title: Oxidative stress in blood in cases of untreated refractory anaemia.
abstract: OBJECTIVE
  To examine some features of free radical processes in the blood of patients with untreated refractory anaemia (RA) and to interpret their pathogenetic role.
  
  
  METHODS
  Products of the lipid peroxidation (malondialdehyde-MDA) in whole blood, some antioxidant systems - superoxide dismutase (SOD) in erythrocytes, catalase (CTS) activity and the concentration of sulfhydryl groups (SHG) in whole blood, as well as the spontaneous and stimulated chemiluminescent activity of polymorphonuclear leucocytes (PMNL), reflecting the production of oxygen free radicals, were studied in the blood of 21 patients suffering from untreated RA (study group) and in 45 healthy individuals (control group).
  
  
  RESULTS
  Increased content of MDA (p<0.001), lowered level of CTS activity (p<0.001) and concentration of SHG (p<0.05), increased SOD activity (p<0.05) and an increase in the spontaneous PMNL oxidative activity (p<0.05) were found in the study group compared with the control group.
  
  
  CONCLUSIONS
  Strong oxidative stress was recorded in the blood of patients with untreated RA. An assumption was made that the initial iron overload helps the initiation of free radical oxidative processes in blood, accompanied with spontaneous activation of PMNL. Erythrocyte membranes probably are the main target for oxidative attack.
authors.affiliation: Clinic of Haematology, Medical University, Pleven, Bulgaria.
authors.forename: N
authors.initials: N
authors.lastname: Tzvetkov
authors.forename: P
authors.initials: P
authors.lastname: Bochev
authors.forename: M
authors.initials: M
authors.lastname: Alexandrova