BackgroundAlthough pleural fluid lactate dehydrogenase (LDH) and adenosine deaminase (ADA) levels are often used to distinguish between tuberculous pleural effusion (TPE) and parapneumonic pleural effusion (PPE), this can be challenging as the LDH level may vary from normal to severely increased in PPE and a significantly elevated ADA is frequently measured in both conditions. In this study, we evaluated use of the pleural fluid LDH/ADA ratio as a new parameter to discriminate TPE from PPE.MethodsA retrospective study was conducted in patients with pathologically-confirmed TPE (n = 72) and PPE (n = 47) to compare pleural fluid LDH and ADA levels and LDH/ADA ratios between the 2 groups. A receiver operating characteristic (ROC) curve was constructed for identifying TPE.ResultsThe median pleural fluid LDH and ADA levels and LDH/ADA ratios in the TPE and PPE groups were: 364.5 U/L vs 4037 U/L (P < .001), 33.5 U/L vs 43.3 U/L (P = .249), and 10.88 vs 66.91 (P < .0001), respectively. An area under the ROC curve of 0.9663 was obtained using the LDH/ADA ratio as the indicator for TPE identification, and the sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were, respectively, 93.62%, 93.06%, 13.48, and 0.068 at a cut-off level of 16.20.ConclusionsThe pleural fluid LDH/ADA ratio, which can be determined from routine biochemical analysis, is highly predictive of TPE at a cut-off level of 16.20. Measurement of this parameter may be helpful for clinicians in distinguishing between TPE and PPE.Electronic supplementary materialThe online version of this article (10.1186/s12890-017-0526-z) contains supplementary material, which is available to authorized users.

Background Pleural parasitic infestation (PPI) is a disease prevalent in certain parts of the world. It is frequently misdiagnosed due to its lack of standardized diagnostic criteria. The purpose of this study was to evaluate the clinical characteristics of PPI patients and develop a practical diagnostic approach for PPI. Methods A retrospective study was conducted by reviewing the medical records of 11 patients with PPI. A practical diagnostic approach was proposed based on the unique laboratory findings. Results All patients demonstrated respiratory symptoms, including shortness of breath, cough, fever, chest pain, excessive sputum and hemoptysis. Leukocytosis (> 10,000/μL) and eosinophilia (> 500/μL) of peripheral blood were present in 45.5 and 36.4% patients, respectively. The mean concentrations of pleural effusion lactate dehydrogenase (LDH), adenosine deaminase (ADA), protein and carcinoembryonic antigen (CEA) were 338.2 U/L (range, 61–667 U/L), 11.6 U/L (range, 0.1–28.2 U/L), 43.7 g/dL (range, 21.9–88.1 g/dL), and 1.84 mg/mL (range, 0.28–4.8 mg/mL), respectively. The mean percentage of eosinophils in the pleural effusion was 19.5% (10.5–41%). Blood test was positive for parasite-specific IgG antibody in 9 patients, including 4 for Paragonimus westermani, 3 for Taenia solium, 1 for Clonorchis sinensis and 1 for Echinococcus granulosus. Eggs of Clonorchis sinensis were detected in the stool of two patients. Sparganum was found in the pleural effusion of one patient. Respiratory symptoms and abnormal appearances in pulmonary radiographic examination were disappeared in all patients who received anti-parasitic treatment. Conclusions In patients with unexplained pleural effusion, parasite-specific IgG antibody tests should be performed when pleural fluid testing shows eosinophilic pleural effusion. It is preferable to consider the diagnosis of PPI in clinical practice when serum parasite-specific IgG antibody test is positive.

BackgroundThe most efficient approach to diagnose malignant pleural effusions (MPEs) is still controversial and uncertain. This study aimed to evaluate the utility of a combined approach using ultrasound (US)-guided cutting-needle biopsy (CNB) and standard pleural biopsy (SPB) for diagnosing MPE.MethodsPleural effusions were collected from 172 patients for biochemical and microbiological analyses. US-guided CNB and SPB were performed in the same operation sequentially to obtain specimens for histological analysis.ResultsUS-guided CNB and SPB procedures provided adequate material for histological analysis in 90.7 and 93.0% of cases, respectively, while a combination of the 2 techniques was in 96.5% of cases. The sensitivity, specificity, positive-predictive value (PPV), negative-predictive value (NPV) and diagnostic accuracy of US-guided CNB versus SPB were: 51.2 vs 63.4%, 100 vs 100%, 100 vs 100%, 64.9 vs 72.2% and 74.4 vs 81.3%, respectively. When CNB was combined with SPB, the corresponding values were 88.6, 100, 100, 88.6 and 93.9%, respectively. Whereas sensitivity, NPV and diagnostic accuracy were not significantly different between CNB and SPB, the combination of CNB and SPB significantly improved the sensitivity, NPV and diagnostic accuracy versus each technique alone (p < 0.05). Significant pain (eight patients), moderate haemoptysis (two patients) and chest wall haematomas (two patients) were observed following CNB, while syncope (four patients) and a slight pneumothorax (four patients) were observed following SPB.ConclusionsUse of a combination of US-guided CNB and SPB afforded a high sensitivity to diagnose MPEs, it is a convenient and safe approach.Electronic supplementary materialThe online version of this article (doi:10.1186/s12890-016-0318-x) contains supplementary material, which is available to authorized users.

Background: Eosinophilic pleural effusion (EPE) is attributed to several well-recognised causes. However, some patients remain idiopathic, even after thorough clinical work-up. The present study aimed to better characterize idiopathic EPE (IEPE) and to outline the diagnostic procedure for this disease. Methods: Complete clinical data of 11 consecutive patients with IEPE were prospectively collected and analysed. Preliminary diagnostic procedure of IEPE in our hospital was performed. Results: All the 11 patients had respiratory symptoms and unilateral pleural effusion (PE) occurred in 4 patients. The mean percentage of eosinophils in PE was 22.4% (range, 12.4-50.5%). Lactate dehydrogenase, adenosine deaminase, proteins and carcinoembryonic antigen in PE were 246.0 U/L (range, 89.8-421.9 U/L), 13.8 U/L (range, 1.8-24.0 U/L), 42.6 g/dl (range, 32.8-52.6 g/dl) and 2.17 mg/mL (range, 0.46-4.31 mg/mL), respectively. Parasitespecific IgG antibody in blood and parasite eggs in stool were both negative. No evidence of tuberculosis or malignancy was observed in pleural biopsy. Symptoms and abnormal pulmonary imaging were eliminated after glucocorticoid use. Conclusions: IEPE is a diagnosis of exclusion. Patients with EPE without a clear cause should be asked to provided complete medical, surgical and drug-related histories. A thorough work-up is essential. Moreover, we recommend follow-up after the use of glucocorticoid until effusion resolves.