Chelation therapy, transfusion requirement, and iron balance in young thalassemic patients

BCL11A Polymorphism in Egyptian Children with β-Thalassemia: Relation to Phenotypic Heterogeneity

Fetal hemoglobin (HbF) is a potent genetic modifier of β-thalassemia phenotype. B-cell lymphoma 11A ( BCL11A ) gene results in significant silencing of HbF. The aim of this study was to assess the prevalence of different BCL11A genotypes among a cohort of Egyptian children with β-thalassemia and to correlate them to HbF and clinical severity score. Eighty-two children with β-thalassemia (aged 12.95 ± 3.63 years) were recruited from the Pediatric Hematology Clinic, Ain Shams University. They were divided based on the clinical severity of β-thalassemia into three subgroups: 20 mild (24.4%), 24 moderate (29.3%), and 38 severe (46.3%). Age, gender, age of diagnosis, initial HbF level, transfusion history, and history of splenectomy were assessed. Anthropometric measures, signs of anemia and hemosiderosis, and the severity score were determined. Laboratory investigations such as complete blood picture, ferritin, and single gene polymorphism genotyping of the rs11886868 were also performed. Our findings showed that 16 children had CC genotype (19.5%), 38 had TC genotype (46.3%), and 28 had TT genotype (34.1%) of the rs#. β-thalassemia children with TT genotype had significantly higher severity scoring than the other two groups ( p  < 0.001). Moreover, mean initial HbF was found to be lower in children with TT genotype followed by TC and CC genotypes ( p  < 0.001). Increased γ-globin expression associated with BCL11A gene polymorphism is associated with better clinical severity of β-thalassemia.

How I treat thalassemia

The purpose of this article is to set forth our approach to diagnosing and managing the thalassemias, including β-thalassemia intermedia and β-thalassemia major. The article begins by briefly describing recent advances in our understanding of the pathophysiology of thalassemia. In the discussion on diagnosing the condition, we cover the development of improved diagnostic tools, including the use of very small fetal DNA samples to detect single point mutations with great reliability for prenatal diagnosis of homozygous thalassemia. In our description of treatment strategies, we focus on how we deal with clinical manifestations and long-term complications using the most effective current treatment methods for β-thalassemia. The discussion of disease management focuses on our use of transfusion therapy and the newly developed oral iron chelators, deferiprone and deferasirox. We also deal with splenectomy and how we manage endocrinopathies and cardiac complications. In addition, we describe our use of hematopoietic stem cell transplantation, which has produced cure rates as high as 97%, and the use of cord blood transplantation. Finally, we briefly touch on therapies that might be effective in the near future, including new fetal hemoglobin inducers and gene therapy.

Improved post-transfusion quality of density separated AS-3 red cells after extended storage

A centrifugal method of red cell density separation was utilized for unit processing in these studies to determine the quality of the lighter fraction (neocytes) after storage for up to 42 d and to evaluate whether the heavier fraction (gerocytes) deteriorated more rapidly than neocytes during storage. Each unit was passed through a Leukotrap filter to remove white cells prior to density separation. Red cell recovery and survival were evaluated using double label technetium-99m with either chromium-51 or nonradioisotopic chromium which permitted concurrent paired analysis. In vivo neocyte red cell recovery, as tested on the same 11 donors on days 1, 7 and 42 of storage, was effectively unchanged. Recovery and survival half-life (that is, the number of days after transfusion at which half of the cells infused remain in the circulation) of 42 d stored gerocytes were significantly lower than similarly stored neocytes (75.5 +/- 7.2% and 20.1 +/- 6.5 d for gerocytes versus 84.4 +/- 4.9% and 39.0 +/- 9.0 d for neocytes). One-day stored neocytes showed a 16.5% increase in red cell availability over the combined average for 42 d stored neocytes and gerocytes. Statistically, while there were significantly higher ATP, 2,3-DPG, and lactate levels pre-storage by paired t-test for neocytes compared to gerocytes, by day 42 there were no significant differences detected between the two red cell fractions by any of the in vitro variables measured. These studies suggest that this simple separation technique for leucocyte-poor red cell units provides a neocyte population with improved viability and the potential for increased transfusion intervals in chronically transfused patients.

Preparation of young red cells for transfusion using the Fenwal CS 3000 cell separator

A pheresis procedure was devised to isolate young red cells by centrifugation using the Fenwal CS 3000 continuous flow cell separator. Young red cell enriched products were collected in a 2.5-3-hour procedure. Large numbers of white cells and platelets were collected with the red cells, but cryopreservation and subsequent washing removed 99% of the contaminating cells. At the completion of all processing a product yielding 70% of the total hemoglobin content of a standard frozen/deglycerolized red cell unit was produced. Autologous radiochromium survival of young red cells, measured in 12 normal donors, showed an average 24-hour recovery of 89.9% with a T50Cr of 40.8 days. In paired autologous studies (N = 4) there was a mean increase of 35% in the observed T50Cr of young red cells as compared to standard frozen red cells.

Partial splenic embolization in the management of thalassemia major

Six patients with beta-thalassemia major underwent partial splenic embolization as an alternative to splenectomy. One patient required 2 embolizations. All 6 patients showed a marked reduction in transfusion requirements. Transfusion requirements fell to a level within that reported by other authors following total splenectomy, although significantly above that of a group of patients from the same institution who underwent total splenectomy. It is felt that this procedure provides an acceptable alternative to splenectomy in these patients with the possible preservation of some splenic immune function.

Chelation therapy in beta-thalassemia major. III. The role of splenectomy in achieving iron balance

Transfusion requirements for 1978 were compiled for 79 patients with thalassemia major (ages 1 to 29 years) who were maintained at hemoglobin concentrations of greater than 10 gm/dl. In 46 patients with intact spleens, the mean transfusion requirement was 258 ml/kg/year, and there was a clear increase with age. The transfusion history prior to 1978 had no influence on the increase of transfusion requirement with age. In contrast, in 33 splenectomized patients, the mean transfusion requirement was 203 ml/kg/year and it did not increase with age. Urinary iron excretion in response to deferoxamine increased with age, with no obvious difference between splenectomized and nonsplenectomized patients. The ability to achieve iron balance with a daily dose of 20 mg/kg of deferoxamine was a function of the transfusion requirement splenectomized patients with lower blood requirements generally achieved negative iron balance, whereas nonsplenectomized patients did not. We conclude that the spleen should be removed when the transfusion requirement exceeds 250 ml/kg/year, which usually occurs between 6 and 8 years of age. In young patients with intact spleens, a higher dose of deferoxamine may be use in order to prevent hemosiderosis.