Current status of beta-thalassemia and its treatment strategies.

BACKGROUND: Thalassemia is an inherited hematological disorder categorized by a decrease or absence of one or more of the globin chains synthesis. Beta-thalassemia is caused by one or more mutations in the beta-globin gene. The absence or reduced amount of beta-globin chains causes ineffective erythropoiesis which leads to anemia. METHODS: Beta-thalassemia has been further divided into three main forms: thalassemia major, intermedia, and minor/silent carrier. A more severe form among these is thalassemia major in which individuals depend upon blood transfusion for survival. The high level of iron deposition occurs due to regular blood transfusion therapy. RESULTS: Overloaded iron raises the synthesis of reactive oxygen species (ROS) that are noxious and prompting the injury to the hepatic, endocrine, and vascular system. Thalassemia can be analyzed and diagnosed via prenatal testing (genetic testing of amniotic fluid), blood smear, complete blood count, and DNA analysis (genetic testing). Treatment of thalassemia intermediate is symptomatic; however; it can also be accomplished by folic supplementation and splenectomy. CONCLUSION: Thalassemia major can be cured through regular transfusion of blood, transplantation of bone marrow, iron chelation management, hematopoietic stem cell transplantation, stimulation of fetal hemoglobin production, and gene therapy.

Changing patterns in the epidemiology of ß-thalassemia.

ß-thalassemia major is an inherited hemoglobinopathy that requires lifelong red blood cell transfusions and iron chelation therapy to prevent complications due to iron overload. Traditionally, ß-thalassemia has been more common in certain regions of the world such as the Mediterranean, Middle East, and Southeast Asia. However, the prevalence of ß-thalassemia is increasing in other regions, including Northern Europe and North America, primarily due to migration. This review summarizes the available data on the changing incidence and prevalence of ß-thalassemia as well as factors influencing disease frequency. The data suggest that the epidemiology of ß-thalassemia is changing: Migration has increased the prevalence of the disease in regions traditionally believed to have a low prevalence, while, at the same time, prevention and screening programs in endemic regions have reduced the number of affected individuals. Various approaches to prevention and screening have been used. Region-specific prevention and treatment programs, customized to align with local healthcare resources and cultural values, have been effective in identifying patients and carriers and providing information and care. Significant challenges remain in universally implementing these programs.

Activity of cytochrome P450 1A2 in relation to hepatic iron accumulation in transfusion-dependent ß-thalassaemia major patients.

BACKGROUND: Cytochrome P450 1A2 (CYP1A2) is a cytochrome enzyme with a pivotal role in hepatic drug metabolism. Data from CYP1A2((-/-)) mouse suggest that CYP1A2 plays a role in aspects of hepatic iron toxicity. The aim of this study was to assess the activity of CYP1A2 in relation to hepatic iron load in patients with transfusion-dependent ß-thalassaemia major. METHODS: The (13) C-methacetin continuous breath test was performed on 30 consecutive patients with transfusion-dependent ß-thalassaemia major. CYP1A2 activity was measured by the rate at which the (13) C substrate is metabolized and exhaled expressed as percentage dose recovery (PDR) per hour. CYP1A2 activity was correlated with clinical and laboratory parameters and hepatic iron accumulation by T2* magnetic resonance imaging (T2*MRI). RESULTS: Cytochrome P450 1A2 activity in patients with transfusion-dependent ß- thalassaemia major was positivity correlated with plasma ferritin levels. No correlation was found with age, duration and amount of red blood cell transfusion and type of iron chelation therapy. Low CYP1A2 activity was negatively associated with hepatic iron accumulation (T2*MRI ≤ 6.3 ms); adjusted odds ratio (OR; 95% CI) for hepatic iron accumulation in patients with low CYP1A2 activity was 0.047 (0.003-0.72; P = 0.021). Of the six patients with decreased activity of CYP1A2, five had no hepatic iron accumulation and one had mild hepatic iron accumulation by T2*MRI. CONCLUSION: Activity of CYP1A2 is associated with hepatic iron accumulation in patients with transfusion-depended ß-thalassaemia major. Further studies are needed to assess the exact role of CYP1A2 in iron metabolism in human.

Risk factors for death in patients with beta-thalassemia major: results of a case-control study.

This retrospective one to one matched case-control study was aimed at evaluating risk factors for death in beta-thalassemic patients followed in Italian centers between 1997 and 2001. The mortality risk was lower in patients with good compliance to iron chelation therapy and in those treated with deferiprone.