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.

Biomarkers of infection for the differential diagnosis of pleural effusions

“…CRP CRP, an acute-phase reactant released from the liver, is a common diagnostic test within hospital laboratories for the screening or monitoring of infections and noninfectious inflammatory diseases. CRP levels have been studied in pleural fluid and have been found to be higher in PPEs than in other types of exudative or transudative effusions [5][6][7]. We showed that a pleural fluid CRP level .80 mg?L -1 argues for the presence of a PPE (LR+ 7.4), whereas CRP levels ,20 mg?L -1 are a strong indicator against an infectious pleural effusion, whether of bacterial or mycobacterial nature (LR-0.22).…”

Synovial fluid adenosine deaminase and high-sensitivity C-reactive protein activity in differentiating monoarthritis

“…Higher SF CRP levels reXect greater degrees of joints inXammation in RA and OA [16]. CRP level is also used for the diVerentiation of infectious, tuberculosis and malignant pleural eVusions [17,18].…”

Mediators in pleural effusions of different origin: a two-step diagnostic study

“…Increased levels of interleukin (IL)-6 and IL-8 but decreased levels of the soluble form of the interleukin 6 receptor (sIL-6R) were found in pleural effusion fluid of patients with lung cancer and malignant pleural effusions (CA) and could be used for differential diagnosis against effusions of tuberculous origins (TB) [1,2]. In another study matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) were examined.…”

“…IFN-γ, IL-12p40, and IL-6 proved useful in differentiating tuberculous and malignant effusions [12]. C-reactive protein (CRP), IL-6, and TNF-α provided useful information for the differentiation of parapneumonic, tuberculous and malignant effusions in clinical practice [2]. Applying a decision tree analysis that contained age, temperature, pleural fluid ADA, and LDH was helpful in the differential diagnosis of tuberculous and malignant pleural effusions [13].…”