title: [Ability of procalcitonin to predict bacteremia in patients with community acquired pneumonia].
abstract: OBJECTIVE
  To analyze the usefulness and ability of procalcitonin (PCT) to predict the presence of bacteremia in patients with community-acquired pneumonia (CAP) caused by Streptococcus pneumoniae (S. pneumoniae) or other bacteria.
  
  
  METHODS
  This is an observational, prospective and descriptive study involving patients who were diagnosed with CAP in our Emergency Department. Data collected included socio-demographic and comorbidity variables, Charlson index, stage in the Pneumonia Severity Index and criteria of severe NAC, microbiologic studies and biomarker determinations (PCT and C reactive protein). The follow-up was carried out during 30 days to calculate the predictive power and the diagnostic performance for bacteremia caused or not by S. pneumoniae.
  
  
  RESULTS
  Four hundred and seventy-four patients were finally included in the study. Blood cultures were positive in 85 individuals (17.9%) and S. pneumoniae was identified as the responsible pathogen in 75 of them (88.4%) (in 5 cases together with another agent). The area under the Receiver Operating Characteristic curve for PCT to predict bacteremia (caused by S. pneumoniae or not) was 0.988 (95% confidence interval 0.908-0.995; P<.001) and, considering a cut-off value≥0.95ng/mL, the negative predictive value and the positive likelihood ratio were>98% and>10, respectively. The most frequently isolated serotypes of S. pneumoniae were 19A, 7F, 1 and 3. The highest mean levels of PCT were found in serotypes 7F, 19A, 3 and 1, which showed statistically significant differences with regard to the others serotypes considered (P=.008). Serotypes associated with the highest percentage of severe sepsis-septic shock, 30-days mortality and multi-lobe or bilateral affection were 3, 1 and 19A; 1, 3 and 19A; and 3, 19A and 6A, respectively.
  
  
  CONCLUSIONS
  PCT had a remarkable diagnostic ability to discard or suspect bacteremia and to guide the etiology of CAP caused by S. pneumoniae. Serotypes 1, 3, 19A and 7F showed greater frequency, systemic inflammatory response and clinical severity.
authors.affiliation: Servicio de Urgencias-Medicina Interna, Complejo Hospitalario de Toledo, Toledo, España. Electronic address: agustinj@sescam.jccm.es.
authors.forename: Agustín
authors.initials: A
authors.lastname: Julián-Jiménez
authors.affiliation: Servicio de Análisis Clínicos y Bioquímica, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Jesús
authors.initials: J
authors.lastname: Timón Zapata
authors.affiliation: Servicio de Análisis Clínicos y Bioquímica, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Emilio José
authors.initials: EJ
authors.lastname: Laserna Mendieta
authors.affiliation: Centro de Salud de Madridejos, Madridejos, Toledo, España.
authors.forename: Raquel
authors.initials: R
authors.lastname: Parejo Miguez
authors.affiliation: Servicio de Urgencias-Medicina Interna, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Manuel
authors.initials: M
authors.lastname: Flores Chacartegui
authors.affiliation: Servicio de Urgencias-Medicina Interna, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Pablo
authors.initials: P
authors.lastname: Gallardo Schall
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D017714:Community-Acquired Infections / Q000097:blood / Q000150:complications / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000097:blood / Q000150:complications* / Q000382:microbiology; D011018:Pneumonia, Pneumococcal / Q000097:blood / Q000150:complications; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012372:ROC Curve; D055815:Young Adult
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide
keywords: Bacteremia; Bacteriemia; Biomarcadores; Biomarkers; Community-acquired pneumonia; Emergency Department; Mortalidad; Mortality; Neumonía adquirida en la comunidad; Procalcitonin; Procalcitonina; Servicio de Urgencias; Streptococcus pneumoniae