Antioxidant status of pediatric sickle cell disease patients with bacteraemia or malaria

Abstract

Objective: Oxidative stress plays an important role in the pathogenesis of sickle cell disease (SCD) and many other infectious diseases. Antioxidant levels are known to be reduced in SCD and in malaria; however, there is no information on the antioxidant status of SCD patients with concomitant malaria or bacteremia. The objective of the present study was to determine potential effect of acute malaria or invasive bacteremia on selected antioxidant levels in SCD patients. Methods: The levels of ascorbic acid (ASC) and reduced glutathione (GSH), and activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) were measured in red blood cell pellets of SCD children (n = 70) with (i) culture-proven bacteremia (n = 23), (ii) parasitologically confirmed malaria (n = 26) or (iii) steady state (n = 21). The antioxidant levels of SCD children were compared with those of non-SCD children (hemoglobin genotype HbAA, n = 51) with (a) parasitologically confirmed malaria (n = 26) or (b) non-malarial acute febrile illness (n = 25). Selected clinical, demographic and hematological parameters were determined for all recruited children. Results: The concentrations of ASC and activity of GPx were significantly higher in the SCD steady state patients compared with the SCD malaria patients, SCD bacteremia patients or non-SCD malaria patients. The GSH level was significantly higher in the non-SCD groups, compared with the SCD bacteremia patients or the SCD steady state patients. The levels or activities of these antioxidants were not increasingly reduced in the SCD patients with bacteremia or malaria. Hematological indices were significantly different between the SCD and non-SCD groups, and between the SCD malaria or bacteremia groups compared with SCD steady state patients. Conclusion: Antioxidant levels in SCD subjects with acute infections were low, but the potential effect of malaria or bacteremia was inconsistent, probably reflecting a complex relationship that merits further studies.