Effect of Hemodialysis on Plasma Myeloperoxidase Activity in End Stage Renal Disease Patients.

End stage renal disease (ESRD) patients on hemodialysis (HD) have an increased oxidative stress, with a high risk of atherosclerosis and other co-morbid conditions. Recent studies have suggested that myeloperoxidase (MPO)-mediated oxidative stress may play a role in the pathogenesis of cardiovascular complications in dialysis patients. Furthermore, dialysis treatment 'per se' can aggravate oxidative stress. Hence this study was designed to determine whether HD leads to an alteration in the plasma levels of MPO and malondialdehyde (MDA), a marker of oxidative stress in ESRD patients on maintenance HD. To study the effect of HD, plasma MPO and MDA were determined before and after HD in forty ESRD patients (24 men and 16 women, age between 8 and 71 years, median being 40.5 years) on maintenance HD. Plasma MPO and MDA were assayed by spectrophotometric methods. Haematological and other biochemical parameters were obtained from patients' case records. Plasma MPO and MDA levels were significantly higher after HD when compared with pre-dialysis levels (p < 0.05). There was no correlation between MPO and MDA (r = 0.184, p = 0.10) and other biochemical parameters (p > 0.05). However, there was a significant correlation between MPO and MDA with haemodialysis vintage (p < 0.05). In univariate regression analysis duration of HD (β = 1.470, p = 0.045, β = 0.388, p = 0.013), was independently associated with MPO and MDA. Although HD is indispensable for survival of patients with ESRD, it is fraught with undesirable side-effects, such as an increase in the plasma MPO and MDA levels. The elevated levels of MPO contribute to the increased oxidative stress as free radicals are produced by the reaction catalyzed by it.