title: Serum amyloid alpha in parapneumonic effusions.
abstract: OBJECTIVE
  To assess serum amyloid alpha (SAA) pleural fluid levels in parapneumonic effusion (PPE) and to investigate SAA diagnostic performance in PPE diagnosis and outcome.
  
  
  METHODS
  We studied prospectively 57 consecutive patients with PPE (empyema (EMP), complicated (CPE), and uncomplicated parapneumonic effusion (UPE)). SAA, CRP, TNF-α, IL-1β, and IL-6 levels were evaluated in serum and pleural fluid at baseline. Patients were followed for 6-months to detect pleural thickening/loculations.
  
  
  RESULTS
  Pleural SAA levels (mg/dL) median(IQR) were significantly higher in CPE compared to UPE (P < 0.04); CRP levels were higher in EMP and CPE compared to UPE (P < 0.01). There was no significant difference between IL-1β, IL-6, TNF-α level in different PPE forms. No significant association between SAA levels and 6-month outcome was found. At 6-months, patients with no evidence of loculations/thickening had significantly higher pleural fluid pH, glucose levels (P = 0.03), lower LDH (P = 0.005), IL-1β levels (P = 0.001) compared to patients who presented pleural loculations/thickening.
  
  
  CONCLUSIONS
  SAA is increased in complicated PPE, and it might be useful as a biomarker for UPE and CPE diagnosis. SAA levels did not demonstrate considerable diagnostic performance in identifying patients who develop pleural thickening/loculations after a PPE.
authors.affiliation: Respiratory Department, University Hospital of Larissa, Biopolis, Larissa, Greece.
authors.forename: Vagelis
authors.initials: V
authors.lastname: Boultadakis
authors.forename: Vasilis
authors.initials: V
authors.lastname: Skouras
authors.forename: Demosthenes
authors.initials: D
authors.lastname: Makris
authors.forename: Aggeliki
authors.initials: A
authors.lastname: Damianaki
authors.forename: Dimitrios J
authors.initials: DJ
authors.lastname: Nikoulis
authors.forename: Theodoros
authors.initials: T
authors.lastname: Kiropoulos
authors.forename: Smaragda
authors.initials: S
authors.lastname: Oikonomidi
authors.forename: Irene
authors.initials: I
authors.lastname: Tsilioni
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Gourgoulianis
mesh_terms: D000368:Aged; D016724:Empyema, Pleural / Q000473:pathology / Q000503:physiopathology*; D005122:Exudates and Transudates / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010994:Pleura / Q000473:pathology; D010996:Pleural Effusion / Q000378:metabolism*; D011446:Prospective Studies; D012372:ROC Curve; D000685:Serum Amyloid A Protein / Q000378:metabolism*
chemical_list: D000685:Serum Amyloid A Protein