Ultrastructure of pleural mesothelioma and pulmonary adenocarcinoma in malignant effusions as compared with reactive mesothelial cells.

OBJECTIVE: To determine the ultrastructural features of diffuse malignant pleural mesothelioma cells in cytologic specimens from pleural effusions. STUDY DESIGN: We retrospectively studied 35 pleural effusions: 12 diffuse malignant pleural mesotheliomas (8 epithelial type, 4 biphasic type), 12 pulmonary adenocarcinomas and 11 cases of reactive mesothelial cells. RESULTS: In the cytoplasm, reactive and malignant mesothelial cells had more-abundant intermediate filaments (P < .05, P < .01) and fewer free ribosomes (P < .001, P < .001) than adenocarcinoma cells. Reactive mesothelial cells had fewer mitochondria than mesothelioma cells (P < .05). Mesothelioma cells had longer, thinner microvilli on the cell surfaces (P < .001); length/diameter ratios of microvilli were 19.1 +/- 7.0 (mesothelioma) vs. 9.1 +/- 2.2 (adenocarcinoma) and 9.2 +/- 2.4 (mesothelial cells). Giant intercellular junctions (desmosomes or desmosomelike structures > 1 micron in length) were found in eight cases of mesothelioma. Core filaments or rootlets in microvilli were present in two cases of adenocarcinoma. CONCLUSION: Because cytologic specimens from pleural effusions were easy to obtain, we think ultrastructural cytology is useful in distinguishing mesothelioma from adenocarcinoma and benign effusions.     

Cell origins and diagnostic accuracy of interleukin 27 in pleural effusions

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.     

Bacterial induction of pleural mesothelial monolayer barrier dysfunction

Pneumonia remains one of the most common infectious causes of mortality. Patients with pneumonia develop parapneumonic effusions with a high neutrophil count as well as high protein concentrations. We hypothesized that pulmonary parenchymal bacterial infection causes a permeability change in the pleural mesothelium by inducing the production of vascular endothelial growth factor (VEGF). Complicated parapneumonic pleural effusions (empyema) have a 19-fold higher VEGF level than pleural fluids secondary to congestive heart failure and a 4-fold higher level than pleural fluids secondary to uncomplicated parapneumonic effusions. We also analyzed the influence of live Staphylococcus aureus on mesothelial barrier function using a model of confluent mesothelial monolayers. There was a significant drop in electrical resistance across S. aureus-infected pleural mesothelial cell (PMC) monolayers. Recombinant VEGF also decreases PMC electrical resistance. Neutralizing antibodies to VEGF significantly inhibited the drop in PMC electrical resistance caused by S. aureus. S. aureus infection also caused a significant increase in protein leak across confluent mesothelial monolayers. Our results suggest that bacterial pathogens induce VEGF release in mesothelial cells and alter mesothelial permeability, leading to protein exudation in empyema.     

Pleural Fluid Adenosine Deaminase (Pfada) in the Diagnosis of Tuberculous Effusions in a Low Incidence Population

IntroductionPrevious studies have assessed the diagnostic ability of pleural fluid adenosine deaminase (pfADA) in detecting tuberculous pleural effusions, with good specificity and sensitivity reported. However, in North Western Europe pfADA is not routinely used in the investigation of a patient with an undiagnosed pleural effusion, mainly due to a lack of evidence as to its utility in populations with low mycobacterium tuberculosis (mTB) incidence.MethodsPatients presenting with an undiagnosed pleural effusion to a tertiary pleural centre in South-West England over a 3 year period, were prospectively recruited to a pleural biomarker study. Pleural fluid from consecutive patients with robust 12-month follow up data and confirmed diagnosis were sent for pfADA analysis.ResultsOf 338 patients enrolled, 7 had confirmed tuberculous pleural effusion (2%). All mTB effusions were lymphocyte predominant with a median pfADA of 72.0 IU/L (range- 26.7 to 91.5) compared to a population median of 12.0 IU/L (range- 0.3 to 568.4). The optimal pfADA cut off was 35 IU/L, which had a negative predictive value (NPV) of 99.7% (95% CI; 98.2-99.9%) for the exclusion of mTB, and sensitivity of 85.7% (95% CI; 42.2-97.6%) with an area under the curve of 0.88 (95% CI; 0.732–1.000).DiscussionThis is the first study examining the diagnostic utility of pfADA in a low mTB incidence area. The chance of an effusion with a pfADA under 35 IU/L being of tuberculous aetiology was negligible. A pfADA of over 35 IU/L in lymphocyte-predominant pleural fluid gives a strong suspicion of mTB.     

Cautious Application of Pleural N-Terminal Pro-B-Type Natriuretic Peptide in Diagnosis of Congestive Heart Failure Pleural Effusions among Critically Ill Patients

Background and Objective

Several studies on diagnostic accuracy of pleural N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) for effusions from congestive heart failure (CHF) conclude that pleural NT-pro-BNP is a useful biomarker with high diagnostic accuracy for distinguishing CHF effusions. However, its applicability in critical care settings remains uncertain and requires further investigations.

Methods

NT-proBNP was measured in pleural fluid samples of a prospective cohort of intensive care unit patients with pleural effusions. Receiver operating characteristic curve analysis was performed to determine diagnostic accuracy of pleural NT-proBNP for prediction of CHF effusions.

Results

One hundred forty-seven critically ill patients were evaluated, 38 (26%) with CHF effusions and 109 (74%) with non-CHF effusions of various causes. Pleural NT-proBNP levels were significantly elevated in patients with CHF effusions. Pleural NT-pro-BNP demonstrated the area under the curve of 0.87 for diagnosing effusions due to CHF. With a cutoff of 2200 pg/mL, pleural NT-proBNP displayed high sensitivity (89%) but moderate specificity (73%). Notably, 29 (27%) of 109 patients with non-CHF effusions had pleural NT-proBNP levels >2200 pg/mL and these patients were more likely to experience septic shock (18/29 vs. 10/80, P<0.001) or acute kidney injury (19/29 vs. 9/80, P<0.001).

Conclusions

Among critically ill patients, pleural NT-proBNP measurements remain a useful diagnostic aid in evaluation of pleural effusions. However, patients with non-CHF effusions may exhibit high pleural NT-proBNP concentrations if they suffer from septic shock or acute kidney injury. Accordingly, it is suggested that clinical context should be taken into account when interpreting pleural NT-proBNP values in critical care settings.     

DNA flow cytometry of pleural effusions. Comparison with pathology for the diagnosis of malignancy

A study was undertaken to determine the potential value of DNA flow cytometry (FCM) for the diagnosis of malignancy in pleural effusions and to compare its results with those of traditional cytomorphology. Forty-one pleural fluids from 37 patients were evaluated by DNA FCM and routine cytologic techniques. Of the 41 pleural fluids, 29 (70.7%) demonstrated an abnormal DNA content by FCM. Two of the 29 pleural fluids had been originally diagnosed as benign by cytology. Cytologic review of these two cases showed no abnormal cells; therefore, there were no false-negative cases based on cytology. In 12 (29.3%) of the 41 fluids, DNA FCM and cytologic evaluation both indicated benign processes. Our preliminary observations indicate that FCM is an accurate and reliable technique that may be of aid in the diagnosis of malignant effusions. The technique may prove to be of special value in the differential diagnosis of reactive mesothelial cells versus malignant mesothelioma as well as for following patients who receive chemotherapy for malignant pleural effusions. DNA FCM may also complement cytomorphologic diagnoses in other serous, exfoliative or aspiration material.     

Lower proliferation rate in metastatic effusion mesothelial cells than in benign effusions

OBJECTIVE: To determine the proliferation rates of mesothelial cells in metastatic and benign effusions. STUDY DESIGN: Immunohistochemistry was performed on formalin-fixed pellets from 16 malignant and 9 benign clinical effusions. Dual staining with antibodies against Ki-67 (MIB-1) and desmin was applied to all effusions to differentiate between benign mesothelial cells and malignant cells, and the proportions of desmin+/Ki-67+ and desmin+/Ki-67- cells were calculated. RESULTS: In 7 malignant effusions no proliferating mesothelial cells were found, whereas some rate of proliferation could always be demonstrated in mesothelial cells in the benign effusions. Further, the median proportions of proliferating cells, malignant 2% vs. benign 11%, differed significantly. CONCLUSIONS: To our knowledge this finding has not been previously described, and it may have implications for both cytologic diagnosis and the understanding of tumor biology and the interaction between tumor cells and mesothelial cells.     

Cardiac autonomic function in Blacks with congestive heart failure: vagomimetic action, alteration in sympathovagal balance, and the effect of ACE inhibition on central and peripheral vagal tone.

Cardiac autonomic dysfunction is common in heart disease with or without congestive heart failure, and can cause sudden cardiac death. However, cardiac autonomic abnormalities in non-ischemic (hypertensive) heart failure, which is prevalent in Black Africans is poorly documented. We conducted a cross-sectional study of 32 patients with congestive heart failure, mostly secondary to hypertension (aged 52 +/- 15 years, with ejection fraction of 0.38 +/- 11) and 30 age- and sex-matched healthy volunteers (aged 51 +/- 11 years, 14 males/16 females). Cardiac autonomic function was assessed by the Valsalva's maneuver, respiratory sinus arrhythmia (for cardiac vagal tone) and the pressor and chronotropic changes following forearm isometric handgrip exercise and the assumption of upright posture (tests of sympathetic function). The exercise tolerance of the cardiac patients was assessed by the distance covered during 6 min of walking. The Valsalva ratio was significantly lower in chronic heart failure, 1.10 +/- 0.08 compared to the healthy controls 1.47 +/- 0.20 (p<0.001). Specifically, the phase IV bradycardia in heart failure, was significantly attenuated to 650 +/- 121 msec compared to the value of 935 +/- 101 msec in healthy controls (p<0.001). The phase 11 Valsalva tachycardia did not differ between the patients and controls. The respiratory sinus arrhythmia was also significantly reduced in chronic heart failure (p<0.05) compared to controls. Treatment of the heart failure patients with enalapril-digoxin and diuretics by 4 weeks, resulted in a reversal of the autonomic abnormalities. The phase IV bradycardia increased significantly to 798 +/- 164 msec (p<0.01) and the Valsalva ratio to 1.35 +/- 0.25 (p<0.01) and the respiratory sinus arrhythmia increased toward normal. There was close positive correlation between the Valsalva's ratio and the 6 min self paced distance covered (r = 0.44, p = 0.03 ANOVA), and a weak inverse correlation to cardiac size and cardiothoracic ratio (r = -0.31, p = 0.09). This study demonstrates cardiac autonomic dysfunction (especially reduced vagal tone) in Black Nigerians with mainly non-ischemic congestive heart failure. The parasympathetic dysfunction significantly correlates with severity of heart failure. Current treatment reverses autonomic dysfunction to values seen in healthy age matched controls, mainly through augmentation of cardiac parasympathetic activity.     

Mycobacterium kansasii infection diagnosed by pleural fluid cytology: a case report

BACKGROUND: Identification of disseminated nontuberculous Mycobacterium infection is a challenge, especially when it occurs in patients without a known cause of immunosuppression. Acid-fast organisms in the pleural fluid are rare and easily missed, especially when they occur in patients without a clinical suspicion of infection. The classical cytologic picture of tuberculous pleural fluid with lymphocytosis and paucity of mesothelial cells is not seen. CASE: A 57-year-old man presented with chronic neutrophilia of unknown etiology together with chest pain and bilateral pleural effusions. Pleural fluid cytology revealed organisms seen in the cytoplasm of numerous macrophages and neutrophils, creating a "negative image" on Diff-Quik smears. Acid-fast stains demonstrated intracellular acid-fast bacilli consistent with mycobacteria. Microbiologic studies with DNA probe technology resulted in identification of the mycobacterial organism as Mycobacterium kansasii. CONCLUSION: Nontuberculous Mycobacterium should be included in the differential diagnosis in patients with inflammatory, exudative pleural effusions.     

ACE/ACE2 Ratio and MMP-9 Activity as Potential Biomarkers in Tuberculous Pleural Effusions

Objective: Pleural effusion is common problem, but the rapid and reliable diagnosis for specific pathogenic effusions are lacking. This study aimed to identify the diagnosis based on clinical variables to differentiate pleural tuberculous exudates from other pleural effusions. We also investigated the role of renin-angiotensin system (RAS) and matrix metalloproteinase (MMPs) in the pathogenesis of pleural exudates.Experimental design: The major components in RAS and extracellular matrix metabolism, including angiotensin converting enzyme (ACE), ACE2, MMP-2 and MMP-9 activities, were measured and compared in the patients with transudative (n = 45) and exudative (n = 80) effusions. The exudative effusions were come from the patients with tuberculosis (n = 20), pneumonia (n = 32), and adenocarcinoma (n = 28).Results: Increased ACE and equivalent ACE2 activities, resulting in a significantly increased ACE/ACE2 ratio in exudates, were detected compared to these values in transudates. MMP-9 activity in exudates was significantly higher than that in transudates. The significant correlation between ACE and ACE2 activity that was found in transudates was not found in exudates. Advanced analyses showed significantly increased ACE and MMP-9 activities, and decreased ACE2 activity in tuberculous pleural effusions compared with those in pneumonia and adenocarcinoma effusions. The results indicate that increased ACE and MMP-9 activities found in the exudates were mainly contributed from a higher level of both enzyme activities in the tuberculous pleural effusions.Conclusion: Interplay between ACE and ACE2, essential functions in the RAS, and abnormal regulation of MMP-9 probably play a pivotal role in the development of exudative effusions. Moreover, the ACE/ACE2 ratio combined with MMP-9 activity in pleural fluid may be potential biomarkers for diagnosing tuberculous pleurisy.     

Diagnostic interest of the monoclonal antibody CA1 in malignant pleural effusion

The Ca1 antibody was used in an immunohistochemical procedure on smears of cells from 40 patients with malignant pleural effusion. The control group consisted of 25 benign pleural effusions with a high percentage of reactive mesothelial cells. The Ca1 Mc Ab was positive in 19 (79%) of the 24 pleural effusions with positive malignant cytology. In all the benign cases the Ca1 Mc Ab was negative (100% specificity). The Ca1 Mc Ab detected malignant mesothelial cells in two cases and was negative with reactive mesothelial cells and other nucleated cells present in the pleural effusion. We conclude that the Ca1 antibody offers a useful diagnostic method for malignant pleural effusions, when the morphological interpretation is doubtful.     

Diagnostic value of ferritin in the differential diagnosis of malignant effusions

The diagnostic value of ferritin in pleural effusions or ascites was studied in 151 samples from 147 patients (four patients had both kind of effusions). Samples (99 pleural effusions, 52 ascites) were evaluated in 4 groups: benign transudate (27 cases), benign nontuberculous exudate (26 cases), tuberculous exudate (47 cases) and malignant exudate (51 cases). Median ferritin levels in effusions were 67 ng/ml, 805 ng/ml, 889 ng/ml, 998 ng/ml and median effusion/serum (E/S) ratios were 0.7. 2.0, 4.9, 3.2 respectively. There was a significant difference between the concentrations of ferritin in malignant (51 cases) and nonmalignant effusions (100 cases) (p < 0.001), but the specificity and positive predictive value were low (43% and 45% respectively). Ferritin levels in transudate group were significantly lower than those in the others (p < 0.001). However, ferritin concentrations in three exudate groups were similar (p > 0.05). When compared the all inflammatory effusions (malignant, tuberculous, nontuberculous inflammatory exudates) with noninflammatory effusions (transudate and exudate), we determined a significant difference (p < 0.001). CONCLUSIONS: 1) Elevated ferritin concentration in effusions is significant indicators of exudates; 2) It is not good a parameter to discriminate the malignant effusions from the benign ones; 3) They can be useful in the differential diagnosis of the inflammatory exudations from the noninflammatory ones.     

Characterizing subpopulations of neoplastic cells in serous effusions. The role of immunocytochemistry

OBJECTIVE: To analyze the role of immunochemistry in serous effusions. STUDY DESIGN: We analyzed cell blocks of 18 pleural and 18 peritoneal effusions diagnosed as malignant (18), benign (14) and suspicious (4). They were immunostained by the avidin-biotin complex method with a panel of four monoclonal antibodies--CEA, Ber-EP4, LeuM1 (CD15) and p53--and, for lectins (Ulex europaeus) UEA-l, ConA and ConBr. RESULTS: Seventeen of the 18 cases of adenocarcinoma were positive for CEA (95%), 12 (66.6%) for Ber-EP4, 11 (61%) for CD15 and 11 (61%) for p53. Twelve of the 18 (66.6%) were positive for UEA-1, CEA, Ber-EP4 and CD15. UEA-1 did not react with mesothelial cells. p53 Gave a positive reaction in only one case, reactive mesothelial cells. ConA and ConBr reacted indiscriminately with benign and malignant cells; thus, it was not useful in distinguishing between these cells. CONCLUSION: In this context no antibody used alone is reliable for corroborating a diagnosis, but the selective use of a small panel of three markers (CEA, Ber-EP4 and LeuM1) can be very useful in solving diagnostic difficulties in the cytodiagnosis of serous effusions.     

Distribution of diaphragmatic lymphatic stomata

In seven anesthetized rabbits we measured the size, shape, and density of lymphatic stomata on the peritoneal and pleural sides of the diaphragm. The diaphragm was fixed in situ and processed for scanning electron microscopy. Results are from 2,902 peritoneal and 3,086 pleural fields (each 1,620 microns 2) randomly chosen from the various specimens. Stomata were seen in 9% of the fields examined, and in 30% of the cases they appeared grouped in clusters with 2-14 stomata/field. Stoma density was 250 +/- 242 and 72 +/- 57 (SD) stomata/mm2 on peritoneal and pleural sides, respectively, and it was similar over the muscular and tendinous portion of the two surfaces. The maximum diameter ranged from less than 1 to approximately 30 microns, with an average value of 1.2 +/- 3.1 micron. The ratio of the maximum to the minimum diameter and the surface area averaged 2 +/- 1.4 and 0.7 +/- 2.4 micron 2, respectively. The maximum and minimum diameter and surface area values followed a lognormal frequency distribution, suggesting that stomata geometry is affected by diaphragmatic tension.     

细胞因子IFN-γ,IL-2,TNF-α和ADA对结核性和恶性胸腔积液鉴别诊断的价值

目的：探讨细胞因子γ-干扰素（IFN-γ）、白介素-2（IL-2）、肿瘤坏死因子-α（TNF-α）和腺苷脱氨酶（ADA）对结核性和恶性胸腔积液的鉴别诊断的价值。方法：以2012年9月至2013年3月期间在青岛大学医学院附属医院呼吸科及青岛胸科医院未经治疗的胸腔积液患者为研究对象,其中恶性胸腔积液患者46例,结核性胸腔积液患者42例。采用双抗体夹心酶联免疫吸附测定法（ELISA）分别检测结核性和恶性胸腔积液患者中IFN-γ、IL-2、TNF-α及ADA的表达情况。并应用ROC曲线分析两组患者胸腔积液中IFN-γ、IL-2、TNF-α及ADA的表达差异及意义。结果：结核性胸腔积液组IFN-γ、IL-2、TNF-α及ADA的表达明显高于恶性胸腔积液组,差异有统计学意义（t=8.118、8.126、8.066、7.221;P=0.000、0.000、0.000、0.000,P〈0.001）;ROC曲线分析结果显示胸腔积液中IFN-γ、IL-2、TNF-α及ADA的诊断临界值为201.45 pg/mL、41.91 pg/mL、21.55 pg/mL、33.78 U/L;诊断敏感度分别为91.3%、93.5%、91.2%、89.1%;特异度分别为91.0%、92.1%、89.9%、90.1%。结论：胸腔积液中IFN-γ、IL-2、TNF-α及ADA的表达对结核性和恶性胸腔积液诊断与鉴别诊断具有重要参考价值。     

The cytologic diagnosis of malignant neoplasms in pleural and peritoneal effusions

This study presents data on 3,011 pleural and peritoneal effusion specimens that were examined over a three-year period (1982 to 1984). Totals of 812 (44%) of 1,846 pleural and 423 (36%) of 1,165 peritoneal specimens were positive for malignant cells. While 535 patients had malignant pleural effusions, 254 patients had malignant peritoneal effusions, and 57 had both malignant pleural and peritoneal effusions. The most common primary neoplasms causing malignant pleural effusions were carcinomas of breast (24%) and lung (19%) and lymphoreticular neoplasms (16%). The most common primary neoplasms causing malignant peritoneal effusions were carcinomas of ovary (32%) and breast (13%) and lymphoreticular neoplasms (7%). There was an average interval of more than 30 months between the histologic diagnosis of the primary neoplasm and the diagnosis of malignant effusions in patients with carcinoma of breast, lymphoreticular neoplasm and malignant melanoma. The average time until death following the diagnosis of a malignant effusions was five months or less, except for patients with carcinoma of the breast and carcinoma of the ovary. One hundred twenty-five patients (15%) presented with malignant effusions caused by neoplasms of unknown primary sites. The most common primary neoplasms that were later diagnosed were, in decreasing order of frequency, carcinoma of the ovary, carcinoma of the lung and lymphoreticular neoplasms.     

Activation of proteinase-activated receptor-2 in mesothelial cells induces pleural inflammation

Pleural inflammation underlies many pleural diseases, but its pathogenesis remains unclear. Proteinase-activated receptor-2 (PAR(2)) is a novel seven-transmembrane receptor with immunoregulatory roles. We hypothesized that PAR(2) is present on mesothelial cells and can induce pleural inflammation. PAR(2) was detected by immunohistochemistry in all (19 parietal and 11 visceral) human pleural biopsies examined. In cultured murine mesothelial cells, a specific PAR(2)-activating peptide (SLIGRL-NH(2)) at 10, 100, and 1,000 muM stimulated a 3-, 42-, and 1,330-fold increase of macrophage inflammatory protein (MIP)-2 release relative to medium control, respectively (P < 0.05 all) and a 2-, 32-, and 75-fold rise over the control peptide (LSIGRL-NH(2), P < 0.05 all). A similar pattern was seen for TNF-alpha release. Known physiological activators of PAR(2), tryptase, trypsin, and coagulation factor Xa, also stimulated dose-dependent MIP-2 release from mesothelial cells in vitro. Dexamethasone inhibited the PAR(2)-mediated MIP-2 release in a dose-dependent manner. In vivo, pleural fluid MIP-2 levels in C57BL/6 mice injected intrapleurally with SLIGRL-NH(2) (10 mg/kg) were significantly higher than in mice injected with LSIGRL-NH(2) or PBS (2,710 +/- 165 vs. 880 +/- 357 vs. 88 +/- 46 pg/ml, respectively; P < 0.001). Pleural fluid neutrophil counts were higher in SLIGRL-NH(2) group than in the LSIGRL-NH(2) and PBS groups (by 40- and 26-fold, respectively; P < 0.05). This study establishes that activation of mesothelial cell PAR(2) potently induces the release of inflammatory cytokines in vitro and neutrophil recruitment into the pleural cavity in vivo.     

Mesothelial cell apoptosis is confirmed in vivo by morphological change in cytokeratin distribution

Apoptosis of mesothelial cells has been demonstrated in vitro but not in vivo. To identify apoptotic pleural cells as mesothelial, we used cytokeratin as a marker and found a striking spheroid, aggregated appearance of cytokeratin in apparently apoptotic mesothelial cells. In in vitro studies, we found that the aggregated cytokeratin pattern correlated with apoptosis in primary mesothelial cells from mice, rabbits, and humans and was not seen with necrosis. In in vivo studies in mice, we then used this cytokeratin pattern to identify and quantitate apoptotic mesothelial cells. Apoptotic mesothelial cells were best harvested by pleural lavage, indicating that they were loosely adherent or nonadherent. Instillation of RPMI 1640 medium or wollastonite for 24 h induced apoptosis in 0.1 +/- 0. 1 (SE) and 1.0 +/- 0.7%, respectively, of all mesothelial cells recovered, whereas instillation of known apoptotic stimuli, crocidolite asbestos (25 microg) for 24 h or actinomycin D plus murine tumor necrosis factor-alpha for 12 h, induced apoptosis in 5. 1 +/- 0.5 and 22.4 +/- 4.5%, respectively (significantly greater than in control experiments, P < 0.05). By analysis of cytokeratin staining, mesothelial cell apoptosis has been confirmed in vivo.     

Levels of soluble VCAM-1, soluble ICAM-1, and soluble E-selectin in patients with tuberculous pleuritis

Tuberculosis is characterized by the presence of activated mononuclear cells both in the peripheral circulation and in pleural fluid. Expression and up-regulation of adhesion molecules is the basis of cell-cell adhesion in granuloma formation and in leukocyte migration to the inflammatory site. Soluble isoforms of adhesion molecules have been described, and their expression at high levels indicated an activated state. The purpose of this study was to evaluate levels of soluble adhesion molecules in serum and pleural fluid from patients with tuberculous pleural effusions, compared with non-tuberculous pleural effusions. We analysed levels of soluble vascular cell adhesion molecule-1 (s.VCAM-1), soluble intercellular adhesion molecule-1 (s.ICAM-1), and soluble E-selectin (sE-selectin) in serum and pleural fluid from patients with tuberculous pleuritis, by sandwich ELISA. Serum levels of s.ICAM-1 and s.VCAM-1 in patients with tuberculosis were higher than those in healthy controls (p < 0.001). Levels of sE-selectin levels were in the normal range compared with control groups. In pleural fluid, levels of s.VCAM-1 and s.ICAM-1 were increased in pleural effusions. Patients with tuberculous pleural effusion exhibited high levels of s.ICAM-1 compared with patients with neoplastic pleural involvement. Up-regulation of s.VCAM-1 and s.ICAM-1 in serum, along with increased levels of sE-selectin in pleural effusions from tuberculous patients, may result in transmigration of activated inflammatory cells inducing pleural damage, which may contribute to the pathological processes involved.     

Determination of the T-cell subset producing gamma-interferon in tuberculous pleural effusion

The percentage of cells of different T-cell subsets and their functions in tuberculous pleural effusion were investigated. The percentage of OKT4-positive cells was 65 +/- 2% (mean +/- SEM, n = 8) and that of OKT8-positive cells was 19 +/- 3% (n = 8). Pleural T lymphocytes of patients with tuberculous pleurisy responded well to stimulation with purified protein derivative of tuberculin, and deoxyribonucleic acid synthesis was observed along with gamma interferon (IFN-gamma) production. When pleural T lymphocytes of patients with tuberculous pleurisy were treated with OKT4 monoclonal antibody and complement, a significant decrease in IFN-gamma production was observed in all eight patients (P less than 0.005), whereas no definite decrease in IFN-gamma production was found after treatment with OKT8 monoclonal antibody and complement. These results suggest that at least the OKT4+/OKT8- T-cell subset is responsible for the antigen-specific IFN-gamma production in pleural T lymphocytes of patients with tuberculous pleurisy.