title: Procalcitonin and neopterin correlation with aetiology and severity of pneumonia.
abstract: OBJECTIVE
  Clinical outcome of pneumonia depends on a multifaceted treatment approach. Not only diagnostic methods but also early indicators of the degree of inflammatory response can aid in therapeutic decisions. The objective was to evaluate the usefulness of procalcitonin and neopterin in distinguishing among aetiologies as well as severity in patients with pneumonia.
  
  
  METHODS
  A total of one hundred sixteen patients with clinical, radiographic and microbiological diagnosis of pneumonia were grouped by aetiology, pneumonia severity index, and by the presence of unilobar or multilobar radiographic pulmonary infiltrates. Procalcitonin and neopterin were measured by immunoassays.
  
  
  RESULTS
  Patients with pneumococcal pneumonia presented elevated procalcitonin and neopterin levels, being higher in bacteraemic than in non-bacteraemic pneumonia. Patients with Legionella pneumonia presented elevated neopterin levels and slightly elevated procalcitonin levels. Patients with tuberculosis and Pneumocystis jirovecii pneumonia presented elevated neopterin and low or not detectable procalcitonin. Procalcitonin and neopterin levels were increased in high-risk classes of pneumonia severity index. Both parameters yielded significant correlation to the radiographic extent and also to young age.
  
  
  CONCLUSIONS
  Procalcitonin and neopterin levels vary depending on age, aetiology and severity of pneumonia. Together with clinical and microbiological data, combined measurement can help to identify patients who might benefit from additional therapies.
authors: Servei de Microbiologia, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Spain. crisprat@telefonica.net
authors: Cristina
authors: C
authors: Prat
authors: Josep
authors: J
authors: Domínguez
authors: Felipe
authors: F
authors: Andreo
authors: Silvia
authors: S
authors: Blanco
authors: Angeles
authors: A
authors: Pallarés
authors: Federico
authors: F
authors: Cuchillo
authors: Carmen
authors: C
authors: Ramil
authors: Juan
authors: J
authors: Ruiz-Manzano
authors: Vicente
authors: V
authors: Ausina
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D005260:Female; D006801:Humans; D007877:Legionnaires' Disease / Q000097:blood*; D008297:Male; D008875:Middle Aged; D019798:Neopterin / Q000097:blood*; D018410:Pneumonia, Bacterial / Q000097:blood*; D011020:Pneumonia, Pneumocystis / Q000097:blood*; D011498:Protein Precursors / Q000097:blood*; D012307:Risk Factors; D014397:Tuberculosis, Pulmonary / Q000097:blood*
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D019798:Neopterin; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide