title: Risk factors for pneumonia in immunocompromised patients with influenza.
abstract: BACKGROUND
  Immunocompromised patients with influenza are at higher risk of pneumonia and death. However, risk factors for progression to pneumonia still need evaluation.
  
  
  METHODS
  Retrospective study in immunocompromised patients with influenza-related respiratory infections. Risk factors for pneumonia were identified by multivariable logistic regression.
  
  
  RESULTS
  We identified 100 immunocompromised patients infected with influenza (68 hematological malignancies, 11 HIV, 21 iatrogenic immunosuppression). Immunofluorescence was positive in 95% of patients, mainly on nasopharyngeal aspirates (84%). Influenza A virus was involved in 80% of patients. Associated infection was documented in 34 patients. All patients presented with upper respiratory tract infection and 53 progressed to pneumonia. Thirty-two patients were critically ill, 11 received mechanical ventilation, and 10 died. All the patients who died had pneumonia. Patients with pneumonia were older (46y (36-63) vs. 33y (13-51), P=0.003) and more often had influenza A (89% vs. 70%, P=0.04) and associated infection (56% vs. 9%, P<0.0001). Factors independently associated with progression to pneumonia were influenza A (OR 5.54, 95% CI [1.16-26.47]) and hematological malignancies (OR 3.85, 95% CI [1.1-14.5]).
  
  
  CONCLUSIONS
  In our cohort of hospitalized immunocompromised patients, influenza progresses to pneumonia in more than half the patients. Patients with hematological malignancies and influenza A infection are at higher risk for pneumonia and should be included in preemptive antiviral therapy trials.
authors.affiliation: AP-HP, Hôpital Saint-Louis, Medical ICU, 1 avenue Claude Vellefaux, 75010 Paris, France. david.schnell@abc.aphp.fr
authors.forename: David
authors.initials: D
authors.lastname: Schnell
authors.forename: Julien
authors.initials: J
authors.lastname: Mayaux
authors.forename: Cédric
authors.initials: C
authors.lastname: de Bazelaire
authors.forename: Jérôme
authors.initials: J
authors.lastname: Legoff
authors.forename: Séverine
authors.initials: S
authors.lastname: Feuillet
authors.forename: Catherine
authors.initials: C
authors.lastname: Scieux
authors.forename: Juliette
authors.initials: J
authors.lastname: Andreu-Gallien
authors.forename: Michael
authors.initials: M
authors.lastname: Darmon
authors.forename: André
authors.initials: A
authors.lastname: Baruchel
authors.forename: Benoit
authors.initials: B
authors.lastname: Schlemmer
authors.forename: Elie
authors.initials: E
authors.lastname: Azoulay
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D005260:Female; D019337:Hematologic Neoplasms / Q000276:immunology* / Q000401:mortality; D017052:Hospital Mortality; D006801:Humans; D016867:Immunocompromised Host; D007251:Influenza, Human / Q000276:immunology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000276:immunology* / Q000401:mortality; D012121:Respiration, Artificial; D012141:Respiratory Tract Infections / Q000276:immunology* / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult