Etiology of pleural effusions: analysis of more than 3,000 consecutive thoracenteses

OBJECTIVE

To investigate the etiology of pleural effusions (PE) in adults and the accuracy of pleural fluid (PF) cytology and cultures in malignant and infectious PE, respectively.

PATIENTS AND METHODS

Retrospective analysis of all consecutive patients with PE undergoing diagnostic thoracentesis during the last 19 years in a university hospital.

RESULTS

The leading causes of PE among the 3,077 patients were: cancer (27%), heart failure (21%), pneumonia (19%), tuberculosis (9%), abdominal surgery (4%), pericardial diseases (4%) and cirrhosis (3%). Tuberculosis was the most common etiology in patients <34 years of age (52%), whereas heart failure predominated in octogenarians (45%). The most common primary tumors in malignant PE were lung (37%) and breast (16%). The overall accuracy of PF cytology was 59%, although it was significantly lower in mesotheliomas (27%) and squamous cell lung cancer (25%). In infectious PE, only 30% of cultures yielded positive results, a percentage which increased two-fold (66%) in purulent fluids (empyemas). Viridans streptococci were the most commonly isolated pathogens (25.5%). The sensitivity of solid media cultures of PF for Mycobacterium tuberculosis was low (18.5%).

CONCLUSIONS

Three-quarters of patients with PE in whom a diagnostic thoracentesis was indicated had cancer, heart failure, pneumonia or tuberculosis. PF cytology and cultures give false negative results in a significant number of cases.

Use of a panel of tumor markers (carcinoembryonic antigen, cancer antigen 125, carbohydrate antigen 15-3, and cytokeratin 19 fragments) in pleural fluid for the differential diagnosis of benign and malignant effusions

STUDY OBJECTIVE

The diagnostic value of tumor markers in pleural fluid is subject to debate. The aim of this study was to evaluate the diagnostic performance of several tumor markers in common use for detecting malignant pleural disease.

DESIGN

Blinded comparison of four tumor markers in pleural fluid with a confirmatory diagnosis of malignancy by pleural cytology or thoracoscopic biopsy.

SETTING

Two teaching hospitals in Spain.

PATIENTS AND METHODS

A total of 416 patients (166 with definite malignant effusions, 77 with probable malignant effusions, and 173 with benign effusions) were enrolled. Among them, there were 42 patients recruited from one of the participant centers with thoracoscopic facilities, who had false-negative fluid cytology findings and malignancy confirmed by medical thoracoscopy. Tumor markers in pleural fluid were determined either by electrochemiluminescence immunoassay (carcinoembryonic antigen [CEA], carbohydrate antigen 15-3 [CA 15-3], cytokeratin 19 fragments [CYFRA 21-1]) or microparticle enzyme immunoassay (cancer antigen 125 [CA 125]) technologies. Cutoff points that yielded 100% specificity (ie, all patients with benign effusions had levels below this cutoff) were selected for each marker.

RESULTS

Malignant pleural effusions (PEs) had higher levels of pleural fluid markers than did effusions due to benign conditions. At 100% specificity, a pleural CEA > 50 ng/mL, CA 125 > 2,800 U/mL, CA 15-3 > 75 U/mL, and CYFRA 21-1 > 175 ng/mL had 29%, 17%, 30%, and 22% overall sensitivities, respectively. The combination of the four tumor markers reached 54% sensitivity, whereas the combined use of the cytology and the tumor marker panel increased the diagnostic yield of the former by 18% (95% confidence interval, 13 to 23%). More than one third of cytology-negative malignant PEs could be identified by at least one marker of the panel.

CONCLUSIONS

No single pleural fluid marker seems to be accurate enough as to be introduced in the routine workup of PE diagnosis. However, a tumor marker panel may represent a helpful adjunct to cytology in order to rule in malignancy as a probable diagnosis, thus guiding the selection of patients who might benefit from further invasive procedures.

Diagnostic performance of adenosine deaminase activity in pleural fluid: a single-center experience with over 2100 consecutive patients

OBJECTIVE

To determine the diagnostic utility of adenosine deaminase (ADA) in a large series of pleural effusions of different etiologies.

METHODS

A retrospective study of 2104 consecutive patients presenting with pleural effusion was carried out at a Spanish university hospital. ADA levels in pleural fluid were determined using a non-Giusti automatic kinetic assay, and a receiver operating characteristics curve analysis was applied to estimate their discriminative properties.

RESULTS

Pleural tuberculosis (TB) accounted for 221 (10.5%) effusions. Pleural fluid ADA >35U/L yielded 93% sensitivity, 90% specificity, a positive likelihood ratio (LR) of 10.05 and a negative LR of 0.07 for the diagnosis of TB among lymphocytic exudates. The ADA activity was significantly higher in neutrophil- (111.6U/L) than in lymphocyte-rich (62.4U/L; p=0.002) TB effusions. Overall, more than 40% of parapneumonics and half of lymphomatous effusions exceeded the cutoff set for TB. These were the only causes of ADA activity above 250U/L. When the prevalence of TB as a cause of exudative effusions is low (e.g., 1%), the estimated positive predictive value of the ADA test may be as low as 7%, although the negative predictive value remains high (99.9%).

CONCLUSION

Where available, pleural ADA should be routinely used to rule TB in or out in areas with moderate to high or low TB prevalence, respectively. A high ADA level is a characteristic not only of lymphocytic, but also of neutrophilic TB effusions. An extremely high ADA activity should raise suspicion of empyema or lymphoma.

Biomarkers of infection for the differential diagnosis of pleural effusions

We aimed to investigate whether pleural fluid concentrations of biomarkers for bacterial infection, namely triggering receptor expressed on myeloid cells (sTREM-1), procalcitonin (PCT), lipopolysaccharide-binding protein (LBP) and C-reactive protein (CRP), might identify infectious effusions and discriminate between complicated (CPPEs) and uncomplicated parapneumonic effusions (UPPEs). Stored pleural fluid samples from 308 patients with different causes of pleural effusion were used to measure the four biomarkers. Receiver-operating characteristic analysis determined the accuracy of the new tests. Median pleural fluid levels of CRP, sTREM-1 and LBP were significantly higher in CPPE compared with those in other aetiologies. The area under the curve for distinguishing infectious (parapneumonics and tuberculosis) from noninfectious effusions was 0.87 for CRP, 0.86 for sTREM-1, 0.57 for PCT and 0.87 for LBP. Regarding the discrimination of nonpurulent CPPE versus UPPE, a multivariate analysis found that pleural fluid glucose < or =60 mg x dL(-1), LBP > or =17 microg x mL(-1) and CRP > or =80 mg x L(-1) were the best parameters. Individually, none of the new biomarkers achieved better performance characteristics than pH, glucose or lactate dehydrogenase in labelling CPPE. In conclusion, elevated pleural fluid levels of CRP, sTREM and LBP identify patients with infectious effusions, particularly those with CPPE. PCT has no value for the differential diagnosis of pleural effusions.

Prognostic significance of pleural fluid data in patients with malignant effusion

BACKGROUND

To determine the effects of the biochemical and cytological properties of the pleural fluid (PF) on the survival of patients with malignant pleural effusion (MPE).

METHODS

A retrospective study of 284 patients with MPE was performed, which measured overall survival, survival of patients with different types of primary tumors, and survival as a function of PF biochemical variables transformed into quartiles.

RESULTS

Median overall survival of MPE patients was 5.4 months following diagnosis. Survival varied significantly depending on the type of the primary tumor: 17.4 months for mesothelioma, 13.2 months for breast cancer, 7 months for lymphoma and 2.6 months for lung cancer. A multivariate analysis of PF biochemical parameters showed that survival was lower as the concentration of lactate dehydrogenase (LDH) increased (11.3 months if LDH was between 140 U/L and 358 U/L vs 2.8 months if LDH was between 1027 U/L and 10,110 U/L) or the concentration of pleural proteins decreased (9.4 months if proteins were between 4.92 g/dL and 7.94 g/dL vs 2.2 months if proteins were between 0.97 g/dL and 3.85 g/dL). We also found that when mesotheliomas were excluded from the analysis, survival was lower in patients with a PF pH lower than 7.3 (2.4 months vs 6.8 months, p=0.03).

CONCLUSIONS

Tumor type as well as some biochemical features of the pleural fluid, such as pH and concentrations of proteins and LDH, influence survival in patients with MPE.

Solving the Light's criteria misclassification rate of cardiac and hepatic transudates

BACKGROUND AND OBJECTIVE

Pleural transudates are most commonly due to heart failure (HF) or hepatic hydrothorax (HH), but a number of these effusions are misclassified as exudates by standard (Light's) criteria. The aim of this study was to determine the prevalence of mislabelled transudates and to establish simple alternative parameters to correctly identify them.

METHODS

We retrospectively analysed the pleural fluid and serum protein, lactate dehydrogenase and albumin concentrations from 364 cardiac effusions and 102 HH. The serum-to-pleural fluid protein and albumin gradients (serum concentration minus pleural fluid concentration), as well as the pleural fluid-to-serum albumin ratio (pleural fluid concentration divided by the serum concentration) were calculated for the mislabelled transudates.

RESULTS

Light's criteria had misclassified more HF-associated effusions than HH (29% vs 18%, P = 0.002). A serum-to-pleural fluid protein gradient >3.1 g/dL correctly identified 55% and 61% of the HF and HH false exudates, respectively. The figures for an albumin gradient >1.2 g/dL were 83% and 62%. Finally, a pleural fluid-to-serum albumin ratio <0.6 had identical accuracy for labelling miscategorized cardiac and liver-related effusions (78% and 77%, respectively).

CONCLUSIONS

If the clinical picture is consistent with HF but the pleural fluid meets Light's exudative criteria, the measurement of the albumin rather than the protein gradient is recommended. In the context of cirrhosis, a potentially 'false' exudate is identified better by the pleural fluid-to-serum albumin ratio.

Vitamin D Deficiency Is Associated with the Presence and Severity of Diabetic Retinopathy in Type 2 Diabetes Mellitus

There is very few evidences on the role of vitamin D in the development of diabetic retinopathy. The aim of the current study was to explore whether there is an association of vitamin D status and diabetic retinopathy in type 2 diabetes. Two groups of patients were selected: 139 and 144 patients with and without retinopathy, respectively, as assessed by an experienced ophthalmologist. Subjects with advanced late diabetic complications were excluded to avoid confounding biases. 25-Hydroxy-vitamin D3 (25(OH)D) concentrations and vitamin D deficiency were associated with the presence of diabetic retinopathy. Additionally, patients with more advanced stages of retinopathy (grades 2-4) had lower concentrations of 25(OH)D and were more frequently vitamin D deficient as compared with patients not carrying this eye complication. In conclusion, our study confirms the association of vitamin D deficiency with the presence and severity of diabetic retinopathy in type 2 diabetes. Further experimental and prospective studies on this issue are clearly warranted.

Contribution of a Pleural Antigen Assay (Binax NOW) to the Diagnosis of Pneumococcal Pneumonia

STUDY OBJECTIVES

To determine whether the detection of pneumococcal antigen in pleural fluid augments conventional microbiological methods used for the etiologic diagnosis of pneumonia.

METHODS

In this retrospective study, a rapid immunochromatographic test (ICT) [NOW Streptococcus pneumoniae assay; Binax; Scarborough, ME] was performed on pleural fluid samples from 34 patients with pneumonia due to S pneumoniae, 89 patients with effusions of nonpneumococcal origin, and 17 patients with pneumonia of unknown etiology. Data on blood cultures, pleural fluid cultures, and urinary antigen tests were recorded.

RESULTS

The ICT test result was positive in 24 of 34 patients (70.6%) with pneumococcal pneumonia and negative in 83 of 89 patients (93.3%) without pneumococcal pneumonia. The sensitivity of the pleural ICT test was higher than that obtained for blood (37.5%) and pleural fluid cultures (32.3%), but lower than the detection of pneumococcal antigen in urine samples (82.1%). However, three patients with pneumococcal pneumonia and a negative ICT urine test result had a positive pleural fluid antigen detection result test. Previous antibiotic exposure did not influence pneumococcal antigen detection in either pleural fluid or urine specimens. Six additional patients with empyema due to anaerobes (three patients), Streptococcus viridans (two patients), and Enterococcus faecalis (one patient) had false-positive pleural ICT test results. Finally, the ICT assay finding was also positive in 5 of 17 patients (29.4%) with pneumonia without a definite microbiological cause.

CONCLUSIONS

The ICT test performed on pleural fluid samples augments the standard diagnostic methods of blood and pleural fluid cultures, even in the case of prior antibiotic therapy, and enhances the ICT urinary antigen assay.

Insulin secretion in patients with latent autoimmune diabetes (LADA): half way between type 1 and type 2 diabetes: action LADA 9

BACKGROUND

The study of endogenous insulin secretion may provide relevant insight into the comparison of the natural history of adult onset latent autoimmune diabetes (LADA) with types 1 and 2 diabetes mellitus. The aim of this study was to compare the results of the C-peptide response to mixed-meal stimulation in LADA patients with different disease durations and subjects with type 2 and adult-onset type 1 diabetes.

METHODS

Stimulated C-peptide secretion was assessed using the mixed-meal tolerance test in patients with LADA (n = 32), type 1 diabetes mellitus (n = 33) and type 2 diabetes mellitus (n = 30). All patients were 30 to 70 years old at disease onset. The duration of diabetes in all groups ranged from 6 months to 10 years. The recruitment strategy was predefined to include at least 10 subjects in the following 3 disease onset categories for each group: 6 to 18 months, 19 months to 5 years and 5 to 10 years.

RESULTS

At all time-points of the mixed-meal tolerance test, patients with LADA had a lower stimulated C-peptide response than the type 2 diabetes group and a higher response than the type 1 diabetes group. The same results were found when the peak or area under the C-peptide curve was measured. When the results were stratified by time since disease onset, a similar pattern of residual insulin secretory capacity was observed.

CONCLUSIONS

The present study shows that the magnitude of stimulated insulin secretion in LADA is intermediate between that of type 1 and type 2 diabetes mellitus.

Latent autoimmune diabetes in adults is perched between type 1 and type 2: evidence from adults in one region of Spain

BACKGROUND

The aim of this study was to characterize the clinical characteristics and insulin secretion in adults with latent autoimmune diabetes in adults (LADA). We also compared these characteristics in subjects with antibody-negative type 2 diabetes (T2DM) or adult-onset type 1 diabetes (T1DM) to subjects with LADA.

METHODS

In this cross-sectional study, 82 patients with LADA, 78 with T1DM and 485 with T2DM were studied. Clinical and metabolic data, in particular those that related to metabolic syndrome, fasting C-peptide and islet-cell autoantibodies [glutamic acid decarboxylase (GADAb) and IA2 (IA2Ab)] were measured.

RESULTS

The frequency of metabolic syndrome in patients with LADA (37.3%) was higher than in those with T1DM (15.5%; p = 0.005) and lower than in patients with T2DM (67.2%; p < 0.001). During the first 36 months of the disease, the C-peptide concentration in LADA patients was higher than in subjects with T1DM but was lower than in T2DM patients (p < 0.01 for comparisons). Glycemic control in LADA patients (HbA1c 8.1%) was worse than in patients with T2DM (HbA1c 7.6%; p =0.007). An inverse association between GADAb titers and C-peptide concentrations was found in subjects with LADA (p < 0.001). Finally, LADA patients rapidly progressed to insulin treatment.

CONCLUSIONS

As in other European populations, patients with LADA in Spain have a distinct metabolic profile compared with patients with T1DM or T2DM. LADA is also associated with higher impairment of beta-cell function and has worse glycemic control than in T2DM. Beta cell function is related to GADAb titers in patients with LADA.

Usefulness of the British Thoracic Society and the American College of Chest Physicians guidelines in predicting pleural drainage of non-purulent parapneumonic effusions

AIM

To assess the value of the British Thoracic Society (BTS) and the American College of Chest Physicians (ACCP) guidelines to predict which patients with non-purulent parapneumonic effusions (PPE) warrant chest tube drainage.

METHODS

A retrospective chart review was performed on all patients who underwent thoracentesis because of a PPE over a 10-year period at a Spanish medical center. Classification of PPE as complicated (CPPE) or uncomplicated (UPPE) was based on the clinician's decision to insert a chest tube to resolve the effusion. Empyema was defined as pus in the pleural space. Data collected included patient demographics, size of the effusion, and microbiological and pleural fluid chemistries that might influence the physician's decision to place a chest tube.

RESULTS

Of the 240 patients with PPE who entered the study, 85 had UPPE, 67 had CPPE, and 88 had empyema. Individual pleural fluid parameters, namely a pH<7.20, a glucose<40 mg/dL or <60 mg/dL, a LDH>1000 U/L or a positive culture had a relatively high specificity (from 78% for LDH to 94% for glucose<40 mg/dL), but low to moderate sensitivity (from 25% for culture to 73% for LDH) in predicting the need for chest tube placement in non-purulent PPE. While pleural fluid cultures performed poorly in discriminating UPPE from CPPE (likelihood ratio positive 1.7), effusion's size performed the best (likelihood ratio positive 5.7). BTS and ACCP guidelines yielded measures of sensitivity (98% and 97%, respectively), and negative likelihood ratio (0.03 and 0.05, respectively) for identifying a CPPE.

CONCLUSIONS

Both guidelines have similar accuracy and perform satisfactorily in distinguishing CPPE from UPPE, albeit at an admissible cost of needlessly increasing chest tube drainage.

Analysis of pleural effusions in acute pulmonary embolism: Radiological and pleural fluid data from 230 patients

BACKGROUND AND OBJECTIVE

The aims of this study were to describe the frequency and radiographical characteristics of pleural effusions in a large population of patients with acute pulmonary embolism (PE) and characterize the pleural fluid biochemistry in those patients who underwent diagnostic thoracentesis.

METHODS

This was a retrospective observational single-centre study. A total of 230 consecutive patients with a diagnosis of PE over a 9-year period were enrolled. Spiral CT pulmonary angiography (52%) and high-probability ventilation and perfusion scans (42%) were used as the main reference methods.

RESULTS

Pleural effusions were observed in 32% and 47% of patients by CXR and CT, respectively. Typically, pleural effusions were small (90% occupied less than one third of the hemithorax) and unilateral (85%), but occasionally they reached more than a half of the hemithorax. On CT, 21% of pleural effusions showed loculation. In patients with loculated pleural fluid the diagnosis of PE had been delayed for a mean of 12.2 days after symptoms developed. The presence of pleural fluid was not related to infarction. Twenty-six of 93 (28%) patients with effusions on imaging underwent thoracentesis. All the fluids met Light's criteria for exudate, 58% contained erythrocyte counts >10,000/microL and 46% showed neutrophilic predominance.

CONCLUSIONS

Small pleural effusions, mostly unsuitable for diagnostic thoracentesis, were present in about one third of patients with PE. All the pleural effusions due to PE were exudates. If PE diagnosis was delayed the pleural effusion tended to become loculated.

Pleural fluid C-reactive protein contributes to the diagnosis and assessment of severity of parapneumonic effusions

BACKGROUND AND AIMS

Prompt identification of parapneumonic effusions has immediate therapeutic benefits. We aimed to assess whether C-reactive protein (CRP) and routine biochemistries in pleural fluid are accurate markers of parapneumonic effusions, and to evaluate their properties as indicators for drainage (complicated parapneumonic effusion).

METHODS

A retrospective review of 340 non-purulent parapneumonic effusions and 1,659 non-parapneumonic exudates from a single center was performed and the discriminative properties of pleural fluid routine biochemistries and, when available, CRP were evaluated. CRP, along with classical fluid parameters, was also applied to classify patients as having complicated or uncomplicated parapneumonic effusions. ROC analysis established the threshold of CRP for discriminating between groups.

RESULTS

Pleural fluids with neutrophilic predominance and CRP levels >45 mg/dL were most likely to be parapneumonic in origin (likelihood ratio=7.7). When attempting to differentiate non-purulent complicated from uncomplicated effusions, a CRP >100mg/L had the same performance characteristics (area under the curve=0.81) as the widely accepted biochemistries pH and glucose. Combinations of CRP with pH or glucose resulted in incrementally discriminating values, pertaining to either sensitivity (75-80%) or specificity (97%), for complicated effusions.

CONCLUSION

Pleural fluid CRP may be a useful adjunctive test in pleural effusions, both as a marker of parapneumonics and, particularly, as a differentiator between complicated and uncomplicated effusions.

Tumor Necrosis Factor-α in Pleural Fluid

STUDY OBJECTIVES

We sought to determine whether pleural fluid tumor necrosis factor (TNF)-alpha is a more accurate parameter to identify nonpurulent complicated parapneumonic effusion (CPPE) than the classical chemistries, namely pH, glucose, or lactate dehydrogenase (LDH).

METHODS

We studied 80 consecutive patients with parapneumonic effusions (35 with uncomplicated parapneumonic effusion [UPPE], 23 with nonpurulent CPPE, and 22 with empyema). Concentrations of standard biochemical parameters together with TNF-alpha were measured in pleural fluid, the latter by using an immunoenzymometric assay.

RESULTS

Pleural TNF-alpha was significantly higher in CPPE (133.0 pg/mL) and empyema (142.2 pg/mL) than in UPPE (39.1 pg/mL). A cut-off value of 80 pg/mL for pleural TNF-alpha resulted in a sensitivity, specificity, and area under receiver operating characteristic curve (AUC) of 78%, 89%, and 0.87, respectively, for the diagnosis of nonpurulent CPPE. A multivariate analysis selected both pleural TNF-alpha > or = 80 pg/mL and LDH > or = 1,000 U/L (sensitivity, 74%; AUC = 0.86), but excluded pleural glucose < or = 60 mg/dL (sensitivity, 39%; AUC = 0.82) and pH < or = 7.20 (sensitivity, 41%; AUC = 0.78), for identifying the need for drainage. The combined sensitivity of pleural fluid TNF-alpha and LDH was found to be 91%.

CONCLUSIONS

Pleural TNF-alpha may contribute to the identification of patients with nonpurulent CPPE with at least the same diagnostic accuracy, if not better, than the use of pH, glucose, or LDH.

Xpert® MTB/RIF in pleural fluid for the diagnosis of tuberculosis

An automated nucleic acid amplification assay that simultaneously identifies Mycobacterium tuberculosis and rifampicin resistance, the Xpert® MTB/RIF test, has undergone extensive evaluation in sputum samples. Our aim was to define its diagnostic accuracy when performed on pleural fluid specimens. In 67 patients with pleural effusions, of whom half had tuberculous pleuritis, Xpert yielded 15% sensitivity and 100% specificity in the detection of tuberculosis (TB). Positive Xpert results tended to be more common in patients with microbiologically confirmed TB. Due to its low sensitivity, Xpert testing of pleural fluids has a limited role in the work-up of pleural effusions.

Antinuclear antibody testing in pleural fluid for the diagnosis of lupus pleuritis

We sought to determine whether measuring antinuclear antibodies (ANA) and their specificities [dsDNA, extractable nuclear antigens (ENA)] on pleural fluid may contribute to the differential diagnosis of pleural effusions. ANA were tested by indirect immunofluorescence on Hep-2 cells in the pleural fluid of 266 patients with effusions of different etiologies, including 15 lupus pleuritis. The cutoff value for diagnostic use was set at 1: 160. Pleural fluid analysis of specific autoantibodies, such as anti-dsDNA and anti-ENA, was also performed if a positive ANA test was obtained. All patients with lupus pleurisy and 16 of 251 (6.4%) patients with pleural effusions secondary to other causes were ANA positive. Fifty-six percent of the positive ANAs in non-lupus pleural fluids were due to neoplasms. The pleural fluid ANA titers were low (≤1: 80) or absent in two patients with systemic lupus erythematosus (SLE) and effusions due to other factors. Whereas ANA staining patterns in pleural fluid did not help to discriminate lupus pleuritis from non-lupus etiologies, the absence of pleural fluid anti-dsDNA or anti-ENA favored the latter. ANAs in pleural fluid provided no additional diagnostic information beyond that obtained by the measurement in serum and, therefore, these tests need not be routinely performed on pleural fluid samples. However, in patients with SLE and a pleural effusion of uncertain etiology, lack of ANAs or specific autoantibodies in pleural fluid argues against the diagnosis of lupus pleuritis.

Comparing serum and pleural fluid pro-brain natriuretic peptide (NT-proBNP) levels with pleural-to-serum albumin gradient for the identification of cardiac effusions misclassified by Light's criteria

BACKGROUND AND OBJECTIVES

To assess the diagnostic performance of the amino-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) in pleural fluid and serum for the identification of pleural effusions owing to heart failure, and to determine if these measurements allow better categorization of cardiac effusions that have been misclassified by Light's criteria, than do serum-pleural fluid albumin and protein gradients.

METHODS

The study prospectively evaluated NT-proBNP in serum and pleural fluid from patients with effusions owing to heart failure (n = 53) and other causes (n = 40). Measurements were made of levels of NT-proBNP by an electrochemiluminiscence immunoassay, and serum-pleural fluid protein and albumin gradients.

RESULTS

Using a cut-off value of 1500 pg/mL for serum and pleural samples, the accuracy of NT-proBNP for identifying pleural effusions from cardiac causes was 89% and 90%, respectively. The area under the receiver operating characteristic curve for the diagnosis of pleural effusions from heart failure was similar for pleural fluid (0.931, 95% CI: 0.871-0.991) and serum (0.919, 95% CI: 0.855-0.984) NT-proBNP. Six (75%) of eight patients with cardiac effusions that were misclassified as exudates by Light's criteria would have been correctly categorized by either NT-proBNP or the albumin gradient, whereas only four (50%) would have been correctly classified by the protein gradient.

CONCLUSIONS

NT-proBNP is a useful marker for the diagnosis of pleural effusions from heart failure when measured in either serum or pleural fluid. At a cut-off of 1500 pg/mL, NT-proBNP is at least as accurate as the albumin gradient to correctly identify cardiac effusions misclassified as exudates by standard criteria, but at much higher cost.

Low-grade Inflammatory Marker Profile May Help to Differentiate Patients With LADA, Classic Adult-Onset Type 1 Diabetes, and Type 2 Diabetes

OBJECTIVE

To test whether differences in serum concentrations of adiposity-related low-grade inflammatory mediators could help to differentiate patients with latent autoimmune diabetes in adults (LADA), classic adult-onset type 1 diabetes, and type 2 diabetes.

RESEARCH DESIGN AND METHODS

This cross-sectional study involved 75 patients with LADA, 67 with classic adult-onset type 1 diabetes, and 390 with type 2 diabetes. Serum concentrations of adiponectin, soluble tumor necrosis factor-α receptor 2 (sTNFRII), interleukin-6, hs-CRP, and total leukocyte number were measured. To evaluate the differences of these markers among diabetes types, we performed logistic regression models and evaluated area under the receiver-operating characteristic curve (AUC_ROC) values.

RESULTS

The profile of innate immunity-related inflammatory markers correlated with metabolic syndrome components. LADA versus classic adult-onset type 1 diabetes was independently related to sTNFRII (odds ratio [OR] 1.9 [95% CI 1.01-3.97]; P = 0.047) and hs-CRP levels (OR 0.78 [95% CI 0.62-0.96]; P = 0.019), and a higher number of total leukocytes lowered the risk of LADA compared with type 2 diabetes (OR 0.98 [95% CI 0.97-0.99]; P = 0.036). The logistic regression model including explanatory biomarkers explained 35% of the variation for LADA versus classic adult-onset type 1 diabetes (AUC_ROC 0.83 [95% CI 0.74-0.92]; P < 0.001) and 15% of the variation for LADA versus type 2 diabetes (AUC_ROC 0.73 [95% CI 0.70-0.80]; P < 0.001).

CONCLUSIONS

Inflammatory, adiposity, and immune-related markers could help to differentiate a LADA diagnosis from that of classic adult-onset type 1 diabetes, and also LADA from that of type 2 diabetes, along with islet autoantibody positivity.

High levels of tumor markers in pleural fluid correlate with poor survival in patients with adenocarcinomatous or squamous malignant effusions

BACKGROUND

The aim of this study was to determine whether several pleural fluid (PF) tumor markers, either alone or in combination, could be used to predict survival time of patients with malignant pleural effusion secondary to adenocarcinoma or squamous cell carcinoma.

METHODS

A total of 224 patients with confirmed metastatic pleural malignancies due to adenocarcinoma or squamous cell carcinoma were enrolled. PF tumor markers were determined either by electrochemiluminescence immunoassay (CEA, CA 15-3, CYFRA 21-1) or microparticle enzyme immunoassay (CA 125) technologies. Cutoff points that predicted death during the first month after diagnoses, with a specificity of 60%, were selected for each marker, using receiver operating characteristic analysis.

RESULTS

In patients with adenocarcinomatous or squamous malignant effusion, the combination of PF CA 125>or=1000 U/mL and CYFRA 21-1>or=100 ng/mL predicted a lower survival (4 vs. 11.7 months, p=0.03; and 0.3 vs. 8.4 months, p=0.003 respectively). This tumor marker combination remained as an independent predictor of poor outcome when adjusted for age and tumor type.

CONCLUSION

High PF tumor marker levels identify a subgroup of patients with a shorter median survival.

Rapid pleurodesis with doxycycline through a small-bore catheter for the treatment of metastatic malignant effusions

GOALS OF WORK

The goal of the study was to evaluate the safety and efficacy of bedside pleurodesis with doxycycline using a short-term indwelling chest catheter for the palliative treatment of malignant effusions.

MATERIALS AND METHODS

A prospective study of 36 rapid pleurodesis procedures in 34 patients with malignant pleural effusions was conducted over a 5-year period in a university hospital. A 12F chest catheter placement was facilitated utilizing the Seldinger percutaneous entry technique. Patients received 500 mg of intrapleural doxycycline combined in half of the cases with mepivacaine. We assessed success or failure of pleurodesis in addition to the frequency of complications and survival.

MAIN RESULTS

Chest tubes were removed within 24 h in 69% and within 48 h in 94% of the patients. Complete success of pleurodesis was achieved in 17 (55%), partial success in eight (26%), and failure in six (19%) out of 31 evaluative procedures. Thus, the overall success rate of pleurodesis was 81%. Toxicity was mild and included pain (36%), fever (8%), and pneumothorax (6%). The median survival was 105 days. There was no relationship between instillation of intrapleural anesthetics and development of pain.

CONCLUSIONS

Rapid pleurodesis with doxycycline, which can be accomplished within 24 to 48 h, is a valid option for the symptomatic treatment of malignant effusions. This technique can be used as a first-line procedure in the majority of cases, particularly if thoracoscopic facilities are not available.