ICITRU : Randomized Trial of Immunonutrition With L-citrulline in Patients Hospitalized in Intensive Care for Sepsis or Septic Shock

Overview

Immunonutrition in intensive care has not yet demonstrated a beneficial effect on organ failure, the acquisition of nosocomial infections, or mortality. It did not correct for acquired immunosuppression in intensive care patients. Despite numerous methodological problems (use of several pharmaconutrients, very heterogeneous set of patients) and the absence of clinical data, deleterious effects have been attributed to immunonutrition in intensive care, in particular in septic patients and patients in intensive care . Arginine (ARG) is a semi-essential amino acid involved in many immunological mechanisms. It is synthesized in sufficient quantity under normal conditions but quickly becomes insufficient under catabolic conditions such as in severe sepsis. Arginine is not only the precursor of nitrogen monoxide (NO) but also an essential substrate for numerous enzymatic reactions which participate in the maintenance of immune homeostasis, in particular T lymphocyte function. Depletion of the cellular medium in arginine will induce an abnormality in the metabolism of immune cells responsible for a dysfunction of these cells (lymphopenia linked to early apoptosis) and thus expose patients to organ failure and nosocomial infections. It has been found that hypoargininemia in intensive care patients is associated with the persistence of organ dysfunction (SOFA score), the occurrence of nosocomial infections and mortality. Also, it has been demonstrated that in these patients, enteral administration of ARG was not deleterious and increased ornithine synthesis, suggesting a preferential use of ARG via the arginases route, without significant increase in argininaemia or effect on immune functions. L-citrulline (CIT), an endogenous precursor of ARG, constitutes an interesting alternative for increasing the availability of ARG. Sponsor recent data demonstrate that the administration of CIT in intensive care is not deleterious and that it very significantly reduces mortality in an animal model of sepsis, corrects hypoargininemia, with convincing data on immunological parameters such as lymphopenia, which is associated with mortality, organ dysfunction and the occurrence of nosocomial infections. The availability of ARG directly impacts the mitochondrial metabolism of T lymphocytes and their function. Our hypothesis is therefore that CIT supplementation is more effective than administration of ARG in correcting hypoargininemia, reducing lymphocyte dysfunction, correcting immunosuppression and organ dysfunction in septic patients admitted to intensive care.

Strategy : Enteral administration of citrulline for 5 days versus iso-nitrogenous placebo. Amino acid assay and immunological parameters (monocytic expression of HLA-DR, MDSCs, cytokines / chemokines, lymphocyte number and phenotype, apoptosis and lymphocyte proliferation and mitochondrial function and T lymphocyte repertoire) will only be carried out on patients included in Rennes (60 patients).