Pleural Fluid C-reactive Protein Research Articles

Evaluation and outcome of parapneumonic effusion among children attending Assiut University Pediatric Hospital

BackgroundEmpyema is the most frequent suppurative complication of bacterial pneumonia in childhood. As parapneumonic effusion (PPE) progresses, fibrin and cellular debris accumulate, the purulent fluid becomes septated, and a thick peel forms over the pleura.AimTo describe and compare clinical, laboratory, microbiological findings in patients with PPE and to verify the prognostic accuracy of pleural fluid C-reactive protein in disease progression.Patients and methodsIn all, 25 children aged from 1 month to 16 years, with PPE and empyema were enrolled in this prospective study, which was carried out at Assiut University Children Hospital, from January 1, 2019 to June 30, 2019.ResultsFever and dyspnea occurred in 88 and 64% of patients, respectively. Right effusion occurred in 64% of patients. Hemoglobin was less than 10 g/dl in 72% of patients. Pleural fluid C-reactive protein after 1 week, decreased significantly (15.21 ± 9.45 vs. 50.70 ± 20.85 mg/dl). Blood culture showed no growth in 11 (44%) patients while six (24%) patients had Staphylococcus aureus. Pleural culture revealed no growth in 13 (52%) patients while S. aureus was found in seven (28%) patients.ConclusionS. aureus is the most common isolated organism in both blood and pleural fluid positive cultures. All children received the recommended antibiotics for the treatment of empyema and empyema drainage with an intercostal tube without using fibrinolytic therapy and only 12% of the children were advised for surgical treatment in the form of open thoracotomy with decortication.

The Role of Pleural Fluid C-Reactive Protein in the Diagnosis of Exudative Pleural Effusions.

Background and objectivePleural effusion develops when there is disequilibrium between pleural fluid formation and absorption. Light's criteria are currently used to differentiate transudative from exudative effusion. If the pleural effusion is exudative, it requires extensive diagnostic workup to identify the local cause of the effusion. Pleural fluid cell count and differentials, glucose level, adenosine deaminase (ADA), fluid GeneXpert for Mycobacterium tuberculosis (MTb), fluid culture, and cytology are currently used for further evaluation of exudative pleural effusions. However, the sensitivity and specificity of the above tests are not dependable. The pleural fluid C-reactive protein (CRP) is likely to reflect serum CRP levels because the CRP in the pleural fluid may be caused by increased diffusion from the blood due to inflamed capillary leakage. In this study, we aimed to examine the role of pleural fluid CRP levels in the differential diagnosis of exudative effusion.Materials and methodsBased on Light's criteria, this study included 100 patients with exudative pleural effusion. Serum CRP and pleural fluid CRP were assessed with the CRP-Turbilatex-quantitative turbidometric immunoassay method based on the principle of an agglutination reaction. Receiver operating characteristic (ROC) curves were generated by plotting sensitivity against 1-specificity, and the area under the curve (AUC) with a 95% confidence interval (CI) was calculated. After data collection, statistical analysis was performed using SPSS Statistics v28.0 (IBM, Armonk, NY).ResultsOur study showed a significant difference in pleural fluid CRP levels (p<0.001). Pleural fluid CRP was significantly higher in the empyema and parapneumonic groups compared to tuberculous and malignant effusions. The optimal cut-off value of CRP ≥47.4 mg/dl yielded 87.5% sensitivity and 92.5% specificity in differentiating parapneumonic effusion from tuberculous effusion. Pleural fluid CRP proved to be an excellent marker for distinguishing parapneumonic effusion from malignancy (cut-off value ≥49.2 mg/dl, 75% sensitivity, and 85.7% specificity) and parapneumonic plus empyema from tuberculous effusion plus malignant effusion (cut-off value ≥47.4 mg/dl, 84.6% sensitivity, and 90.8% specificity).ConclusionPleural fluid CRP levels can be used as an additional tool in the differential diagnosis of exudative effusion. It significantly differentiates parapneumonic effusion and empyema from tuberculous and malignant effusions.

Diagnostic value of pleural C-reactive protein levels in assessing severity of pediatric parapneumonic effusions

The immediate determination of complicated parapneumonic effusion is featured by instant remedial advantages. Consequently, we attempted to evaluate whether C-reactive protein (CRP) in pleural fluid can ameliorate the identification of cases with parapneumonic effusions that eventually require intervention. Patients and methods. A case-control study enrolled 43 patients with parapneumonic effusions from the inpatient ward and emergency room of Ain Shams Pediatric University Hospital, Egypt. Twenty of those patients had complicated effusions (complicated parapneumonic pleural effusion, CPPE), and 23 had uncomplicated parapneumonic pleural effusions (UCPPE). The differentiation characteristics of pleural fluid biochemical parameters as well as pleural CRP were estimated. Pleural fluid parameters were applied to classify cases of CPPE or UCPPE. ROC analysis established CRP setting to distinguish between both groups. Results. Pleural CRP was significantly higher in CPPE and empyema (48.97 mg/L) than in UCPPE (7.75 mg/L). The optimal cut-off point between CPPE and UCPPE in relation to pleural CRP was found to be 12.26 mg/L with a sensitivity of 95.00%, specificity of 95.65%, and AUC of 94.8%. Conclusion. Pleural fluid CRP can indeed be a beneficial spare test in pleural effusions and contribute to the differential diagnosis of CPPE and UCPPE. Key words: parapneumonic effusion, empyema, pleural CRP, pediatrics

Combined analysis of C-reactive protein in pleural fluid and serum is effective in the differential diagnosis of exudative pleural effusions.

BackgroundExudative pleural effusion (EPE) is one of the common pleural manifestations of various diseases. Differential diagnosis of EPE is imperative clinically as it identifies different causes of EPE, thereby, enabling effective treatments. Thoracoscopy is a useful tool for differential diagnosis of EPE; however, some patients refuse thoracoscopic examination due to its invasive nature. In addition, the specificity and sensitivity of existing routine tests of EPE are unsatisfactory. Therefore, there is a great need to establish an effective method for the differential diagnosis of EPE.MethodsThis study was a single-institution retrospective analysis of diagnostic efficiency of C-reactive protein (CRP) and procalcitonin (PCT) between March 2018 and September 2018. A total of 87 patients diagnosed with EPE were enrolled. All participants underwent diagnostic thoracentesis. The EPE was examined using biochemical, routine, microbiological, and cytological methods. Pathological cytology detection was necessary for those suspected of malignant PE. Benign PE originates in patients with pneumonia, empyema, and tuberculosis. The levels of CRP and PCT in EPE and serum were measured before treatment. Correlation analysis and receiver-operating characteristic (ROC) curve analysis were conducted to determine the underlying relationship between levels of CRP and PCT, and for differential diagnosis.ResultsThe ROC analysis showed that the sensitivity and specificity for the analysis of pleural fluid CRP (p-CRP) were higher (cut-off: 17.55 pg/mL; sensitivity: 75.00%, specificity: 83.90%) than that of serum CRP (s-CRP, cut-off: 23.90 pg/mL; sensitivity: 71.00%, specificity: 80.4%) in the differential diagnosis for EPE. However, the analysis of pleural fluid PCT (p-PCT) and serum PCT (s-PCT) did not demonstrate correlations with EPE. Combined analysis of p-CRP (cut-off: 17.55 mg/dL) with s-CRP (cut-off: 23.9 pg/mL) showed the highest diagnostic accuracy (88.4%) in diagnosing infectious EPE.ConclusionsThe data support the close relationship between combined analysis of p-CRP with s-CRP and effective and accurate differential diagnosis of EPE, due to its higher sensitivity and specificity. However, as a highly sensitive marker for diagnosing bacterial infections, neither s-PCT nor p-PCT, showed correlations with the differential diagnosis of EPE.

Diagnostic Value of C-Reactive Protein in Discrimination between Uncomplicated and Complicated Parapneumonic Effusion.

Objectives: The role of serum C-reactive protein (CRPs) and pleural fluid CRP (CRPpf) in discriminating uncomplicated parapneumonic effusion (UCPPE) from complicated parapneumonic effusion (CPPE) is yet to be validated since most of the previous studies were on small cohorts and with variable results. The role of CRPs and CRPpf gradient (CRPg) and of their ratio (CRPr) in this discrimination has not been previously reported. The study aims to assess the diagnostic efficacy of CRPs, CRPpf, CRPr, and CRPg in discriminating UCPPE from CPPE in a relatively large cohort. Methods: The study population included 146 patients with PPE, 86 with UCPPE and 60 with CPPE. Levels of CRPs and CRPpf were measured, and the CRPg and CRPr were calculated. The values are presented as mean ± SD. Results: Mean levels of CRPs, CRPpf, CRPg, and CRPr of the UCPPE group were 145.3 ± 67.6 mg/L, 58.5 ± 38.5 mg/L, 86.8 ± 37.3 mg/L, and 0.39 ± 0.11, respectively, and for the CPPE group were 302.2 ± 75.6 mg/L, 112 ± 65 mg/L, 188.3 ± 62.3 mg/L, and 0.36 ± 0.19, respectively. Levels of CRPs, CRPpf, and CRPg were significantly higher in the CPPE than in the UCPPE group (p < 0.0001). No significant difference was found between the two groups for levels of CRPr (p = 0.26). The best cut-off value calculated by the receiver operating characteristic (ROC) analysis for discriminating UCPPE from CPPE was for CRPs, 211.5 mg/L with area under the curve (AUC) = 94% and p < 0.0001, for CRPpf, 90.5 mg/L with AUC = 76.3% and p < 0.0001, and for CRPg, 142 mg/L with AUC = 91% and p < 0.0001. Conclusions: CRPs, CRPpf, and CRPg are strong markers for discrimination between UCPPE and CPPE, while CRPr has no role in this discrimination.

Role of Pleural Fluid C-Reactive Protein in the Aetiological Diagnosis of Exudative Pleural Effusion

Introduction: Pleural effusions, the result of the accumulation of fluid in the pleural space, are a major diagnostic problem due to its anatomical nature with no direct access. There is variation in management, depending on the pleural disease. The pleural effusion can either exhibit specific or nonspecific characteristics. Aim: To determine the clinical significance and diagnostic role of pleural fluid C-Reactive Protein (CRP) level in the aetiological diagnosis of exudative pleural effusion. Materials and Methods: This was a cross-sectional study performed during the study period of September 2013 to December 2014. A total of 53 Patients identified with pleural effusion were recruited in the study and pleural fluid was subjected for the measurement of CRP level. Pleural fluid CRP was assessed with CRP-Turbilatex-Quantitative turbidimetric immunoassay method which is based on the principle agglutination reaction. The data was subjected to statistical analysis using Epi info software version 3.4.3. The Receiver Operating Characteristic (ROC) curve was plotted to illustrate the diagnostic ability. The smallest cut-off value was the minimum observed test value minus 1, and the largest cut-off value was the maximum observed test value plus 1. All the other cut-off values were the averages of two consecutive ordered observed test values. Results: Among the 53 patients in the study, 42 had exudative effusions (79.20%) and 11 had transudative effusions (20.80%). The common cause of exudative effusion was tuberculosis 26 (61.90%), followed by 9 malignancy (21.40%) and 7 parapneumonic effusion (16.70%). In our study, the pleural fluid CRP was statistically significant (p&lt;0.001) marker to differentiate exudative effusions with CRP-value &lt;30 suggestive of malignancy, CRP-value 30-50 mg/L suggestive of tuberculosis and CRP-value &gt;70 mg/L suggestive of parapneumonic effusions. Conclusion: Determination of pleural fluid CRP is a useful diagnostic marker for differentiating exudative and transudative effusions. Also, Pleural fluid CRP is a statistically significant marker in differentiating tubercular effusions from nontubercular exudative effusions.

Use of C-reactive protein level in diagnosis of tubercular pleural effusion

Background: C-reactive protein in both pleural fluid and serum has been found to be higher in tubercular pleural effusion than in other causes of pleural effusion.&#x0D; Objectives: The main aim of this study was to find out the diagnostic value of C-reactive protein in patients withlymphocytic pleural effusion.&#x0D; Methodology: A cross-sectional study was conducted in 90 patients with pleural effusion who underwent thoracocentesis at Kathmandu Medical College Teaching Hospital, Kathmandu, Nepal. The complete biochemical tests of pleural fluid and serum were performed. The C-reactive protein concentrations of both pleural fluid and serum were then measured from samples from patients with lymphocytic exudative pleural effusion.&#x0D; Results: Ninety patients with exudative lymphocytic pleural effusion were included. Male patients were 56 (62.2%) and female were 34 (37.8%) with the male to female ratio of 1.64. Mean age of the patients was 51±21.54 (Mean ± Standard Deviation). The pleural fluid C-reactive protein levels in tubercular pleural effusion were higher (48.87±24.19 mg/dl) compared to non-tubercular group (38.30±17 mg/dl; p&lt;0.001). Similarly, the serum fluid C-reactive protein levels in tubercular pleural effusion were higher (29.60±13mg/dl) compared to non-tubercular group (18.14±9.2mg/dl; p&lt; 0.001). The sensitivity of pleural fluid C-reactive protein level in diagnosing tubercular pleural effusion was 86%.&#x0D; Conclusion: Simple and inexpensive test like C-reactive protein is useful in the diagnostic workup of lymphocytic pleural effusions. High C-reactive protein levels are very suggestive of tubercular pleural effusion.

C REACTIVE PROTEIN IN DIFFENTIAL DIAGNOSIS OF PLEURAL EFFUSION

Present study has included 95 Pleural Effusion patients. Pleural fluid were collected from them and classified as Transudate and Exudate according to the standard criteria. Pleural Fluid C-Reactive Protein (CRP) concentrations indicated towards diagnosis and severity of exudates. CRP in pleural fluid is a helpful tool in diagnosis and monitoring of pleural effusion patients.&#x0D; Keywords: Pleural effusion, Exudate, CRP

The usefulness of pleural fluid presepsin, C-reactive protein, and procalcitonin in distinguishing different causes of pleural effusions

BackgroundWe aimed to determine the presepsin concentration in pleural fluid from patients with pleural effusions of different aetiologies and to compare its diagnostic value with that of pleural fluid C-reactive protein (CRP) and procalcitonin (PCT).MethodsWe enrolled 132 patients with pleural effusion who underwent diagnostic evaluation, and we classified them into six categories: empyema, parapneumonic effusion, tuberculous effusion, malignant effusion, paramalignant effusion, and transudate effusion. Additionally, all pleural effusions were categorised as infectious or non-infectious effusions.ResultsReceiver operating characteristic analysis was used to evaluate diagnostic performance. When diagnosing empyema, the marker with the highest sensitivity was pleural fluid presepsin (cut-off: 754 pg/mL; sensitivity: 90.9%, specificity: 74.4%) and that with the highest specificity was pleural fluid CRP (cut-off: 4.91 mg/dL; sensitivity: 63.6%, specificity: 89.3%). Pleural fluid PCT tended to be lower in patients with empyema than in those with parapneumonic effusion, but this was not useful for the diagnosis of empyema. When diagnosing infectious pleural effusion, a combination of pleural fluid CRP (cut-off: 2.59 mg/dL) and presepsin (cut-off: 680 pg/mL) produced the highest diagnostic accuracy (83.3%).ConclusionsPleural fluid presepsin was found at high levels in patients with empyema and parapneumonic effusion. This pattern closely resembles the previously reported pattern of pleural fluid CRP. Some combinations of pleural fluid inflammatory markers may be more clinically useful than these markers in isolation.

Value of C-reactive protein in differentiation between tuberculous and malignant pleural effusion

BackgroundFew studies had reported the value of Creactive protein (CRP) in differentiating between tuberculous pleural effusion (TBPE) and malignant pleural effusion (MPE).AimThe aim of this study was to investigate the diagnostic value of CRP in differentiating between TBPE and MPE.Settings and designThis prospective study was conducted in a University Hospital.Patients and methodsDuring a period of 18 months, a prospective study included 59 adult patients with pleural effusion. The study included two groups: group I, which included 29 patients with TBPE, and group II, which included 30 patients with MPE. Serum C-reactive protein (s-CRP) and pleural fluid C-reactive protein (p-CRP) were measured and compared in both groups, using enzyme-linked immunosorbent assay.ResultsThe mean values of s-CRP were 28.34±14.41 and 27.87±13.21 mg/dl in TBPE and MPE, respectively, with no significant difference. The mean values of p-CRP were 36.51 ±3.91 and 26.39±7.57 mg/dl in TBPE and MPE, respectively, with a highly significant difference (P=0.001). There were significantly positive correlations between s-CRP and p-CRP in both TBPE and MPE (r=0.685 and P=0.001; r=0.594 and P=0.006, respectively). With the use of cutoff values of 31.6 and 43.3 mg/l for p-CRP and s-CRP, sensitivity and specificity were 89.47 and 80.00% for p-CRP, and 15.79 and 100.00%, respectively, for s-CRP. The area under the receiver operating characteristic curve of p-CRP was 0.888, superior to that of s-CRP (0.525).ConclusionMeasurement of CRP levels in the pleural fluid has a good utility in the diagnostic workup of patients with pleural effusion. p-CRP can be a useful adjunctive test, as a potential differentiator between TBPE and MPE.

Factors influencing pleural drainage in parapneumonic effusions

ObjectiveThe identification of parapneumonic effusions (PPE) requiring pleural drainage is challenging. We aimed to determine the diagnostic accuracy of radiological and pleural fluid findings in discriminating between PPE that need drainage (complicated PPE (CPPE)) and those that could be resolved with antibiotics only (uncomplicated PPE (UPPE)). Subjects and methodsA retrospective review of 641 consecutive PPE, of which 393 were categorized as CPPE and 248 as UPPE. Demographics, radiological (size and laterality on a chest radiograph) and pleural fluid parameters (pus, bacterial cultures, biochemistries) were compared among groups. Logistic regression was performed to determine variables useful for predicting chest drainage, and receiver-operating characteristic curves assisted in the selection of the best cutoff values. ResultsAccording to the likelihood ratios (LR), findings increasing the probability of chest tube usage the most were: effusions occupying ≥1/2 of the hemithorax (LR 13.5), pleural fluid pH ≤7.15 (LR 6.2), pleural fluid glucose ≤40mg/dL (LR 5.6), pus (LR 4.8), positive pleural fluid cultures (LR 3.6), and pleural fluid lactate dehydrogenase >2000U/L (LR 3.4). In the logistic regression analysis only the first two were selected as significant predictors of CPPE. In non-purulent effusions, the effusion's size and pleural fluid pH retained their discriminatory properties, in addition to a pleural fluid C-reactive protein (CRP) level >100mg/L. ConclusionLarge radiological effusions and a pleural fluid pH ≤7.15 were the best predictors for chest drainage in patients with PPE. In the subgroup of patients with non-purulent effusions, pleural fluid CRP also contributed to CPPE identification.

Factors influencing pleural drainage in parapneumonic effusions

ObjectiveThe identification of parapneumonic effusions (PPE) requiring pleural drainage is challenging. We aimed to determine the diagnostic accuracy of radiological and pleural fluid findings in discriminating between PPE that need drainage (complicated PPE (CPPE)) and those that could be resolved with antibiotics only (uncomplicated PPE (UPPE)). Subjects and methodsA retrospective review of 641 consecutive PPE, of which 393 were categorized as CPPE and 248 as UPPE. Demographics, radiological (size and laterality on a chest radiograph) and pleural fluid parameters (pus, bacterial cultures, biochemistries) were compared among groups. Logistic regression was performed to determine variables useful for predicting chest drainage, and receiver-operating characteristic curves assisted in the selection of the best cutoff values. ResultsAccording to the likelihood ratios (LR), findings increasing the probability of chest tube usage the most were: effusions occupying ≥1/2 of the hemithorax (LR 13.5), pleural fluid pH ≤7.15 (LR 6.2), pleural fluid glucose ≤40mg/dL (LR 5.6), pus (LR 4.8), positive pleural fluid cultures (LR 3.6), and pleural fluid lactate dehydrogenase >2000U/L (LR 3.4). In the logistic regression analysis only the first two were selected as significant predictors of CPPE. In non-purulent effusions, the effusion's size and pleural fluid pH retained their discriminatory properties, in addition to a pleural fluid C-reactive protein (CRP) level >100mg/L. ConclusionLarge radiological effusions and a pleural fluid pH ≤7.15 were the best predictors for chest drainage in patients with PPE. In the subgroup of patients with non-purulent effusions, pleural fluid CRP also contributed to CPPE identification.

Distinguishing complicated from uncomplicated parapneumonic effusions.

Treatment of parapneumonic effusions (PPEs) is challenged by the decision of whether or not to insert chest tubes. This review focuses on the factors that may aid in determining which patients require an immediate drainage of the pleural space, that is, have a complicated PPE. Clinical guidelines advocate the evaluation of radiological (large effusion or loculation), bacteriological (Gram-positive stain or culture), biochemical (pH < 7.20 or glucose <60 mg/dl), and macroscopic (pus) characteristics of the pleural fluid to assist in the identification of complicated PPEs. In the past few years, a number of new pleural fluid biomarkers have been tested for the same purpose, but with the exception of C-reactive protein (CRP), they should be considered investigative. A pleural fluid CRP higher than 100 mg/l or a serum CRP higher than 200 mg/l, when combined with pleural fluid pH or glucose, may greatly increase our capability to predict the need for instituting tube thoracostomy. Although some ultrasonographic and computed tomography features favor the diagnosis of pleural infection, their role in uncomplicated-complicated PPE discrimination has not been systematically evaluated. No pleural fluid tests, other than pH or glucose, have gained wide acceptance for the assessment of patients with PPE. However, if corroborated with further studies, the measurement of pleural fluid or serum CRP, in combination with the classical fluid parameters, may have the potential to be incorporated into medical decision making.

C-reactive protein and serum amyloid A levels in discriminating malignant from non-malignant pleural effusion

IntroductionDistinction between malignant and non-malignant pleural effusion is of great importance in the patient management. The aimWe examined the diagnostic value of C-reactive protein (CRP) and serum amyloid A (SAA) in distinguishing different etiologies of pleural effusion and if they could discriminate between malignant and non-malignant pleural effusions. Subject and methodsCRP and SAA levels in both serum and pleural fluid were measured in 92 patients with pleural effusion. Of the 92 patients included in our study; 44 were diagnosed with malignant pleural effusions (group I) [with male to female ratio (M/F) 23/21 and mean age 57.7±11.5years in the form of mean±2SD] and 48 were diagnosed with non-malignant pleural effusion (group II) [with M/F ratio 33/15 and mean age 54.7±10.4years in the form of mean±2SD]. ResultsCRP and SAA values were significantly higher in both serum and pleural effusion of malignant vs. non-malignant group (P<0.003), but there was no statistical significant difference as regards pleural/serum CRP and pleural/serum SAA ratios between the two groups (P=0.148 and P=0.453 respectively). A statistically significant positive correlation between pleural fluid CRP and pleural fluid SAA in malignant and non-malignant effusions was detected (r=0.315 and P=0.002 respectively). Diagnostic performance of pleural fluid CRP and pleural fluid SAA in both infectious and malignant pleural effusions showed that at a cutoff value of 96.15μg/ml for CRP; diagnostic sensitivity was 61% and specificity was 45%, while for pleural fluid SAA, a cutoff value of 137.5μg/ml was associated with 41% sensitivity and 93% specificity. ConclusionMeasurement of SAA and CRP levels in pleural fluid has good diagnostic utility in differentiation between malignant and non-malignant pleural effusion and pleural SAA has a better diagnostic performance than CRP.

Diagnostic value of procalcitonin and C-reactive protein in differentiation between some benign and malignant pleural effusions

Pleural effusion is relatively common clinical condition that requires differential diagnosis. It is defined as collection of fluid in pleural space. Pleural effusion is often diagnostic dilemma for the physician.The aim of the study was to assess the procalcitonin (PCT) and C-reactive protein (CRP) levels in serum and pleural fluid to evaluate their usefulness in the differentiation among benign and malignant pleural effusions.This study was conducted in Chest Department, Tanta University Hospital, it included 54 adult patients with pleural effusions of different etiologies, 8 transudative effusion, 14 para-pneumonic effusion, 14 tuberculous effusion and 18 malignant effusion. We measured serum and pleural procalcitonin and C-reactive protein by ELISA.The mean serum and pleural fluid procalcitonin (PCT) levels in parapneumonic effusions were significantly higher compared with transudative, tuberculous and malignant pleural effusions p<0.05. A significant positive correlation between serum and pleural fluid PCT levels was observed in the studied groups. The mean serum and pleural fluid CRP concentration were significantly lower in malignant and transudative pleural effusion than tuberculous and para-pneumonic effusion p<0.05.Significant positive correlation between serum and pleural fluid CRP levels was observed in the studied groups. Procalcitonin levels in serum and pleural effusion were significantly lower in malignant effusion compared to para-pneumonic pleural effusion and CRP levels were significantly lower compared to other types of exudative pleural effusion.

Cut-off value of pleural fluid C-reactive protein in etiologic diagnosis of pleural fluid

BackgroundClassification of effusion into transudates or exudates is considered as the corner stone in the etiological diagnosis of pleural effusion. ObjectivesTo determine the validity of pleural fluid (high sensitivity-CRP) concentration in etiologic diagnosis of pleural effusion and to obtain a cut-off value of pleural fluid CRP at which we can discriminate between exudative and transudative pleural effusions. Patients and methodsA study was conducted upon a hundred patients with pleural effusion. All patients were subjected to: history, clinical examination, chest radiography and thoracic ultrasound, tuberculin test and aspiration of pleural fluid. The fluid was sent for biochemical examination including: Protein, L.D.H, A.D.A and CRP levels, cytological examination and bacteriologic examination. Classification of pleural fluid into transudative or exudative is based upon Light’s criteria. Data were compared by independent sample t-test for 2 groups or by a one-way analysis of variance (ANOVA) for more than 2 groups of variables. Simple correlations between variables were examined by calculating Pearson’s product correlation coefficient, Receiver operating characteristic (ROC) curve used to calculate cut off points, area under the curve (AUC), sensitivity and specificity, and 2 tailed P<0.05 was considered significant. ResultsThere were significant differences between both groups as regards serum, fluid levels and fluid/serum ratio for LDH, total protein and CRP except for CRP fluid/serum ratio. There was a significant correlation between CRP and LDH and total protein fluid levels. Receiver operating characteristic (ROC) curve was used to calculate the sensitivity and specificity of CRP fluid level and also the cut off value of CRP fluid level. Out of the 44 patients with exudative pleural effusion, two cases were diagnosed as cardiac effusion and one case as liver cirrhosis. The three cases were receiving diuretics and the pleural fluid analysis was repeated after withdrawal of the diuretics which turned to be transudative according to Light’s criteria. ConclusionCRP could be a useful diagnostic marker for differentiation between exudative and transudative pleural effusions and also it is more accurate than protein in distinguishing those transudative effusions receiving diuretic therapy which are falsely diagnosed by Light’s criteria to be exudates.

Pleural fluid prealbumin and C-reactive protein in the differential diagnosis of infectious and malignant pleural effusions

Clinical history and physical examination are helpful in indicating the potential causes of pleural effusions (PEs). However, the accurate diagnosis and establishment of the causes of PE is an ongoing challenge in daily clinical practice. The primary aim of this study was to distinguish between infectious PE and malignant PE (MPE) by measuring two major acute phase response biomarkers: prealbumin (PA) and C-reactive protein (CRP). The study was a prospective trial involving 151 patients who were diagnosed with infectious PE or MPE. Patients with infectious PE were divided into two subgroups: tuberculous PE (TBPE) and parapneumonic PE (PNPE). A further 58 patients with PEs that showed no evidence of MPE, TBPE or PNPE were classified as the chronic non-specific PE (NSPE) group. Demographic characteristics and pleural fluids of the subjects were collected consecutively. The discriminative properties of pleural fluid routine biochemistries, and PA and CRP were evaluated. PA, CRP and classical fluid parameters were also applied to classify patients with infectious PE and MPE. Receiver operating characteristics (ROC) analysis established the cutoffs of PA and CRP for discriminating between groups. Pleural fluid PA levels were significantly higher in the MPE group (n=47) than in the infectious PE group (n=104). Pleural fluid CRP levels were significantly higher in the infectious PE group than in the MPE group. Pleural fluid PA levels were identified to be moderately negatively correlated with CRP levels in the MPE group, with a statistically significant correlation coefficient of −0.352. The ROC curve showed that the sensitivity and specificity of PA for the diagnosis of MPE were 0.851 and 0.548, respectively, at the cutoff of 28.3 mg/l. The area under the curve (AUC) was 0.784 (95% CI, 0.707–0.861). Using CRP as a diagnostic parameter resulted in an comparable AUC of 0.810 (95% CI, 0.736–0.885), at the cutoff of 35.2 mg/l. Combinations of PA and CRP resulted in incrementally discriminating values for MPE, with a sensitivity of 0.617 and a specificity of 0.903. The measurement of PA and CRP levels in pleural fluid may be a useful adjunctive test in PE, as a potential differentiator between infectious PE and MPE.

English

CONTEXT: Pleural effusion occurs secondary to various diseases. Common causes of exudative effusion are tuberculosis, bacterial pneumonia, and malignancy. Transudative effusion is due to systemic diseases like cardiac failure, cirrhosis of liver. Conventional methods of diagnosis may not be able to establish the cause of pleural effusion. Early diagnosis and management reduces the morbidity and mortality. AIM: The objective of the study is to estimate pleural fluid Adenosine Deaminase (ADA) and C - reactive protein (CRP) levels and to evaluate their efficacy in differential diagnosis of transudative and exudative, tuberculous and non tuberculous and inflammatory and non inflammatory effusions. MATERIAL AND METHODS: Fifty two patients of pleural effusion were investigated and divided into four groups based on diagnosis. Group I, II, III and IV had 24 cases of tuberculous effusion, 13 cases of transudative effusion, 08 cases of malignant effusion and 07 cases of parapneumonic effusion respectively. Pleural fluid was analyzed for ADA (Guisti and Galanti's method) and CRP (turbidometric immunoassay). STATISTICAL ANALYSIS: The statistical analysis was done using unpaired student't' test and p value < 0.05 was considered statistically significant. RESULTS: In the present study pleural fluid ADA revealed highly significant increase in tuberculous effusion than non tuberculous effusions (p <0.001) and also when compared with non tuberculous subgroups, transudative effusion (p < 0.001), malignant effusion (p<0.001), and PPE (p<0.01). ADA levels at a cutoff value of 40U/L, showed sensitivity, specificity, positive predictive value and negative predictive value of 91.67%, 89.3%, 88% & 92.6% respectively in tuberculous effusion. Pleural fluid CRP levels in parapneumonic effusion were significantly higher compared to other types of effusions (p<0.001). Significantly higher levels of CRP were seen in exudative effusion compared to transudative effusion (p<0.001) and in inflammatory effusion compared to non inflammatory effusion (p<0.001).

The Diagnostic Utility of Pleural Fluid Tests in Clinical Practice

The analysis of pleural fluid (PF) is the most important diagnostic element in identifying the cause of pleural effusions. The measurement of proteins and lactate dehydrogenase in PF and blood establishes the transudative or exudative nature of effusions. Elevated concentrations of natriuretic peptide NT-proBNP (>1500 pg/mL) are virtually pathognomonic of heart failure. In exudates with predominantly polymorphonuclear leukocytes (>50%), a bacterial infection of the pleural space should be considered, particularly if pleural fluid C-reactive protein levels are high. A pleural pH <7.20 in a parapneumonic effusion is an indication for the need of a drainage tube. When lymphocytes predominate in an exudate, cancer and tuberculosis are the two main diagnoses to consider; an adenosine deaminase activity >35 U/L strongly supports the diagnosis of tuberculosis. The cytological study of PF is negative in 40% of malignant effusions. Performing immunocytochemistry on the cell block and measuring tumor markers, such as mesothelin, can increase the diagnostic yield for malignancy. Keywords: Empyema, malignant pleural effusion, pleural effusion, tuberculous pleuritis, tumor markers.

Pleural fluid C-reactive protein contributes to the diagnosis and assessment of severity of parapneumonic effusions

Background and aimsPrompt identification of parapneumonic effusions has immediate therapeutic benefits. We aimed to assess whether C-reactive protein (CRP) and routine biochemistries in pleural fluid are accurate markers of parapneumonic effusions, and to evaluate their properties as indicators for drainage (complicated parapneumonic effusion). MethodsA retrospective review of 340 non-purulent parapneumonic effusions and 1,659 non-parapneumonic exudates from a single center was performed and the discriminative properties of pleural fluid routine biochemistries and, when available, CRP were evaluated. CRP, along with classical fluid parameters, was also applied to classify patients as having complicated or uncomplicated parapneumonic effusions. ROC analysis established the threshold of CRP for discriminating between groups. ResultsPleural fluids with neutrophilic predominance and CRP levels >45mg/dL were most likely to be parapneumonic in origin (likelihood ratio=7.7). When attempting to differentiate non-purulent complicated from uncomplicated effusions, a CRP >100mg/L had the same performance characteristics (area under the curve=0.81) as the widely accepted biochemistries pH and glucose. Combinations of CRP with pH or glucose resulted in incrementally discriminating values, pertaining to either sensitivity (75–80%) or specificity (97%), for complicated effusions. ConclusionPleural fluid CRP may be a useful adjunctive test in pleural effusions, both as a marker of parapneumonics and, particularly, as a differentiator between complicated and uncomplicated effusions.