Oxidation and antioxidant capactiy in children with henoch-schönlein purpura

- 55 -SUMMARYOxidation and antioxidant capacity in children with Henoch-Schönlein vasculitisHenoch-Schönlein purpura (HSP) vasculitis is one of the most frequent form ofvasculitis in children. Oxidative damage comprises various inflammatory, toxic andreperfusion injuries and is initiated by reactive oxygen molecules. In this study, we aimed toevaluate alterations of the oxidant/anti-oxidant balance in the active phase of childhood HSP.A total of 29 children with HSP, who applied to Dicle University Hospital,Department of Pediatrics, and 30 matched healthy controls were enrolled. Complete bloodcounts, serum biochemistry, IgA, complement factors 3 and 4, anti-streptolysin-O (ASO), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and blood pressures weremeasured. In order to evaluate oxidant/anti-oxidant balance; serum catalase, total anti-oxidantactivity (TAOA), malondialdehyde (MDA) and paraoxonase levels (as a first time for HSP)were measured.There were no differences in the biochemical results between patients and controls(P>0.05). In patient group, elevated IgA levels were detected in 51% of patients and elevatedC3 in 6.8%. Moderate leukocytosis (WBC>15.000/mm3) were found in 31% andthrombocytosis (Platelet counts>400.000/mm3) in 48%. Furthermore, elevated ASO werefound in 24%, positive CRP in 17% and increased ESR in 79% of patients. Increased acutephase reactants were considered to be related to their measurements during active disease.There was gastro-intestinal involvement in 58% of patients, joint involvement in 48%and renal involvement in 45% of patients. No significant correlations were found betweendifferent organ involvements and the levels of oxidant/antioxidants (P>0.05). Children withHSP had significantly lower catalase (49.7±27.5 vs. 68.3±21.4 IU/L, respectively, P=0.004),TAOA (0.52±0.12 vs. 0.69±0.13 mmol Trolox Equival/L, P<0.001) and Paraoxonase(97.5±48.4 vs. 135.9±95.2 U/L, P=0.047) compared with healthy controls. However, themean MDA levels of HSP patients were significantly lower than that of controls (15.4±7.34vs. 7.80±3.88 nmol/L, respectively, P<0.001).In conclusion; TAOA, catalase and paraoxonase levels were found to be decreased andMDA levels increased in the active phase of childhood HSP. The levels of antioxidantenzymes (catalase and paraoxonase) did not increase as a compansation against increasedlipid peroxidation. The role of antioxidants in the management of childhood HSP remains tobe investigated in future.Key Words: Henoch-Schönlein purpura, catalase, malondialdehyde, antioxidantcapacity, paraoxonase