title: Calprotectin: a novel biomarker for the diagnosis of pleural effusion.
abstract: BACKGROUND
  Novel non-invasive biomarkers for the precise diagnosis of malignancy in pleural effusion (PE) are needed. The aim of this study was to determine the diagnostic accuracy of calprotectin for predicting malignancy in patients with exudative PE.
  
  
  METHODS
  Calprotectin concentration was measured in 156 individuals diagnosed with exudative PE (67 malignant and 89 benign). Calprotectin accuracy for discriminating between malignant and benign PE was evaluated using receiver operating characteristic (ROC) curves. Univariate and multivariate logistic regression were performed to test the association between calprotectin levels and malignant PE.
  
  
  RESULTS
  Calprotectin levels were significantly lower in malignant pleural fluid (257.2 ng ml(-1), range: 90.7-736.4) than benign effusions (2627.1 ng ml(-1), range: 21-9530.1). The area under the curve was 0.963. A cutoff point of ≤ 736.4 ng ml(-1) rendered a sensitivity of 100%, with a specificity of 83.15%, which could prove useful to delimit those patients with negative cytology tests that should be referred for more invasive diagnostic procedures. Logistic regression demonstrated a strong association between calprotectin and malignancy (adjusted OR 663.14).
  
  
  CONCLUSIONS
  Calprotectin predicts malignancy in pleural fluid with high accuracy and could be a good complement to cytological methods.
authors.affiliation: Department of Biochemistry, Genetics and Immunology, Facultad de Biología, Universidad de Vigo, 36310 Vigo, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Sánchez-Otero
authors.forename: S
authors.initials: S
authors.lastname: Blanco-Prieto
authors.forename: M
authors.initials: M
authors.lastname: Páez de la Cadena
authors.forename: L
authors.initials: L
authors.lastname: Vázquez-Iglesias
authors.forename: A
authors.initials: A
authors.lastname: Fernández-Villar
authors.forename: M I
authors.initials: MI
authors.lastname: Botana-Rial
authors.forename: F J
authors.initials: FJ
authors.lastname: Rodríguez-Berrocal
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000175:diagnosis*; D016066:Pleural Effusion, Malignant / Q000175:diagnosis*; D012372:ROC Curve
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex