Genetic polymorphisms of glutathione-S-transferase and microsomal epoxide hydrolase in acquired aplastic anemia

Glutathione-S-transferase [GST] and microsomal epoxide hydrolase [mEh] are detoxifing enzymes that modulate the effects of exposure to various environmental cytotoxic and genotoxic agents, including those associated with increased risk of acquired aplastic anemia [AAA]. The GST mu1 [GSTM1], GST the ta1 [GSTT1] and mEh genes have polymorphisms with functional alteration that could explain the interindividual risks for AAA. To determine the frequency of GST and mEh polymorphisms as a risk factor for the susceptibility, clinical severity and response to treatment in a group of Egyptian paediatric patients with AAA. GST and mEh genotypes were determined by multiplex-PCR and PCR-RFLP analysis respectively in 21 patients with AAA and 20 healthy matched control subjects. The mEh enzyme activities genotypes were assessed. The incidence of the GSTT1 null genotype was significantly higher in AAA patients compared with the controls [85.7% vs. 50%] [OR 2.8, 95% CI 1.1-7.8, p=0.01]. The incidence of the heterozygous arginine [Arg] 139 polymorphism in exon 4 of the mEh gene was significantly higher in AAA patients compared with the controls [61.9% vs. 20%], [OR 3.07; 95% CI, 1.23-7.7, p=0.005]. The incidence of the fast mEh activity genotype was significantly higher in AAA patients compared with the controls [33.3% vs. 15%] [OR 2.9; 95% CI, 1.09-8.9, p=0.03]. Most patients with normal functional phenotype responded significantly favorably to treatment than patients with abnormal enzyme activity [p=0.027]. Genetic polymorphisms in biotransformation enzymes: GSTT1-null genotype, mEh His/Arg polymorphism and fast putative functional activity could be considered as risk factors to develop AAA. Moreover, abnormal functional activity of mEh enzyme was associated with worse prognosis of the disease

Rapid flow cytometric test for the diagnosis of hereditary spherocytosis and its relevance to clinical severity

The causes of non-immunehereditary hemolyticanaemia include enzymopathy, hemoglobinopathy, abnormal cation transport and membranopathy. Hereditary spherocytoris [HS] is the most common membranopathy. In this study a new flow cytometic test measures the fluorescence in tensity of intact red cells labeled with eosin -5- maliernide. The dye reacts covalentily with lys-430 on the first extracellular loop of band 3 protein. In this study, red cells from patients with HS produced a greater degree of reduction of mean channel fluorescence [MCF] readings than those for other patients groups with other causes of anaemia and normal controls. The MCF for spherocytic patients was 20.4 +/- 5.2 as compared to the control group whose MCF was 35.9 +/- 2.6. The MCF readings of other patients groups included in the study were for thalassaemia patient [39.8 +/- 2.2], glucose -6- phosphate dehydrogenase deficiency patients [34.8 +/- 1.9] iron deficiency anaemia patient [30.25 +/- 1.2], autoimmune hemolytic anaemia patients [32.5 +/- 1.7] and chronic renal failure patients [34.6 +/- 1.7]. All these groups of patients gave MCF readings that were higher than those of HS. Thus the dye method proved to be a reliable and speedy diagnostic test [2 hours from sample collection to result] for the diagnosis of hereditary spherocytosis in routine hematology