title: Acute phase markers for the differentiation of infectious and malignant pleural effusions.
abstract: Acute-phase markers, such as C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha), have been studied in inflammatory and malignant disorders. We examined the diagnostic value of these markers for the differentiation among parapneumonic, tuberculous and malignant effusions. We studied 124 patients with pleural effusions, classified as exudates [total (n=97), parapneumonic (n=15), tuberculous (n=25), malignant (n=57)] and transudates due to congestive heart failure (n=27). CRP, IL-6 and TNF-alpha were measured in pleural fluid and serum. Pleural fluid CRP was higher in parapneumonic compared to tuberculous and malignant effusions, providing 100% sensitivity for a cut-off point of 5.3mg/dL. IL-6 was higher in both parapneumonic and tuberculous compared to malignant effusions. TNF-alpha was higher in tuberculous compared to malignant effusions, providing 96.0% sensitivity, and 93.0% specificity for a cut-off point of 88.1 pg/mL. Pleural fluid CRP levels were lower than serum in all groups, probably reflecting systemic inflammation, whereas IL-6 and TNF-alpha were higher in pleural fluid indicating local production. Our data suggest that these markers may provide useful information for the differentiation of infectious and malignant effusions in clinical practice. However, further studies are needed for the validation of these findings in usual clinical circumstances.
authors.affiliation: Department of Respiratory Medicine, School of Medicine, University of Thessaly, University Hospital of Larissa, 41110 Larissa, Greece. ktk@otenet.gr
authors.forename: Theodoros S
authors.initials: TS
authors.lastname: Kiropoulos
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kostikas
authors.forename: Smaragda
authors.initials: S
authors.lastname: Oikonomidi
authors.forename: Irene
authors.initials: I
authors.lastname: Tsilioni
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Nikoulis
authors.forename: Anastasios
authors.initials: A
authors.lastname: Germenis
authors.forename: Konstantinos I
authors.initials: KI
authors.lastname: Gourgoulianis
mesh_terms: D000209:Acute-Phase Proteins / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D003937:Diagnosis, Differential; D004812:Epidemiologic Methods; D005122:Exudates and Transudates / Q000378:metabolism; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000209:etiology* / Q000378:metabolism; D016066:Pleural Effusion, Malignant / Q000175:diagnosis; D018410:Pneumonia, Bacterial / Q000150:complications / Q000175:diagnosis*; D014396:Tuberculosis, Pleural / Q000175:diagnosis*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood / Q000378:metabolism
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein