Rataya Luechapudiporn, Noppawan Phumala Morales, Suthat Fucharoen, Udom Chantharaksri
The reduction of cholesteryl linoleate in lipoproteins: an index of clinical severity in ?-thalassemia/Hb E
Background: Oxidative modification of lipoproteins has been reported in ?-thalassemia and has been suggested to relate to atherogenesis-risk. This study focused on the change in cholesteryl esters in plasma lipoproteins under oxidative stress resulting from iron overload in ?-thalassemia/hemoglobin E (?-thal/Hb E) patients.
Methods: Markers of oxidative damage and cholesteryl esters (CEs) were measured in plasma and lipo-proteins from 30 ?-thal/Hb E patients and compared to those from 10 healthy volunteers. CEs in plasma, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) were separated and identified using HPLC.
Results: ?-Thal/Hb E patients presented iron overload, a precipitous decrease in ?-tocopherol and increased lipid peroxidation (thiobarbituric acid-reactive substances; TBARs) in both plasma and lipoproteins. Cholesteryl linoleate, the most abundant CE in lipoproteins, showed a reduction of 70% in LDL, while other CEs showed a lower reduction (50%). An inverse relationship between the cholesteryl linoleate/cholesteryl oleate ratio (CL/CO) and the degree of clinical severity suggested that the CL/CO ratio is an index of damaged lipoproteins and could be used as a pathologic marker of underlying iron overload. Good correlation of non-transferrin-bound iron (NTBI) and TBARs (r=0.8, p<0.01) in LDL strongly supported the contention that iron overload is responsible for initiating the lipid peroxidation in ?-thal/Hb E.
Conclusions: This study suggests that cholesteryl linoleate is the primary target of oxidative modification induced by NTBI in ?-thal/Hb E patients and that reduction in cholesteryl linoleate in lipoproteins could be used as a severity index for ?-thal/Hb E.
Clinical Chemical Laboratory Medicine, Walter de Gruyter
Print ISSN: 1434-6621
Volume: 44, 05/2006
Pages: 574 - 581
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