Non-interventional, prospective, monocentric study on the exploration of leukocyte morphological parameters according to the infectious condition and response to corticosteroid therapy of septic patients.

Sepsis is a major public health issue, caused by an organ disorder related to an immune response not controlled by the infection.

Several randomized trials have shown that the combination of glucocorticoids and mineralocorticoids improves the survival rate of patients in septic shock. The optimal use of this therapeutic approach requires identifying the pro-inflammatory phase patients likely to respond to corticosteroid therapy.

Hyperactivation of immune cells is accompanied by morphological changes likely to be characterized by modern hematology instruments, particularly the DxH900 (Beckman Coulter). The DxH900 is able to use specific techniques to determine a significant number of morphological characteristics (CPD or Cell Population Data) for circulating leukocytes. Recently, one of these leukocyte morphological parameters, MDW (Monocyte Distribution Width), has been clinically approved for identifying septic patients or those at risk of developing sepsis. This MDW parameter currently has the CE IVD mark and is approved by the American FDA.

The aim of the study is to explore the hypothesis that leukocyte morphological parameters, including MDW, may constitute functional biomarkers of pro-inflammatory response and help to identify septic patients likely to optimally respond to a combination treatment of glucocorticoids and mineralocorticoids, and thus improve their chances of survival.

The proposed study is a non-interventional, prospective, monocentric cohort study to explore the variation of leukocyte morphological parameters measured on the DxH900 hematology analyzer according to the different infectious conditions of patients ranging from a known or suspected infection to septic shock versus non-infected control patients, and possibly based on the response. This observational cohort study will consist of patients with a known or suspected infection, sepsis or in septic shock on their date of admission into one of the medical or surgical departments and monitored up to day 7 of the hospital stay or on the date of discharge from the hospital, whichever occurs first.

Inclusion Criteria:

• an infection (known or suspected)

• sepsis

• sepsis + vasopressor

• septic shock

  • responders to corticosteroid therapy
  • non-responders to corticosteroid therapy

Exclusion Criteria:

• Pregnant women
• Patients with onco-hematological diseases with the presence of blasts.

Non infected (n=50) Infection (n=50) Sepsis + SOFA > 2 (n=25) Sepsis (SOFA > 2) + vasopressors and lactate ≤ 2 mmol/L (n=25) Septic shock (SOFA > 2 + vasopressor + lactate > 2 mmol/L) (n=25)