Search

Objective: To evaluate the drug metabolizing enzyme CYP1A2 activity in pediatric hemoglobin E-beta-thalassemia patients, since CYP1A2 is responsible for the metabolism of a number of drugs. Alteration of its activity may have clinical consequences., Material and Method: Twenty-three hemoglobin E-beta thalassemia pediatric patients and 24 age-matched controls were recruited in the present study. Caffeine in the form of a soft drink was orally administered as a test probe for CYP1A2 activity. Plasma collected at pre-dose and 6 hr after intake was analyzed for the levels of caffeine and paraxanthine, its major metabolite to represent the activity of CYPIA2., Results: Biochemical markers, including blood glutathione and urinary lipid hydroperoxides indicated that patients were in an oxidant stress state. The plasma ratio of paraxanthine to caffeine was unchanged between patients and controls. Multiple regression analysis revealed that gender and the liver enzyme were the significant determinants of CYP1A2 activity (adjusted r2 = 0.48, p < 0.001). Male gender was associated with higher activity of CYP1A2 activity., Conclusion: The CYP1A2 activity is not apparently changed in thalassemia patients despite the presence of an oxidative stress state.

Background: Beta-thalassemia/Hemoglobin E (beta-thal/Hb E) is a congenital hemolytic anemia that is prevalent in Thailand Pulmonary arterial occlusion is the cause of morbidity and mortality in these patients. Abnormality of platelets has been implicated as pathogenesis of this condition. However the blood-borne factors that induce platelet activation are not identified Recently, oxidized low-density lipoproteins (ox-LDLs) had been identified in thalassemic blood., Objective: Identify whether oxidized LDL is the blood bone factor that induce platelet activation in beta-thal/Hb E patients., Material and Method: Platelet activation was measured by monitoring platelet shape change parameter using plasma-free human platelets. The shape change parameter was monitored following exposure to normal LDL, oxidized LDL, and thalassemic LDL., Results: Oxidized LDL, but not the native LDL and thalassemic LDL, showed platelet activation activity. Oxidation of thalassemic LDL with copper give rise to oxidized LDL with platelet activating activity. However less copper was needed by LDL from splenectomized beta-thal/Hb E patients than those from nonsplencectomized beta-thal/Hb E patients., Conclusion: LDL from splenectomized beta-thal/Hb E patients is more susceptible for oxidation and gives rise to oxidized-LDL that plays an important role in thrombosis event in these patients.

An 18-year-old woman had a hepatocellular adenoma of 4 cm across in the right lobe of the liver which was severely hemosiderotic because of beta-thalassemia hemoglobin E disease with numerous blood transfusions. The lesion was an accidental postmortem finding. To our knowledge, this is the second example of liver-cell adenoma occurring in a patient with beta-thalassemia hemoglobin E disease with secondary iron overload. It is suggested that this is an association between hepatocellular adenoma and secondary iron overload of liver cells, a similar event to the relation observed in hepatocellular carcinoma and secondary iron overload of hepatocytes.

The mean +/- S.D. of LAP score in neutrophil of the normal control, non splenectomised patients and splenectomised patients were 116 +/- 78, 94 +/- 48 and 37 +/- 23 Kaplow units, respectively. The significant reduction in the leukocyte alkaline phosphatase level (P less than 0.05) was found in beta thalassemia/HbE patients. The degree of reduction was greater in the splenectomised patients (P less than 0.05). The decreased LAP levels in PMN was persistent. This was in contrast to the LAP in PMN of other patients where as LAP returned to normal after splenectomy. The relevance to the increased susceptibility to infection and low LAP in beta thalassemia/HbE should be further investigated.