الفهرس 
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Abstract
βeta-Thalassemia is a worldwide single gene autosomal recessive genetic disorder characterized by excess unpaired alpha globin chains and deficient or absent beta globin chains. Excessive increase of unpaired α-globin chains in red blood cells (RBC) causes hemolysis and ineffective erythropoiesis (IE) leading to chronic anemia and hypoxia, that triggers most of the symptoms that the patients exhibit.
βeta-Thalassemia comprises three principal types, the first being β-thalassemia major (TM), known as “Cooley’s anemia”, the second type is β-thalassemia intermedia (TI) and finally the third one referred to as thalassemia minor. Recently patients with thalassemia disease are described according to their transfusion requirements into transfusion-dependent thalassemia (TDT) and non-transfusion-dependent thalassemia (NTDT).
The decrease in hemoglobin (Hb) leads to expansion of the bone marrow to counterbalance the loss of RBCs which causes the characteristic bone deformities encountered in these patients. The occurrence of extramedullary hemopoiesis leads to hepatosplenomegaly. Excessive hemolysis may predispose the patients to occurrence of pulmonary hypertension, pigmented gall stones, leg ulcers and restricted growth. Moreover, hypercoagulability is another complication of such a disease. Thromboembolic events (TEE) are a known complication observed in thalassemic patients yet, the pathogenesis of β-thalassemia induced hypercoagulable state, is still not clearly comprehended.
Multifactorial mechanisms are tangled in the pathogenesis of TEE in thalassemia, including the combination of the classical components of the hemostatic process such as increased platelet activation and aggregation and increased endothelial activation, together with the disease-specific features, namely abnormal RBCs caused by exposure of phosphatidylserine of hemolyzed RBCs and decreased nitric oxide (NO) secondary to hemolysis, splenectomy, iron overload organ dysfunction caused by hemochromatosis, and natural anticoagulant deficiencies leading to hypercoagulable state.
Glycoprotein IIb/IIIa (GpIIb/IIIa or GpIIb/IIIa also, known as integrin αIIbβ3) is an integrin complex found on surface of platelets. It is a receptor for fibronectin, fibrinogen, plasminogen, prothrombin, thrombospondin and vitronectin. Its activation leads to platelet/platelet interaction via binding of soluble fibrinogen consequently causing prompt platelet aggregation.
Our study aimed to estimate the plasma level of soluble glycoprotein IIb/IIIa (GpIIb/IIIa) in β- thalassemia major patients.
Forty-seven patients suffering from β thalassemia major (TM) and twenty healthy volunteers as control subjects were enrolled in our study. The patient group consisted of 47 patients suffering from transfusion dependent beta thalassemia, 17 (36.2%) patients were males, and 30 patients (63.8%) were females. The control group consisted of twenty healthy subjects, 7 (35%) subjects were males, and 13 (65%) were females. The deleterious impact of thalassemia major on health was manifested in patients, where only 9 patients had a normal spleen size while the rest had either enlarged spleen 13/47 (27.7%) or had a splenectomy 25/47 (53.2%).
Hematological parameters: Hb levels, hematocrit and red blood cells counts were significantly lower in thalassemic group whether splenectomised or not than in controls. with a p value of <0.001. However, the platelet count was significantly higher among the splenectomised and non splenectomised groups than the controls and higher among splenectomised group than the non splenectomised one with a p value of <0.001.
Serum levels of CRP and ferritin were significantly higher among the thalassemic group than control group with a p value of <0.001.
Regarding GpIIb/IIIa concentration in the patient group ranged from 2.94 ng/mL to 21.11 ng/mL, with a median concentration of 5.88 ng/mL while that of the control group ranged from 0.04 ng/mL to 3.92 ng/mL, with a median concentration of 2.16 ng/mL. It was significantly higher in the thalassemic group as compared to the control group with a p value <0.001 and higher in the splenectomised group than the non splenectomised one (p=0.002).
The frequency of high risk of VTE according to TRT-RSS was 4.3 %, while the intermediate risk was 46.8 % and the low risk was 48.9 %. The TRT-RSS score was significantly higher among the splenectomised group than the non splenectomised one with a p value <0.001.