Delayed increase of plasma selenoproteins and absence of side effect induced by infusion of pharmacological dose of sodium selenite in septic shock: Secondary analysis of a multicenter, randomized controlled trial

International audienceBackground: In sepsis, neutrophil respiratory bursts participate in endothelium damage, the first step to multiple organ failure. In plasma two antioxidant selenoenzymes, which protect the endothelium, decrease: selenoprotein-P, and to a lesser extent glutathione peroxidase (GPX3). Sodium selenite (Na2SeO3) is a Se donor, but also an oxidant chemotherapy drug depending on its concentration. In a previous published study, Na(2)SeO(3 )continuous infusion in septic shock patients at a pharmacological dose of 4 mg1 Se/day on day-1, followed by a high nutritional dose of 1 mg Se/day during 9 days, showed no beneficial effect on weaning of catecholamine nor on survival. In this ancillary study, we report clinical and biological effects of such continuous infusion of Na2SeO3. Methods: This was a multicenter, placebo-controlled, double-blind study on 60 patients. Na(2)SeO(3)or placebo in continuous infusion as described above. Evolution with time of plasma Se, selenoprotein-P, GPX(3), Organ dysfunction (sequential organ failure assessment SOFA scores, including PaO2/FiO(2), for respiratory failure, and plasma lactate) and quality of life at 6 months (by SF36 scores) were analyzed using two-way (time, treatment) non-parametric repeated-measures analysis of variance (Friedman test). Main Results: At baseline, plasma Se was about a quarter of reference values. From baseline to day-4 plasma Se, selenoprotein-P and GPX(3) significantly increased by 3.9, 2.7 and 1.8 respectively in the Na(2)SeO(3 )group as compared with placebo and remained elevated by 2.3, 2.7 and 2.1 at day-14 respectively (p < 0.001). Na(2)SeO(3 )did not affect global and organ by organ SOFA Scores and plasma lactate concentration at day-1 and later up to day-14. The evolution of PaO2/FiO(2) until day-14 was similar in the two groups. Quality of life in the surviving patients at 6 months was similar between the two groups. Conclusion: Continuous infusion of Na(2)SeO(3 )at 4 mg Se at day-1 seems to have neither beneficial nor toxic effect at day-1 or later and induces a late increase of selenoprotein-P at day-4. Preclinical studies are required to confirm the use of Na(2)SeO(3 )as a cytotoxic drug against neutrophils and protection of the endothelium by sele-noprotein-P