The role of oxidative stress in children with acute and chronic idiopathic thrombocytopenic purpura

Aim:To investigate whether oxidative damage is involved in acute and chronic idiopathic thrombocytopenic purpura (ITP) in childhood. Materials and Methods:Twenty-seven patients with a diagnosis of chronic ITP (Group I) and 27 with a diagnosis of acute ITP (Group II) applying to the Karadeniz Technical University Faculty of Medicine Pediatric Department Hematology Division between 01/05/2011 and 01/05/2012 were included in the study group. Thirty-one healthy children (Group III) applying to healthy children clinic constituted the control group. Total blood count, direct Coombs test, antinuclear antibodies,a product of DNA oxidation: 8-OH deoxy-guanosine (8-OHdG), a product of protein oxidation: protein carbonyl,a product of lipid peroxidation: malondialdehyde (MDA) and also total oxidative stress (TOS), total antioxidant capacity(TAC) and oxidant stress index (OSI) for analysis of the oxidant/antioxidant balance were all investigated from specimens collected from peripheral blood in all three groups. OSI value was obtained from the TAC/TOS ratio(OSI=(TOS, µmol/l)/TAC, mmol trolox equivalent/lx100). Data for the three groups were compared using SPSS 13.01. Results:A statistically significant difference was determined in 8-OHdG, MDA, TAC and TOS levels between the three groups (p=0.000, p=0.000, p=0.004 and p=0.000, respectively). No significant difference was observed in protein carbonyl and OSI levels between the three groups (p=0.208 and p=0.066, respectively). 8-OHdG level in Group II was statistically higher compared to those in the Group I and Group III (p=0.013 and p=0.000, respectively).8-OHdG level in Group I was higher not statistically compared to those in the Group III (p=0.129). MDA level in Group I and Group II were statistically higher compared to Group IIII (p=0.000 and p=0.000, respectively).However MDA level, were not statistically different between Group I and Group II (p=0.064). TAC level in the Group I, was statistically higher than Group III (p=0.004). TOS level in the Group I and Group II was statistically higher compared to those in the Group III (p=0.000 and p=0.000, respectively).In terms of patients? demographic characteristics, mean age of the patients in Group 1 was greater than in groups II and III. Thrombocyte numbers in Group II were lower than those in groups I and III (p=0.000). Conclusion: Both oxidant stress and total antioxidant response as a response to this rise in acute and chronic ITP patients. 8-OH deoxy-guanosine, MDA, TAC which shows the antioxidant defense system and TOS were higher in acute and chronic ITP patients compared to the control group. Protein carbonyl, exhibited no statistically significant difference among the groups,suggesting that oxidative damage occurring in ITP affects the lipid in thrombocytes and DNA before the protein oxidation stage. In conclusion, we think that oxidative damage is involved in the pathogenesis of acute and chronic ITP.