C-Reactive Protein in Lymphocytic Pleural Effusions: A Diagnostic Aid in Tuberculous Pleuritis

Abstract

Background:C-reactive protein (CRP) pleural fluid levels have been found to be higher in tuberculosis and parapneumonic effusions than in other causes of pleural effusion. Objective:The aim of this study was to analyze whether CRP (a simple and inexpensive test) may be a diagnostic aid for tuberculosis in lymphocytic pleural effusions. Methods:One hundred and forty-four patients with a lymphocytic pleural effusion (more than 50% lymphocytes in the differential white blood cell count) were included. The patients were 93 men (65%) and 51 women (35%), aged 64 ± 18 years (mean ± SD). The diagnoses were as follows: tuberculosis, 20; pleural effusion associated with malignancy, 69; transudates, 38; other benign exudates, 17. Results: The CRP pleural fluid level was higher in tuberculous pleuritis (54 ± 24 mg/l) than in lymphocytic effusions of other origin (21 ± 16 mg/l; p < 0.001). High CRP levels (≧50 mg/l) have a high specificity for tuberculosis (95%), and low levels (<30 mg/l) have a high sensitivity (95%) for excluding disease. Conclusions: CRP pleural fluid level determination is useful in the diagnostic workup of lymphocytic pleural effusions. High CRP levels are very suggestive of tuberculous pleuritis, and low CRP levels make this diagnosis unlikely.

Osteopontin and C-reactive protein in Egyptian patients affected with tuberculous and malignant pleural effusion

“…This ¢nding could be explained by increased local production of CRP as a result of granuloma formation 35 and as a defence mechanism against the tubercle bacilli. Our results are concordant with other authors 4,36,37 who found a signi¢cant increase in pleural £uid CRP and suggested the use of CRP as an indication of tuberculous e¡usion. Moreover, in the current study, ROC curve analysis has shown that CRP and OPN are more sensitive markers for tuberculous rather than malignant e¡usion and CRP outperformed OPN as a marker for tuberculous e¡usion.…”

Biomarkers of infection for the differential diagnosis of pleural effusions

“…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). Indeed, a number of studies provide support for the use of CRP as a diagnostic aid in tuberculous pleuritis; low pleural CRP levels (,30 mg?L -1 ) make this diagnosis unlikely while being more indicative of a malignancy in patients with exudates [8][9][10]. In addition, our findings complement the scarce previous literature on the application of CRP for identifying CPPE [11,12].…”

Evaluation of Adapted Whole-Blood Interferon-γ Release Assays for the Diagnosis of Pleural Tuberculosis

“…Invasive interventions such as closed pleural biopsy or thoracoscopy are often needed to confirm the diagnosis. Surrogate pleural fluid markers such as adenosine deaminase (ADA) and interferon (IFN)-γ have been proposed as an alternative [4, 5]. ADA determination by a technically simple colorimetric measurement has a mean sensitivity of 92% (range 56–100) and a mean specificity of 89% (range 55–100) [6].…”