Publication:

Oxidative stress in childhood steroid sensitive nephrotic syndrome and its correlation with DNA damage

Background Imbalance in oxidative state has been hypothesized as causative factor in renal injury. Oxidant stress can result in DNA damage which can be measured by comet assay. The aim of the study was to assess the oxidative stress and DNA damage in children with NS.

Methods Children of NS during first episode/relapse and remission were recruited. Blood malondialdehyde (MDA), reduced-glutathione (GSH) and superoxide dismutase (SOD) levels were done to assess oxidative state and compared with controls. DNA damage was assessed by comet assay. Percentage DNA in tail, tail length and olive tail moment (OTM) were calculated. Comparison of various groups was done and correlation determined by appropriate statistical tests.

Results Study group consisted of 38 children in each group. MDA levels were high in NS group compared to remission and controls with statistical significance (p<0.001 and 0.005 respectively). GSH and SOD levels were lower in relapse and remission group compared to controls. p value was <0.001 when NS group was compared with control. When proteinuria group was compared with remission, p value was <0.001 for GSH and 0.045 for SOD. Mean percentage DNA in tail in children with proteinuria was significantly more compared to control (p=0.052) and it correlated best with MDA assay (r=0.227; p=0.003) suggesting a relation between oxidative stress and DNA damage.

Conclusions Oxidative stress persisted in NS even after remission and DNA damage can occur as result of persistent oxidant stress. There was significant increase in antioxidants levels when children went into remission. The levels of oxidant MDA correlated with DNA damage.