title: The Diagnostic Value of the Pleural Fluid C-Reactive Protein in Parapneumonic Effusions.
abstract: Purpose. The aim of this study was to evaluate the sensitivity of pleural C-reactive protein (CRP) biomarker levels in identifying parapneumonic effusions. Methods. A single-center, retrospective review of 244 patients diagnosed with pleural effusions was initiated among patients at the Rabin Medical Center, Petah Tikva, Israel, between January 2011 and December 2013. The patients were categorized into 4 groups according to their type of pleural effusion as follows: heart failure, malignant, post-lung transplantation, and parapneumonic effusion. Results. The pleural CRP levels significantly differentiated the four groups (p < 0.001) with the following means: parapneumonic effusion, 5.38 ± 4.85 mg/dL; lung transplant, 2.77 ± 2.66 mg/dL; malignancy, 1.19 ± 1.51 mg/dL; and heart failure, 0.57 ± 0.81 mg/dL. The pleural fluid CRP cut-off value for differentiating among parapneumonic effusions and the other 3 groups was 1.38 mg/dL. The sensitivity, specificity, positive predictive value, and negative predictive value were 84.2%, 71.5%, 37%, and 95%, respectively. A backward logistic regression model selected CRP as the single predictor of parapneumonic effusion (OR = 1.59, 95% CI = 1.37-1.89). Conclusions. Pleural fluid CRP levels can be used to distinguish between parapneumonic effusions and other types of exudative effusions. CRP levels < 0.64 mg/dL are likely to indicate a pleural effusion from congestive heart failure, whereas levels ≥ 1.38 mg/dL are suggestive of an infectious etiology.
authors.affiliation: The Pulmonary Institute, Rabin Medical Center, Beilinson Hospital, 49100 Petah Tikva, Israel; The Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel; 2nd Department of Medicine, Semmelweis University, Budapest 1088, Hungary.
authors.forename: Shimon
authors.initials: S
authors.lastname: Izhakian
authors.affiliation: Mayanei HaYeshua Medical Center, 51544 Bnei Brak, Israel; Rambam Health Care Campus, 3109601 Haifa, Israel.
authors.forename: Walter G
authors.initials: WG
authors.lastname: Wasser
authors.affiliation: The Pulmonary Institute, Rabin Medical Center, Beilinson Hospital, 49100 Petah Tikva, Israel; The Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Fox
authors.affiliation: The Pulmonary Institute, Rabin Medical Center, Beilinson Hospital, 49100 Petah Tikva, Israel; The Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel.
authors.forename: Baruch
authors.initials: B
authors.lastname: Vainshelboim
authors.affiliation: The Pulmonary Institute, Rabin Medical Center, Beilinson Hospital, 49100 Petah Tikva, Israel; The Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel.
authors.forename: Mordechai R
authors.initials: MR
authors.lastname: Kramer
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D002097:C-Reactive Protein / Q000032:analysis*; D005122:Exudates and Transudates / Q000737:chemistry*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010996:Pleural Effusion / Q000145:classification / Q000175:diagnosis*; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D002097:C-Reactive Protein