title: Persistent lymphopenia is a risk factor for ICU-acquired infections and for death in ICU patients with sustained hypotension at admission.
abstract: BACKGROUND
  Severely ill patients might develop an alteration of their immune system called post-aggressive immunosuppression. We sought to assess the risk of ICU-acquired infection and of mortality according to the absolute lymphocyte count at ICU admission and its changes over 3 days.
  
  
  METHODS
  Adults in ICU for at least 3 days with a shock or persistent low blood pressure were extracted from a French ICU database and included. We evaluated the impact of the absolute lymphocyte count at baseline and its change at day 3 on the incidence of ICU-acquired infection and on the 28-day mortality rate. We categorized lymphocytes in 4 groups: above 1.5 × 103cells/µL; between 1 and 1.5 × 103cells/µL; between 0.5 and 1 × 103cells/µL; and below 0.5 × 103cells/µL.
  
  
  RESULTS
  A total of 753 patients were included. The median lymphocyte count was 0.8 × 103cells/µL [0.51-1.29]. A total of 174 (23%) patients developed infections; the 28-day mortality rate was 21% (161/753). Lymphopenia at admission was associated with ICU-acquired infection (p < 0.001) but not with 28-day mortality. Independently of baseline lymphocyte count, the absence of lymphocyte count increase at day 3 was associated with ICU-acquired infection (sub-distribution hazard ratio sHR: 1.37 [1.12-1.67], p = 0.002) and with 28-day mortality (sHR: 1.67 [1.37-2.03], p < 0.0001).
  
  
  CONCLUSIONS
  Lymphopenia at ICU admission and its persistence at day 3 were associated with an increased risk of ICU-acquired infection, while only persisting lymphopenia predicted increased 28-day mortality. The lymphocyte count at ICU admission and at day 3 could be used as a simple and reproductive marker of post-aggressive immunosuppression.
authors.affiliation: Physiology Department, Cochin University Hospital, AP-HP, Paris Descartes University, 27 rue du Faubourg Saint Jacques, 75014, Paris, France. christophe.adrie@cch.aphp.fr.|Polyvalent ICU, Delafontaine Hospital, Saint-Denis, France. christophe.adrie@cch.aphp.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Adrie
authors.affiliation: Medical ICU, Grenoble 1 University, Albert Michallon Hospital, Grenoble, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Lugosi
authors.affiliation: Medical and Infectious Diseases ICU, Bichat University Hospital, AP-HP, Paris, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Sonneville
authors.affiliation: Clermont-Ferrand University, Medical ICU, Gabriel Montpied Hospital, Clermont-Ferrand, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Souweine
authors.affiliation: UMR 1137 IAME Inserm- Paris Diderot University, 75018, Paris, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Ruckly
authors.affiliation: Medical ICU, Grenoble 1 University, Albert Michallon Hospital, Grenoble, France.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Cartier
authors.affiliation: Polyvalent ICU, St Joseph Hospital, Paris, France.
authors.forename: Maité
authors.initials: M
authors.lastname: Garrouste-Orgeas
authors.affiliation: Medical ICU, Grenoble 1 University, Albert Michallon Hospital, Grenoble, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Schwebel
authors.affiliation: Medical and Infectious Diseases ICU, Bichat University Hospital, AP-HP, Paris, France.|UMR 1137 IAME Inserm- Paris Diderot University, 75018, Paris, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Timsit
keywords: Absolute lymphocyte count; ICU; Immunosuppression; Infection; Nosocomial; Shock; Survival