Carmen Alemán

Association between inflammatory mediators and the fibrinolysis system in infectious pleural effusions.

The response of the fibrinolytic system to inflammatory mediators in empyema and complicated parapneumonic pleural effusions is still uncertain. We prospectively analysed 100 patients with pleural effusion: 25 with empyema or complicated parapneumonic effusion, 22 with tuberculous effusion, 28 with malignant effusion and 25 with transudate effusion. Inflammatory mediators, tumour necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8) and polymorphonuclear elastase, were measured in serum and pleural fluid. Fibrinolytic system parameters, plasminogen, tissue-type plasminogen activator (t-PA) and urokinase PA, PA inhibitor type 1 (PAI 1) and PAI type 2 concentrations and PAI 1 activity, were quantified in plasma and pleural fluid. The Wilcoxon signed-rank test was used to compare plasma and pleural values and to compare pleural values according to the aetiology of the effusion. The Pearson correlation coefficient was used to assess the relationship between fibrinolytic and inflammatory markers in pleural fluid. Significant differences were found between pleural and plasma fibrinolytic system levels. Pleural fluid exudates had higher fibrinolytic levels than transudates. Among exudates, tuberculous, empyema and complicated parapneumonic effusions demonstrated higher pleural PAI levels than malignant effusions, whereas t-PA was lowest in empyema and complicated parapneumonic pleural effusions. PAI concentrations correlated with TNF-alpha, IL-8 and polymorphonuclear elastase when all exudative effusions were analysed, but the association was not maintained in empyema and complicated parapneumonic effusions. A negative association found between t-PA and both IL-8 and polymorphonuclear elastase in exudative effusions was strongest in empyema and complicated parapneumonic effusions. Blockage of fibrin clearance in empyema and complicated parapneumonic effusions was associated with both enhanced levels of PAIs and decreased levels of t-PA.

The value of chest roentgenography in the diagnosis of pneumothorax after thoracentesis

PURPOSE We sought to assess the yield of chest roentgenography for the detection of pneumothorax among hospitalized patients with pleural effusion who have undergone diagnostic or therapeutic thoracentesis. SUBJECTS AND METHODS We performed a prospective study of 506 thoracentesis procedures in 370 patients. After the procedure, each operator filled out a note recording patient data and the characteristics of the thoracentesis. A chest radiograph was performed within 12 hours after the procedure in all patients. RESULTS Eighteen (4%) pneumothoraces occurred in 17 patients, 9 (2%) of which required chest tube drainage. Of the 488 patients without symptoms, only 5 (1%) developed a pneumothorax, only 1 of which required chest tube drainage. By contrast, of the 18 patients with symptoms, 13 developed a pneumothorax, 8 of which required chest tubes. There were two independent predictors of pneumothorax: presence of symptoms (odds ratio [OR] = 250; 95% confidence interval [CI]: 65 to 980) and male gender (OR = 5.4; 95% CI: 1.9 to 69). CONCLUSIONS Among the symptom-free patients in our sample, the risk of developing pneumothorax with clinical consequences was so low that the practice of routine chest roentgenography may not be justified.

Polymorphonuclear Elastase in the Early Diagnosis of Complicated Pyogenic Pleural Effusions

Background: Polymorphonuclear elastase (PMN-E) is a neutrophilic marker that has been implicated in acute inflammatory responses. Objectives: To evaluate the accuracy of PMN-E in the diagnosis of complicated pyogenic effusions. Patients and Method: We studied 536 patients with pleural effusion of various etiologies. There were 125 pyogenic bacterial effusions (42 typical parapneumonic, 17 borderline complicated parapneumonic and 66 complicated parapneumonic or empyema), 83 tuberculous, 91 malignant, 42 paramalignant, 95 transudates, 28 miscellaneous and 72 effusions of unknown origin. Classic markers (pH, glucose, proteins, adenosine deaminase, LDH, leukocytes and differential count) and the PMN-E level were quantified in pleural fluid. The accuracy of PMN-E as an early marker in the diagnosis of complicated pyogenic infectious effusions was evaluated among pleural effusions that were not diagnosed with classic biochemical markers, radiological findings or Gram stain. Since results of pleural fluid culture and cytological examination are generally available after a 48-hour delay, they were not included as early markers in the initial diagnosis of pleural effusions. Results: Early diagnosis of complicated pyogenic bacterial effusions was achieved in only 48 of 66 cases with classic markers. Among those that were not diagnosed with these parameters, a pleural PMN-E value >3,500 µg/l discriminated between complicated and noncomplicated pyogenic bacterial effusions with a sensitivity of 67% and a specificity of 97%. Conclusions: PMN-E is useful in the early diagnosis and management of complicated pyogenic infectious effusions, which may be delayed with classic markers.

Angiogenic Factors and Angiogenesis Inhibitors in Exudative Pleural Effusions

The angiogenesis system has been implicated in inflammatory and neoplastic processes; nevertheless, it has been little studied in relation to the pleural space. Our aim is to analyze pleural and plasma levels of the activators-vascular endothelial growth factor, basic fibroblastic growth factor, and inhibitors-endostatin and thrombospondin-1 and to estimate the association between these factors and related biochemical markers. We analyzed pleural fluid from 105 patients with one of the following types of pleural effusion: empyema or complicated parapneumonic, non-complicated parapneumonic, tuberculous, neoplastic and transudative. Angiogenesis activators were higher in exudates than in transudates (p < 0.001) and in empyema than in non-complicated parapneumonic patients (p < 0.001). Endostatin showed no significant differences. Trombospondin-1 showed higher levels in exudates than in transudates and in empyema than in non-complicated parapneumonic effusions (p < 0.001). In pleural exudates there was a positive correlation of angiogenesis activators and trombospondin-1 with low glucose and pH and high LDH. There was no correlation between pleural and plasma levels of the angiogenesis factors. We conclude that exudative pleural effusions showed higher vascular endothelial growth factor, basic-fibroblastic growth factor and trombospondin-1 values than transudative effusions -that associated to low glucose and pH, and high LDH. There was no correlation between pleural and plasma concentrations, suggesting a compartmentalized response.

Pleural fluid mesothelin for the differential diagnosis of exudative pleural effusions

BACKGROUND Malignant mesothelioma (MM) is a highly aggressive tumor that can be difficult to diagnose, resulting in a delayed diagnosis in some cases. Recent studies have reported that determination of soluble mesothelin-related peptides (SMRP) in pleural fluid may be a promising marker for use in the diagnosis of MM. PATIENTS AND METHODS Pleural fluid SMRP concentration was measured in 68 patients: 47 had malignant pleural effusions (18 MM and 29 metastatic effusion) and 21 had benign pleural effusion (8 infectious disease and 13 idiopathic effusion). Mann-Whitney analysis was used to compare SMRP values according to the etiology of the effusion. RESULTS Pleural fluid SMRP concentration was significantly higher in patients with malignant pleural effusion than in those with benign effusion (P=0.02). When malignant pleural effusions were analyzed separately, MM patients had the highest median pleural fluid SMRP concentration, with significant differences as compared to patients with idiopathic pleural effusion. CONCLUSIONS Soluble mesothelin-related peptide measurement in pleural fluid may aid in the diagnosis of patients presenting with pleural effusion.

Computed tomography scoring system for discriminating between parapneumonic effusions eventually drained and those cured only with antibiotics

Due to limited data, we aimed to develop and validate a computed tomography (CT)‐based scoring system for identifying those parapneumonic effusions (PPEs) requiring drainage.

Pleural fluid myeloperoxidase as a marker of infectious pleural effusions

Background: The aim of this study was to establish the diagnostic accuracy of neutrophil markers (elastase, lysozyme, myeloperoxidase) found in pleural fluid in differentiating between infectious and non-infectious pleural effusions (PE). Methods: We studied 184 patients over 18 years of age with PE, classified as either infectious (34 complicated parapneumonic, 32 non-complicated parapneumonic, 45 tuberculous) or non-infectious (31 neoplasms and 42 undiagnosed exudates). Polymorphonuclear elastase (PMN-E) was determined using an immunoactivation method and lysozyme using a turbidimetric method. Myeloperoxidase (MPO) was measured by double antibody competitive radioimmunoassay. Receiver operating characteristic (ROC) curves were used to evaluate diagnostic accuracy. Results: Pleural fluid MPO was the biochemical marker that best differentiated between infectious and non-infectious PE. The ROC area under the curve (AUC) for myeloperoxidase was 0.86. MPO values over 550 &mgr;g/l diagnosed infectious PE with a specificity of 90.4% and a sensitivity of 77.4%. After excluding purulent parapneumonic PE, the sensitivity of a pleural MPO value >/=550 &mgr;g/l was 72.6%. Conclusions: Pleural fluid MPO was the marker that best differentiated between infectious and non-infectious PE.

Postprandial serum cholylglycine in the detection of hepatotoxicity induced by antituberculous agents

Abstract Background : Measurement of bile acid levels has been proven helpful in the detection of hepatic abnormalities when routine liver function test results are normal or only slightly elevated. We compared the effectiveness of postprandial serum cholylglycine (CG), as determined by RIA, with commonly used liver function tests (SGOT, SGPT, alkaline phosphatase, gamma-glutamyl transpeptidase) in order to detect liver injury in patients receiving antituberculous agents. Method : We studied 100 patients receiving antituberculous agents. Laboratory tests were carried out before the initiation of therapy and after 1, 2, 3 and 8 weeks of treatment. The risk of hepatotoxicity in relation to age (>35 years) and/or the addition of pyrazinamide to the 6-month isoniazid–rifampin regimen was also assessed. Results : The percentage of patients with hepatic dysfunction detected by abnormal serum CG levels was significantly greater than that detected with conventional liver function tests. Neither age over 35 years nor the use of pyrazinamide was associated with a greater number of abnormalities in liver function tests. Conclusion : Postprandial serum CG by RIA proved to be a sensitive parameter for detecting hepatotoxicity by antituberculous agents.