Decreased blood catalase activity is not related to specific beta-thalassemia mutations in Hungary Z. KO ´ SA*, T. NAGY*, E. NAGY † , F. FAZAKAS ‡ , L. GO ´ TH* INTRODUCTION Thalassemia is a hereditary anemia resulting from defects in hemoglobin production. Beta-thalassemia, which is caused by a decrease in the production of beta-globin chains, affects multiple organs and is asso- ciated with considerable morbidity and mortality (Cunningham et al., 2004). *Department of Biomedical Laboratory and Imaging Science, Faculty of Medicine, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary † Department of Clinical Biochemistry and Molecular Pathology, Faculty of Medicine, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary ‡ Clinical Research Center, Faculty of Medicine, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary Correspondence: La ´szlo ´ Go ´ th PhD, Department of Biomedical Laboratory and Imaging Science, Faculty of Medicine, Med- ical and Health Science Center, University of Debrecen, Debrecen, Nagyerdei krt 98 H-4012, Hungary. Tel.: +36 52 255 170(55995); Fax: +36 52 255 170; E-mail: goth@dote.hu doi:10.1111/j.1751-553X.2011.01377.x Received 15 May 2011; accepted for publication 4 August 2011 Keywords Blood catalase, blood hemoglobin, HbA 2 , HbF, beta-globin gene SUMMARY Introduction: Thalassemia erythrocytes are exposed to oxidative stress especially to hydrogen peroxide, which is regulated with the enzyme catalase. The aim of this study was to examine blood catalase activity and the relationship of blood catalase and beta-thalassemia gene mutations. Methods: Blood catalase activity, hemoglobin, HbA 2 , HbF, and beta- globin gene mutations were determined in 43 Hungarian patients with beta-thalassemia trait. Results: Compared to controls, the beta-thalassemia trait patients showed a low mean (P < 0.001) of blood catalase (men: 84 ± 29 MU/L vs. sex-matched controls: 118 ± 18 MU/L and women: 74 ± 18 MU/L vs. 108 ± 114 MU/L) and a low mean of blood cata- lase-to-blood hemoglobin ratio (men: 0.72 ± 0.22 MU/g vs. 0.85 ± 0.12 MU/g, women: 0.77 ± 0.26 MU/g vs. 0.84 ± 0.11 MU/g). The HbA 2 determination showed high sensitivity and specificity for the detection of beta-thalassemia trait patients. Mutation analyses revealed 13 beta-thalassemia trait mutations, of which six have not been reported before in Hungarian beta-thalassemia trait patients. Each group of mutations revealed decreased (P < 0.01) mean of blood catalase and catalase-to-hemoglobin ratio. Acatalasemia muta- tions were not found in beta-thalassemia trait patients. Conclusion: The decrease in blood catalase activity might be due to the damaging effects of free radicals on the catalase protein. Conse- quently, these beta-thalassemia trait patients may be relatively susceptible to damage caused by oxidative stress. ORIGINAL ARTICLE INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY 172 Ó 2011 Blackwell Publishing Ltd, Int. Jnl. Lab. Hem. 2012, 34, 172–178 International Journal of Laboratory Hematology The Official journal of the International Society for Laboratory Hematology