Pleural Fluid Lactate Dehydrogenase Research Articles

Aetiology of pleural effusions in children living in a high TB endemic setting.

<sec id="st1"><title>BACKGROUND</title>Confirming the aetiology of pleural effusion in children may be difficult in TB-endemic settings. We investigated the role of polymerase chain reaction (PCR) and routine biochemical tests in discriminating pleural effusion caused by bacteria from other aetiologies.</sec><sec id="st2"><title>METHODS</title>This is a cross-sectional post-hoc analysis among children with pleural effusion in a tertiary hospital in South Africa, incorporating new data from PCR testing of stored pleural fluid. Aetiological classification was defined by microbiological confirmation.</sec><sec id="st3"><title>RESULTS</title>Ninety-one children were enrolled; the median age 31 months (IQR 12-102). The aetiology of pleural effusion was 40% (36/91) bacteria, 11% (10/91) TB, 3% (3/91) viruses, 11% (10/91) polymicrobial and 35% (32/91) had no pathogen identified. The most common pathogen was Staphylococcus aureus (27/91, 30%) with similar yields on culture and PCR, followed by Streptococcus pneumoniae (12/91, 13%), detected more commonly by PCR. PCR reduced the number of children with unconfirmed aetiologies from 48 to 32. Characteristics of children with no pathogen most resembled those with TB. Pleural fluid lactate dehydrogenase ≥1,716 U/L best discriminated bacterial pleural effusion from other aetiologies (sensitivity of 86%; specificity 95%).</sec><sec id="st4"><title>CONCLUSION</title>PCR improved detection of pathogens and reduced number of children with unconfirmed aetiologies in presumed exudative pleural effusion.</sec>.

A Study of Serum to Pleural Fluid Albumin Gradient in Differentiation of Exudative and Transudative Pleural Effusion in Comparison to Light’s Criteria

Pleural effusion is the accumulation of fluid between the parietal and visceral pleura called the pleural cavity. It can occur by itself or can be the result of surrounding parenchymal diseases like infection, malignancy or inflammatory conditions. Pleural effusion is one of the major causes of pulmonary mortality and morbidity. Both the visceral and the parietal pleura play an important role in fluid homeostasis in the pleural space. Pleural effusions develop when there is excess hydrostatic pressure in the pulmonary capillaries, when fluid removal is impaired by compromised lymphatic drainage or when protein and cell rich fluid enters the pleural space through leaky capillary and pleural membranes. Pleural fluid is classified as a transudate or exudate based on modified Light’s criteria, proposed by Light et al., in 1972 which has been the standard differentiation method. It is considered an exudative effusion if at least one of the criteria is met:  Pleural fluid protein/serum protein ratio of more than 0.5  Pleural fluid lactate dehydrogenase (LDH)/serum LDH ratio of more than 0.6  Pleural fluid LDH is more than two-thirds of the upper limits of normal laboratory value for serum LDH. Commonly performed tests on the pleural fluid to determine etiology are a measurement of fluid pH, fluid protein, albumin and LDH, fluid glucose, fluid triglyceride, fluid cell count differential, fluid gram stain and culture and fluid cytology.

Role of Pleural Fluid Lactate Dehydrogenase to Adenosine Deaminase Ratio in the Etiological Differentiation of Exudative Pleural Effusion

Abstract Background: Although pleural fluid adenosine deaminase (ADA) level &gt;70 U/L suggestive tuberculous pleural effusion (TPE). High ADA levels can also be seen in pneumonia, empyema, lymphoma, malignancy, and rheumatoid pleuritis. Elevated pleural fluid lactate dehydrogenase (LDH) is seen in tubercular pleural effusion (TPE), parapneumonic pleural effusion (PPE), and malignant pleural effusion (MPE). Therefore, it is challenging distinguish between TPE, PPE, and MPE based on elevated pleural fluid ADA and LDH levels. In this study, we evaluated the use of pleural fluid LDH/ADA ratio as a new parameter for etiological differentiation of exudative pleural effusions. Materials and Methods: A retrospective hospital-based observational study conducted in GHCCD, Visakhapatnam. A total of 52 patients (TPE – 19, PPE – 16, and MPE – 17) with exudative pleural effusion who fulfilled inclusion criteria were taken into study. Qualitative variables have been described in the form of frequency and percentages. Median and interquartile ranges were used for nonnormal distribution values. Receiver operating curve (ROC) curves with area under the curve (AUC) were calculated. P ≤ 0.05 was considered statistically significant. Results: The mean ADA value for TPE was 75.4 U/L (25–195 U/L), PPE was 59.1 U/L (13–180 U/L), and for MPE was 35.52 U/L (10–75 U/L). The mean LDH value for TPE was 887.8 U/L (139–2213 U/L), PPE was 1128 U/L (334–3110 U/L), and for MPE was 1470 U/L (234–4285 U/L). On ROC analysis, pleural LDH/ADA ratio ≤20.81 diagnose TPE with (sensitivity – 84.2%, specificity – 63.6%) with AUC of 0.758 (95% confidence interval [CI]: 0.619–0.866) (P = 0.0001) whereas LDH/ADA ratio in the diagnosis of PPE was found to be &gt;23.39 (sensitivity – 50%, specificity – 66.7%) with AUC of 0.535 (95% CI: 0.391–0.674) (P = 0.689) and the cutoff LDH/ADA ratio in the diagnosis of MPE was found to be &gt;20.86 (sensitivity – 70.6%, specificity – 68.6%) with AUC of 0.724 (95% CI: 0.583–0.839) (P = 0.007). The cutoff value of the LDH/ADA ratio in PPE does not reach the statistical significant value. Conclusion: Pleural fluid LDH/ADA ratio ≤20.81 U/L is predictive of TPE, and &gt;20.86 U/L is predictive of MPE and the cutoff value of 20.8 U/L can be used for etiological differentiation of pleural effusion.

The role of lactate dehydrogenase of the pleural liquid in the cytopathological diagnosis

Elevated serum or pleural fluid lactate dehydrogenase (LDH)enzyme levels can be associated with various conditions, including neoplasia, reticuloendothelial tumors, and leukemia. These conditions can lead to cell damage or death, causing LDH to be released into the bloodstream and pleural fluid. An increase in LDH levels may prompt further investigation into the underlying cause, which could include malignancies or other diseases. Elevated LDH levels in pleural fluid are often associated with certain conditions, and our study seeks to establish a quantitative assessment of LDH in conjunction with cytopathological examination for diagnostic purposes. We show here that the presence of abnormal or malignant cells in pleural fluid, as indicated by positive cytopathological results, can be concerning and often necessitates further evaluation. Elevated LDH levels provide biochemical evidence that supports the cytopathological findings, strengthening the case for a potential underlying disease or condition.

Assessment of computed tomography for the diagnosis of exudative and transudative pleural effusion

Introduction: The basic computed tomography (CT) characteristics of pleural effusion (PE) were analyzed, and the association between demographic factors and prominent CT findings with different types of PE was assessed. The individual CT characteristics and Light’s criteria for exudative PE were also evaluated. In addition, a cutoff for attenuation values of CT scans for exudative PE was determined. Methods: A cross-sectional study among 92 participants with PE was carried out at Bir Hospital, Kathmandu, Nepal. The χ2 test, logistic regression analysis, and diagnostic statistics were calculated. The ethical clearance was obtained from the institutional review committee of Institutional review board of National Academy of Medical Sciences (NAMS), Bir Hospital (Ref. 876/076/77). Results: The study examined 92 cases of PE, with 78.3% occurring in males and the majority affecting individuals aged 55–74 years old. Results showed that on CT scans, pleural thickening [odds ratio (OR): 13.89, 95% CI: 4.96–38.86, P &lt; 0.05], pleural nodules (OR: 12.72, 95% CI: 2.64–61.18, P &lt; 0.05) and loculations (OR: 13.46, 95% CI: 4.03–44.89, P &lt; 0.05) were significantly associated with exudative PE. Of these, pleural nodules had the highest specificity (96.4%) and positive likelihood ratio (9), whereas pleural thickening had the highest sensitivity (70.3%). When using the criterion “pleural fluid Lactate Dehydrogenase concentration as positive if it was over two-thirds of the upper limit of normal serum Lactate Dehydrogenase,” the CT scan had a positive likelihood ratio of 22.52. The study also found that an attenuation value ≥9.70 HU could indicate an exudative PE (area under the curve: 0.80, 95% CI: 0.70–0.90, P &lt; 0.05). Conclusion: The CT characteristics, such as pleural thickening, pleural nodules, and loculations, were more likely to be present in exudative PE. In addition, the attenuation values of PE could also determine its nature as either exudate or transudate, with an attenuation value of &gt;9.70 HU indicating an exudative PE.

Comparison of the Efficacy of Light's Criteria With Serum-Effusion Albumin Gradient and Pleural Effusion Glucose.

Introduction While Light's criteria exhibit high sensitivity (98%) in detecting exudative pleural effusions, the capacity to rule out transudates is relatively limited. A previous study showed thatapproximately one-fifth of patients with congestive cardiac failure on diuretics also met the criteria for exudate. This study compares the diagnostic value of Light's criteria, the serum-effusion albumin gradient (SEAG) method, and pleural effusion glucose levels for accurately categorizing pleural effusion as transudate or exudate. Methodology We conducted this cross-sectional observational study in a tertiary care hospital in Ahmedabad, India. Two hundred patients with pleural effusion undergoing thoracentesis were included. Laboratory parameters measured in pleural fluid analysis included pleural fluid protein, pleural fluid lactate dehydrogenase (LDH), pleural fluid albumin, and pleural fluid glucose. Serum protein, serum LDH, and serum albumin were also collected. Mean values and standard deviations (SDs) were calculated for analysis. Results A significant difference was observed in the mean value of exudative and transudative effusions for each parameter (pleural fluid protein/serum fluid protein ratio, pleural fluid LDH/serum fluid LDH ratio, pleural fluid LDH, SEAG, and pleural fluid glucose) (P < 0.001). Light's criteria demonstrated the highest efficacy in diagnosing exudates (accuracy = 97.50%), while SEAG demonstrated the highest efficacy in diagnosing transudates (accuracy = 97.50%). Conclusion SEAG is an effective alternative diagnostic tool for identifying transudates misclassified by Light's criteria. Its use can contribute to prompt diagnosis and timely treatment of patients with pleural effusion, improving patient outcomes.

LENT Score as a Prognosis Factor for Overall Survival and Progression-Free Survival in Malignant Pleural Effusion Patients at Tertiary Hospitals in West Sumatera, Indonesia

Background: Malignant pleural effusion (MPE) has a variable survival rate and prognosis. The LENT score is one method for assessing survival rates in patients with MPE. This study aimed to investigate the LENT score as a prognostic factor for overall survival (OS) and progression-free survival (PFS) of patients with MPE at a tertiary hospital in West Sumatera.&#x0D; Methods: This study was an observational analytic study involving several tertiary hospitals in West Sumatera with a minimum observation period of 2 years. Data were collected from medical records. We used Kaplan Meier analysis to assess OS and PFS.&#x0D; Results: A total of 198 subjects met the inclusion criteria. Most MPE patients in this study were aged ≥60 years, male, smokers, pleural fluid lactate dehydrogenase value &lt;1500, ECOG 1, serum NLR value &lt;9, and high-risk cancer, namely lung cancer. The distribution of LENT scores for MPE patients was evenly distributed among the low, medium, and high-risk groups. Kaplan Meier analysis showed that the median OS based on LENT scores were 804 days, 275 days, and 161 days, respectively (log-rank test p = 0.000). The median PFS based on LENT scores were 715 days, 202 days, and 106 days, respectively (log-rank test p=0.000). The OS and PFS findings are longer than previous studies.&#x0D; Conclusion: Based on LENT scores, overall survival and progression-free survival MPE patients at tertiary hospitals in West Sumatera have a better prognosis compared to previous studies.

Clinical predictors and outcomes of non-expandable lung following percutaneous catheter drainage in lung cancer patients with malignant pleural effusion.

Non-expandable lung (NEL) often occurs during pleural fluid drainage in patients with malignant pleural effusion (MPE). However, data regarding the predictors and prognostic impact of NEL on primary lung cancer patients with MPE receiving pleural fluid drainage, compared to malignant pleural mesothelioma (MPM), are limited. This study was aimed to investigate the clinical characteristics of lung cancer patients with MPE developing NEL following ultrasonography (USG)-guided percutaneous catheter drainage (PCD) and compare the clinical outcomes between those with and without NEL. Clinical, laboratory, pleural fluid, and radiologic data and survival outcomes of lung cancer patients with MPE undergoing USG-guided PCD were retrospectively reviewed and compared between those with and without NEL. Among 121 primary lung cancer patients with MPE undergoing PCD, NEL occurred in 25 (21%). Higher pleural fluid lactate dehydrogenase (LDH) levels and presence of endobronchial lesions were associated with development of NEL. The median time to catheter removal was significantly extended in those with NEL compared to those without (P = .014). NEL was significantly associated with poor survival outcome in lung cancer patients with MPE undergoing PCD, along with poor Eastern Cooperative Oncology Group (ECOG) performance status (PS), the presence of distant metastasis, higher serum C-reactive protein (CRP) levels, and not receiving chemotherapy. NEL developed in one-fifth of lung cancer patients undergoing PCD for MPE and was associated with high pleural fluid LDH levels and the presence of endobronchial lesions. NEL may negatively affect overall survival in lung cancer patients with MPE receiving PCD.

Diagnostic accuracy of pleural fluid lactate dehydrogenase to adenosine deaminase ratio for tuberculous pleural effusion: an analysis of two cohorts

BackgroundThis study aimed to evaluate the diagnostic accuracy of pleural fluid (PF) lactate dehydrogenase (LDH) to adenosine deaminase (ADA) (LDH/ADA) ratio for tuberculous pleural effusion (TPE). Especially to explore whether the LDH/ADA ratio provides added diagnostic value to ADA.MethodsThe diagnostic accuracy of PF LDH/ADA ratio and ADA for TPE was evaluated in two cohorts, named the BUFF (Biomarkers for patients with Undiagnosed pleural eFFusion) cohort (62 with TPE and 194 with non-TPE) and the SIMPLE (a Study Investigating Markers in PLeural Effusion) cohort (33 with TPE and 177 with non-TPE). Receiver operating characteristic (ROC) curve and decision curve were used to measure the diagnostic accuracy of the PF LDH/ADA ratio. The added diagnostic value of the LDH/ADA ratio to ADA was evaluated with net reclassification improvement (NRI) and integrated discrimination improvement (IDI).ResultsThe area under the ROC curves (AUCs) of PF ADA and LDH/ADA ratio in the BUFF cohort were 0.76 and 0.74, respectively. In the SIMPLE cohort, the AUCs of PF ADA and LDH/ADA ratio were 0.80 and 0.85, respectively. The decision curves of PF LDH/ADA and ADA were close in both the BUFF and SIMPLE cohorts. The NRI and IDI analyses did not reveal any added diagnostic value of LDH/ADA to ADA.ConclusionsPF LDH/ADA ratio has moderate diagnostic accuracy for TPE. It does not provide added diagnostic value beyond ADA. The current evidence does not support LDH/ADA ratio for diagnosing TPE.

Diagnostic utility of LDH measurement for determining the etiology of modified transudate pleural effusion in cats.

Fluid analysis is an initial approach for determining the underlying causes of body cavity effusions. Modified transudate is commonly diagnosed in pleural effusion in cats, however, it provides limited diagnostic information. Aims of this study were to investigate common etiologies causing different pleural fluid types and to evaluate the usefulness of lactate dehydrogenase (LDH) for differentiating the etiology in modified transudates in cats. Pleural effusion samples from 122 cats were analyzed and classified into three types: transudate, modified transudate, and exudate. Causes of pleural effusion were classified into four conditions: cardiac disease, neoplasia, feline infectious peritonitis (FIP), and pyothorax. The relationship of underlying etiology and fluid types was described. The LDH levels in pleural fluid and plasma were compared between the causes in the samples classified as modified transudate. The fluid analysis of pleural effusion showed that modified transudate was the most common fluid type (44.2%). Neoplasia was predominantly diagnosed (38.5%) as the etiology of pleural effusion. There was no significant correlation between pleural fluid and plasma LDH level in any type of pleural fluid, suggesting that pleural fluid LDH does not appear to be affected by plasma LDH. The occurrence of modified transudate was not associated to its etiologies, however, the LDH level in modified transudates showed significant differences between etiologic groups. The LDH level in modified transudate was excellent in separating cardiac from non-cardiac diseases with a cut-off value of <535 U/L and separating FIP from non-FIP diseases with a cut-off value of >641 U/L. Based on the current findings, pleural fluid LDH can be a useful adjunctive marker for differentiating some causes of modified transudate pleural effusion and should be added in the routine diagnostic work-up of feline patients with pleural effusions.

Characteristics of pleural effusion with a high adenosine deaminase level: a case–control study

BackgroundIncreased pleural fluid adenosine deaminase (ADA) is useful for diagnosing tuberculous pleurisy (TB), but high ADA levels are associated with other diseases. In this study, we compare various disease characteristics in patients with high-ADA pleural effusion.MethodsWe retrospectively collected data for 456 patients with pleural fluid ADA levels of ≥ 40 U/L from January 2012 to October 2021. Cases were classified as TB (n = 203), pleural infection (n = 112), malignant pleural effusion (n = 63), nontuberculous mycobacteria (n = 22), malignant lymphoma (ML) (n = 18), autoimmune diseases (n = 11), and other diseases (n = 27), and data were compared among those diseases. Predictive factors were identified by comparing data for a target disease to those for all other diseases. A diagnostic flowchart for TB was developed based on those factors.ResultsThe most frequent disease was TB, though 60.0% of patients were diagnosed with other diseases. Median ADA levels in patients with TB were 83.1 U/L (interquartile range [IQR] 67.2–104.1), higher than those of patients with pleural infection (median 60.9 [IQR 45.3–108.0], p = 0.004), malignant pleural effusion (median 54.1 [IQR 44.8–66.7], p < 0.001), or autoimmune diseases (median 48.5 [IQR 45.9–58.2], p = 0.008), with no significant difference from NTM (p = 1.000) or ML (p = 1.000). Pleural fluid lactate dehydrogenase (LDH) levels of < 825 IU/L were beneficial for the diagnosis of TB. Neutrophil predominance or cell degeneration, white blood cell count of ≥ 9200/µL or C-reactive protein levels of ≥ 12 mg/dL helped in diagnosing pleural infection. Pleural fluid amylase levels of ≥ 75 U/L and a pleural fluid ADA/total protein (TP) ratio of < 14 helped in diagnosing malignant pleural effusion. High serum LDH and high serum/pleural fluid eosinophils helped in diagnosing ML and autoimmune diseases, respectively. The flowchart was comprised of the following three factors: pleural fluid LDH < 825 IU/L, pleural fluid ADA/TP of < 14, and neutrophil predominance or cell degeneration, which were decided by a decision tree. The diagnostic accuracy rate, sensitivity, and specificity for the diagnosis of TB were 80.9%, 78.8%, and 82.6%, respectively.ConclusionCases involving high pleural fluid ADA levels should be investigated using several factors to distinguish TB from other diseases.

Combined Pleural Fluid Cholesterol and Total Protein in Differentiation of Exudates and Transudates

The management strategy to be adopted in pleural effusion depends on whether an effusion is a transudate or exudate. To evaluate the usefulness of pleural fluid cholesterol and/or total protein measurements for differentiating between exudates and transudates, and to compare it with Light's criteria. In this prospective study 60 patients with pleural effusion were included. Pleural fluid total protein, lactate dehydrogenase (LDH) and cholesterol as well as serum total protein and LDH levels along with other investigations were studied. Clinical classification of transudate or exudate was done on the basis of aetiology. Based on clinical signs and symptoms, chest radiograph, other investigations and response to treatment, 49 of these effusions were classified as exudates and 11 as transudates. Using pleural fluid cholesterol levels at a cut-off point of greater than 60 mg/dL and/or total protein at a cut-off point of greater than 3 g/dL for distinguishing transudates and exudates, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), were 100 percent. Using Light's criteria for discriminating transudates and exudates, sensitivity, specificity, PPV and NPV were found to be 98%; 100%; 100% and 92%, respectively. The differences resulted from a mis-classification of one expected exudate as transudate by Light's criteria. Pleural fluid cholesterol and total protein are simple, cost-effective, and useful parameters in distinguishing pleural transudates from exudates, with the advantage of requiring only two laboratory determinations and no simultaneous blood sample, compared to the use of Light's criteria.

Comparison of Diagnostic Yield and Complications in Ultrasound-Guided Closed Pleural Biopsy Versus Thoracoscopic Pleural Biopsy in Undiagnosed Exudative Pleural Effusion.

IntroductionMalignancy, tuberculosis, and non-tubercular pleural infections account for most exudative pleural effusion. Pleural fluid cytology, biochemical tests and even pleural fluid cell block studies may fail to yield a diagnosis in certain cases. Medical thoracoscopy is the gold standard for the diagnosis of unexplained pleural effusions. However, access to medical thoracoscopy may be limited, particularly in developing countries. Also, certain patients may not be fit to undergo the procedure because of medical conditions. An ultrasound-guided pleural biopsy is an option in such conditions. The present study is intended to compare the diagnostic yield and complications of both methods of pleural biopsy in undiagnosed exudative pleural effusion under a randomized controlled trial.MethodAfter fulfilling all the inclusion criteria, participants were randomized to either ultrasound-guided closed pleural biopsy or thoracoscopic-guided pleural biopsy groups. The primary outcome was to compare the diagnostic yield of ultrasound-guided Tru-Cut® (Newtech Medical Devices, Faridabad, India) closed pleural biopsy versus thoracoscopic pleural biopsy, and the secondary outcomes were to compare the complications rate, duration of the procedure, and hospital stay in the patients undergoing ultrasound-guided pleural biopsy versus thoracoscopic pleural biopsy, and predictors of a positive biopsy result in both groups.ResultA total of 118 patients with pleural effusion were screened; 39 of them who were eligible, randomized into the ultrasound group (20 patients) and the thoracoscopic group (19 patients). The median age of participants was 53.5 (50-58) years and 55 (45-64) years in the ultrasound and thoracoscopic groups, respectively. Pleural fluid cell count, protein, adenosine deaminase (ADA), and lactate dehydrogenase (LDH) were similar in both groups, although pleural fluid glucose was low in the ultrasound group. Diagnostic yield was 90% (18/20) and 94.7% (18/19) in the ultrasound and thoracoscopic groups, respectively, which was statistically non-significant (p=0.963). The median duration of hospital stay was 9.5 (5.3-27) days and 15 (12-22) days in ultrasound and thoracoscopic groups respectively. The thoracoscopic group had a more prolonged stay compared to the ultrasound group, but it was statistically non-significant (p=0.09). The duration of the procedure was significantly longer in the thoracoscopic group 90 (85-105) minutes, in comparison to ultrasound 47.5 (41.3-55) minutes (p=0.001). No major complications were seen in both groups. Subcutaneous emphysema was the most common complication in the thoracoscopic group (10%), followed by hemorrhage (5.3%), and respiratory failure (5.3%). Hypotension was the only complication in the ultrasound group (5%). The rate of complications was significantly higher in the thoracoscopic group (p<0.01).ConclusionUltrasound-guided closed pleural biopsy is as good as thoracoscopic pleural biopsy in undiagnosed exudative pleural effusion. It was associated with a shorter procedure duration, a shorter hospital stay, and fewer complications as compared to thoracoscopic biopsy. Both the procedures were safe in experienced hands and a hospital setup, but the thoracoscopic pleural biopsy was associated with complications.

The role of LENT and PROMISE scores in predicting survival in malignant pleural effusion.

Background:Malignant pleural effusion (MPE) is a condition, that can be seen in 15% of patients diagnosed with cancer. Because of the short overall survival, it is important to identify the appropriate treatment. In addition to the palliation of secondary symptoms due to MPE, it should also be decided in which cases a more aggressive treatment is to be followed. The purpose of the study was to evaluate the performance of LENT and clinical PROMISE scores in predicting survival in patients with MPEMethods:Age, sex, smoking history, Eastern Cooperative Oncology Group (ECOG) score, cancer type, history of chemotherapy/radiotherapy, laboratory values, and pleural fluid lactate dehydrogenase were recorded. The LENT and the PROMISE scores were calculated and risk categories were determined. During the follow-up, blood tests and tomography controls were performed on the patients as routine. The overall survival was calculated as the period from the date of diagnosis of MPE to death or until December 31, 2019Results:A total of 169 patients were included. The median age was 65 (26–86). In the single-variable analysis, there was a significant increase in mortality risk in the poor performance score and if the LENT risk group progressed from the low-to medium-/high-risk group or PROMISE categories A to B, A to C or A to D. In multivariate analysis, mortality risk in 1, 3, 6, and 12 months increased significantly in poor performance score, in PROMISE category B, C, and D. In high LENT risk-group, an increased mortality risk was shown in only 12 months of survivalConclusions:Our data show that poor performance score (ECOG 3-4), PROMISE category B, C, and D significantly increase mortality risk and the LENT score is inadequate in predicting survival.

The role of pleural fluid lactate dehydrogenase-to-adenosine deaminase ratio in differentiating the etiology of pleural effusions.

Exudative pleural effusion includes tuberculous pleural effusion (TPE), parapneumonic pleural effusion (PPE), and malignant pleural effusion (MPE). An elevated pleural fluid adenosine deaminase (ADA) typically implies TPE, but the rule may not apply to every individual case. Recent studies proposed that the pleural fluid lactate dehydrogenase (LDH)-to-ADA ratio showed a higher diagnostic power than pleural fluid ADA alone in differentiating the etiology of pleural effusion. Hence, we aimed to investigate the performance of pleural fluid LDH-to-ADA ratio as a biomarker in assistance with the diagnosis of TPE, PPE, and MPE. All patients who underwent thoracentesis for the first time with a pleural fluid ADA >40 U/L were included in this retrospective study. The clinical data including pleural fluid ADA and LDH-to-ADA ratio were analyzed. A total of 311 patients were enrolled during the study interval. The pleural fluid LDH-to-ADA ratio <14.2 (sensitivity: 74.2%; specificity: 90.4%) favored TPE, while the pleural fluid LDH-to-ADA ratio >14.5 (sensitivity: 79.9%; specificity: 78.5%) favored PPE. Besides, the pleural fluid LDH-to-ADA ratio >46.7 (sensitivity: 56.3%; specificity: 78.3%) favored MPE owing to primary lung cancers. In conclusion, the pleural fluid LDH-to-ADA ratio was an effective indicator in differentiating the etiology of pleural effusions in the cases of high ADA level in the pleural fluid.

Aetiology and presentation of childhood pleural infections in the post-pneumococcal conjugate vaccine era in South Africa.

Background Complications of respiratory infections including pleural effusion (PE) are associated with a high morbidity. Differentiating between PE caused by Mycobacterium tuberculosis (Mtb) infection and other bacterial infections in endemic areas is difficult in children, thus, impacting treatment. Objectives To investigate the aetiology of PE and features distinguishing tuberculosis (TB) from bacterial PE in children. Methods We conducted a prospective study in children with PE admitted to a tertiary hospital in Cape Town from December 2017 to December 2019. Clinical information and routine laboratory investigations were compared between children with bacterial, Mtb or unclassified PE, categorised according to study definitions. Results A total of 91 patients were included in the present study and their median age was 31 months (interquartile range (IQR) 11.8 - 102.1). The aetiology was bacterial in 40% (n=37), Mtb in 39% (n=36) and unclassified in 20% (n=18) of patients. Staphylococcus aureus was the most common bacterial isolate, confirmed in 65% (n=24/37) patients, and Streptococcus pneumoniae was confirmed in only 8% of patients. TB was microbiologically confirmed in 33% (n=12/36) of patients. Patients with TB were older (91.6 v. 11.8 months; p<0.001), with more weight loss (28 v. 12 patients; p<0.001), and longer cough duration (10 v. 4 days; p<0.001) than those with other bacterial PE. In contrast, the latter had significantly higher serum C-reactive protein (median 250 v. 122 mg/L; p<0.001), procalcitonin (11 v. 0.5 mg/L; p<0.001), pleural fluid lactate dehydrogenase (7 280 v. 544 U/L; p<0.001), and adenosine deaminase levels (162 v. 48 U/L; p<0.001) and lower glucose levels (1.3 v. 4 mmol/L; p<0.001). Conclusion Post 13-valent pneumococcal conjugate vaccine, S. aureus is the dominant cause of PE in children using traditional culture methods, while Mtb remains a common cause of PE in our setting. Useful clinical and laboratory differences between Mtb and other bacterial PE were identified, but the cause of PE in 20% of children was underdetermined. Molecular testing of pleural fluid for respiratory pathogens may be useful in such children.

The pleural fluid lactate dehydrogenase /adenosine deaminase and pleural fluid adenosine deaminase /serum C-Reactive Protein ratios for differentiating between Tuberculosis and other causes in a sample of Iraqi patients

Objectives: This study aim is to evaluate the importance of pleural fluid LDH/ADA ratio and pleural fluid ADA/serum CRP ratio in differentiating tuberculous pleural effusion from other causes in a sample of Iraqi patients. Methods: A prospective study of 100 patients&nbsp; with pleural effusion whom age ranges from 18-70&nbsp; years&nbsp; where admitted at medical department at Al-Imamein Kadhimein medical city in Bagdad&nbsp; and in Marjan and Al-Sadik hospitals at Babylon province. Out of 61(61%) are males and 39 (39%) are females. The study period was 9 months started from&nbsp; 1st of February to End of October 2019. &nbsp; Results: in this study the result of comparison of mean level of pleural fluid&nbsp; LDH/ADA ratio&nbsp; and pleural fluid&nbsp; ADA/Serum CRP ratio&nbsp; between tuberculous and para pneumonic pleural effusions were significant =0.025 and 0.002 respectively. Also the comparison of pleural fluid&nbsp; LDH /ADA ratio and pleural fluid&nbsp; ADA/Serum CRP ratio between tuberculous and malignant pleural effusions were significant =0.005 in both. Conclusion: Pleural fluid LDH /ADA ratio is of great value in differentiation tuberculous pleural effusion from malignant pleural effusion with predominant lymphocytes, pleural fluid ADA/serum CRP ratio is of great value in differentiation tuberculous pleural effusion from para pneumonic pleural effusion with elevated pleural fluid ADA and elevated serum CRP.

Pleural Fluid Bilirubin to Serum Bilirubin Ratio, comparison with Light’s Criteria.

Introduction: Pleural fluid bilirubin and pleural fluid bilirubin to serum bilirubin ratio evaluation had been reported by several in distinguishing exudative from transudative pleural effusions along with Light’s Criteria. The aim of this study was to assess whether pleural fluid bilirubin to serum bilirubin ratio, was a sensitive marker in classifying the pleural effusion as exudative and transudative and its correlation with Light’s criteria.&#x0D; Methods: A cross-sectional, observational study of Pleural fluid bilirubin to serum bilirubin ratio ≥ 0.6 for exudates was taken and compared with Light’s criteria overall and its individual parameters to classify exudative and transudative along with the diagnosis. Statistical analysis was done using SPSS 16, Sensitivity, specificity, Positive predictive value (PPV), Negative predictive value (NPV) and diagnostic accuracy of each tests were calculated.&#x0D; Results: By diagnosis on discharge out of 86 samples of pleural effusion, 78(90.69%) were exudative and 8(9.3%) were transudative effusion. Among transudative effusion, 72 were classified correctly and 6 were misclassified by pleural fluid Lactate dehydrogenase (LDH) &gt; 2/3rd of serum LDH criteria and out of 8 transudative, 4 were misclassified as exudative. When the pleural fluid to serum bilirubin ratio ≥0.6 was used to differentiate , it categorized 67 as exudative effusion by pleural fluid LDH &gt; 2/3rd of serum LDH criteria and 11 were misclassified as transudative. This criterion had a sensitivity, specificity, PPV and NPV of 85.53%, 50%, 92.88% and 27.78 % respectively with a significant p value of &lt;0.01. &#x0D; Conclusion: The pleural fluid to serum bilirubin ratio can serve as an alternative easy and cost-effective diagnostic tool in differentiating between exudative and transudative pleural effusion. Though, it misclassified 11 exudative pleural fluids as transudative and 4 transudative as exudative. By taking Light’s criteria as a standard, pleural fluid bilirubin to serum bilirubin ratio ≥0.6 was found to be inferior to the Light’s criteria also in terms of sensitivity, specificity, PPV and NPV. Still the pleural fluid to serum bilirubin ratio can serve as an alternative easy and cost-effective diagnostic tool in differentiating between exudative and transudative pleural effusion in low resource settings.

Breast and Lung Effusion Survival Score Models: Improving Survival Prediction in Patients With Malignant Pleural Effusion and Metastasis

Evidence-based guidelines recommend management strategies for malignant pleural effusions (MPEs) based on life expectancy. Existent risk-prediction rules do not provide precise individualized survival estimates. Can a newly developed continuous risk-prediction survival model for patients with MPE and known metastatic disease provide precise survival estimates? Single-center retrospective cohort study of patients with proven malignancy, pleural effusion, and known metastatic disease undergoing thoracentesis from 2014 through 2017. The outcome was time from thoracentesis to death. Risk factors were identified using Cox proportional hazards models. Effect-measure modification (EMM) was tested using the Mantel-Cox test and was addressed by using disease-specific models (DSMs) or interaction terms. Three DSMs and a combined model using interactions were generated. Discrimination was evaluated using Harrell's C-statistic. Calibration was assessed by observed-minus-predicted probability graphs at specific time points. Models were validated using patients treated from 2010 through 2013. Using LENT (pleural fluid lactate dehydrogenase, Eastern Cooperative Oncology Group performance score, neutrophil-to-lymphocyte ratio and tumor type) variables, we generated both discrete (LENT-D) and continuous (LENT-C) models, assessing discrete vscontinuous predictors' performances. The development and validation cohort included 562 and 727 patients, respectively. The Mantel-Cox test demonstrated interactions between cancer type and neutrophil to lymphocyte ratio (P< .0001), pleural fluid lactate dehydrogenase (P= .029), and bilateral effusion (P= .002). DSMs for lung, breast, and hematologic malignancies showed C-statistics of 0.72, 0.72, and 0.62, respectively; the combined model's C-statistics was 0.67. LENT-D (C-statistic, 0.60) and LENT-C (C-statistic, 0.65) models underperformed. EMM is present between cancer type and other predictors; thus, DSMs outperformed the models that failed to account for this. Discrete risk-prediction models lacked enough precision to be useful for individual-level predictions.

48-Year-Old Woman With Dyspnea and Chest Pain

48-Year-Old Woman With Dyspnea and Chest Pain