Pleural Fluid Adenosine Deaminase Levels Research Articles

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 >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 >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 >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 >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.

Validity of Adenosine Deaminase (ADA) Level in Pleural Fluid for the Diagnosis of Tuberculosis

Introduction: The 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. Despite wide variations in the reported sensitivity and specificity of pleural fluid ADA level, it can be used as a surrogate for pleural biopsy when the latter is not feasible. Adenosine deaminase (ADA) is the most cost-effective pleural fluid marker and is routinely used in high prevalence settings, whereas its value is questioned in areas with low prevalence. The lymphocyte proportion (LP) is known to increase the specificity of ADA for this diagnosis. Objectives: To determine the diagnostic accuracy of ADA level in pleural fluid for the diagnosis of TB as compared to other conventional methods available like gene expert. Materials & Methods: The design of this study was a cross sectional study design. This study was conducted in Medicine Unit III, S.P.H. Quetta and the duration of this study was from 23rd October 2019 to 22nd April 2020. A total of 423 patients with pulmonary TB between the ages of 25 years to 45 years, having developed pleural effusion were included. Patients with pleural effusion due to causes other than TB, having extra pulmonary TB and those with other respiratory infections were excluded. Tests done specifically for TB in our setup include sputum AFB, CXR, and genexpert. These patients’ pleural fluid ADA were then sent. Results: Adenosine deaminase (ADA) found that 217 were True Positive and 13 were False Positive. Among 193, adenosine deaminase (ADA) negative patients, 12 (False Negative) had TB on gene expert whereas 181 (True Negative) had no TB on gene expert (p=0.0001). Overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of ADA level in pleural fluid for the diagnosis of TB as compared to other conventional methods available like gene expert was 94.76%, 93.30%, 94.35%, 93.78% and 94.09% respectively. Practical Implication: This study was conducted to determine the validity of ADA levels for the diagnosis of TB and the results of this study if favorable will decrease the need for other laboratory tests usually done which take longer time, thus helping to decrease the need for multiple tests, early availability of report and timely management of the disease. This will further help to reduce the contact rate of TB and the risk of developing MDR TB by starting early treatment. Conclusion: This study concluded that diagnostic accuracy of ADA level in pleural fluid for the diagnosis of TB is quite high. Keywords: Pulmonary Tuberculosis, Pleural Fluid, Adenosine Deaminase, Biochemical, Mycobacterium .

Correlation of TB LAM Ag (Tuberculosis Lipoarabinomannan Antigen) Results from Urine with Adenosine Deaminase Levels from Pleural Fluid Patients with Pulmonary TB Accompanied by Pleural Effusion

Background: One of the newest testing methods for active TB uses TB LAM Antigen, in which lipoarabinomannan (LAM) as the examined substance serves as the main component of the cell wall of M. tuberculosis (MTB) and the degradation product of MTB by macrophages in the human body. Patients with active TB with or without HIV infection may experience a decreased antibody response, which causes LAM not to bind to antibodies so that it can pass through the normal glomerular basement membrane and can be detected in the urine. Lateral flow urine lipoarabinomannan assay (LF-LAM) can detect this material with urine samples from active TB patients. Another TB screening method uses the measurement of adenosine deaminase (ADA) activity. ADA has a very important function for the proliferation and differentiation of lymphoid cells, especially T cells, and assists in the maturation of monocytes into macrophages. Objective: This study aims to qualitatively prove the correlation between the pleural fluid ADA levels of pulmonary TB patients with pleural effusion using the LF-LAM test results and examine the potential of TB LAM Ag, which correlates with increased pleural fluid ADA levels, as a diagnostic tool for diagnosing pulmonary TB. Method: It is an observational analytic study with a crosssectional design. Materials for this study included temporary urine from active TB patients at Dr. Soetomo Regional Public Hospital collected in May-August 2022. The descriptive analysis was conducted using SPSS 25.0. The data were tested for normal distribution and with the homogeneity test of Shapiro-Wilk's data. The statistical analysis was performed using the Mann-Whitney test, while the kappa suitability test was carried out to determine the correlation and level of concordance between the ADA cut-off value of pleural fluid and the TB LAM Ag test results. Results: This study involved 50 subjects consisting of 22 (44%) subjects with ADA test results between 40-100 IU/L compared to 28 subjects (56%) with ADA test results below 40 IU/L. There were 14 (28%) subjects with positive TB LAM Ag test results, consisting of 10 (45%) active TB subjects with a high ADA test cut-off of 40-100 IU/L and 4 (14%) active TB subjects with a low ADA test cut-off below 40 IU/L, with a p-value = 0.012. Conclusions: There is a correlation between TB Lipoarabinomannan antigen test results of TB patients with pleural effusion. TB LAM Ag can be detected positive on ADA test results of < 40 IU/L and more positive in active TB patients with high ADA test results of > 40-100 IU/L. Therefore, the TB LAM Ag test is more sensitive than the ADA test. The cut-off value of the ADA test reached 76.4 U/L, and a positive TB LAM was found.

Diagnostic accuracy of different cut-off values of adenosine deaminase levels in tuberculous pleural effusion.

To assess the diagnostic accuracy of different cut-off values of pleural fluid adenosine deaminase levels as a diagnostic method for tuberculous pleural effusion. The prospective study was conducted from 2014 to 2016 at the Aga Khan University Hospital, Karachi, and comprised pleural fluid samples of adult patients with and without tuberculosis which were tested for adenosine deaminase levels, and divided into tuberculosis group A and non-tuberculosis group B. Sensitivity, specificity, negative predictive value and positive predictive value were calculated using different cut-offs. Data was analysed using IBM SPSS (Statistical Package for Social Sciences) version 21.0 (IBM Corp., Armonk, NY). Of 155 patients, 46(29.7%) had tuberculosis; 30(65.2%) males and 16(34.8%) females. Those who did not have tuberculosis were 109(70.3%); 69(63.3%) males and 40(36.7%) females. The adenosine deaminase levels were elevated in group A compared to group B (p<0.001). The cut-off of 30U/L showed the highest sensitivity (71.7%) and negative predictive value (87.4%), and a specificity of 82.6%. The cut-off of 50U/L showed the highest specificity (89.9%) with sensitivity 52.2%, and the cut-off of 40U/L showed the highest positive predictive value of 68.9% with sensitivity 67.4% and specificity 87.2%. Pleural fluid adenosine deaminase testing for diagnosing tuberculosis pleuritis revealed highest sensitivity and moderate specificity for cut-off value of 30U/L.

Clinical and Etiological Profile of an Exudative Pleural Effusion in a Tertiary Care Center

Background: Pleural effusion is common clinical entity in day-to-day clinical practice. There are various etiologies for pleural effusion. Among those tubercular pleural effusion, parapneumonic effusion, malignant effusion, and congestive heart failure were the most common causes of pleural effusion. Here, we have done a retrospective study to see the etiology of pleural effusion in our tertiary care center. Patients and Methods: This retrospective study conducted in a tertiary care center over 1 year period. A total of 63 patients were included in this study after verifying in patient records of all patients who were admitted with exudative pleural effusion. The demographic data collected and complete history was obtained. Investigations such as complete hemogram, random blood sugar; renal function tests, serum proteins, chest x-ray, and pleural fluid analysis and investigations such as ultrasonogram of the chest and abdomen, echocardiogram, computed tomography scan of chest, fine-needle aspiration cytology, and pleural biopsy reports (if done) were collected. Results: Among the study participants, 40 were male and 23 were female patients with male-to-female ratio of 1.7:1. Mean age of the study population was 48.8 ± 18.7 years. The most common presenting symptom was dyspnea (84%) followed by cough (80%), fever (65%), and chest pain (43%). The most frequent cause of pleural effusion was tuberculosis in 38% of patients, followed by parapneumonic effusion (28.5%) and malignant pleural effusion (22.2%). Three patients had chylothorax, two patients had pancreatic pleural effusion and the diagnosis was unknown in two patients. Mean ± standard deviation (SD) adenosine deaminase (ADA) value of the study population was 45.3 ± 28.1. Mean ± SD of ADA values in tuberculous, parapneumonic, and malignant pleural effusion was 54.5 ± 16.8, 65.2 ± 30.7, and 18.2 ± 11.0, respectively. Conclusions: Tuberculosis is one of the common causes of exudative effusions along with parapneumonic effusions and malignancy. Pleural fluid ADA levels are highly sensitive with good specificity for the diagnosis of etiology of tubercular effusions. However in view of high levels of ADA in pleural fluid in parapneumonic effusions also, other measures such as clinical evaluation, lymphocyte to neutrophil ratio, and glucose levels are necessary to separate both these entities.

Diagnostic Value of Pleural Fluid Adenosine Deaminase In Patients With Pleural Tuberculosis

Background and Objectives Extra-pulmonary tuberculosis occurs in about 10-20% of patients with tuberculosis. It most commonly manifests as tuberculous lymphadenitis or pleural effusion. Pleural fluid Adenosine deaminase (ADA) activity considered as a useful biomarker for detecting pleural tuberculosis. The purpose of this study was to evaluate the diagnostic accuracy of pleural fluid adenosine deaminase level in patients with pleural tuberculosis. Methods In this study, 113 patients with exudative pleural effusion with unknown underlying diagnosis, were enrolled. Physical examination, chest CT, ADA level of pleural fluid, direct thoracoscopic examination, and biopsy of pleura were obtained for all individuals. ADA level and thoracoscipoc appearance of the lesions was then compaierd among the patients with regard to the pleural biopsy report as the diagnostic goldstandard. Results The diagnosis of tuberculous pleurisy was established in 40 individuals based on the pathology reports. The mean ADA level of the TB and the non-TB group was 39.90±22.93 IU/L and 30.74±38.27 IU/L, respectively (P-value=0.167). Sensitivity, specificity, positive predictive value, and negative predictive value of ADA test were 35%, 86.30%, 58.33%, and 70.79%, respectively. Conclusion Based insuffiecient sensitivity and specificity of ADA, in patients with unexplained exudative pleural effusion especially in those with a high suspicion of tuberculous pleurisy, despite the low level of ADA, direct thoracoscopic pleural evaluation with obtaining multiple biopsies of pleura is highly recommended.

TUBERCULOUS PLEURAL EFFUSION MASQUERADING AS DRUG-INDUCED LUPUS

TUBERCULOUS PLEURAL EFFUSION MASQUERADING AS DRUG-INDUCED LUPUS

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.

DIAGNOSTIC SIGNIFICANCE OF ADENOSINE DEAMINASE AND LYMPHOCYTES IN SUSPECTED TUBERCULOUS PLEURAL EFFUSION

CONTEXT: Tuberculosis is a major public health problem in India. Tuberculous pleural effusion is a paucibacillary manifestation of the Tuberculosis, so isolation of Mycobacterium tuberculosis is difficult, biomarkers being an alternative for diagnosis. Pleural fluid Adenosine deaminase (ADA) level is being used in diagnosis of Tubercular pleural effusion. The combination of ADA and pleural fluid lymphocyte count is being recognized as a better method for increasing the specificity of ADA test. The present study was conducted to analyze the diagnostic usefulness ofAIM: ADA alone (≥ 40U/L) compared with the combination of ADA and pleural fluid lymphocyte count ( ≥ 50% ). SETTINGS AND DESIGN: METHODS AND MATERIAL:Retrospective study. Study was conducted for a period of one year from May 2017 to April 2018. A total of 110 pleural fluid samples data was analysed. SPSS 20STATISTICAL ANALYSIS USED: statistical software. ADA level in Tuberculous pleural effusion ranged from 40U/L to 112U/L with mean value ofRESULTS: 69.4U/L. Sensitivity, Specificity, Positive predictive valve (PPV) and Negative predictive values (NPV) for ADA alone were 93.2%, 76.4%, 82% and 90.6% respectively. For ADA and lymphocyte count the Specificity and PPV increased (98% and 98.1% respectively) with hardly any decrease in sensitivity or NPV (89.8% and 89.5% respectively). CONCLUSION: Combined use of ADA and pleural fluid lymphocyte count increases the specificity and PPV when compared to the specificity of ADA test alone in diagnosing Tubercular pleural effusion.

Novel biomarkers for Diagnosis of Pulmonary Tuberculosis and Tuberculous Pleural Effusion

Background: The present study aimed to evaluate the importance of serum, pleural adenosine deaminase (ADA), and Gene Xpert in Diagnosis of TB and TB Pleural Effusion (TB-PLE.).Material &amp; Methods:The study was done with 75 TB cases, 50 cases of them were diagnosed as Pulmonary TB and 25 cases as TB pleural effusion, collecting also 50 non-TB pleural effusion, Malignant and acute bacterial infection comprise 21 and 29 cases respectively. Cases with transudative pleural effusion were excluded from the study. Finally, 75 were healthy control group.Results:There was a highly significant difference between the mean age of TB-PE Patients and Patients non-TB-PLE (P-value &lt;0.001), while there was a non-significant difference with patients with P-TB (P-value &gt;0.05). Mean of Serum ADA level were highest 53.16 U/L in TB-PE cases, shown to be statistically significant when compared to 43.2 U/L in P-TB and 25.4 U/L in non TBpleural effusion. With p-value of 0.02 and 0.001respectively.Conclusions:We concluded that GeneXpert can be a useful diagnostic method in patients with suspected pulmonary tuberculosis. Serum and pleural fluid ADA level is a very helpful test to rule out a TB and can help differentiate tubercular etiology from non-tubercular.

Mycoplasma pneumoniae Pleural Effusion in Adults.

Parapneumonic effusions often complicate Mycoplasma pneumoniae (MP) pneumonia, contrary to the notion that they are a rare feature of MP infection. Increased research and evidence on MP parapneumonic effusions (MPPE) can help elucidate its clinical significance as one of the variable manifestations of MP infection. This article aims to summarize the existing literature about the clinical characteristics of MPPE in adults and discuss its diagnostic implications from the perspective of pleural fluid analysis. Approximately 20–25% of adult patients with MP pneumonia develop MPPE, and its frequency in children and adults seems to be similar. Although the pathogenesis of MPPE remains to be elucidated, MP-induced cell-mediated immune mechanisms might be partially associated with the development of MPPE. MPPE usually shows mononuclear leukocyte predominance with elevated adenosine deaminase (ADA) activity, similar to tuberculous pleural effusion (TPE). The degree of increase in pleural fluid ADA levels and serum inflammatory biomarkers may help differentiate between MPPE and TPE. During the acute phase, a single positive IgM and positive polymerase chain reaction results allow for a precise and reliable MP infection diagnosis. The mainstay of treatment is the selection of adequate anti-mycoplasma antibiotics with or without corticosteroid, based on the local epidemiologic data on macrolide resistance.

Value of Adenosine Deaminase in the diagnosis of tuberculous pleurisy at Tikur Anbessa specialized hospital, Addis Ababa, Ethiopia

Objectives: Tuberculous (TB) pleurisy is a common form of extrapulmonary tuberculosis in high burden countries including Ethiopia. Adenosine deaminase (ADA) has been used in the early diagnosis of TB pleurisy. This study was designed to evaluate the diagnostic role of ADA in TB pleurisy at Tikur Anbessa Specialized Hospital (TASH). Materials and Methods: A cross-sectional hospital-based study was designed to evaluate the diagnostic value of ADA in consecutive adult patients with unexplained pleural effusions presenting to Chest Clinic at TASH from June 2016 to August 2018. All referred patients underwent thorough clinical and laboratory examinations including assessment of pleural fluid ADA, where a value of ≥40 IU/I was used to suggest TB pleurisy (per manufacturer’s recommendation). A final diagnosis of TB pleurisy was made based on pleural fluid Gene Xpert, AFB smear, pleural biopsy, and cytology results in addition to a clinical and radiologic response to anti-TB therapy. Results: A total of 67 patients were included in the study. The median age was 38.5(±14.5) years; 36 (53.7%) of the participants were males. TB pleurisy was confirmed in 38 (56.7%) subjects. The mean pleural fluid ADA levels was significantly higher in those with TB pleurisy as compared to those without TB pleurisy, 65.8 IU/l versus 28 IU/I (P &lt; 0.05), respectively. Pleural fluid ADA had a sensitivity of 84% and specificity of 79%, resulting in a positive predictive value of 84.2%, a negative predictive value of 79.3%, and an overall test accuracy of 82% in our study population. Conclusion: In our study, pleural fluid ADA played a useful role in the diagnosis of TB pleurisy.

English

BACKGROUND Medical thoracoscopy, in the educated fingers of a pulmonologist, is a secure and powerful process for the diagnosis and treatment of many pleural diseases. If the centres for thoracoscopy are available, thoracoscopy should be carried out on those undiagnosed sufferers due to its excessive sensitivity in malignant and tuberculous pleural effusions. That is why the ultimate decade witnessed an interest in thoracoscopy as a diagnostic device for pleural diseases. In the existing study, we wanted to describe our experience with the function of thoracoscopic biopsy in patients who underwent thoracoscopy for diagnostic purposes. METHODS The study protocol and ethical approval were taken by the Institutional Review Board for human studies of B. J. Medical College, Gujarat. It was a prospective study conducted in the Department of Pulmonary Medicine, B. J. Medical College, Ahmedabad, between July 2014 and November 2016. 39 patients who underwent medical thoracoscopy for undiagnosed pleural effusions were enrolled in this study. Undiagnosed pleural effusion was defined as failure to achieve a diagnosis by initial pleural fluid analysis including pleural fluid adenosine deaminase (ADA) levels and at least three pleural fluid analyses negative for malignant cells. Diagnostic pleural fluid aspiration was done to obtain pleural fluid specimens. RESULTS In the present study with the help of thoracoscopy, 36 (92.31 %) patients were diagnosed successfully while only 3 patients remained undiagnosed. In the present study, on thoracoscopic examination 21 (53.85 %) patients had pleural nodules, 5 (12.82 %) patients had pleural thickening, 5 (12.82 %) patients had pleural plaquelike erythema. The remaining patients had other uncommon findings e.g. nonspecific pleuritis 3 (7.69 %). CONCLUSIONS Among all the patients with undiagnosed exudative pleural effusion, irrespective of smoking status which fails to respond to conventional medical management, diagnostic thoracoscopy should be considered as early as possible. The diagnostic yield of thoracoscopy for pleural pathology remains very high (92.3 %). KEYWORDS Diagnosis, Malignant Pleural Effusion, Thoracoscopy.

Pleural fluid investigations for pleural infections

: Over 1.5 million patients are admitted to hospital with pneumonia in the United States each year. Up to 50% of them can develop a parapneumonic effusion which is associated with higher mortality. The incidence of pleural infection continues to rise, particularly in the elderly and those with comorbidities. Parapneumonic effusions cover a spectrum of presentations from a free-flowing ‘simple parapneumonic effusion’ to a septated ‘complicated parapneumonic effusion’ (CPE) (usually from bacterial pleural invasion) and ‘empyema’ (presence of pleural pus). Pleural infection is defined as either CPE or empyema, and usually requires evacuation of the infected fluid. Laboratory investigations play an essential part of the diagnosis and management of pleural infection. A parapneumonic effusion is typically a neutrophil-rich exudate. Presence of bacteria from culture of the fluid defines pleural infection but conventional culture methods have a low yield. Surrogate pleural fluid markers are often employed to confirm a CPE, including low pleural fluid pH (<7.2) or glucose (<3.3 mmol/L) and elevated lactate dehydrogenase (LDH). Measurement of pleural fluid triglyceride and chylomicrons (for chylothorax) and cholesterol (for pseudochylothorax) may be needed to separate lipid pleural effusions from empyema. Tuberculous pleural effusions usually result from a hypersensitivity pleuritis and are lymphocyte predominant with elevated pleural fluid adenosine deaminase (ADA) and interferon gamma levels. Culture yield of mycobacteria is typically low. Caseating granulomas on pleural tissue biopsy is often considered diagnostic. Common organisms for community-acquired pleural infection include Streptococcus pneumoniae, Streptococcus anginosus group bacteria and Staphylococcus aureus. Hospital-acquired pleural infections have higher mortality and are often polymicrobial which can include S. aureus, Enterobacteriaceae and anaerobes. Antibiotics and evacuation of the infected fluid, usually by chest tube drainage, remain the mainstay of treatment. Intrapleural fibrinolytic and deoxyribonuclease therapy, or occasionally surgical drainage, may be required.

Improving the yield of diagnostic medical thoracoscopy for undiagnosed exudative pleural effusions using a rigid diagnostic algorithm.

Establishing the etiology of exudative pleural effusions in the setting of an unrewarding pleural fluid analysis often requires biopsies from the parietal pleura. However, it may be noted that diagnosis such as pulmonary embolism and connective tissue diseases can result in an exudative pleural effusion where a pleural biopsy can yield nonspecific results. Medical thoracoscopy (MT) is a minimally invasive procedure performed under local anesthesia or moderate sedation with excellent yield and favorable safety profile. We analyzed the diagnostic yield of MT for exudative pleural effusions after employing a rigid diagnostic algorithm. The study was undertaken to ascertain the yield of MT in establishing the diagnosis in diagnosis of exudative pleural effusions, to find out the relative contribution of pleural tuberculosis (TB) as a cause of undiagnosed exudative pleural effusion, to describe the etiology of undiagnosed exudative pleural effusion in patients undergoing MT and to determine the correlation between pleural fluid adenosine deaminase (ADA) levels and TB pleuritis in patients undergoing MT. This was a retrospective study. Patients with undiagnosed exudative pleural effusion were included in the study. MT was performed with semirigid thoracoscope (Olympus LTF 160) under local anesthesia and conscious sedation. Gross appearance and ADA level of pleural fluid were noted. Pleural biopsy material was subjected to histopathology examination and culture for mycobacteria along with cartridge-based nucleic acid amplification test for TB. The yield of MT for establishing the etiology of pleural effusion and the relative contribution of tuberculous pleuritis as a cause of undiagnosed pleural effusion was ascertained. Correlation of pleural fluid ADA levels was done with a final diagnosis of TB pleuritis in patients undergoing MT. Twenty-five patients with undiagnosed exudative pleural effusion underwent thoracoscopy of which 16 were male and 9 were female. MT was able to establish the diagnosis in all cases, providing a diagnostic yield of 100%. Histopathological examination of biopsy specimens yielded a diagnosis of malignant involvement of pleura in 10 patients and granulomatous pleuritis consistent with TB in 14 patients. Pleural TB contributed to 60% of undiagnosed pleural effusions in the present study. The mean ADA value among those who turned positive was 56.338 and 35.300 among those who turned negative using genexpert, which was found to be statistically significant. A value of 31 IU/L showed a sensitivity of 93.3% and specificity of 99.8% and hence can be taken as a cut off value for the diagnosis of pleural TB based on receiver-operating characteristic analysis. TB contributed to 60% of undiagnosed exudative pleural effusions in the present study. MT had 100% yield in the diagnosis of undiagnosed exudative effusions. Pleural fluid ADA levels may help in differentiating TB versus malignant effusion.

A case of hodgkin's lymphoma presenting with pleural effusion

Pleural effusion has been reported in 7%–30% of patients with Hodgkin's lymphoma.[1] Unilateral and bilateral effusions are equally prevalent. Increasing stage, any extranodal involvement, and bulky mediastinal disease were each predictive of pleural effusions.[2] Pleural fluid Adenosine deaminase (ADA) levels in such cases may be elevated, normal, or in the indeterminate range (40–60 IU/l), which alone should not be the criteria for starting anti-tubercular therapy without comprehensive radiological and pathological investigations to look for any malignant etiology.

Laboratory and radiological discrimination between tuberculous and malignant pleural effusions with high adenosine deaminase levels.

Background/AimsPleural fluid adenosine deaminase (ADA) levels are useful in discriminating tuberculous pleural effusions (TPEs) from malignant pleural effusions (MPEs). However, some patients with MPE exhibit high-ADA levels, which may mimic TPEs. There is limited data regarding the differential diagnosis between high-ADA MPE and high-ADA TPE. This study aimed to identify the predictors for distinguishing high-ADA MPEs from high-ADA TPEs.MethodsPatients with TPE and MPE with pleural fluid ADA levels ≥ 40 IU/L were included in this study. Clinical, laboratory, and radiological data were compared between the two groups. Independent predictors and their diagnostic performance for high-ADA MPEs were evaluated using multivariate logistic regression analysis and receiver operating characteristic curve.ResultsA total of 200 patients (high-ADA MPE, n = 30, and high-ADA TPE, n = 170) were retrospectively included. In the multivariate analysis, pleural fluid ADA, pleural fluid carcinoembryonic antigen (CEA), and pleural nodularity were independent discriminators between high-ADA MPE and high-ADA TPE groups. Using pleural ADA level of 40 to 56 IU/L (3 points), pleural CEA level ≥ 6 ng/mL (6 points), and presence of pleural nodularity (3 points) for predicting high-ADA MPEs, a sum score ≥ 6 points yielded a sensitivity of 90%, specificity of 96%, positive predictive value of 82%, negative predictive value of 98%, and area under the receiver operating characteristic curve of 0.965.ConclusionsA scoring system using three parameters may be helpful in guiding the differential diagnosis between high-ADA MPEs and high-ADA TPEs.

Diagnostic utility of medical thoracoscopy in undiagnosed exudative pleural effusions

Background: Medical thoracoscopy is a minimally invasive technique to inspect the pleural space and to perform biopsy of pleural lesions under direct vision. In this study, the diagnostic utility of thoracoscopy for undiagnosed exudative lymphocytic pleural effusions from a tertiary care respiratory center will be discussed. Materials and Methods: In a retrospective analysis of thoracoscopic procedures, we performed between September 2017 and August 2019, the yield of thoracoscopic pleural biopsy for achieving a diagnosis in undiagnosed exudative lymphocytic pleural effusions was evaluated. Undiagnosed exudative pleural effusions were defined as pleural effusions where an etiologic diagnosis could not be ascertained by initial pleural fluid biochemical and microbiological analysis, including protein, sugar, lactate dehydrogenase, Gram and acid-fast bacilli stains and Mycobacterium tuberculosis culture, pleural fluid adenosine deaminase levels, and at least two pleural fluid cytologies negative for malignant cells or other definite causes. We analyzed the clinical, radiological, cytological, and histopathological data of the patients and also the complications of thoracoscopy. Results: We performed thoracoscopy in 68 cases of undiagnosed exudative pleural effusions using the rigid thoracoscope. The overall diagnostic yield of thoracoscopic pleural biopsy was 95.6% in patients with undiagnosed exudative pleural effusions. Malignant pleural effusion was diagnosed in 67.6% of patients, while tuberculosis was diagnosed with pleural biopsy in 25% of patients. Three cases of subcutaneous emphysema, 2 cases of postprocedure fever were observed, and one patient had prolonged air leak. Conclusion: Medical thoracoscopy has a good diagnostic yield in patients with undiagnosed exudative lymphocytic pleural effusions and is a safe procedure as well.

A Predictive Model for the Identification of Cardiac Effusions Misclassified by Light's Criteria.

The application of Light's criteria misidentifies approximately 30% of transudates as exudates, particularly in patients on diuretics with cardiac effusions. The purpose of this study was to establish a predictive model to effectively identify cardiac effusions misclassified by Light's criteria. We retrospectively studied 675 consecutive patients with pleural effusion diagnosed by Light's criteria as exudates, of which 43 were heart failure patients. A multivariate logistic model was developed to predict cardiac effusions. The performance of the predictive model was assessed by receiver operating characteristic (ROC) curves, as well as by examining the calibration. It was found that protein gradient of >23 g/L, pleural fluid lactate dehydrogenase (PF-LDH) levels, ratio of pleural fluid LDH to serum LDH level (P/S LDH), pleural fluid adenosine deaminase (PF-ADA) levels, and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels had a significant impact on the identification of cardiac effusions, and those were simultaneously analyzed by multivariate regression analysis. The area under the curve (AUC) value of the model was 0.953. The model also had higher discriminatory properties than protein gradients (AUC, 0.760) and NT-pro-BNP (AUC, 0.906), all at a P value of <.01. In cases of suspected cardiac effusion, or where clinicians cannot identify the cause of an exudative effusion, this model may assist in the correct identification of exudative effusions as cardiac effusions.

A CASE OF ISOLATED TB PLEURAL EFFUSION

SESSION TITLE: Monday Fellow Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Pleural tuberculosis accounts as one of the most common extrapulmonary manifestations of tuberculosis, second only to lymphadenopathy. Tuberculous pleural effusion (TPE) is the most common form of exudative effusion in the developing world. Isolated pleural involvement without parenchymal involvement is unusual. We report a patient with a lymphocytic exudative effusion that was revealed to be TPE only upon result of pleural acid-fast bacilli (AFB) culture, with the sputum and pleural AFB smears and pleural adenosine deaminase (ADA) being nondiagnostic. CASE PRESENTATION: A 64 year old Filipino male presented to the hospital with fever, chills, night sweats, and epigastric pain for 1 week. He was found to have a right pleural effusion with thickened pleural lining suspicious for empyema, measuring 8.8cm x 2.0cm x 8.2cm. He was placed in airborne precautions to rule out tuberculosis. A thoracentesis was performed that revealed a lymphocytic predominant (880 cells, 97% lymphocytes, 1% neutrophils) effusion. No organisms were seen on gram stain, bacterial culture, or AFB smear. Pleural fluid adenosine deaminase level was 37 U/L. After three induced sputum AFB smears resulted as negative, he was discharged at which point his symptoms had resolved. Patient was later seen in clinic a month after discharge at which point he was still asymptomatic. However, his pleural AFB cultures grew Mycobacterium tuberculosis, and he was started on anti-tuberculous therapy with rifampin, isoniazid, ethambutol, and pyrazinamide. DISCUSSION: This case resulted in a diagnosis of tuberculous pleural effusion despite the absence of pulmonary tuberculosis disease. Guidelines for the diagnosis of suspected pleural tuberculosis recommend the measurement of pleural ADA. Proposed pleural ADA cutoff values range from 10 U/L to 71U/L, with most studies using a level <40 U/L as the cutoff to exclude the diagnosis of TPE. Despite the highly lymphocytic predominant effusion, our patient's pleural fluid ADA level of 37 U/L led to a false reassurance of a non-tuberculosis diagnosis and a delay in diagnosis and treatment. In retrospect, a higher index of suspicion for TPE should have been maintained in this patient who presented with such a constellation of symptoms and radiographic evidence of an inflammatory effusion coupled with a suspicious pleural fluid analysis. Further diagnostics that could have been pursued to improve diagnostic sensitivity include needle biopsy or thoracoscopic pleural biopsy. Reference #1: Ciaran F. Keogh, Gordon T. Andrews, Sian D. Spacey, Kevin E. Forkheim, and Douglas A. Graeb. Neuroimaging Features of Heroin Inhalation Toxicity: “Chasing the Dragon” American Journal of Roentgenology 2003 180:3, 847-850 Reference #2: Blasel S, Hattingen E, Adelmann M, Nichtweiss M, Zanella F, Weidauer S. Toxic leukoencephalopathy after heroin abuse without heroin vapor inhalation: MR imaging and clinical features in three patients. Clin Neuroradiol. 2010;20(1):48-53. Reference #3: In Sub Yoo, MD, Sang Hak Lee, MD, Seung-Han Suk, MD, PhD. A Case of Fentanyl Intoxication and Delayed Hypoxic Leukoencephalopathy Caused by Incidental Use of Fentanyl Patch in a Healthy Elderly Man. J Neurocrit Care. 2015;8 (1):35-38. DISCLOSURES: No relevant relationships by Jasanjeet Jawanda, source=Web Response No relevant relationships by Antarpreet Kaur, source=Web Response No relevant relationships by Abhas Khurana, source=Web Response No relevant relationships by Simrina Sabharwal, source=Web Response