title: Incidence, timing, and determinants of bacterial pneumonia among HIV-infected patients: data from the ICONA Foundation Cohort.
abstract: BACKGROUND
  The aim of the study was to evaluate incidence and determinants of bacterial pneumonia (BP) after starting combination antiretroviral therapy (cART) in the Italian Cohort of Antiretroviral-Naive Patients.
  
  
  METHODS
  Patients free from BP at cART initiation enrolled between 1996 and 2011 were analyzed. Kaplan-Meier curves were calculated to estimate the time to the first episode of BP; uni- and multivariable Cox proportional hazard models, with time-updated covariates, were applied to identify the risk factors of the first episode of BP.
  
  
  RESULTS
  Four thousand nine hundred forty-two patients were followed for a median of 63.7 months (interquartile range: 23.6, 106.7); 73% were men, median age 36 years (interquartile range: 32, 42), 35% hepatitis C virus antibody positive, 28% smokers, 15% with an AIDS diagnosis (not BP) before cART, 46% with nadir CD4⁺ T-cell count ≤200 cells per microliter. During 27,569 person years, 137 patients developed 156 BPs, for a crude incidence of 5.66 [95% confidence interval (CI): 4.81 to 6.62] per 1000 person years. The probabilities of first BP at 3, 5, 10, and 14 years from cART initiation were 2.0% ± 0.22%, 2.9% ± 0.28%, 4.3% ± 0.42%, and 5.7% ± 0.75%, respectively. The occurrence of a first BP was associated with low nadir CD4⁺ [hazard ratios (HR) (per 100 cells/μL higher) = 0.86, 95% CI: 0.79 to 0.94], low current CD4 [HR (per 100 cells/μL higher) = 0.88, 95% CI: 0.84 to 0.92], high CD8⁺ [HR (per 100 cells/μL higher) = 1.02, 95% CI: 1.01 to 1.03], low hemoglobin [HR (per g/dL higher) = 0.74, 95% CI: 0.71 to 0.78], and unfavorable virological outcome [HR (HIV-RNA >50 vs <50 copies/mL) = 1.29, 95% CI: 1.04 to 1.60] in addition to older age, male gender, non-Italian nationality, smoking, and longer time to cART initiation.
  
  
  CONCLUSIONS
  BP is an infrequent clinical event in the cART era and is associated with traditional risk factors, viroimmunological failure to cART, and low hemoglobin.
authors.affiliation: Clinic of Infectious Diseases, University of Modena and Reggio Emilia, Modena, Italy. crimuss@unimore.it
authors.forename: Cristina
authors.initials: C
authors.lastname: Mussini
authors.forename: Laura
authors.initials: L
authors.lastname: Galli
authors.forename: Alessandro C
authors.initials: AC
authors.lastname: Lepri
authors.forename: Andrea
authors.initials: A
authors.lastname: De Luca
authors.forename: Andrea
authors.initials: A
authors.lastname: Antinori
authors.forename: Raffaella
authors.initials: R
authors.lastname: Libertone
authors.forename: Gioacchino
authors.initials: G
authors.lastname: Angarano
authors.forename: Paolo
authors.initials: P
authors.lastname: Bonfanti
authors.forename: Antonella
authors.initials: A
authors.lastname: Castagna
authors.forename: Antonella
authors.initials: A
authors.lastname: DʼArminio Monforte
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000009:adverse effects / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy*; D006801:Humans; D015994:Incidence; D008297:Male; D018410:Pneumonia, Bacterial / Q000150:complications* / Q000453:epidemiology; D016016:Proportional Hazards Models; D012307:Risk Factors; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents