Noppawan Phumala Morales, Chalermkhwan Cherlermchoung, Suthat Fucharoen, Udom Chantharaksri
Paraoxonase and platelet-activating factor acetylhydrolase activities in lipoproteins of ?-thalassemia/hemoglobin E patients
Background: Iron-induced oxidative stress may be implicated in the alteration of the lipoprotein-associated antioxidant enzymes paraoxonase 1 (PON1) and platelet-activating factor acetylhydrolase (PAF-AH), leading to atherosclerosis-related vascular complication in patients with ?-thalassemia hemoglobin E (?-thal/Hb E).
Methods: Plasma and lipoprotein enzyme activities of PON1 and PAF-AH were studied in 13 mild to moderate and 15 severe cases of ?-thal/Hb E in comparison with 15 normal subjects.
Results: PON1 activity was significantly reduced in association with oxidative stress in the patients. There were significant correlations between high-density lipoprotein (HDL)-PON1 activity and oxidative stress markers, including plasma levels of ?-tocopherol (r=0.694 p<0.001) and the ratio of cholesteryl linoleate to cholesteryl oleate (CL/CO, r=0.662, p<0.001) in HDL. On the other hand, PAF-AH activity was markedly increased in patients by approximately two-fold and three- to four-fold in plasma and lipoproteins, respectively. Significant correlations of low-density lipoprotein (LDL) and HDL-PAF-AH activity with plasma iron, ?-tocopherol and the CL/CO ratio were also demonstrated.
Conclusions: We suggest that impairment of PON1 activity may be directly caused by oxidative damage, while increased PAF-AH activity possibly results from oxidative stress-induced inflammatory response in ?-thal/Hb E patients.
Clin Chem Lab Med 2007;45:884–9.
Clinical Chemical Laboratory Medicine, Walter de Gruyter
Print ISSN: 1434-6621
Volume: 45, 07/2007
Pages: 884 - 889
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