C-reactive protein in lymphocytic pleural effusions: a diagnostic aid in tuberculous pleuritis

BACKGROUND: C-reactive protein (CRP) pleural fluid levels have been found to be higher in tuberculosis and parapneumonic effusions than in other causes of pleural effusion. OBJECTIVE: The aim of this study was to analyze whether CRP (a simple and inexpensive test) may be a diagnostic aid for tuberculosis in lymphocytic pleural effusions. METHODS: One hundred and forty-four patients with a lymphocytic pleural effusion (more than 50% lymphocytes in the differential white blood cell count) were included. The patients were 93 men (65%) and 51 women (35%), aged 64 +/- 18 years (mean +/- SD). The diagnoses were as follows: tuberculosis, 20; pleural effusion associated with malignancy, 69; transudates, 38; other benign exudates, 17. RESULTS: The CRP pleural fluid level was higher in tuberculous pleuritis (54 +/- 24 mg/l) than in lymphocytic effusions of other origin (21 +/- 16 mg/l; p < 0.001). High CRP levels (>or=50 mg/l) have a high specificity for tuberculosis (95%), and low levels (<30 mg/l) have a high sensitivity (95%) for excluding disease. CONCLUSIONS: CRP pleural fluid level determination is useful in the diagnostic workup of lymphocytic pleural effusions. High CRP levels are very suggestive of tuberculous pleuritis, and low CRP levels make this diagnosis unlikely.     

Use of pleural fluid C-reactive protein in diagnosis of pleural effusions

The aims of the study were to assess whether C-reactive protein (CRP) is a sensitive marker for discriminating between transudative and exudative and pleural effusions to evaluate whether it can be used to distinguish inflammatory pleural effusions from other types of effusion. Pleural fluid and serum CRP levels were obtained in 97 patients with pleural effusion, using an immunoturbidimetric method (Olympus AU-600 autoanalyser). We compared CRP levels between transudates and exudates, inflammatory effusions and other types of effusion. According to the criteria used, 16 patients were included in the transudate group and 81 patients in the exudate group. Pleural fluid CRP levels were significantly lower in the transudate group (P<0.04; 14.9 +/- 4.9 mg l(-1) and 35.5 +/- 4.9 mg l(-1) respectively). Also, the ratio of pleural fluid to serum was significantly lower in the transudate group (P<0.009; 0.8 +/- 0.5 mg l(-1) and 2.8 +/- 0.7 mg l(-1), respectively). In the exudate group, 35 patients had neoplastic effusions, 10 chronic non-specific pleurisy, 19 tuberculous pleurisy, 16 parapneumonic effusion and one Dressler Syndrome. When these sub-groups were compared, the parapneumonic effusion subgroup CRP levels (mean 89 +/- 16.3 mg l(-1)) were significantly higher than those in the other subgroups, other exudate of neoplastic effusion, tuberculous pleurisy and chronic non-specific effusion and the transudate group (P<0.0001; P<0.0001; P<0.0004 and P<0.0001, respectively). The ratio between pleural fluid and serum CRP was significantly higher in the parapneumonic effusion subgroup than in the neoplastic subgroup (P<0.0002; 6.6 +/- 2.7 mg l(-1) and 1 +/- 0.2 mg l(-1), respectively). Pleural fluid CRP levels > 30 mg l(-1) had a high sensitivity (93.7%) and specificity (76.5%) and a positive predictive value of 98.4%. In the differential diagnosis of pleural effusions, higher CRP levels may prove to be a rapid, practical and accurate method of differentiating parapneumonic effusions from other exudate types. Although the high level of CRP obtained in the exudate group may be due to the number of patients with parapneumonic effusion who were included, the pleural CRP level may also be helpful in discriminating between exudative and transudative pleural effusions.     

Useful tests on the pleural fluid in the management of patients with pleural effusions.

Examination of the pleural fluid is useful in establishing the etiology of a pleural effusion. Transudative pleural effusions can be differentiated from exudative pleural effusions by measuring the levels of protein and lactic acid dehydrogenase in the pleural fluid and serum. If a patient clinically appears to have a transudative pleural effusion, but the pleural fluid meets exudative criteria, demonstration that the albumin levels is more than 1.2 gm/dl higher in the serum than in the pleural fluid provides evidence that the effusion is transudative. The gross appearance of the pleural fluid should always be noted. Other tests that routinely should be obtained on exudative pleural fluids are Gram stain and cultures, cell counts and differential, glucose, amylase, lactic acid dehydrogenase, cytology, and a marker for tuberculous pleuritis. The diagnosis of tuberculous pleuritis is strongly suggested by a pleural fluid adenosine deaminase level above 45 IU/L or a gamma interferon level above 3.7 U/ml.     

Diagnostic value of C-reactive protein in exudative pleural effusions

BACKGROUND: Tests able to help in the diagnostic work-up of pleural exudates are needed. C-reactive protein (CRP) may be useful for distinguishing between benign and malignant exudates. METHODS: A total of 123 consecutive patients diagnosed as having exudative pleural effusion (60 associated with malignancy and 63 benign effusions) were included in the study. Sensitivity, specificity, positive and negative predictive values (PV+, PV-), and positive and negative likelihood ratios (LR+, LR-) were established at different cut-off points. RESULTS: Pleural fluid CRP level was 23+/-12 mg/l (mean+/-S.D.) in pleural exudates associated with malignancy and 50+/-33 mg/l in benign effusions (P<0.001). With a cut-off point below 20 mg/l for malignancy, sensitivity of CRP was 0.50, specificity 0.89, PV+ 0.81, PV- 0.65, LR+ 4.50, and LR- 0.65. With a cut-off point above 45 mg/l for benign diseases, sensitivity was 0.44, specificity 0.95, PV+ 0.90, PV- 0.62, LR+ 8.89, and LR- 0.58. CONCLUSIONS: The pleural CRP level provides useful information for the study of pleural exudates. A level below 20 mg/l suggests a malignant origin and a level above 45 mg/l virtually rules out this possibility. Additional advantages of measuring CRP level are that it is an inexpensive test and is easy to perform.     

Usefulness of pleural effusion antinuclear antibodies in the diagnosis of lupus pleuritis

We performed this study to determine sensitivity and specificity of pleural effusion antinuclear antibodies (ANA) at a titer of ≥1?:?160, and the ratio of pleural effusion to serum ANA of ≥1, to distinguish between pleural fluid from lupus pleuritis and other causes. A prospective study of 54 patients with pleural effusion (12 lupus pleuritis, seven parapneumonic effusion, 26 malignancy-associated pleural effusions, nine transudative effusions) was performed. ANA at a titer of ≥1?:?160 were found in 11 of 12 lupus pleuritis samples, and in four of 42 pleural effusions from non-systemic lupus erythematosus (SLE) patients. The pleural effusion ANA at a titer of ≥1?:?160 gave a sensitivity of 91.67% for lupus pleuritis, with a specificity of 83.33% when compared with all other pleural effusions, 90.91% when compared with exudative effusion (parapneumonic effusion and malignancy-associated effusion) and 55.56% when compared with the transudative pleural effusion group. Using the ratio of pleural effusion to serum ANA of ≥1, the sensitivity and the specificity decreased to 75.00% and 78.57%, respectively. This study provides further evidence that the pleural effusion ANA at a titer of ≥1?:?160 is a sensitive and specific diagnostic biomarker for lupus pleuritis in patients with lupus. However, pleural effusion ANA can occasionally be found in other conditions.     

Diagnostic value of adenosine deaminase in nontuberculous lymphocytic pleural effusions.

Adenosine deaminase (ADA) can aid in the diagnosis of tuberculous pleural effusions, but false-positive findings from lymphocytic effusions have been reported. The purpose of this study is to assess the ADA levels in nontuberculous lymphocytic pleural effusions (lymphocyte count > 50%) of different aetiologies. Altogether, 410 nontuberculous lymphocytic pleural fluid samples were consecutively selected. These included malignant effusions (n = 221), idiopathic effusions (n = 76), parapneumonic effusions (n = 35), postcoronary artery bypass graft surgery effusions (n = 6), miscellaneous exudative effusions (n = 21) and transudative effusions (n = 51). The ADA level reached the diagnostic cut-off for tuberculosis (40 U x L(-1)) in seven of the 410 cases (1.71%). The negative predictive value of ADA for the diagnosis of pleural tuberculosis was 99% (403 of 407 cases) in the group of lymphocytic pleural effusions. In five of these seven patients ADA1 and ADA2 were measured, and in all these cases (100%) ADA1/ADA(p) correctly classified these lymphocytic effusions as nontuberculous (ratio < 0.42). This prospective study provides additional evidence that adenosine deaminase levels in nontuberculous lymphocytic pleural effusions seldom exceed the cut-off set for tuberculous effusions. The pleural fluid adenosine deaminase levels were significantly higher in different types of exudative effusions than in transudates. An adenosine deaminase level < 40 IU x L(-1) virtually excluded a diagnosis of tuberculosis in lymphocytic pleural effusions. Adenosine deaminase1/adenosine deaminase(p) correctly classified all nontuberculous lymphocytic pleural effusions with high adenosine deaminase levels.     

Diagnostic significance of interferon-gamma in tuberculous pleural effusions

STUDY OBJECTIVES: Tuberculosis (TB), the single most frequent infectious cause of death worldwide, also is a major cause of pleural effusion, which in TB usually has lymphocytic and exudative characteristics. Differential diagnosis between TB and nontuberculous pleural effusion can be sometimes difficult, representing a critically important clinical problem. METHODS: We studied 46 patients presenting with pleural effusion to the National Sanyo Hospital between April 2000 and January 2001 (34 men and 12 women; mean age, 64 years). Ten patients (22%) had tuberculous pleurisy, 19 patients (41%) had malignant pleuritis, and 17 patients (37%) had pleural effusion due to an etiology other than tuberculosis or cancer. Pleural fluid concentrations of four suggested markers were measured using commercially available kits. RESULTS: The pleural fluid levels (mean +/- SE) of adenosine deaminase (83.3 +/- 18.2 U/L vs 25.8 +/- 20.4 U/L, p < 0.0001), interferon-gamma (137 +/- 230 IU/mL vs 0.41 +/- 0.05 IU/mL, p < 0.0001), immunosuppressive acidic protein (741 +/- 213 micro g/mL vs 445 +/- 180 micro g/mL, p < 0.001) and soluble interleukin 2 receptor (7,618 +/- 3,662 U/mL vs 2,222 +/- 1,027 U/mL, p < 0.0001) were significantly higher for tuberculous pleuritis than for other causes of effusion. Receiver operating characteristic analysis demonstrated that pleural fluid content INF-gamma was the best indicator of tuberculous pleurisy among four relevant biological markers. CONCLUSIONS: INF-gamma in pleural fluid is the most sensitive and specific among four biological markers for tuberculous pleuritis. Thus, our results suggest that determination of INF-gamma at the onset of pleural effusion is informative for the diagnosis of tuberculous pleuritis. Further studies including larger numbers of patients are needed to verify this result.     

Tumour necrosis factor-alpha in comparison to adenosine deaminase in tuberculous pleuritis

BACKGROUND: Adenosine deaminase (ADA) is already used for the differential diagnosis of tuberculosis pleurisy. Tumour necrosis factor-alpha (TNF) is another marker which has been investigated for this purpose. OBJECTIVE: We evaluated the diagnostic value of pleural fluid and serum TNF concentrations in tuberculous pleuritis and compared them to ADA. METHODS: Sixty-two patients (24 tuberculous pleuritis, 38 non-tuberculous pleuritis) with exudative pleurisy were included. Serum and pleural fluid TNF concentrations were determined in all patients and ADA activity in 54 patients. Pleural fluid TNF concentrations and pleural fluid/serum TNF were compared to pleural fluid ADA activity and pleural fluid/serum ADA. RESULTS: When the tuberculous and non-tuberculous groups were compared, pleural fluid TNF concentrations (65.4 +/- 136.9 pg/ml vs. 54.5 +/- 144.2 pg/ml, respectively; p < 0.001), pleural fluid ADA activity (74.2 +/- 33.3 U/l vs. 23 +/- 16.3 U/l; p < 0.0001), pleural fluid/serum TNF (2.55 +/- 5.23 vs. 0.26 +/- 0.2; p < 0.001) and pleural fluid/serum ADA (4.58 +/- 8.14 vs. 1.15 +/- 0.7; p < 0.0001) were significantly higher in the tuberculous group. When cut-off points were assessed, 8 pg/ml and 40 U/l were found for pleural fluid TNF concentrations and pleural fluid ADA activity, respectively. Sensitivity, specificity, area under the curve were 87.5%, 76.3%, 0.772 for pleural fluid TNF concentrations and 90.9%, 89.5%, 0.952 for pleural fluid ADA activity, respectively; the difference between these areas under the curves was significant (p < 0.05). CONCLUSIONS: Pleural fluid TNF levels and pleural fluid/serum TNF were higher in tuberculous effusions than in other exudates, but their diagnostic value appears to be poorer than that of ADA.     

Transforming growth factor beta-1 level in pleural effusion

OBJECTIVE: Transforming growth factor-beta1 is an important immunomodulator. The diagnostic role of TGF-beta1 has not been systematically investigated in pleural effusion. METHODOLOGY: A prospective clinical study of 45 patients (23 men, 22 women; mean age 49 +/- 21 years) with pleural effusion was performed. Of these patients, 19 had malignant pleural effusion, 14 had tuberculous pleural effusion, seven had empyema/parapneumonic pleural effusion, and five had transudative pleural effusion due to congestive heart failure. The concentrations of TGF-beta1 were measured by ELISA in all pleural fluid samples and in serum samples only from patients with malignant and tuberculous pleural effusions. RESULTS: The median TGF-beta1 levels of malignant, tuberculous and empyema/parapneumonic pleural effusions were 7.25 ng/mL, 7.81 ng/mL, and 9.75 ng/mL, respectively. There was no significant difference between them. The median TGF-beta1 level was 5.62 ng/mL in the transudate pleural effusion group and it was significantly lower than that in the empyema/parapneumonic group (P < 0.05). The pleural fluid TGF-beta1 levels did not correlate with cell profiles of the pleural fluid. The median serum TGF-beta1 levels in malignant and tuberculous pleural effusion groups were 7.38 ng/mL and 7.38 ng/mL, respectively. There was no significant difference between the levels of TGF-beta1 in paired samples of serum and pleural fluid. CONCLUSIONS: This study shows that TGF-beta1 concentrations in exudative pleural effusions are higher than those in transudative effusions secondary to congestive heart failure but TGF-beta1 concentrations do not assist in differentiating exudative effusions.     

Evaluation of a new inflammatory molecule (triggering receptor expressed on myeloid cells-1) in the diagnosis of pleural effusion

BACKGROUND AND OBJECTIVE: The triggering receptor expressed on myeloid cell-1 (TREM-1) is a newly discovered molecule that is associated with the inflammatory response to microorganisms. We investigated the role of surface and soluble TREM-1 in differentiating different disease entities in pleural effusion formation. METHODS: Sixty-seven patients with pleural effusion due to transudate (14), malignancy (15), tuberculous pleuritis (16), para-pneumonic effusion (10) and empyaema (12) were included in this study. Surface TREM-1 was measured by flow cytometry and was expressed as mean fluorescence intensity and soluble TREM-1 was measured by ELISA and expressed as pg/mL. Results are given as mean levels +/- SEM. RESULTS: Surface TREM-1 was measured in 24 patients and the levels were highest in para-pneumonic effusion (30.0 +/- 8.4) and lowest in malignant pleural effusion (5.2 +/- 1.1) and tuberculous pleuritis (5.2 +/- 2.4). Soluble TREM-1 was highest in effusions of infectious aetiology (para-pneumonic effusion (979.4 +/- 229.6) and empyaema (1712.6 +/- 299.5)) and lowest in non-infectious effusions (transudate (81.2 +/- 4.5 pg/mL) and malignancy (111.3 +/- 20.7). At a cut-off value of 114 pg/mL, soluble TREM-1 yielded a sensitivity of 87.5% and a specificity of 89.7% in differentiating non-infectious effusion from tuberculous pleuritis. At a cut-off value of 374 pg/mL, sTREM-1 yielded a sensitivity of 93.8% and a specificity of 90.9 in differentiating tuberculous pleuritis from bacterial pleural effusion. Conclusion: Soluble and surface TREM-1 are valuable markers in establishing the aetiology of pleural effusions.     

Adenosine deaminase levels in nontuberculous lymphocytic pleural effusions

OBJECTIVES: Adenosine deaminase (ADA) can aid in the diagnosis of tuberculous pleural effusions, but false-positive findings from lymphocytic effusions have been reported. We studied the ADA levels in a variety of nontuberculous lymphocytic effusions and analyzed the relationships between ADA and conventional hematologic and biochemical parameters. METHODS: One hundred six lymphocytic pleural fluid samples (lymphocyte count > 50%) were analyzed. These included post-coronary artery bypass grafting (CABG) effusions (n = 45), malignant effusions (n = 27), miscellaneous exudative effusions (n = 10), and transudative effusions (n = 24). ADA levels were determined using the Giusti method. In 22 randomly selected cases, ADA was measured again on the same sample 6 weeks later. RESULTS: The ADA level reached the diagnostic cutoff for tuberculosis (40 U/L) in only three cases (2.8%): two lymphomas and one complicated parapneumonic effusion. There was no significant correlation between effusion ADA levels and the total leukocyte (r = 0.08), differential lymphocyte (r = 0.18) or monocyte (r = - 0.18) counts. ADA levels were significantly lower in the transudative effusions (7.2 +/- 3.5 U/L) than in post-CABG (16.6 +/- 7.2 U/L), malignant (15.3 +/- 11.2 U/L), and other exudative (15.4 +/- 13.1 U/L) effusions (p < 0.001). ADA measurements were consistent when assayed 6 weeks apart (r = 0.95; p < 0.00001; coefficient of variation, 14%). CONCLUSIONS: ADA levels in nontuberculous lymphocytic effusions seldom exceeded the diagnostic cutoff for TB. Effusion ADA levels cannot be predicted from total or differential leukocyte counts. Post-CABG pleural fluids had ADA levels similar to other nontuberculous lymphocytic effusions. ADA is stable in effusion fluids, and its measurement is reproducible.     

High diagnostic accuracy of NT-proBNP for cardiac origin of pleural effusions.

A prospective study was performed to evaluate the diagnostic accuracy of N-terminal-pro-B-type natriuretic peptide (NT-proBNP) levels, measured simultaneously in serum and pleural fluid, in identifying pleural effusions due to heart failure. Pleural fluid and serum samples from all patients presenting for thoracentesis between April 2004 and May 2005 were simultaneously collected. The discriminative properties of NT-proBNP levels in identifying pleural effusions due to heart failure were determined by receiver operating characteristic curve analysis and compared to the diagnostic value of finding a transudate by Light's criteria. Ninety-three patients were evaluated, 27% with cardiac effusion and 73% with exudative effusions of various cause. Levels of NT-proBNP in pleural fluid and serum correlated closely. Serum and pleural fluid NT-proBNP levels were significantly elevated in patients with cardiac effusion. With a cut-off value of 4,000 ng.L(-1), NT-proBNP levels in pleural fluid and serum displayed comparably high diagnostic accuracies of 92 and 91%, respectively. All patients misclassified by Light's criteria were correctly identified by measuring NT-proBNP levels. N-terminal-pro-B-type natriuretic peptide levels in either pleural fluid or serum showed a high diagnostic accuracy compared to traditional criteria. Thus measuring N-terminal-pro-B-type natriuretic peptide is a valuable additional diagnostic tool for the detection or exclusion of cardiac origin of pleural effusions.     

Antibody detection for the diagnosis of tuberculous pleuritis.

SETTING: University Hospital, Bangkok, Thailand. OBJECTIVE: To evaluate the diagnostic value of antibody detection in serum and in pleural effusion as a marker of tuberculous pleuritis (TBP). DESIGN: Cross-sectional study. MATERIALS AND METHODS: One hundred and fifty-five patients with pleural effusion who underwent diagnostic evaluation at Siriraj Hospital between March 1999 and May 2000 were recruited. Samples of pleural fluid were examined biochemically, cytologically and microbiologically. Pathological examination of pleural tissue was also performed. The diagnosis of TBP or other diagnosis was made by either pathological finding or culture result. Immunochromatographic tuberculosis (ICT-TB) tests for antibody detection were then performed using the stored serum samples and effusions from those patients with a final definite diagnosis. This test detects antibodies to five secreted antigens of Mycobacterium tuberculosis, including the 38 kDa antigen. RESULTS: We investigated 67 patients with TBP, 44 with malignant pleural effusions, seven with transudates and one with cryptococcal pleuritis. The combined ICT-TB serum and effusion tests were positive in 34/67 TBP and 22/52 non-TBP patients. The sensitivity, specificity, positive predictive value and negative predictive value of the ICT-TB test were 50.7, 57.7, 60.7 and 47.6%, respectively. In 11 TBP patients with human immunodeficiency virus (HIV) co-infection, the sensitivity of the ICT-TB test was 45.6%. There was no correlation between the test positivity and culture result or duration of disease. CONCLUSIONS: The diagnostic value of antibody detection in TBP is modest in an area with intermediate prevalence of tuberculosis, independently of HIV serological status.     

联合检测对结核性和恶性胸腔积液的鉴别诊断价值

目的探讨联合检测胸腔积液中腺苷脱氨酶(ADA)、C反应蛋白(CRP)、癌胚抗原(CEA)、乳酸脱氢酶(LDH)对结核性和恶性胸腔积液的诊断价值。方法以我院2012年1月至2012年12月112例住院的胸腔积液患者为研究对象,其中62例结核性胸腔积液患者,50例恶性胸腔积液患者,以酶比色法,免疫比浊法,速率法和电化学发光法检测上述患者胸腔积液中ADA、CRP、CEA和LDH浓度。结果结核性胸腔积液患者ADA和CRP的诊断敏感性显著高于恶性胸腔积液患者(P0.01),恶性胸腔积液患者CEA的诊断敏感性较结核性胸腔积液患者明显增高(P0.01)。以胸腔积液CEA7 ng/ml及LDH245 U/L为诊断标准,诊断恶性胸腔积液的敏感性,特异性分别为78.0%,80.6%;而以CEA7 ng/ml,LDH245 U/L及ADA40 U/L,CRP5 mg/L为诊断标准,诊断恶性胸腔积液的敏感性,特异性分别为94.0%,95.2%。以胸腔积液ADA40 U/L,CRP5 mg/L为诊断标准,诊断结核性胸腔积液的敏感性,特异性分别为82.3%,86.0%;而以CEA7 ng/ml,LDH245 U/L及ADA4 0U/L,CRP5 mg/L为诊断标准,诊断结核性胸腔积液的敏感性,特异性分别为96.8%,92.0%。结论联合检测胸腔积液中ADA、CRP、CEA、LDH的浓度可提高结核性和恶性胸腔积液鉴别诊断的敏感性和特异性。     

Use of acute phase proteins in pleural effusion discrimination

The differentiation between exudates and transudates is fundamental when investigating the cause of pleural effusions. Acute-phase proteins could be potentially useful markers in this discrimination. In the attempt to define diagnostic criteria for the differentiation of pleural exudates from transudates, we measured alpha 1 acid glycoprotein, C-reactive protein, haptoglobin, ceruloplasmin and transferrin in pleural effusions and serum in patients with pleural effusions of various etiologoies. We measured the concentrations of the above proteins in the serum and pleural fluid of 80 (54 exudate, 26 transudate) consecutive patients by immunoturbidometrical methods. Pleural effusion acute phase proteins were elevated in the patients with exudate compared to patients with transudate (p< 0.001 for all). In receiver operator characteristic analysis showed that pleural fluid ceruloplasmin levels and the ratio pleural fluid/serum transferrin were superior to the others. Using the optimum cut-off point of 0.16 g/L pleural fluid ceruloplasmin achieves a sensitivity of 92% with a specificity of 85%. In addition to, the optimum cut-off point for pleural fluid/serum transferrin ratio was 0.4 with sensitivity and specificity of 92% and 80%. When using together these parameters sensitivity and specificity were increased (95%, 85%). In differential diagnosis, none of these proteins were significantly different in subgroups of pleural exudate. We conclude that when using together ceruloplasmin levels in pleural fluid and the ratio of pleural to serum transferrin have a high sensitivity and specificity in discrimination of exudative pleural effusions.     

多指标联合检测鉴别渗出与漏出性胸腔积液的研究

目的 检测胸腔积液患者胸腔积液胆固醇( PE CHOL)、胸腔积液胆固醇与血清胆固醇比值(P/S CHOL)、胸腔积液C-反应蛋白(PE CRP)和血清-胸腔积液白蛋白差(SEAG),并与Light标准进行比较,探讨多指标联合检测在鉴别渗、漏出性胸腔积液中的价值.方法 将137例不同病因的胸腔积液患者分成漏出液组和渗出...     

Lupus pleuritis. Clinical features and pleural fluid characteristics with special reference to pleural fluid antinuclear antibodies

Eighteen patients with lupus erythematosus (LE) and pleural effusions were evaluated. Fourteen patients had lupus pleuritis and four had pleural effusions of other etiologies. All patients were symptomatic, and the presenting signs and symptoms did not help distinguish between lupus pleuritis and pleural effusions of other causes. The presence of LE cells confirmed the diagnosis of lupus pleuritis in seven of eight patients. In 11 of 13 patients with lupus pleuritis, the pleural fluid antinuclear antibody (ANA) titer was greater than or equal to 1:160, and in nine of 13 patients with lupus pleuritis, the pleural fluid to serum (PF/S) ANA ratio was greater than or equal to 1. In the four patients with LE and a pleural effusion of another etiology, the pleural fluid ANA titer was negative in two and low titer in two (1:40, 1:80); the pleural fluid to serum ANA titer was always less than one. Of 67 patients with pleural effusions of other etiologies, the pleural fluid ANA was negative. The signs and symptoms of lupus pleuritis are nonspecific, however; the findings of LE cells in pleural fluid confirms the diagnosis and a high pleural fluid ANA titer (greater than or equal to 1:160) and a PF/S ANA ratio of greater than or equal to 1 strongly supports the diagnosis.     

Alkaline phosphatase in pleural effusions

BACKGROUND: Pleural effusion (PF) is a common clinical presentation in several diseases. Various parameters from pleural fluid have been studied to identify the cause. The diagnostic value of these parameters varies. The present study was carried out to evaluate the value of alkaline phosphatase concentration in the pleural effusions as a diagnostic tool. METHODS: One hundred and one patients with pleural effusion admitted over a period of two years were studied. The diagnosis was confirmed by pleural biopsy and cytology for malignant cells. RESULTS: Pleural fluid alkaline phosphatase levels of more than 75 mg/dl was found in exudative effusions and less than 75 mg/dl in transudative ones. But it did not differentiate tubercular pleural effusions from other exudative ones. CONCLUSION: Pleural fluid alkaline phosphatase of >75 mg/dl is a useful biochemical marker to suggest exudative effusions.     

多指标检测对渗出性胸腔积液的鉴别诊断意义

目的检测胸腔积液患者胸水中CRP、HPT、ADA三项指标水平，探讨多指标检测在胸腔积液鉴别诊断中的价值。方法将68例不同病因的渗出性胸腔积液分为良性渗出液组及恶性渗出液组二组，检测患者胸腔积液三项指标水平。结果二组胸腔积液患者CRP、HIT及ADA均有显著性差异（均P〈0．05）。结论胸腔积液CRP、HPT及ADA水平检测对鉴别渗出性胸腔积液性质有较好的临床实用价值。     

Significance of alpha-2-macroglobulin, alpha-1-acid glycoprotein, and C-reactive protein in pleural effusion differentiation

BACKGROUND: The differentiation between exudates and transudates is fundamental when investigating the cause of pleural effusions. Acute-phase proteins could be potentially useful markers in this discrimination. OBJECTIVE: The present study was designed to evaluate whether the acute-phase proteins: alpha(2)-macroglobulin (AMG), alpha(1)-acid glycoprotein (AAG) and C-reactive protein (CRP) are useful in investigating the pleural effusions. METHODS: We prospectively measured the concentrations of the above proteins in the serum and pleural fluid of 84 consecutive patients with various diseases using a nephelometric assay. RESULTS: Pleural effusion AMG, AAG and CRP were all significantly elevated in the group of patients with exudates compared to patients with transudates (p < 0.001, p < 0.001 and p < 0.01, respectively). An AAG value >63 mg/dl in a pleural effusion is predictive of an exudate with a sensitivity of 90% and a specificity 85%. Similarly, an AMG value >44 mg/dl in a pleural effusion is predictive of an exudate with a sensitivity and a specificity of 90% and 60%, respectively. Moreover, pleural AAG was significantly higher in cancerous exudates than in exudates and transudates of all other cause taken together (p < 0.001). Finally, to differentiate the same pleural effusion, the cut-off value of 1.0 mg/dl of pleural CRP has a sensitivity and a specificity of 74% and 74%, respectively. CONCLUSIONS: We conclude that both AAG and AMG concentrations in pleural effusions have a high sensitivity and are therefore useful parameters in distinguishing exudates from transudates, but the latter is inferior due to its unacceptably low specificity.