الفهرس 
ThalassemiaOnly 14 pages are availabe for public view
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Abstract
Thalassemia is the most common hereditary hemoglobinopathy, and occurs in 4.4/10,000 live births. In the developing world, the majority of patients die before the age of 20 years. Occurs due to absent or reduced synthesis of the β-globin chain results in ineffective erythropoiesis, peripheral hemolysis and haemolytic anemia. Thalassemia is treated with lifelong red blood cell transfusions associated with chelation therapy in order to limit chronic complications and premature deaths related to iron overload. This conventional therapy has dramatically improved survival and quality of life of patients. Excess iron is stored in hepatocytes and macrophages within a dynamic cycle of iron utilization and recycling. The liver is the initial site of iron deposition, which results in fibrosis and then cirrhosis. Cirrhosis and hepatocellular carcinoma may develop as result of chronic hepatitis and/or severe iron overload. Iron chelation with desferrioxamine can reduce excessive body iron, but the efficacy is limited by poor compliance and dose related toxicity. The prevalence of cirrhosis is reported to be 10–40% and the prevalence of liver fibrosis is about 40–80%. Despite remarkable improvements in medical care for patients with β-thalassemia, there is still only one definitive treatment option: allogeneic hematopoietic stem cell (HSC) transplantation, it is the only curative treatment in clinical practice. HSCT has been successfully erformed over the last 30 years with current thalassemia-free survival rates of 80-90% in children transplanted with HLA-matched sibling donor (MSD) before the onset of complications related to their disease or to the supportive treatment. Hematopoietic stem cell transplantation potentially results in a better long-term quality of life than that observed in patients treated with regular transfusion and chelation therapy. The outcome of BMT is related to the pretransplantation clinical conditions, specifically the presence of hepatomegaly, extent of liver fibrosis, history of regular chelation and hence severity of iron accumulation. Transient elastography (TE) is a recently developed, rapid, noninvasive technique designed to predict liver fibrosis, based on a mechanical wave generated by vibration. The measurement of the speed of propagation of the wave across the hepatic parenchyma provides an estimate of the liver elasticity, which is a surrogate marker of liver fibrosis. In studies comparing the results of TE versus liver biopsy as the reference standard, TE showed a satisfactory accuracy in identifying patients with chronic liver disease (CLD) accompanied by significant fibrosis or cirrhosis and it has been shown to have a good interobserver and interobserver reproducibility. In patients with beta thalassemia major who experiencing some degree of liver fibrosis, HSCT alone cannot reduce liver iron overload and liver fibrosis may increase or decrease. The aim of this study is to evaluate the degree of hepatic fibrosis in beta thalassemia major children before and after hematopoietic stem cell transplantation and its correlation with other coexisting confounding factors.