Background and study aim: Thalassemia syndromes are genetic disorders in globin chain production. There is excessive synthesis of reactive oxygen species in thalassemia which leads to oxidative stress. Excessive production of malondialdehyde (MDA) provides evidence that thalassemic erythrocytes contain a significant amount of membrane-bound iron. Inflammatory cytokines trigger the production of haptoglobin (Hp) in the liver. It is characterized by molecular heterogeneity brought on by genetic polymorphism. The aim of the work was to study the impact of haptoglobin gene polymorphism on phenotypic variability in thalassemia patients and its relation to iron overload and oxidative stress.
Patients and Methods: This study was carried out on 50 β-thalassemia major patients in addition to 25 healthy age and sex-matched individuals as control. All patients and control were subjected to: history taking, physical examination, Laboratory investigations, Iron profile, Serum ferritin, Serum haptoglobin (Hp), Serum malondialdehyde (MDA), and Haptoglobin gene polymorphism by (PCR).‎
Results: The study revealed significant decrease in serum haptoglobin and significant increase in MDA and ferritin level in thalassemic patients compared to the control group. Higher incidence of Hp2-2 in thalassemic group while control group showed more prevalence of Hp2-1. Serum level of MDA was significantly higher and haptoglobin levels were significantly lower in patients with Hp2-2 genotype. Serum ferritin was higher in the same genotype but did not reach significant value‎.
Conclusion: Haptoglobin polymorphism and phenotypic variability have a major influence on oxidative stress in thalassemia patients‎.