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العنوان
Ischemia modified albumin as a marker of oxidative
stress in β-thalassemia Patients: relation to lipid
peroxidation, iron overload and vascular
dysfunction /
المؤلف
Shameia,Sara Hamed Elmetwally.
هيئة الاعداد
باحث / Sara Hamed Elmetwally Shameia
مشرف / Amira Abd ElMoneam Adly
مشرف / Eman Abdel Rahman Ismail
مشرف / Nayera Hazaa Khalil ElSherif
تاريخ النشر
2016
عدد الصفحات
215p.:
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
طب الأطفال ، الفترة المحيطة بالولادة وصحة الطفل
تاريخ الإجازة
1/1/2016
مكان الإجازة
جامعة عين شمس - كلية الطب - طب الاطفال
الفهرس
Only 14 pages are availabe for public view

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from 32

Abstract

Background: Patients with β-thalassemia major (β-TM) have oxidative stress and tissue injury due to iron overload. Ischemia modified albumin (IMA) is an altered type of serum albumin that forms under conditions of oxidative stress. Aim: To measure the levels of IMA in β-thalassemia patients as a marker of oxidative stress, and to assess its relation to lipid peroxidation as well as the effect on vascular complications, subclinical atherosclerosis and the efficacy of iron chelation. Methods: Forty-five β-TM patients without symptoms of heart disease were compared to 30 healthy controls and studied stressing on splenectomy, transfusion history, chelation therapy and serum ferritin. IMA levels were measured by enzyme linked immunosorbent assay (ELISA) and MDA was assessed by measuring the production of Thiobarbituric Acid Reactive Substances (TBARS). Echocardiography was performed and carotid intima media thickness (CIMT) was measured using Doppler ultrasound. Results: Pulmonary hypertension risk (elevated tricuspid regurgitant jet velocity [TRV] >2.5 m/sec) was found in 22.2% while heart disease was found in 20% of patients. Comparison between β-thalassemia major patients with mean serum ferritin ≥2500 µg/L and those with serum ferritin <2500 µg/L revealed significantly higher transfusion index as well as elevated TRV and CIMT with lower ejection fraction (EF) in patients with serum ferritin ≥2500 µg/L. IMA and MDA levels were significantly higher in β-TM patients compared with control group (p<0.001). IMA was significantly higher among patients with heart disease and pulmonary hypertension risk than those without (p<0.05). ROC curve analysis revealed that the cutoff value of IMA at 17.5 U/mL could differentiate patients with and without heart disease and the cutoff value of IMA at 75 U/mL could differentiate patients with and without pulmonary hypertension risk with high sensitivity and specificity. Serum IMA and MDA levels were elevated among patients with serum ferritin ≥2500 µg/L compared with patients below this cutoff (p<0.001) while patients compliant to chelation had significantly lower IMA and MDA levels than non-compliant ones (p<0.05). Significant positive correlations were found between IMA levels and disease duration, WBC count, serum ALT, AST and TRV. Both IMA and MDA levels were positively correlated there was a significant positive correlation between these two markers and mean serum ferritin in last 2 years prior to the study as well as CIMT among TM patients. Significant negative correlations between were found between both IMA and MDA levels and each of ejection fraction and fractional shortening. Multiple linear regression analysis revealed that mean serum ferritin, MDA, TRV, ejection fraction and CIMT were independently related to IMA levels among thalassemia patients. Conclusion: Our results highlight the role of oxidative stress in the pathophysiology of vascular complications in thalassmeia. We suggest that IMA is a promising marker of oxidative stress in β-TM patients. IMA is elevated in patients with cardiopulmonary complications and significantly correlated with echocardiographic parameters. Thus, it could be useful for screening of patients at risk of cardiac complications because this alteration occurs in early stage subclinical cardiac disease. The positive correlation between CIMT and IMA suggests that it could be used as a marker of vascular dysfunction and subclinical atherosclerosis in β-TM patients. Good selection of chelation therapy based on the patients compliance, iron overload status is needed in order to decrease oxidative stress and the incidence of cardiac morbidities as well as atherosclerosis risk among β-TM patients and consequently, lower IMA levels.