Prognostic role of antioxidant enzymes in sepsis: preliminary assessment

Abstract

The prognostic potential of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) was evaluated in sepsis. Enzyme concentrations were determined in samples obtained from septic patients at time of diagnosis. Statistically significant increases in activities of total plasma SOD (P < 0.003, n = 32), erythrocyte (RBC) SOD (P < 0.007, n = 16), plasma CAT (P < 0.0001, n = 32), and RBC CAT (P < 0.005, n = 16) were found in septic patients when compared with healthy adult controls (n = 7). Further, within the group of septic patients, statistically significant differences were found for total plasma SOD (P < 0.05) and plasma CAT (P < 0.009) (but not for RBC determinations) when survivors (n = 15) were compared with nonsurvivors (n = 17). No significant differences were found for either plasma or RBC enzyme concentrations when patients who developed adult respiratory distress syndrome were compared with those who did not. The most striking finding was that plasma total SOD values of > 10 kU/L were found in 7 of 21 (30%) patients who did not survive their sepsis and that these values did not overlap with any surviving patients or controls. However, while high total plasma SOD activity appears to have some potential as a prognostic indicator, lower values (0.0-8.8 kU/L) do not. For plasma CAT, despite finding statistically significant differences between survivors and nonsurvivors, the substantial overlap in the values obtained for the two groups limits the practical prognostic potential of this enzyme.

Erythrocyte SOD1 activity, but not SOD1 polymorphisms, is associated with ICU mortality in patients with septic shock

“…Warner et al showed that the plasma SOD concentration was elevated in septic patients, and levels were higher in non-survivors of sepsis compared to survivors [27]. Recently, we showed that lower erythrocyte SOD1 activity was an early predictor of the development of acute renal injury in patients with septic shock [8].…”

“…When total redox capacity is measured is sepsis, a clear decrease is seen in septic patients compared to healthy controls [25]. In addition, this redox capacity usually remains low in patients who die, whereas it returns to normal in patients who survive sepsis [25][26][27]. It is also important to observe that mitochondria are a major source of ROS, and at the same time, a target for oxidative damage [3][4][5][6].…”

“…Experimental and clinical studies evaluated the association of SOD and sepsis [27][28][29][30][31]. Macarthur et al showed in Sprague-Dawley rats that, postinfection treatment with the superoxide dismutase mimetic, protects against hypotension, vascular hyporeactivity to catecholamines, and mortality associated with septic shock [28].…”

“…In the present study, we showed that increased erythrocyte SOD1 activity was associated with decreased ICU mortality in patients with septic shock. Although these results initially appear contradictory, Warner et al evaluated the plasma levels of SOD1, but not its activity [27]. In addition, they included only 32 patients, with sepsis and septic shock, and they did not evaluated SOD1 polymorphisms or nutrition status of them [27].…”

Oxidative stress in severe acute illness

“…This difference is expected because of the increased production of the superoxide ion and hydrogen peroxide in septic patients. Plasma SOD is high in non-survivors of sepsis but tends to decrease to about a third of these high levels in survivors [23] . When total redox capacity is measured in sepsis instead of individual free radicals or oxidized cell components, a clear decrease is seen in septic patients compared to healthy controls.…”