Copeptin Kinetics in Critically Ill Patients With Posterior Reversible Encephalopathy Syndrome

Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological entity associating various neurological manifestations (e.g., encephalopathy, seizures) with a typical subcortical brain edema. While the pathophysiology of PRES remains elusive, the involvement of the arginine vasopressin (AVP) axis has recently been suggested by its stimulation in almost all etiologies of PRES as well as by its pathogenesis in the generation of brain edema that has been established in different preclinical models (e.g., traumatic brain injury, intracerebral hemorrhage) (Largeau et al., Mol Neurobiol 2019 - PMID: 30924075). Copeptin, a stable peptide derived from the same precursor as AVP and released in an equimolar ratio to AVP, is largely used in vivo to monitor AVP secretion. In a series of 225 critically ill patients free from PRES, median copeptin admission level was 50 pmol/L (Krychtiuk et al., PLOS ONE 2017- PMID: 28118414). By analogy to copeptin kinetics in patients with traumatic brain injury (Dong et al., J Trauma 2011 - PMID: 21502880), copeptin could attain peak level during the first week of PRES. Blocking vasopressin receptors with vaptan appears to be a promising approach for PRES treatment. This study aims to investigate the relationship between copeptin and PRES in order to establish the optimal therapeutic time window for vaptan treatment against PRES. XPRESSE is a multicenter observational prospective biomarker study in which critically ill patients in 4 French ICUs with MRI-based PRES diagnosis will have copeptin kinetics from a daily blood sample for 6 days and a 3-month follow-up. Data collection using an eCRF will include demographic data, medical history and data related to PRES: onset modalities and date of symptoms control, radiological features of PRES, biological investigations, results of etiological investigations and therapeutic management (e.g., anticonvulsants, antihypertensive drugs, supportive treatments). Outcomes will include modified Rankin scale score and Glasgow Outcome Scale score at ICU discharge, 3-month modified Rankin Scale score and 3-month mortality.