Regression of extramedullary haemopoiesis and augmentation of fetal haemoglobin concentration during hydroxyurea therapy in β thalassaemia

Abstract

Summary.Hydroxyurea increases fetal haemoglobin in many patients with sickle cell anaemia, but its effectiveness in thalassaemia appears to be less consistent. We describe the response to hydroxyurea in an adult male with homozygous b thalassaemia, symptomatic paraspinal extramedullary haemopoiesis, bone pain, and progressive tissue iron loading. Prior to therapy with hydroxyurea the circulating haemoglobin (Hb) concentration was 7·0 g/dl and absolute fetal haemoglobin concentration was 5·0 g/dl.Administration of sodium phenylbutyrate had induced no increase in either parameter. Subsequent therapy with hydroxyurea was associated with increases in total haemoglobin to 9·0 g/dl, and in fetal haemoglobin to 7·6 g/dl. Ineffective erythropoiesis was reduced and extramedullary haemopoiesis regressed during therapy.

EPO-mediated expansion of late-stage erythroid progenitors in the bone marrow initiates recovery from sublethal radiation stress

“…However, chronic severe pathologic stressors such as myelofibrosis, thalassemia, or sickle cell anemia leads to extramedullary erythropoiesis in humans. [47][48][49][50][51] The mechanisms regulating the establishment of extramedullary erythropoiesis have yet to be elucidated. Thus, the re-establishment of splenic erythropoiesis during recovery from sublethal radiation provides a model for the future investigation of erythroid progenitor circulation and homing to extramedullary sites.…”

Hydroxyurea can eliminate transfusion requirements in children with severe β-thalassemia

“…1,2 A significant benefit could also be expected in patients with ␤-thalassemia, because the imbalance in globin chains could be ameliorated by the newly synthesized ␥-chains being able to neutralize the excess ␣-chains, which could partially correct ineffective erythropoiesis. Clinical and hematologic improvements have been reported in patients with thalassemia intermedia, [3][4][5][6][7][8] but responses in patients with thalassemia major are controversial. 5,9 We have followed 7 children with transfusiondependent ␤-thalassemia, 6 of them with severe transfusional complications, and have treated them with hydroxyurea in the hope that this drug could reduce transfusional needs.…”

Spinal cord compression due to extramedullary hematopoiesis in a patient with E-beta-thalassemia managed without radiation or surgery

“…It was previously used in cases where radiation was contraindicated such as in pregnancy [7]; and as adjunct therapy when improvement in neurological symptoms was transient and slow [2]. The successful use of hydroxyurea as monotherapy has been reported in the management of EMH masses [8–10]. These patients either had autoimmune hemolytic anemia limiting the use of transfusion [9], hemoglobin level was above 7 g/dL [11], hemoglobin level was at baseline [8], or clinical presentations involving sites other than the spinal cord lessening the urgency of mass shrinkage [12].…”

“…The successful use of hydroxyurea as monotherapy has been reported in the management of EMH masses [8–10]. These patients either had autoimmune hemolytic anemia limiting the use of transfusion [9], hemoglobin level was above 7 g/dL [11], hemoglobin level was at baseline [8], or clinical presentations involving sites other than the spinal cord lessening the urgency of mass shrinkage [12]. Hydroxyurea monotherapy was also the treatment of choice in a patient with cirrhosis when there was a concern for volume overload from transfusion [13], but the response was short lived.…”