This paper describes a case of filarial pleural effusion, the fifth such to be reported. Microfilariae of Wuchereria bancrofti were detected in the pleural fluid on cytological examination. There was a prompt and complete response to treatment with diethylcarbamazine. There were, however, no symptoms and signs of tropical pulmonary eosinophilia nor any peripheral eosinophilia.
Minimally invasive investigations, such as pleural fluid cytological assessment and closed percutaneous pleural biopsy, are often performed first in the investigation of suspected malignant pleural effusions. Malignant pleural effusions can be diagnosed with pleural fluid cytology alone in most cases; however, closed pleural biopsy is performed to increase the diagnostic yield when pleural fluid cytology is negative. This additional yield is at the expense of increased complication rates. We report a 64-year old man with a negative pleural fluid cytology but suspected malignant pleural effusion who underwent a closed pleural biopsy, which was complicated by pneumothorax, pneumomediastinum and severe subcutaneous emphysema. Pulmonary laceration by the pleural biopsy needle is the most likely aetiology of these complications. Our case report highlights an infrequent but significant complication of closed percutaneous pleural biopsy.
The concentration of ferritin was measured in the pleural fluid of 108 patients with pleural effusions. In all groups of patients the ferritin concentration was higher in pleural fluid than in serum. The greatest differences, with up to 100 times more ferritin in the pleural fluid, were found for patients with rheumatoid pleurisy, malignant effusions, and empyema. In patients with non-malignant inflammatory pleural effusions the concentration of ferritin in pleural fluid correlated significantly with other pleural fluid indices of inflammation: there was a positive correlation with lactate dehydrogenase activity and a negative correlation with concentrations of glucose and complement components C3 and C4. Ferritin was detected immunocytochemically only in the macrophages found among the pleural fluid cells. Our study shows that large amounts of ferritin accumulate locally in the pleural cavity in certain types of pleural inflammation. The accumulation is probably partly the result of increased local reticuloendothelial system activity. Determination of the concentration of ferritin in pleural fluid may provide corroborative information for differential diagnosis and may further our understanding of the pathogenetic events that lead to the perpetuation of inflammatory activity in pleural effusions.
Pleural effusion remains the most common manifestation of pleural pathology. Sometimes it is difficult to differentiate between tubercular and malignant pleural effusion in spite of routine biochemical and cytological examination of pleural fluid.
This study aims to evaluate the role of pleural biopsy to determine the etiology of pleural effusion and to correlate it with the biochemical and cytological parameters of pleural fluid.
Settings and Design:
Seventy two consecutive patients of pleural effusion were selected from the out patient and indoor department of a tertiary hospital of Kolkata. It was a prospective and observational study conducted over a period of one year.
Materials and Methods:
Biochemical, cytological and microbiological evaluation of pleural fluid was done in all cases. Those with exudative pleural effusions underwent pleural biopsy by Abram’s needle. Subsequently, the etiology of effusion was determined.
Malignancy was the most common etiology, followed by tuberculosis. Pleural biopsy was done in 72 patients. Pleural tissue was obtained in 62 cases. Malignancy was diagnosed in 24, tuberculosis in 20 and non-specific inflammation in 18, on histopathological examination. Out of 20 histological proven tuberculosis cases adenosine de-aminase (ADA) was more than 70 u/l in 11 cases.
In our study, malignancy is more common than tuberculosis, particularly in elderly. When thoracoscope is not available, pleural fluid cytology and pleural biopsy can give definite diagnosis. Pleural fluid ADA ≥ 70 u/l is almost diagnostic of tuberculosis, where pleural biopsy is not recommended.
Malignancy; pleural biopsy; pleural effusion; tuberculosis
Objectives. To study the diagnostic value of pleural fluid cholesterol in differentiating transudative and exudative pleural effusion. To compare pleural fluid cholesterol level for exudates with Light's criteria. Design. Cross sectional descriptive study. Settings. Medical wards of Tribhuvan University Teaching Hospital. Methods. Sixty two cases of pleural effusion with definite clinical diagnosis admitted in TUTH were taken and classified as transudates (19) and exudates (43). The parameters pleural fluid protein/serum protein ratio (pfP/sP), pleural fluid LDH/ serum LDH ratio, pleural fluid LDH (pfLDH) and pleural fluid cholesterol (pCHOL) were compared with clinical diagnosis with regard to their usefulness for distinguishing between pleural exudates and transudates. Results. The pCHOL values determined were 1.92 ± 0.75 for exudates, 0.53 ± 0.28 for transudates, the differences between the transudates and others are statistically significant (P < 0.0001).
It is seen that pfP/sP ratio has a sensitivity of 81.4% and specificity of 82.6%; pfLDH/sLDH ratio has a sensitivity of 86% and specificity of 94.7% and pCHOL with sensitivity of 97.7% and specificity of 100% for differentiating exudative and transudative PE.
Conclusion. The determination of pCHOL is of great value for distinguishing between pleural exudates and transudates and should be included in routine laboratory analysis of pleural effusion.
OBJECTIVE: To determine the presence of Chlamydia trachomatis in hydrocele fluid. METHODS: 90 male patients with hydrocele of tunica vaginalis from an endemic area for bancroftian filariasis were investigated for the presence of Chlamydia trachomatis in their hydrocele fluids. C trachomatis antigen detection tests-a direct immunofluorescence assay and an enzyme immunoassay along with polymerase chain reaction assay for amplification of a 517 bp fragment of C trachomatis endogenous plasmid-were used in this study. The patients were also tested for the presence of microfilaria in their hydrocele fluids and night blood. Histopathological examination was carried out to detect adult filarial worm in tunica vaginalis testes. RESULTS: Eight (8.88%) patients had chlamydia antigen in the hydrocele fluids; C trachomatis plasmid sequences could be amplified from five of these. Seven (7.77%) patients had microfilaria in the hydrocele fluids, three of them having adult worm in tunica vaginalis. CONCLUSION: C trachomatis infection might be associated with hydrocele in some of these patients.
Noninvasive diagnosis of pleural tuberculosis (TB) remains a challenge due to the paucibacillary nature of the disease. As Mycobacterium tuberculosis (MTB)-specific T cells are recruited into pleural space in TB effusion; their indirect detection may provide useful clinical information.
Evaluation of pleural fluid interferon (INF)-γ levels vs Quantiferon–TB Gold In tube assay (QFT- IT) in blood and its adapted variants, using pleural fluid or isolated pleural fluid cells in the diagnosis of pleural TB.
Thirty-eight patients with pleural effusion of unknown etiology presented at Assiut University Hospital, Egypt, were recruited. Blood and pleural fluid were collected at presentation for INF-γ assays. Ex vivo pleural fluid INF-γ levels, QFT-IT in blood and its adapted variants were compared with final diagnosis as confirmed by other tools including blind and/or thoracoscopic pleural biopsy.
The final clinical diagnosis was TB in 20 (53%), malignancy in 10 (26%), and effusion due to other causes in eight patients (21%). Ex vivo pleural fluid INF-γ levels accurately identified TB in all patients and were superior to the QFT-IT assays using blood or pleural fluid (70 and 78% sensitivity, with 60 and 83% specificity, respectively). QFT-IT assay applied to isolated pleural fluid cells had 100% sensitivity and 72% specificity. The optimal cut-off obtained with ROC analysis was 0.73 for TB Gold assay in blood assay, 0.82 IU/ml for the cultured pleural fluid assay, and 0.94 for isolated pleural cells assay.
The ex vivo pleural fluid INF-γ level is an accurate marker for the diagnosis of pleural TB. QFT- IT assay in peripheral blood or its adapted versions of the assay using pleural fluid and/or washed pleural fluid cells had no diagnostic advantage over pleural fluid INF-γ in the diagnosis of pleural TB.
Diagnosis; interferon-γ; interferon-γ release assays; quantiferon–TB gold in tube assay; tuberculous effusion
The nonspecific clinical presentation and paucibacillary nature of tuberculous pleuritis remains a challenge for diagnosis. Diagnosis of tuberculous pleural effusion depends on the demonstration of the presence of tubercle bacilli in the sputum, pleural fluid, or pleural biopsy specimen, or demonstration of granuloma in pleura by histological examination. We examined the clinical utility of the diagnosis of pleural tuberculosis using the in house N-PCR assay, AFB smear microscopy and culture. Besides pleural fluid the inclusion of sputum in the efficacy of diagnosis of pleural tuberculosis was scrutinized.
Pleural fluid and sputum samples of 58 tuberculous and 42 non-tuberculous pleural effusion patients were processed for AFB smear microscopy, culture and the N-PCR assay. Mycobacteria were detected exclusively in tuberculous pleural effusion samples. None of the non-tuberculous pleural effusion samples were positive for mycobacteria. Comparative analysis showed that the N-PCR assay had the highest sensitivity. Inclusion of sputum along with pleural fluid increased N-PCR sensitivity from 51.7 to 70.6% (p<0.0001).This improved sensitivity was reflected in AFB smear microscopy and isolation by culture. The sensitivity enhanced on inclusion of sputum from 3.4 (p = 0.50) to 10.3% (p = 0.038) for AFB smear microscopy and for isolation of mycobacteria from 10.3(p = 0.03) to 22.4% (p = 0.0005). Thirteen isolates were obtained from 58 pleural tuberculosis patients. Eleven mycobacterial isolates were identified as M.tuberculosis and two as M.fortuitum and M.chelonae. Complete concordance was seen between the biochemical identification of isolates and the N-PCR identification of mycobacterial species prior to isolation.
To the best of our knowledge this is the first PCR based report on utility of sputum for diagnosis of pleural tuberculosis. The present study demonstrates that a combination of pleural fluid with sputum sample and N-PCR improved the diagnosis of pleural tuberculosis.
Pleural fluid cytology for malignant cells is the easiest way to diagnose malignant pleural effusion with good sensitivity and specificity. With the introduction of medical thoracoscopy, the use of closed pleural biopsy for the diagnosis of cytology negative malignant pleural effusion is gradually decreasing. However use of thoracoscopy is limited due to its high cost and procedure related complications.
The aim was to assess the usefulness of closed pleural biopsy in the diagnosis of malignant pleural effusion.
Materials and Methods:
Sixty-six patients of pleural effusion associated with malignancy were selected from the patients admitted in the chest ward of a tertiary care hospital over a period of 1 year. Pleural fluid aspiration for cytology and closed pleural biopsy were done in all the patients.
Out of 66 patients, 46 (69%) patients showed malignant cells in pleural fluid cytology examination. Cytology was positive in 35 (52%), 10 (15%), and 1 (1.5%) patients in the first, second, and third samples respectively. Closed pleural biopsy was positive in 32 (48%) patients. Among them, 22 also had positive cytology. Additional 10 cytology negative patients were diagnosed by pleural biopsy. Cytology–histology concordance was seen in 12 patients. Definite histological diagnosis could be achieved in five patients with indeterminate cytology. Pleural biopsy was not associated with any major postoperative complication.
Closed pleural biopsy can improve the diagnostic ability in cytology negative malignant pleural effusion. Closed pleural biopsy has still a place in evaluation of malignant pleural effusion especially in a resource-limited country like India.
Closed pleural biopsy; malignant pleural effusion; pleural fluid cytology
BACKGROUND: High pleural fluid levels of neurone-specific enolase (NSE) have been reported, not only in patients with small cell lung cancer but also in those with chronic inflammatory diseases. METHODS: NSE concentrations were determined in pleural fluid and serum from 342 patients with pleural effusions including 17 with rheumatoid arthritis. RESULTS: The median NSE concentration in pleural fluid was higher in rheumatoid effusions than in any other condition studied. The median pleural fluid:serum NSE ratio was highest in patients with rheumatoid arthritis (11.6) and about unity in all other diseases including small cell lung cancer (0.9). In patients with rheumatoid arthritis pleural fluid concentrations of NSE correlated inversely with pleural fluid glucose concentrations and the pH of the pleural fluid. CONCLUSIONS: A high pleural fluid:serum NSE ratio was found consistently in pleural effusions from patients with rheumatoid disease.
To evaluate the value of pleural fluid alkaline phosphatase and pleural fluid/serum alkaline phosphatase ratio for the purpose of differentiating tuberculous from nontuberculous pleural effusion.
Materials and Methods:
A total of 60 indoor patients, admitted to our hospital, having pleural effusion and suffering from varying etiologies, were included in this study. According to the final diagnosis, these 60 patients were divided into two groups: Tuberculous (30) and nontuberculous (30) pleural effusion.
The mean pleural alkaline phosphatase and pleural fluid/serum alkaline phosphatase ratio was significantly higher in tuberculous compared to nontuberculous pleural effusion. (P < 0.0001). In receiver operating characteristic curve analysis, sensitivity and specificity values were 90% and 80% for a cut-off value of 71 IU/L for pleural alkaline phosphatase activity; and were 90% and 86.66% for a cut-off value of 0.51 for pleural fluid/serum alkaline phosphatase ratio.
From this study it is concluded that alkaline phosphatase activity remains a useful test in differentiation of tuberculous from nontuberculous pleural effusion.
Alkaline phosphatase; differentiation; pleural effusion; tuberculosis
A possible role for C1q in antibody-dependent granulocyte-mediated killing of nonphagocytosable targets was investigated utilizing IgG-dependent granulocyte cytotoxicity directed against microfilariae of Dirofilaria immitis. Granulocyte-mediated killing of microfilariae is enhanced by addition of fresh serum. Lack of C4 did not significantly reduce the observed increase in cytotoxicity. The addition of highly purified monomeric human Clq (0.2 microgram/ml) in the presence of immune IgG resulted in a two- to fivefold enhancement of killing (P less than 0.025). C1q enhancement of killing occurred in the absence of fluid-phase IgG, but killing was significantly less than when both fluid-phase IgG and C1q were present. The effect of C1q was inhibited by the addition of solubilized type I collagen (44-92% inhibition of killing, P less than 0.05). Significant 125I-Clq binding to microfilariae occurred only in the presence of immune IgG. In addition, C1q in concentrations ranging from 0.5 to 2.0 micrograms/ml resulted in a dose-dependent increase in binding of 125I-immune IgG to microfilariae. Finally, when purified C1q was added to preopsonized, washed microfilariae, granulocyte production of superoxide was increased from 0.25 +/- 0.07 to 0.68 +/- 0.07 nm/10(6) cells.10 min (P less than 0.01). These results describe a novel functional role for C1q in enhancement of antibody-dependent cellular cytotoxicity towards nonphagocytosable targets.
Differentiation between exudative and transudative pleural effusions is the initial step in assessment of pleural effusion. The aim of this study was to determine whether high sensitivity C-reactive protein (hsCRP) and tumor necrosis factor α (TNFα) are diagnostic utilities for exudative pleural effusion.
This experimental study assessed 79 patients with pleural effusion who underwent diagnostic evaluations at Imam Reza hospital, Mashhad, Iran in 2009-2010. The complete biochemical analysis of pleural fluid, pleural fluid culture, and pathological examination of pleural fluid and tissue were performed. Moreover, hsCRP and TNFα concentrations were measured in pleural fluid samples. The data was analyzed by student's t-test and Mann-Whitney test.
According to Light's criteria, 50 patients (63.30%) had exudative effusions while 29 subjects (36.70%) had transudative effusion. The pleural fluid concentrations of hsCRP and TNFα were significantly higher in the exudative group than the transudative group (p < 0.05). At a cutoff value of 5 mg/L for hsCRP, the results showed 94% sensitivity and 96.6% specificity. Regarding TNFα, a cutoff value of 12.9 ng/dl represented 96% sensitivity and 93% specificity.
HsCRP and TNFα levels may be considered as beneficial diagnostic factors for detecting exudative effusion in patients with pleural effusion.
Pleural Effusion; Exudative; Transudative; HsCRP; TNFα
The objective of the present study was to investigate the presence of interleukin (IL)-27 in pleural effusions and to evaluate the diagnostic significance of pleural IL-27. The concentrations of IL-27 were determined in pleural fluids and sera from 68 patients with tuberculous pleural effusion, 63 malignant pleural effusion, 22 infectious pleural effusion, and 21 transudative pleural effusion. Flow cytometry was used to identify which pleural cell types expressed IL-27. It was found that the concentrations of pleural IL-27 in tuberculous group were significantly higher than those in malignant, infectious, and transudative groups, respectively. Pleural CD4+ T cells, CD8+ T cells, NK cells, NKT cells, B cells, monocytes, macrophages, and mesothelial cells might be the cell sources for IL-27. IL-27 levels could be used for diagnostic purpose for tuberculous pleural effusion, with the cut off value of 1,007 ng/L, IL-27 had a sensitivity of 92.7% and specificity of 99.1% for differential diagnosing tuberculous pleural effusion from non-tuberculous pleural effusions. Therefore, compared to non-tuberculous pleural effusions, IL-27 appeared to be increased in tuberculous pleural effusion. IL-27 in pleural fluid is a sensitive and specific biomarker for the differential diagnosing tuberculous pleural effusion from pleural effusions with the other causes.
While pleural effusion in multiple myeloma is relatively infrequent, myelomatous pleural effusion is extremely rare. We experienced a 61-year-old woman with IgD-lambda multiple myeloma and pleural effusion. The diagnosis was made originally by pleural biopsy, pleural fluid cytology and immunoelectropheresis of pleural fluid. Transient improvement of the pleural effusion was observed after administration of combination chemotherapy of vincristine, melphalan, cyclophosphamide, prednisone (VMCP)/vincristine, cyclophosphamide, adriamycin, prednisone (VCAP). Two months later, myelomatous pleural effusion recurred and no response to salvage therapy was observed. We reviewed the clinical feature of this case and literature concerning myelomatous pleural effusion.
Pleural tuberculosis (TB) diagnosis often requires invasive procedures such as pleural biopsy. The aim of this study was to evaluate the role of real-time polymerase chain reaction (PCR) for the IS6110 sequence of M. tuberculosis in pleural fluid specimens as a rapid and non-invasive test for pleural TB diagnosis.
For this cross-sectional study, 150 consecutive patients with pleural effusion diagnosed by chest radiography, who were referred for diagnostic thoracocentesis and pleural biopsy and met eligibility criteria, had a pleural fluid specimen submitted for real-time PCR testing. Overall, 98 patients had pleural TB and 52 had pleural effusion secondary to other disease. TB diagnosis was obtained using acid-fast bacilli (AFB) smear or culture for mycobacteria and/or histopathologic examination in 94 cases and by clinical findings in 4 cases. Sensitivity, specificity, positive and negative predictive values of PCR testing for pleural TB diagnosis were 42.8% (95% CI 38.4 - 44.8), 94.2% (95% CI 85.8 - 98.0), 93.3% (95% CI 83.6 - 97.7), and 48.5% (95% CI 44.2 - 50.4), respectively. The real-time PCR test improved TB detection from 30.6% to 42.9% when compared to AFB smear and culture methods performed on pleural fluid specimens, although the best sensitivity was achieved by combining the results of culture and histopathology of pleural tissue specimens.
The real-time PCR test of pleural fluid specimens is a useful and non-invasive additional assay for fast diagnosis of pleural TB.
It is well known that renal and neurological complications may occur after antifilarial treatment of patients infected with Loa loa. Conversely, spontaneous cases of visceral complications of loiasis have been rarely reported. A 31-year-old Congolese male patient who had not received any antifilarial drug developed oedema of the lower limbs, and then transient swellings of upper limbs. Two months after, he developed troubles of consciousness within several hours. At hospital, the patient was comatose with mild signs of localization. Laboratory tests and an abdominal echography revealed a chronic renal failure due to a glomerulopathy. Three weeks after admission, Loa microfilariae were found in the cerebrospinal fluid, and a calibrated blood smear revealed a Loa microfilaraemia of 74,200 microfilariae per ml. The level of consciousness of the patient improved spontaneously, without any specific treatment, but several days after becoming completely lucid, the patient died suddenly, from an undetermined cause. Unfortunately, no biopsy or autopsy could be performed. The role of Loa loa in the development of the renal and neurological troubles of this patient is questionable. But the fact that such troubles, which are known complications of Loa infection, were found concomitantly in a person harbouring a very high microfilarial load suggests that they might have been caused by the filarial parasite. In areas endemic for loiasis, examinations for a Loa infection should be systematically performed in patients presenting an encephalopathy or a glomerulopathy.
BACKGROUND—A study was
undertaken to evaluate the diagnostic value of pleural fluid
concentrations of interferon gamma (IFN-γ) as a marker of tuberculosis.
admitted to King Chulalongkorn Memorial Hospital between April 1997 and
January 1998 with a lymphocytic exudative pleural effusion were
enrolled into the study. The pleural fluids were examined for cytology,
staining for acid fast bacilli, and mycobacterial culture. Pathological
examination and mycobacterial culture were performed on each pleural
biopsy specimen. The diagnosis of tuberculosis was made when one of the
following criteria was met: (1) Mycobacterium
tuberculosis was isolated from either the pleural fluid or
pleural tissue; (2) granulomas were demonstrated in the pleural tissue
which stained positive for acid fast bacilli (AFB); or (3) in the
presence of granulomas negative on staining for AFB in pleural tissue
there was a response to antituberculous treatment on follow up. All
pleural fluid samples were stored at -70°C and the IFN-γ level was
measured by immunoassay. Analysis was made using sensitivity,
specificity, and likelihood ratio for a positive test result. The best
cut off point was determined by the highest likelihood ratio and
receiver operating characteristic curve.
RESULTS—A total of 66 patients were enrolled and tuberculosis was confirmed in 39 of them.
The diagnoses in the non-tuberculous group included malignancy (15),
paramalignancy (11), and chronic pleuritis secondary to infective
endocarditis (1). The mean (SE) IFN-γ level in the pleural fluid was
significantly higher in the tuberculous group than in the
non-tuberculous group (1493.3 (131.3) pg/ml versus 80.1 (50.4) pg/ml,
p<0.001). The overlap between the two groups was minimal. At the cut
off value of 240 pg/ml the sensitivity was 94.9% (95% CI 86.6 to
100), the specificity was 96.3% (95% CI 89.2 to 100), and the
likelihood ratio for a positive test result was 25.6.
pleural fluid concentration of IFN-γ is a good and useful diagnostic
marker of tuberculosis presenting as a lymphocytic exudative pleural effusion.
The diagnosis of malignant pleural effusions (MPE) is often clinically challenging, especially if the cytology is negative for malignancy. DNA integrity index has been reported to be a marker of malignancy. The aim of this study was to evaluate the utility of pleural fluid DNA integrity index in the diagnosis of MPE.
We studied 75 pleural fluid and matched serum samples from consecutive subjects. Pleural fluid and serum ALU DNA repeats [115bp, 247bp and 247bp/115bp ratio (DNA integrity index)] were assessed by real-time quantitative PCR. Pleural fluid and serum mesothelin levels were quantified using ELISA.
Based on clinico-pathological evaluation, 52 subjects had MPE (including 16 mesotheliomas) and 23 had benign effusions. Pleural fluid DNA integrity index was higher in MPE compared with benign effusions (1.2 vs. 0.8; p<0.001). Cytology had a sensitivity of 55% in diagnosing MPE. If cytology and pleural fluid DNA integrity index were considered together, they exhibited 81% sensitivity and 87% specificity in distinguishing benign and malignant effusions. In cytology-negative pleural effusions (35 MPE and 28 benign effusions), elevated pleural fluid DNA integrity index had an 81% positive predictive value in detecting MPEs. In the detection of mesothelioma, at a specificity of 90%, pleural fluid DNA integrity index had similar sensitivity to pleural fluid and serum mesothelin (75% each respectively).
Pleural fluid DNA integrity index is a promising diagnostic biomarker for identification of MPEs, including mesothelioma. This biomarker may be particularly useful in cases of MPE where pleural aspirate cytology is negative, and could guide the decision to undertake more invasive definitive testing. A prospective validation study is being undertaken to validate our findings and test the clinical utility of this biomarker for altering clinical practice.
Malignant pleural effusions; Mesothelioma; Lung cancer; DNA integrity index; Mesothelin
The diagnosis of bronchopulmonary carcinoma was either corroborated or arrived at in 13 out of a total of 26 cases by pleural biopsy. Taken as a whole, pleural biopsy is inferior to repeated examination of the pleural exudate for neoplastic cells. In individual observations, however, the former can be found positive at a time when neither the pleural fluid nor any other material provide a diagnostic clue.
In an instance of primary pleural growth (mesothelioma) its nature was recognizable in the pleural biopsy material.
Pleural biopsy can correctly lead to the diagnostic exclusion of growth in favour of tuberculosis.
Pleural biopsy can be suggestive of the rheumatic aetiology of changes.
A pleural biopsy positive for carcinoma can be obtained on both sides.
All stages, from early submesothelial deposition of individual neoplastic cells to the dense infiltration of the subserous connective and fat tissue, were observed.
The pleural surfaces of the lung and chest wall slide against each other with low friction. Normal load support can be effected either by a combination of quasi-static fluid pressure and solid-solid contacts of relatively stiff asperities, or by shear-induced hydrodynamic pressures in the pleural fluid layer. To distinguish between these mechanisms, we measured surface topography and spatial distribution of stiffness of rat parietal pleura using atomic force microscopy. The topography of the pleural surface has unevenness at length scales smaller than the thickness of pleural fluid, similar to mesothelial cell diameters. The estimated maximum normal contact pressure that could be borne by asperities of the soft pleura is much less than that required to support a substantial difference between pleural fluid pressure and the pleural surface pressure. These results suggest that during sliding motion, unevenness of the pleural surface is smoothed by local hydrodynamic pressure, preventing any significant contribution of solid-solid contacts.
Parietal pleura; AFM; Elastohydrodynamic lubrication; Rat; Topography
The cause of pleural effusion was studied in 300 consecutive patients by clinical examination and laboratory tests. The three most common causes were found to be cancer 117 cases (metastatic 65, bronchogenic 34, mesothelioma 10, lymphoma 7, other 1); tuberculous infection 53; and bacterial infection 38. The cause was not found in 62 patients. Cancer diagnosis was established by cytological examination of pleural fluid (63), closed pleural biopsy (37), and open pleural biopsy (11). Tuberculosis was diagnosed by culture of pleural fluid (12), closed pleural biopsy (38), and open pleural biopsy (3). In cases of empyema 12 Gram-positive and two Gram-negative cocci and two anaerobes were identified. The various causes and the usefulness of the different investigative procedures are discussed, and the data evaluated in the light of current knowledge about mechanisms of transfer through the pleural space.
Pleural effusions are classified into transudates and exudates. Various criteria have been used with Light's et al being the most accepted ones. Glycosaminoglycans (GAGs) have been detected during pleural fluids (PF) analysis in various causes. In this pilot study, we investigated: (a) the usefulness of GAGs in the assessment of pleural effusions, and (b) whether and in what way GAGs correlate with established criteria used to indicate an exudate.
LDH, total protein, cholesterol and GAG levels were measured in pleural fluid and serum from 50 patients with pleural effusion. GAG levels were defined by the photometric method of Hata. The discriminative properties of pleural GAGs (pGAG), pleural fluid/serum GAG ratio (GAGR), serum GAGs (sGAG) and serum LDH (sLDH) were explored with ROC analysis.
According to ROC analysis, pGAG and GAGR exhibited satisfactory discriminative properties in the separation of pleural effusions. For GAGR, at a 1.1 cut off point, sensitivity and specificity reached 75.6%; 95%CI: 60.5–87.1 and 100%; 95%CI: 47.8–100, respectively. For pGAG at a cut off value of 8.4 μg/ml, these percentages changed to 86.7%; 95%CI: 73.2–94.9 and 100%; 95%CI: 47.8–100. The study also revealed the differential role of sGAG between malignancies and benign cases, scoring 68.8%; 95%CI: 50.0–83.9 for sensitivity, and 84.6%; 95%CI: 54.5–97.6 for specificity at a 7.8 μg/ml cut off.
Our results suggest that glycosaminoglycan measurement of both serum and pleural effusions could be useful for simultaneous differentiation of exudates from transudates, and of malignant from benign exudates.
Pleural TB is notoriously difficult to diagnose due to its paucibacillary nature yet it is the most common cause of pleural effusions in TB endemic countries such as The Gambia. We identified both cellular and soluble biomarkers in the pleural fluid that allowed highly accurate diagnosis of pleural TB compared to peripheral blood markers. Multi-plex cytokine analysis on unstimulated pleural fluid showed that IP-10 resulted in a positive likelihood ratio (LR) of 9.6 versus 2.8 for IFN-γ; a combination of IP-10, IL-6 and IL-10 resulted in an AUC of 0.96 and positive LR of 10. A striking finding was the significantly higher proportion of PPD-specific IFN-γ+TNF-α+ cell population (PPD-IGTA) in the pleural fluid compared to peripheral blood of TB subjects. Presence of this pleural PPD-IGTA population resulted in 95% correct classification of pleural TB disease with a sensitivity of 95% and specificity of 100%. These data suggest that analysis of the site of infection provides superior diagnostic accuracy compared to peripheral blood for pleural TB, likely due to the sequestration of effector cells at this acute stage of disease.
Multiple myeloma is a malignant proliferation of plasma cells that mainly affects bone marrow. Pleural effusions secondary to pleural myelomatous involvement have rarely been reported in the literature. As it is rarely detected, we aimed to report a case in which pleural effusion of a multiple myeloma was confirmed as true myelomatous involvement by flow cytometry method. A 52-years old man presented to our clinic with chest and back pain lasting for 3 months. On the chest radiography, pleural fluid was detected in left hemithorax. Pleural fluid flow cytometry was performed. In the flow cytometry, CD56, CD38 and CD138 found to be positive, while CD19 was negative. True myelomatous pleural effusions are very uncommon, with fewer than 100 cases reported worldwide. Flow cytometry is a potentially useful and simple method for detection of pleural fluid involvement in multiple myeloma.