Plasma lipid pattern and red cell membrane structure in β-thalassemia patients in Jakarta

Abstract

Background: Over the last 10 years, we have investigated thalassemia patients in Jakarta to obtain a comprehensive picture of iron overload, oxidative stress, and cell damage.

Methods: In blood samples from 15 transfusion-dependent patients (group T), 5 non-transfused patients (group N) and 10 controls (group C), plasma lipids and lipoproteins, lipid-soluble vitamin E, malondialdehyde (MDA) and thiol status were measured.  Isolated  eryhtrocyte  membranes  were  investigated  with  electron  paramagnetic  resonance  (EPR)  spectroscopy  using doxyl-stearic acid and maleimido-proxyl spin lables. Data were analyzed statistically with ANOVA.

Results: Plasma triglycerides were higher and cholesterol levels were lower in thalassemic patients compared to controls. Vitamin  E,  group  C:  21.8  vs  T:  6.2  μmol/L)  and  reactive  thiols  (C:  144  vs.  T:  61  μmol/L)  were  considerably  lower  in  transfused patients, who exert clear signs of oxidative stress (MDA, C: 1.96 vs T: 9.2 μmol/L) and of tissue cell damage, i.e.,  high  transaminases  plasma  levels.  Non-transfused  thalassemia  patients  have  slight  signs  of  oxidative  stress,  but  no  signifi  cant  indication  of  cell  damage.  Erythrocyte  membrane  parameters  from  EPR  spectroscopy  differ  considerably  between all groups. In transfusion-dependent patients the structure of the erythrocyte membrane and the gradients of polarity and fl uidity are destroyed in lipid domains; binding capacity of protein thiols in the membrane is lower and immobilized.

Conclusion: In  tranfusion-dependent  thalassemic  patients,  plasma  lipid  pattern  and  oxidative  stress  are  associated  with structural damage of isolated erythrocyte membranes as measured by EPR spectroscopy with lipid and protein-thiol spin labels. (Med J Indones 2011; 20:178-84)