a severe fetal anemia resulting from ineffective erythropoiesis. When non-immune fetal hydrops is found, it is essential an early etiological diagnosis to give the parents the most appropriate therapeutic options.