Elevated Adenosine Dehydrogenase (ADH) and Positive Tuberculin Test Firstly Misdiagnosed as Tuberculous Pleural Effusion Finally Proved as Pleural Mesothelial Sarcoma by Thoracoscopic Biopsy Pathology: a Case Report and Literature Review

BACKGROUND

In China, tuberculous pleural effusion is the most common cause for pleural effusion. Elevated ADH and positive tuberculin test usually are characteristic of tuberculous pleural effusion. We reported a 71-year-old male patient with elevated ADH and positive tuberculin test firstly misdiagnosed as tuberculous pleural effusion finally proven as pleural mesothelial sarcoma by thoracoscopic pathology.

METHODS

Appropriate laboratory tests and thoracentesis were carried out. Thoracoscopy and pathological biopsy were performed to differentiate tuberculous pleural effusion.

RESULTS

Chest CT showed right pleural effusion. ADH in pleural effusion was over 45 U/L and PPD test was positive. No abnormal cells were found in pleural effusion pathology. Pathology of thoracoscopic biopsy proved pleural mesothelioma.

CONCLUSIONS

Elevated ADH and positive tuberculin test are not a specific index for tuberculosis and thoracoscopic biopsy pathology is crucial for differential diagnosis.

Pleural effusion adenosine deaminase is not accurate in diagnosis of pediatric tuberculous pleural effusion: a retrospective study

OBJECTIVE

Pleural effusion (PE) adenosine deaminase (ADA) has good performance in detection of tuberculous pleural effusion (TPE). However, few study was conducted for its value in pediatric patients. To evaluate PE ADA in diagnosis of pediatric TPE, a retrospective study was performed.

PATIENTS AND METHODS

204 pediatric PE patients were enrolled, and then were grouped into TPE group (77 cases, aged 11.51 ± 0.40 years) and non-TPE group (127 cases, aged 6.39 ± 0.35 years). Man-Whitney U test was used to compare difference in pleural ADA between the two groups. The correlation between age and ADA activity was analyzed by Spearman's correlation coefficient analysis.

RESULTS

In our study, there was no difference in pleural ADA between TPE (62.1 ± 4.2 U/L) and non-TPE patients (87.7 ± 10.0 U/L). Compared with empyema patients (183.8 ± 30.0 U/L), pleural ADA was lower in parapneumonic effusion (PPE) patients (63.4 ± 3.8, p < 0.01), or TPE patients (p <0.01). Correlation analysis showed that there were no correlation between age and pleural ADA within TPE, PPE or both patients (all p > 0.05). Meanwhile, there was no significant difference in PE ADA level between genders.

CONCLUSIONS

Considering the fact that the majority of pediatric PEs is TPE and PPE, our study suggests that PE ADA isn't accurate in detection of pediatric TPE. Meanwhile, an extremely high ADA activity should raise suspicion of empyema or lymphoma.

Influence of storage time on pleural fluid adenosine deaminase activity

BACKGROUND

Storing pleural fluid samples for research purposes is a common practice, but whether adenosine deaminase (ADA), an enzyme used for the diagnosis of tuberculous pleuritis, is stable over long periods of time is unknown.

METHODS

We evaluated the stability of pleural ADA concentrations in 223 samples frozen at -800C as compared to values obtained immediately following the initial thoracentesis. Sample storage time ranged from several months to slightly more than 10 years.

RESULTS

ADA activity was stable for up to 2.6 years. Afterwards, it decreased 6 to 8 U/L, enough to drop 2 (3.3%) tuberculous patients below the diagnostic ADA cutoff.

CONCLUSIONS

As far as ADA enzymatic activity is concerned, pleural fluid samples are viable for extended periods of time. However, some caution in interpreting results from specimens stored for > 2.6 years is prudent.

Role of adenosine deaminase in diagnosis of tubercular pleural effusion

The diagnosis of pleural tuberculosis (TB) continues to be a challenge in clinical practice. Traditional diagnostic methods are very useful for the diagnosis of pulmonary TB but have a low yield when applied to pleural fluid. It is produced during the inflammatory process triggered by the M. tuberculosis. Usefulness of adenosine deaminase (ADA) estimation in pleural fluid has been shown as a reliable chemical bio-marker specially when there is suspicion of tuberculosis in endemic areas. ADA level was determined in the pleural fluid of 100 patients present with pleural effusion admitted at Mymensingh Medical College Hospital during the period of March 2012 to September 2012. ADA level was >40IU/L among the 52 tubercular pleural effusion patients with sensitivity & specificity is 100% and 66% respectively. Thus is evident that ADA level can be used along with conventional methods for diagnosis of pleural TB.

Predictive role of adenosine deaminase for differential diagnosis of tuberculosis and malignant pleural effusion in Turkey

Tuberculous pleural effusion (TPE) is a common problem for differential diagnosis from malignant effusion (MPE) in epidemic areas of tuberculosis (TB). Prediction based on adenosine deaminase (ADA) is dependent on age as well as the tuberculosis incidence. The aim of the study was to evaluate cutoff values for ADA with sensitivity and specificity results for the differential diagnosis of MPE and TPE in a population with intermediate incidence of TB. We retrospectively analysed 196 patients with a definitive diagnosis of TPE (n = 114) and MPE (n = 82). The optimal cutoff value of ADA was determined using the receiver operating characteristic (ROC) curve. There was a statistically significant difference according to the levels of pleural fluid ADA between TPE and MPE groups (p < 0.0001). The cutoff value for diagnosing TPE was > 55 U/L, with a sensitivity = 86.8%, specificity = 86.6%, positive predictive value (PPV) = 90%, negative predictive value (NPV) = 82.6% and accuracy = 82.6%. We then combined ADA > 55 U/L and age < 50 and were able to discriminate the TPE group with increased specifity (95.7 %) and PPV (98.8%) results. The model could correctly classify 21 MPE out of 23 and 82 TPE out of 94 patients. A pleural fluid ADA value < 31 U/L suggests that TPE is highly unlikely with a sensitivity = 43.9 %, specificity = 100%, PPV = 100%, NPV = 71.3% and accuracy = 76.6%. It can be concluded that ADA is a very useful parameter for the differential diagnosis of TPE and MPE, specifically in youngers with a higher incidence of tuberculosis.

[Evaluation of the diagnostic value of adenosine deaminase activity in tuberculous pleuritis]

OBJECTIVE

To investigate the clinical value of pleural fluid adenosine deaminase (ADA) activity in differentiating tuberculous pleural effusions (TPE) from malignant effusions.

METHODS

The serum and pleural adenosine deaminase activity of 91 cases confirmed by pleural biopsy through medical thoracoscopy were retrospectively analyzed. TPE was confirmed in 49 cases and malignant effusion in 42 cases. The optimal cutoff for TPE was determined by using the ROC curve.

RESULTS

The mean pleural ADA was significantly (t = 7.383, P < 0.01) higher in PTE (46 +/- 26) U/L as compared to malignancy (16 +/- 8) U/L, so was the pleural fluid/serum ADA ratio (4.1 +/- 4.0 vs 1.76 +/- 1.2, t = 3.852, P < 0.01), but there was no statistically significant difference between malignant and tuberculous effusion in serum ADA activity [(13 +/- 5) U/L vs (12 +/- 6) U/L, t = 1.582, P > 0.05]. The cutoff value of pleural ADA for PTE was 28.7 U/L, with a sensitivity of 75.5% and a specificity of 95.2%.

CONCLUSIONS

Pleural fluid, but not serum, ADA activity, can be used for the differentiation between tuberculous and malignant pleural effusions.

Pleural fluid ADA, IgA‐ELISA and PCR sensitivities for the diagnosis of pleural tuberculosis

The diagnosis of pleural tuberculosis (pTB) is difficult, and more sensitive and specific techniques are needed. In the period August 1998 to November 2002, we evaluated 132 patients with a pleural effusion submitted to a thoracentesis and pleural biopsy in a tertiary care hospital in Rio de Janeiro, Brazil. Three tests were performed and compared in the pleural fluid: ADA activity measurement, IgA-ELISA for two combined specific Mycobacterium tuberculosis antigens, and polymerase chain reaction (PCR) for detection of M. tuberculosis DNA. Ninety-five patients (72%) were given a final diagnosis of pTB. Overall histopathologic sensitivity was 77%. The sensitivities of pleural fluid culture and AFB smear were 42% and 1%, respectively. Twenty-one (22%) additional patients had a clinical diagnosis of pTB. Median follow-up time of all TB patients after the completion of antituberculous treatment was 13 months. Sensitivities of ADA, IgA-ELISA and PCR were 91%, 78% and 82%, while specificities were 93%, 96% and 85%, respectively. Only ADA sensitivity was significantly higher than the histopathologic examination (McNemar chi2 test; p = 0.002) and also significantly higher than ELISA (p = 0.049), but not higher than PCR (p = 0.143). We conclude that the routine use of ADA activity measurement in pleural fluid can obviate the need for a pleural biopsy in the initial diagnostic approach to pleural effusions, while IgA-ELISA and PCR techniques, potentially more specific tests, need further refinement to improve their accuracy.

The diagnostic utility of adenosine deaminase isoenzymes in tuberculous pleural effusions

SETTING

Pleural adenosine deaminase (ADA) levels have been found to be useful in diagnosing tuberculous pleuritis. Elevated ADA levels have been attributed to ADA2 isoenzyme, although no comprehensive studies have evaluated ADA2 as a diagnostic test.

OBJECTIVE

To estimate the diagnostic accuracy of ADA and ADA2 in diagnosing tuberculous pleurisy.

METHOD

A 3-year retrospective study was carried out. ADA and ADA2 were determined on patients diagnosed according to predetermined criteria.

RESULTS

A total of 951 samples were received, including 387 patients with tuberculosis (TB). ADA values>or=52.4 U/l yielded a sensitivity, specificity and positive (PPV) and negative predictive value (NPV) respectively of 93.7% (95%CI 90.0-96.0), 88.7% (95%CI 85.7-91.3), 85.5% (95%CI 81.7-88.8) and 95.2% (95%CI 92.9-96.9). ADA2 values>or=40.6 U/l yielded a sensitivity, specificity and PPV and NPV of respectively 97.2% (95%CI 95.0-98.7), 94.2% (95%CI 91.8-96.0), 92.2% (95%CI 89.1-94.7) and 98.0% (95%CI 96.3-99.0). The chi2 and McNemar tests proved the superiority of ADA2 statistically.

CONCLUSION

ADA2 is superior to ADA in the diagnosis of tuberculous pleuritis and should be used as a routine test in the diagnostic work-up of patients with pleural effusions in areas with high TB prevalence.

[The diagnostic value of adenosine deaminase coefficient in patients with tuberculous exudative pleurisy]

The authors examined 51 patients aged 37.74 +/- 2.17 years who had tuberculous pleurisy and aged 49.8 +/- 4.6 years who had nonspecific pleurisy. Group 1 comprised 18 patients with isolated tuberculous exudative pleurisy. Group 2 included 13 patients with tuberculosis complicated by tuberculous pleurisy. Group 3 consisted of 10 patients with nonspecific exudative pleurisy. Catarrhal endobronchitis was the leading form of tracheo-broncheal tree lesion among patients with tuberculous exudative pleurisy (n = 20 (64.5%)). The activity of adenosine deaminase (ADA) was 2.18 +/- 0.73, 2.41 +/- 0.80, and 2.47 +/- 1.52 U/l in Groups 1, 2, and 3, respectively. Thus, the measurement of bronchoalveolar fluid ADA separately from other parameters is of no informative value in the differential diagnosis of the etiology of pleurisy. While analyzing the parameters, the authors introduced the coefficient of ADA (CADA) that was calculated using the formula: K(ADA) = ADA/cytosis. In patients with tuberculous pleurisy, K(ADA) was 0.65 +/- 0.17 (this was 0.52 +/-0.13 in isolated tuberculous exudative pleurisy and 0.84 +/- 0.36 in tuberculous exudative pleurisy complicated by pulmonary tuberculosis (p < 0.05), and 0.20 +/- 0.06 in nonspecific pleurisy (p < 0.05). The ADA coefficient of 0.52 or more confirms the tuberculous etiology in isolated pleurisies and permits a differential diagnosis to be made between specific and nonspecific pleurisy with and without lung changes.

Diagnostic significance of adenosine deaminase in pleural tuberculosis

BACKGROUND

Tuberculosis (TB) is a major cause of pleural effusion, which in TB usually has lymphocytic and exudative characteristics. Analysis of adenosine deaminase (ADA) activity is a very useful diagnostic approach to achieve a more rapid and precise diagnosis in cases of Pleural TB (pTB).

METHODS

Fifty male and fifty female patients presenting with tuberculous pleural effusion was included in the study. The patients were taken from the medical ward of Sir Ganga Ram Hospital between September 2001 and September 2002. Activity of Adenosine Deaminase (ADA) was estimated by the technique of Sodium dodecyl sulphate electrophoresis (SDS-EF) using 10% polyacrylamide gel.

RESULTS

Mean age of males was 45.72 +/- 19.22 years and of female was 43.74 +/- 16.09 years. Mean protein level was 3.39 +/- 0.24 g/dl in males, and it was 3.02 +/- 0.26 g/dl in females. Mean specific gravity both in males and females was 1.020 +/- 0.01. The results show an increased level of enzyme ADA in patients as compared to normal subjects.

CONCLUSION

Estimation of ADA activity may provide basis for rapid and efficient diagnosis of pleural TB in different clinical settings. However study should be extended to larger number of patients to reach a better conclusion.

Pleural fluid adenosine deaminase and interferon gamma as diagnostic tools in tuberculosis pleurisy

Several biological markers have been proposed to improve the efficacy of diagnosing tuberculous pleurisy. The study was undertaken to evaluate the accuracy of pleural fluid adenosine deaminase (ADA) activity and interferon-gamma (IFN-gamma) concentration in differentiating tuberculous pleural effusion (TPE) and nontuberculous pleural effusion (non-TPE). Ninety four patients (50 M and 44 F, mean age 60+/-18, range 18-95 years) with pleural effusion (PE) were studied. TPE was diagnosed in patients with: (i) positive pleural fluid or pleural biopsy culture or (ii) granulomas in the pleural biopsy specimen, after exclusion of other granulomatous diseases. Pleural fluid ADA activity was measured with the colorimetric method of Giusti, while IFN-gamma level was measured with ELISA. TPE was diagnosed in 28 patients. The non-TPE group consisted of 35 patients with malignant PE, 20 patients with parapneumonic effusion/pleural empyema, 5 with pleural transudate, and 6 with miscellaneous PE. The ADA activity and IFN-gamma concentration were significantly higher in TPE than in non-TPE (614.1+/-324.5 vs. 15.1+/-36.0 pg/ml, P<0.0001 and 75.1+/-39.1 vs. 11.0+/-16.6 U/l respectively, P<0.0001). The diagnostic sensitivity and specificity of IFN-gamma measurement (cut-off value of 75.0 pg/ml) were 100% and 98.5% respectively and were similar to those of ADA (100% and 93.9% at the cut-off value of 40.3 U/L). We conclude that pleural fluid ADA activity and IFN-gamma concentration are highly sensitive and specific markers of tuberculous pleurisy.

Adenosine deaminase activity is a sensitive marker for the diagnosis of tuberculous pleuritis in patients with very low CD4 counts

BACKGROUND

Adenosine Deaminase Activity (ADA) is a commonly used marker for the diagnosis of tuberculous pleural effusion. There has been concern about its usefulness in immunocompromised patients, especially HIV positive patients with very low CD4 counts. The objective of this study was to evaluate the sensitivity of ADA in pleural fluid in patients with low CD4 counts.

MATERIALS AND METHODS

This was a retrospective case control study. Medical files of patients with tuberculous pleuritis and non-tuberculous pleuritis were reviewed. Clinical characteristics, CD4 cell counts in blood and biochemical markers in pleural fluid, including ADA were recorded.

RESULTS

One ninety seven tuberculous pleuritis and 40 non-tuberculous pleuritis patients were evaluated. Using the cut-off value of 30 U/L, the overall sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of ADA was 94%, 95%, 19, and 0.06 respectively. The mean CD4 cell counts among TB pleuritis patients was 29 and 153 cells/microL in patients with CD4 <50 cells/microL and >50 cells/microL, (p<0.05) respectively. The corresponding mean ADA values for these patients were 76 U/L and 72 U/L respectively (p>0.5). There was no correlation between ADA values and CD4 cell counts (r = -0.120, p = 0.369).

CONCLUSION

ADA analysis is a sensitive marker of tuberculous pleuritis even in HIV patients with very low CD4 counts in a high TB endemic region. The ADA assay is inexpensive, rapid, and simple to perform and is of great value for the immediate diagnosis of tuberculous pleuritis while waiting for culture result and this has a positive impact on patient outcome.

Auxiliary tools in tuberculosis. The hemolysis in pleural fluids underestimate the values of adenosine deaminase activity determined by the method of Giusti

The increase of adenosine deaminase (ADA) activity in pleural fluids (PF) is considered a useful tool in the diagnosis of pleural tuberculosis. It is known that numerous photometric methods are interfered by the hemolysis, as a result, hemolyzed specimens -or with blood- received in the laboratory are frequently rejected. In order to establish if the values of ADA were affected by the hemolysis or blood, ADA was determined in individual and pooled PF samples with the aggregate of erythrocyte lysate (H) or hemolyzed whole blood (HWB) from 312 mg/l to 12 g/l (final concentrations of hemoglobin in the samples), and plasma in appropriate dilutions. Negative interferences were caused by the H and HWB, starting already of 500 mg/l with relative errors until 50% in some cases, depending on the ADA activity. Increments of hemoglobin increased the negative interference. The aggregate of plasma increased slightly the ADA activity although it was insufficient for neutralize the negative effect of hemolysis. The clinical significance of the negative interference is in relation to the amount of hemoglobin present in the sample and the ADA activity. Near the cutoff (40 U/l) this interference can lead to discard erroneously the diagnosis of pleural tuberculosis.

[Diagnostic characteristics of adenosine deaminase test in Byelorussian patients with tuberculous pleurisy]

The results of studying the diagnostic value of changes in the pleural fluid and serum activities of adenosine deaminase (ADA) and its isozymes are analyzed in Byelorussian patients with tuberculous pleurisy. There is an increased serum and pleural fluid ADA activity in the patients with tuberculous pleurisy caused mainly by a rise in ADA2 activity. The test determining the activity of ADA, and ADA2 in particular, has shown high sensitivity and specificity as compared with the results obtained in other countries. The diagnostic efficacy of determination of these indices in the serum is also high, but it is lower than that in the pleural fluid.

[Adenosine deaminase in the blood cells and serum of patients with tuberculous pleurisy]

The common complication of pulmonary tuberculosis is pleurisy that requires not only special treatments, but also gives rise to difficulties in the differential diagnosis of tuberculosis. The investigation has studied the possibility of determining the activity of adenosine deaminase (ADA) as a marker of pleural effusion of tuberculous etiology. The patients with tuberculous pleurisy have been found to have higher lymphocytic and red blood ADA, and ADA, activities and a significantly increased serum ADA2 activity. Thus, the changes in the activity of ADA and its isozymes have been shown to be specific to pleurisy of tuberculous etiology and to be of diagnostic value.

Chitotriosidase activity in pleural effusions

Chitotriosidase (ChT) is mainly secreted by monocyte-derived macrophages, and is considered a useful marker of macrophage activation. Macrophages represent the first line of defence against Mycobacterium tuberculosis, and consequently the study of ChT activity in pleural effusions (PE) would be of clinical value in the laboratory characterization of tuberculous pleurisy. ChT and adenosine deaminase (ADA) activities were determined in 12 tuberculous PE, 26 non-tuberculous lymphocytic PE and 25 neutrophilic PE. The enzyme heterogeneity study for ChT was made by thermal inactivation at 60 degrees C according to Wajner et al. (Clin Biochem 2004;37:893). ChT activity was significantly higher in the group of tuberculous PE than in the non-tuberculous lymphocytic PE group (p < 0.01), although no significant difference was found with respect to neutrophilic PE. The correlation between ChT and ADA was statistically significant, although in the partial correlation keeping the protein concentration constant, statistical significance was only achieved in tuberculous and non-tuberculous lymphocytic PE (r = 0.358, p < 0.05). In lymphocytic PE, a ChT activity greater than 40 mmol/h/mL has a sensitivity of 92%, specificity of 72%, and efficiency of 78% for the biochemical characterization of tuberculous pleurisy. Residual activities obtained for ChT by heat inactivation did not make it possible to differentiate the enzyme isoforms in PE presumably secreted by macrophages and polymorphonuclear leukocytes.

Thoracoscopic pleural biopsy for tuberculous pleurisy under local anesthesia

OBJECTIVE

We directly examined the thoracic cavity by thoracoscopy under local anesthesia, performed pleural biopsy, and made a definitive pathological diagnosis in tuberculous pleurisy.

SUBJECTS AND METHODS

We performed a retrospective study of 32 patients who had been bacteriologically and pathologically diagnosed with tuberculous pleurisy by thoracoscopy under local anesthesia in our hospital between January 1995 and November 2004.

RESULTS

Bacteriological examination of pleural fluids obtained by thoracentesis before examination showed that one sample was polymerase chain reaction (PCR)-positive, and 5 samples were culture-positive. Bacteriological examination of pleural fluids obtained by thoracoscopy revealed that 2 samples were PCR-positive, and 5 samples culture-positive, including 2 preoperatively positive samples. The adenosine deaminase (ADA) levels ranged from 18.3 to 279.0 U/L, with a mean of 72.9 U/L, including 50 U/L or less in 5 patients and 35 U/L or less in 3 patients. Thirty patients (93.8%) were successfully diagnosed by pleural biopsy with pathological examination, and 21 (65.6%) of them by pathological examination alone.

CONCLUSION

In patients with suspected tuberculous pleurisy, thoracoscopic pleural biopsy under local anesthesia should be actively performed, because the technique has a high diagnostic rate, and can be easily and safely performed.

Influence of storage time and temperature on pleural fluid adenosine deaminase determination

OBJECTIVES AND BACKGROUND

The determination of adenosine deaminase (ADA) activity in pleural fluid is important for differentiation of pleural effusions and diagnosing pleural tuberculosis. Although measurement of ADA is simple and inexpensive, controversies exist regarding potential errors caused by time elapsed between sample collection and analysis, storage temperature and the use of anticoagulants. The objective of this study was to evaluate the influence of storage time (1, 3, 7, 10 and 28 days) and temperature (4 degrees C and -20 degrees C) on the determination of ADA in pleural fluid samples collected in EDTA and sent at ambient temperature to the laboratory for initial processing within 1 h of collection.

METHODOLOGY

Twenty-seven pleural exudates obtained from 20 patients with neoplastic disease and seven with tuberculosis were analysed. The ADA activity obtained within 1 h of collection was considered the gold standard and was compared with the other measurements.

RESULTS

The correlation between the initial measurement and all others was >or=0.90 for both temperatures up to the 10th day after thoracocentesis and tended to decrease by 28 days after collection, but this difference was not significant.

CONCLUSIONS

Pleural fluid samples collected in EDTA and sent for analysis within 1 h after collection can be used to determine ADA up to 28 days after collection if stored at 4 degrees C or -20 degrees C, with no evidence of significant increases or decrease in enzyme activity that might distort the results.

[Diagnostic value of serum and pleural fluid adenosine deaminase activity in tuberculous pleurisy]

The biological diagnosis of tuberculous pleurisy poses the problem of the time required to obtain results and of the sensitivity of the usual diagnostic methods. The determination of adenosine deaminase (ADA) activity has been proposed for the diagnosis of tuberculous pleural effusion and for the follow-up. In the present study, ADA in pleural effusion (p-ADA) and in serum (s-ADA) has been measured in 2 groups of patients: tuberculosis (27) and non-tuberculosis (53) patients. The upper limit of the normal values was fixed at 37 U/L. Comparing these 2 groups, we observed a specificity of 81.2% and a sensitivity of 66.6%. The PPV and the NPV were respectively 64.3% and 82.7%. We used p-ADA/s-ADA ratio for diagnosis of tuberculous pleural effusion, a threshold value of 1.8 gave a sensitivity of 82.6% and a specificity of 84.8%. Within the tuberculosis patient group, the activity of ADA decreased after the appropriate treatment initiation. Thus, the determination of ADA activity and/ or the p-ADA/s-ADA ratio, can help to recognize the tuberculosis origin of pleural effusions.

[Adenosine deaminase activity in tuberculous and malignant pleural effusions]

Measurement of pleural adenosine deaminase activity (ADA) is a useful diagnostic tool for tuberculous pleurisy, but false-positive findings from non-tuberculous effusions have been reported. In order to improve diagnostic value of ADA it is recommended to estimate activity of both ADA1 and ADA2 izoenzymes or 2'-deoxyadenosine/adenosine activity ratio. In order to evaluate ADA as a diagnostic parameter total ADA, with adenosine as a substrate, and 2'-deoxyadenosine/adenosine activity ratio were measured in tuberculous and malignant pleural effusions. Altogether, 26 pleural exudates (11 tuberculous and 15 malignant) were selected. ADA either with adenosine or 2'-deoxyadenosine was determined by colorimetric method of Giusti. Each pleural fluid sample was diluted prior to the assay (1:8) to avoid enzyme inhibition which was observed in nondiluted pleural effusions. The ADA level reached the diagnostic cut-off set for tuberculous effusions (40 U/L) in every 11 tuberculous exudates with the mean value of 85,3+/-47,1 U/L; in 9 of these the 2'-deoxyadenosine/adenosine ratio was less than 0,45. In the malignant group of patients, no one ADA level exceed 40 U/L, being estimated at 10,6+/-7,7 U/L (p<0,001). In 10 of these 15 exudates the 2'-deoxyadenosine/adenosine ratio was undetectable, in four it was less than 0,45 and only in one it was over 0,45. We concluded that ADA measured by the Giusti method proceeded by the dilution 1:8 of the pleural effusion samples very good differentiates tuberculous from malignant pleurisy, without the necessity to determine the 2'-deoxyadenosine/adenosine ratio. The investigation needs to be continued on the more numerous groups of patients.

[Adenosine deaminase 2 in the diagnosis of tuberculous pleuritis]

PURPOSE

We examined the usefulness of adenosine deaminase 2 (ADA2) in the diagnosis of tuberculous pleuritis.

SUBJECTS

A hundred cases, 78 male and 22 female, with pleural effusion were examined. With regard to pleural effusion, 18 cases were transudate and 82 cases (9 tuberculous pleuritis, 27 lung cancer, 8 mesothelioma, 5 malignant diseases except lung cancer and mesothelioma, 5 benign asbestos pleurisy, 10 empyema, 10 parapneumonic effusion, one SLE, one parasitic infection, and 6 undetermined etiology) were exudates. The last 6 cases with unknown origin were excluded in this study.

RESULTS

Pleural adenosine deaminase (ADA) was 90.4 +/- 22.4 U/l (mean +/- SD) and pleural ADA2 was 80.4 +/- 21.9 U/l in tuberculous pleuritis, both were significantly higher than those in non-tuberculous exudates (p < 0.001). In the diagnosis of tuberculous pleuritis, pleural ADA showed 100% sensitivity and 88% specificity, whereas pleural ADA2 showed 100% sensitivity and 91% specificity.

CONCLUSION

Pleural ADA2 is useful in the diagnosis of tuberculous pleuritis, which has similar sensitivity and a little better specificity compared with pleural ADA.

The relation of the pleural thickening in tuberculosis pleurisy with the activity of adenosine deaminase

BACKGROUND

Residual pleural thickening (RPT) still occurs in most patients with tuberculosis pleurisy despite advances in the treatment of tuberculosis. The aim of this study was to evaluate the significance of RPT in tuberculosis pleurisy with the patients clinical findings, biochemical and microbiological properties of pleural effusion and with the total adenosine deaminase (ADA) and isoenzymes levels.

METHODS

121 tuberculosis pleurisy patients were evaluated retrospectively. According to posteroanterior chest x-rays, the 63 (52%) cases with the thickness 2 mm or more in lower lateral hemithorax were grouped as I and the 58 (48%) cases without pleural thickness were grouped as II. The amount of pleural effusion was classified into small, medium or massive according to their chest x-rays. In both groups; sex, age, symptoms score, bacteriological and biochemical tests and ADA levels were recorded.

RESULTS

81 (67%) male and 40 (33%) female, overall 121 patients were enrolled into the study. RPT was found higher in males (p=0.014) and the increase ran parallel with the amount of cigarette smoking (p=0.014). RPT was found to be lower in small effusions (p=0.001). The group with RPT, the serum albumin was found lower (p=0.002), pleural fluid total protein (p=0.047) and the ratio of pleural fluid protein to serum protein (p=0.002) were found higher. In group I, total ADA: 69.5 +/- 38.9 IU/L and ADA2: 41.3 +/- 31.6 IU/L were higher than the cases without RPT (p=0.032, p=0.017, respectively).

CONCLUSIONS

We suggest that the immunological mechanisms are effective in the development of pleural thickening.

Metalloproteinases and tissue inhibitors of metalloproteinases in exudative pleural effusions

The aim of this study was to assess the expression of several metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in exudative pleural effusions, and their relationship with inflammatory and fibrinolytic mediators in parapneumonic effusions. The study included 51 parapneumonic effusions (30 empyema or complicated parapneumonic, 21 noncomplicated parapneumonic), 28 tuberculous, 30 malignant and 30 transudates. Inflammatory markers (tumour necrosis factor-alpha, interleukin-8, polymorphonuclear elastase), fibrinolytic system variables (tissue plasminogen activator (PA), urokinase PA (u-PA), plasminogen activation inhibitor (PAI)-1, PAI-2), and several MMPs (MMP-1, MMP-2, MMP-8, MMP-9) and TIMPs (TIMP-1, TIMP-2) were determined by ELISA in plasma and pleural fluid. Elevated MMP-2 and TIMP-1 concentrations were observed in all the pleural fluid samples studied. The group of empyema or complicated parapneumonic effusions showed higher MMP-1, MMP-8 and MMP-9 concentrations than the remaining exudates. There was no correlation between MMP and TIMP levels in plasma and pleural fluid in this group of effusions. In parapneumonic effusions, MMP-1, MMP-8 and MMP-9 showed a positive correlation with the inflammatory markers and with u-PA and PAI-1. Moreover, there was a relationship between MMP-8 concentration in pleural fluid and pleural thickening at the end of treatment. In conclusion, elevated metalloproteinase-1, -8 and -9 expression was found in parapneumonic pleural effusions. These metalloproteinases could be implicated in the local inflammatory response existing in this group of effusions.

Stability of Adenosine Deaminase During Transportation

STUDY OBJECTIVE

Measurement of pleural fluid adenosine deaminase (ADA) levels is useful in the differential diagnosis of pleural effusions. However, at ambient temperatures, the levels of this enzyme decline with time. The purpose of the present study was to identify, test, and optimize additives that stabilize ADA, consequently eliminating the need for dry ice or other cold specimen transport media.

DESIGN

A preliminary screen of historically proven stabilizing agents for specific proteins demonstrated effectiveness of glycerol for maintenance of pleural fluid ADA levels. Systematic studies for exploitation of the glycerol effect included the following: (1) supplements to the glycerol of promising alternate compounds, (2) long-term stability studies at ambient and elevated temperatures, (3) a field test of an effective mixture as a means for reduction of specimen transport costs, (4) thermal stability studies for optimization of the agents for use at otherwise denaturing temperatures, and (5) inclusion of pleural fluids from patients with a variety of etiologies, including tuberculous pleurisy, in order to gauge the effectiveness of the stabilizing agents on both the high and low molecular weight forms of ADA.

RESULTS

A mixture of glycerol and ethylene glycol, each at 5% concentration, maintained pleural fluid ADA levels for at least 21 days at both room temperatures and 37 degrees C. A field test of 32 pleural fluids found that ADA levels in specimens containing this mixture, sent to the laboratory by surface mail at ambient temperatures, were nearly identical to those in aliquots of the same fluids shipped over dry ice. The bias in the measurement was 0.49 IU/L, with a precision of 2.49 IU/L. The correlation coefficient between the two measurements was 0.97. Thermal stability studies found that tuberculous pleural fluids containing 10% glycerol and 0.10 mol/L sodium sulfate maintained constant ADA levels for at least 10 days at 45 degrees C, an otherwise denaturing temperature for nonstabilized specimens.

CONCLUSION

The addition of stabilizing agents to pleural fluid specimens allows the transport of those specimens to distant laboratories at ambient temperatures without a decline in the ADA levels. Employment of those agents will decrease the cost of the test and facilitate its use in second- and third-world countries.

[Clinical investigation of the diagnostic value of interferon-gamma, interleukin-12 and adenosine deaminase isoenzyme in tuberculous pleurisy]

OBJECTIVE

To investigate the diagnostic value of interferon-gamma (IFN-gamma), interleukin-12 (IL-12) and adenosine deaminase isoenzymes (ADA(2)) in tuberculous pleural effusions.

METHODS

One hundred and ninety specimens of pleural effusion were collected from 190 patients with pleural effusion in Peking University People's Hospital, Beijing Chest Hospital, and Beijing Tuberculosis and Thoracic Tumor Institute, from March 2002 to February 2003. Of them 141 pleural specimens were diagnosed as tuberculous, and 49 as malignant. IFN-gamma and IL-12 concentrations and ADA isoenzyme activity in all the specimens were determined by ELISA and enzyme kinetic analytical method respectively.

RESULTS

(1) ADA(2) activity (47.9 +/- 6.9) U/L in tuberculous effusions was significantly higher than that in malignant effusion (13.2 +/- 3.2) U/L (P < 0.01). The IFN-gamma level (112.1 +/- 45.8) ng/L in tuberculous effusion was significantly higher than that in malignant diseases (24.8 +/- 5.9) ng/L (P < 0.01). The IL-12 level (104.3 +/- 32.3) ng/L in tuberculous effusions was significantly higher than that in malignant diseases (61.8 +/- 10.8) ng/L (P < 0.05). (2) By analysis of ROC curves, the cut-off values for IFN-gamma, IL-12 and ADA(2) were defined. The sensitivity and specificity of IFN-gamma for tuberculous effusion were 84.4% and 95.9% respectively. Those of IL-12 for tuberculous effusion were 85.1% and 65.3% respectively, while those of ADA(2) were 84.4% and 91.8%.

CONCLUSIONS

IFN-gamma and IL-12 could be used as valuable parameters for the differentiation of tuberculous effusion from malignant, and IFN-gamma was more sensitive and specific for tuberculous effusion than IL-12 and ADA(2).

Diagnostic value of pleural fluid adenosine deaminase activity in tuberculous pleurisy

BACKGROUND

Diagnosis of tuberculous pleuritis is difficult because of its nonspecific clinical presentation and insufficient efficiency of traditional diagnostic methods. We investigated the use of adenosine deaminase (ADA) activity in tuberculous pleuritis diagnosis.

METHODS

We optimized a kinetic assay and retrospectively analysed 210 patients with exudative pleural effusions. Using the ROC curve, we determined the optimal cutoff for TB pleurisy.

RESULTS

One hundred forty-seven exudative samples were nontuberculous (non-TB) and 63 were tuberculous (TB). There was statistically significant difference (p<0.0001) between the means of pleural fluid ADA levels among the TB and non-TB populations. The disease prevalence of TB pleurisy in the studied population was 30%. The cutoff value for diagnosing TB effusions was >55.8 U/L, with a sensitivity of 87.3% (95% CI: 76.5-94.3%) and specificity of 91.8% (95% CI: 86.2-95.7%). The positive predictive value (PPV) was 82.1% and the negative predictive value (NPV) was 94.4%. A pleural fluid ADA value <16.81 IU/L suggests that a tuberculous effusion is highly unlikely (100% sensitive with 100% NPV and 0% negative likelihood ratio for a pleural fluid ADA level>/=16.81 U/L). In addition, the area under the ROC curve was 0.933 (S.E.=0.0230, 95% CI: 0.890-0.963).

CONCLUSION

Pleural fluid total ADA assay is a sensitive and specific test suitable for rapid diagnosis of TB pleurisy.

Etiology and pleural fluid characteristics of large and massive effusions

STUDY OBJECTIVE

To report the etiology of large and massive pleural effusions, and to compare their biochemical fluid characteristics with those of smaller size, and between malignant and nonmalignant conditions.

DESIGN

Retrospective chart review of all patients undergoing thoracentesis at an academic medical center in Lleida, Spain, during a 10-year period.

PATIENTS

Posteroanterior chest radiographs were available in 766 patients during the study period. Large pleural effusions (ie, two thirds or more of the hemithorax without its complete obliteration) were identified in 70 patients (9%), and massive pleural effusions (ie, hemithorax was completely opacified) were identified in 93 patients (12%).

RESULTS

A similar etiologic spectrum between large and massive pleural effusions was observed. The most frequent cause of these pleural effusions was malignancy (89 patients; 55%), followed by complicated parapneumonic or empyema (36 patients; 22%), and tuberculosis (19 patients; 12%). Compared with nonmalignant pleural effusions, patients with large or massive malignant pleural effusions were more likely to have pleural fluids with higher RBC counts (18.0 x 10(9) cells/L vs 2.7 x 10(9) cells/L, respectively; p < 0.001) and lower adenosine deaminase (ADA) activity (11.5 vs 31.5 U/L, respectively; p < 0.001), which were the two parameters that were selected by a stepwise logistic-regression model as independent predictors of malignancy. In addition, large/massive malignant pleural effusions showed higher median RBC counts (18.0 x 10(9) cells/L vs 4.3 x 10(9) cells/L, respectively; p < 0.001), higher lactate dehydrogenase levels (641 vs 409 U/L, respectively; p = 0.001), lower pH (7.39 vs 7.42, respectively; p = 0.006) content, but similar cytologic yield (63% vs 53%, respectively; p = 0.171) than smaller malignant pleural effusions.

CONCLUSIONS

The presence of a large or massive pleural effusion enables the clinician to narrow the differential diagnosis of pleurisy, since most effusions are secondary to malignancy or infections (either bacterial or mycobacterial). Bloody pleural fluid with low ADA content favors a malignant condition.

Activity of adenosine deaminase and its isoforms in pleural fluid in tuberculous pleuritis

BACKGROUND

The problem of tuberculosis is increasing in a number of countries. Adenosine deaminase activity is considered in many clinics to be a valuable biochemical test of this pathology. Considerable research has been devoted to the activity of enzyme isoforms as significant tests for diagnosing tuberculosis. The aim of our study was to compare the significance of different adenosine deaminase dependent parameters in diagnosing tuberculosis.

MATERIAL/METHODS

The level of adenosine deaminase and the activity of its two isoenzymes in the pleural fluids of patients with tuberculous and non-tuberculous pleurisy were compared.

RESULTS

The adenosine deaminase level in tuberculous pleural effusions was higher than in non-tuberculous pleural effusions. The data we obtained suggest that the enzyme activity level could be a very reliable test in the differential diagnosis of tuberculous pleurisy in the Armenian population. The activity of isoenzymes ADA1 and ADA2, or their ratios to the total ADA activity, though valuable information, has no diagnostic advantage over total ADA activity in diagnosing this pathology.

CONCLUSIONS

The results clearly point up the value of using a total ADA activity assay in Armenian clinics for the differential diagnosis of tuberculous pleurisy. Determinations of the activity level of the ADA1 and ADA2 isoenzymes provide no diagnostic advantage over total ADA activity.

[Activity of pleural fluid adenosine deaminase in tuberculous pleurisy]

Examining the activity of adenosine deaminase in the pleural fluids of 69 patients with tuberculous pleurisy of various etiology from the clinics of Armenia indicated that it was greater than the threshold value of 20 U/L in 95.7 of 47 patients with tuberculous pleurisy. The specificity of this parameter for this disease was 0.91. The prognostic value of the test with positive and negative results was 0.96 and 0.94, respectively. The diagnostic value of the ADA test was 0.94.

[Informative value of adenosine deaminase and 2-deoxyadenosine deaminase in the diagnosis of tuberculous pleurisy]

Adenosine deaminase (ADA) and 2-deoxyadenosine deaminase (2-deoxyADA) activities were measured in pleural exudation of different origin in 373 patients (124 of these with serous tuberculous pleurisy and 75 with specific empyema). High diagnostic value of ADA activity in the presence of threshold value higher than 35 Units/liter was established: the sensitivity of the test in the diagnosis of tuberculous pleurisy and empyema was 94.4 and 93.3% respectively, specificity 93.0 and 89.5%, respectively. Judging by the coefficient of 2-deoxyADA/ADA, total ADA activity is determined by the activity of ADA-2 isoenzyme, while in tuberculous empyema by ADA-1. Additional use of this coefficient, requiring measurement of 2-deoxyADA activity, does not improve the efficiency of the diagnostic process, including measurement of total ADA activity in pleural exudate.

Amylase levels in pleural effusions: a consecutive unselected series of 841 patients

STUDY OBJECTIVES

To describe the causes and relative frequency of amylase-rich pleural effusion (ARPE), and to study the origin and histologic type of the tumors with ARPE, the strength of the association between ARPE and the result of pleural cytology, and whether pleural amylase (PA) is a prognostic factor in the survival of patients with a malignant pleural effusion.

SETTING

Tertiary-care, university-affiliated hospital.

PATIENTS

Eight hundred forty-one consecutive patients with pleural effusion prospectively assessed from 1991 to 1999.

RESULTS

There were 66 ARPEs: 40 neoplastic, and 26 benign with tuberculosis, pancreatitis, and liver cirrhosis as the most frequent causes. Thirty-six percent of patients in our series and 61% of patients with ARPE had a neoplastic disease (odds ratio [OR], 3; p < 0.001); this association got much stronger for cases with PA levels > or = 600 IU/L (95th percentile); [OR, 10; p < 0.001]. The most frequent tumor origin was lung cancer (13 cases). Adenocarcinoma was the most frequent histologic type (18 cases). Two mesothelioma effusions were ARPEs. There was a positive association between ARPE and the finding of tumor cells in pleural fluid (OR, 2.79; p < 0.01). In the malignant group, PA levels > or = 600 IU/L identified a group of patients with quite a short median survival (p = 0.016).

CONCLUSIONS

The most common cause of ARPE was neoplasm. There was a positive association between ARPE and malignancy, stronger with the highest levels (95th percentile). Lung cancer and adenocarcinoma were the most common tumor and histologic type associated with ARPE. Mesothelioma may also produce ARPE. There was an association between ARPE and the finding of tumor cells in the pleural fluid. The highest PA levels identified a group of patients with a median shorter survival.

Occurrence of matrix metalloproteinases and tissue inhibitors of metalloproteinases in tuberculous pleuritis

OBJECTIVE

Matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) have been found in high concentrations in pleural effusions. Because MMP and TIMP may play a part in the causation of the fibrosis seen in tuberculous (TB) pleuritis their occurrence was examined.

DESIGN

Pleural effusion fluid and plasma concentrations of MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, TIMP-1 and TIMP-2 were determined by ELISA in 21 patients with TB pleuritis. To adjust for the total protein content, respective ratios were calculated. Activities of MMP-2 and MMP-9 were measured by gelatine zymography and the MMP-9/MMP-2 ratios calculated. Pleural effusions and plasma of 15 patients with congestive heat failure (CHF) and plasma of 15 healthy persons (CON) served as controls.

RESULTS

Immunoreactive pleural fluid concentrations of MMP-1, MMP-2, MMP-8, and MMP-9 were higher in TB compared to CHF, but plasma concentrations were not different between the groups. TB pleural fluid concentrations of MMP-1, MMP-2, TIMP-1, and TIMP-2 were higher compared to TB plasma. MMP-3 was found in trace amounts only. The MMP-9/total protein ratios in pleural fluid were higher in TB compared to CHF (0.4492+/-0.1633 vs 0.0364+/-0.0145, P<0.005) but the TIMP-1 ratios were lower (139.0+/-28.7 vs 517.8+/-183.7, P<0.0005). In TB pleural fluid vs TB plasma, the respective MMP-1, MMP-2, TIMP-1, and TIMP-2 ratios were increased (0.46+/-0.10 vs 0.17+/-0.02; 25.2+/-2.8 vs 4.2+/-0.9; 139.0+/-28.7 vs 27.8+/-8.2; 0.67+/-0.13 vs 0.18+/-0.04, P<0.0005 each). Gelatine zymography demonstrated MMP-2 and MMP-9 bands of different brightness in TB effusions but in CHF effusions the MMP-9 band was barely visible. The MMP-9/MMP-2 effusion ratios were therefore higher in TB compared to CHF (0.46+/-0.15 vs 0.05+/-0.04, P<0.0005).

CONCLUSION

Compartmentalized MMP-1, MMP-2, TIMP-1, and TIMP-2 and, compared to CHF, a surplus of MMP-1, MMP-2, MMP-8, and MMP-9 in the pleural space obviously contribute to the fibrotic reactions in TB pleuritis.

Utility of polymerase chain reaction using two probes for rapid diagnosis of tubercular pleuritis in comparison to conventional methods

We have used polymerase chain reaction (PCR) with IS6110 and a new set of primers from an insertion element like repetitive sequence, (TRC4) to detect Mycobacterium tuberculosis in pleural effusion samples from 50 patients having pleuritis. The results of PCR were compared with the results of conventional methods like smear, culture and adenosine deaminase activity. Thirty six specimens were positive and 14 were negative by PCR. Among the 36 samples, 33 were from patients with clinical evidence of tuberculosis including response to anti-tuberculosis therapy. Only six samples were positive by the gold standard which is culture, and three were positive by smear. The measurement of adenosine deaminase activity classified 19 samples as positives. The overall sensitivity and specificity of PCR was 100 and 85 per cent respectively. PCR using IS6110 and TRC4 primers is a sensitive test as compared to conventional tests for detection of M. tuberculosis from pleural fluid samples of patients with tubercular pleuritis.

Tuberculous pleurisy: a study of 254 patients

OBJECTIVES

To determine the age at which tuberculous pleural effusions occur, the radiological and biochemical characteristics of the effusions, the sensitivities of the various diagnostic tests, and the utility of combining clinical, radiological, and analytic data in diagnosis.

METHODS

We studied the case histories of 254 patients in whom tuberculous pleural effusions were diagnosed with certainty between January 1, 1989, and June 30, 1997, in a Spanish university hospital in a region with a high incidence of tuberculosis.

RESULTS

The mean (+/-SD) age of the patients was 34.1+/-18.1 years, and 62.2% were younger than 35 years. The effusion was on the right side in 55.9% of patients, on the left side in 42.5% of patients, and on both sides in 1.6% of patients. In 81.5% of patients, less than two thirds of the hemithorax was affected. Associated pulmonary lesions were detected in 18.9% of patients, of whom 14.6% exhibited cavitation. In 93.3% of the effusions, more than 50% of leukocytes were lymphocytes, and almost all had the biologic characteristics of exudates (98.8% had high total protein contents, 94.9% had high cholesterol levels, and 82.3% had high lactate dehydrogenase levels). All but 1 effusion (99.6%) had an adenosine deaminase (ADA) concentration higher than 47 U/L, 96.8% (123/127) of the effusions had high ADA2 levels, and 89% (73/82) of the effusions had high interferon gamma levels. Adenosine deaminase 2 contributed 72.2%+/-12.5% (mean +/- SD) of total ADA activity. Total ADA activity was significantly correlated with ADA2 (r = 0.83) and with interferon gamma (r = 0.30) levels. Definitive diagnosis was based on the observation of caseous granulomas in pleural biopsy tissue samples in 79.8% of patients, on the results of biopsy cultures in 11.7% of patients, and on pleural effusion cultures in the remaining 8.5% of patients. Results of the tuberculin skin test were positive in only 66.5% of patients.

CONCLUSIONS

In these patients, lymphocyte-rich exudative pleural effusions occurred, on average, at a young age, with no preference for either the right or the left side; normally affected no more than two thirds of the hemithorax; and were generally unaccompanied by pulmonary infiltrates. High ADA concentration was a highly sensitive diagnostic sign and was caused by a rise in ADA2 concentration. The most sensitive criterion based on pleural biopsy was the observation of caseous granulomas, and culture of biopsy material further increased overall sensitivity. Negative skin test results were no guarantee of the effusion being nontuberculous. This, together with the low mean age of the patients and the low frequency of associated pulmonary lesions, suggests that tuberculous pleural effusion is a primary form of tuberculosis in this region.

Isoenzymes of adenosine deaminase in pleural effusions: a diagnostic tool?

SETTING

Tygerberg Hospital, an academic teaching hospital, Republic of South Africa.

OBJECTIVE

To identify the adenosine deaminase (ADA) isoenzymes as a diagnostic tool for tuberculosis in pleural effusions with increased ADA activity.

DESIGN

Patients (n = 157) with exudative effusions and ADA activities >20 U/l, due to causes which satisfied predetermined diagnostic criteria, participated in the study. They consisted of 87 tuberculous effusions, 27 infective effusions (12 empyematous and 15 non-empyematous), 37 malignant effusions and six other exudative effusions (systemic lupus erythematosus, pancreatitis and lung embolus). In each case the ADA isoenzymes in the pleural fluid were identified using polyacrylamide gel electrophoresis. In addition, microbiology and cytology (including differential cell counts) were also carried out.

RESULTS

Although ADA1c and ADA2 were the predominant isoenzymes observed in tuberculous effusions, while ADA1c and ADA1m were predominant in infective non-empyematous effusions, no additional diagnostic value was obtained. In the case of neoplastic effusions and other exudates, determination of ADA isoenzyme patterns also did not assist in diagnosing these conditions.

CONCLUSION

Determination of patterns of ADA isoenzymes does not enhance the overall diagnostic value of ADA activity in pleural effusions.

Sequential evaluation of serum adenosine deaminase in patients treated for tuberculosis

STUDY OBJECTIVE

To delineate the course of serum adenosine deaminase (s-ADA) in patients with tuberculosis who are receiving effective therapy.

SETTING

A medical ward and an outpatient clinic in a general hospital.

PATIENTS

Twenty-five immunocompetent patients with pleural or pulmonary tuberculosis.

INTERVENTIONS

All patients received standard chemotherapeutic regimens with isoniazid, rifampin, and pyrazinamide.

MEASUREMENTS AND RESULTS

Six measurements of several variables, including s-ADA, were carried out at different periods of time during the 6 months of follow-up. There were no significant differences in s-ADA values between sexes and there was no significant correlation with age or with the other variables analyzed. There was a significant decline in the s-ADA values during the first 2 months in the patients as a whole (p=0.04), followed by a stabilization of the s-ADA activity. This decline was due to a marked decrease in the s-ADA in the 13 patients (52%) who had initial high levels of the enzyme (p=0.03), whereas there were no changes in those patients with normal initial levels (p=0.27). Patients with increased s-ADA activity at the time of the first measurement reported symptoms for a longer period than patients with normal s-ADA (median, 15 vs 10 days; p=0.02).

CONCLUSIONS

s-ADA levels in patients with tuberculosis decrease during the initial months of effective treatment. Perhaps this decrease might reflect the normalization of the altered lymphocyte turnover induced by tuberculosis. The measurement of s-ADA could be of some help to evaluate the response to therapy, particularly in those patients with increased values of the enzyme.

[Analysis of 90 cases of pleural tuberculosis in relation to adenosine deaminase levels]

BACKGROUND

To analyze the adenosine deaminase (ADA) pleural levels and the possibility of a typical pattern of tuberculous pleuritis (TP) in relation to these values.

PATIENTS AND METHODS

We analyzed 90 consecutive cases of TP dividend into two groups on the basis of the pleural ADA measurements: group 1 (less than 43 U/I) and group 2 (equal or higher than 43 U/I). We compared: age, sex, tuberculous risk factors, clinic onset and duration, PPD, chest roentgenogram, biochemical (LDH, glucose and proteins) and cytological examination of the pleural fluid, microbiologic studies on sputum, pleural fluid and biopsies, histologic findings of the biopsies, evolution and sequelae after the treatment.

RESULTS

36 patients in the group 1 (40%) and 54 in the group 2 (60%) (p = 0.01). All the parameters were similar in both groups excluding LDH pleural levels, that were higher in group 2. In 20 cases of the group 1, we obtained a second analysis of pleural ADA and we observed in 11 cases (55%) an ADA value above 43 U/I.

CONCLUSIONS

We confirmed that ADA pleural level is increased in the majority of our patients with a low initial sensibility of 60%, that can increase with a second determination (72%). ADA activity below 43 U/I cannot exclude the tuberculous aetiology of an effusion and can persist negative in other analyses. The results suggest a response of different chronology without any relation to initial ADA pleural level.

Inhibition of rat pleural mesothelial cell nitric oxide synthesis by transforming growth factor-beta 1

Pleuritis is a common initial clinical manifestation of tuberculosis. It is associated with an accumulation of a variety of cytokines in the pleura and pleural fluid. We have recently shown that these proinflammatory cytokines induce the pleural mesothelial cell to produce large amounts of nitric oxide, a nitrogen intermediate that has been shown to have a tuberculocidal effect. TGF-beta has also been found in situ in tuberculous effusions and pleural tissues and is thought to suppress the immune response and promote tissue repair. This study examined the effects of TGF-beta on cytokine-induced NO synthesis by rat pleural mesothelial cells in vitro. Results demonstrated that TGF-beta significantly inhibited NO synthesis and that this inhibition was associated with a proportionate decrease in iNOS mRNA and iNOS protein. Suppression of pleural mesothelial cell NO synthesis by TGF-beta may be important in the pathogenesis of tuberculous pleuritis.

Adenosine deaminase isozymes in tuberculous pleural effusion

Total adenosine deaminase (ADA) activity and its isozyme (ADA1 and ADA2) activities were measured in pleural effusions and serum samples from patients with tuberculosis and in those from patients with lung cancer as controls. To analyze the cellular source of ADA isozymes in tuberculous pleural effusions, ADA isozyme activities in CD2+ T lymphocytes purified from tuberculous pleural effusions and cultured human cell lines derived from hematopoietic tumors were measured. Tuberculous pleural effusions had a much higher ADA activity than cancerous effusions, and high ADA activity mainly originated from the increase in ADA2 activity. Further, total ADA activity in tuberculous pleural effusions decreased after antituberculosis treatment, because of the decrease in ADA2 activity. On the other hand, measurement of ADA and ADA isozyme activities in T lymphocytes purified from tuberculous pleural effusions and human hematopoietic cell lines showed dominant expression of ADA1 in total ADA activity. In conclusion, we found that ADA2 is a dominant component of tuberculous pleural effusions and that ADA1 is a major component of lymphoid cells. These results suggest that elevation of ADA activity in tuberculous pleural effusions does not always reflect the activation of cell-mediated immunity.

Adenosine deaminase (ADA) isoenzyme analysis in pleural effusions: diagnostic role, and relevance to the origin of increased ADA in tuberculous pleurisy

The rise in adenosine deaminase (ADA) activity in the pleural fluid of tuberculous pleurisy patients, though used for diagnosis, is of unknown origin. In this work, we determined ADA activity and the activities of 2'-deoxyadenosine deaminase and ADA-2 in 350 patients. We also considered whether the results throw light on the origin of high pleural fluid ADA in tuberculous pleurisy and estimated the diagnostic efficiency of 2'-deoxyadenosine deaminase, ADA-2 and total ADA activities with and without the inclusion of the 2'-deoxyadenosine deaminase/ADA activity ratio in a combined criterion. The 350 pleural effusions were classified by previously established criteria as transudates (60 males/18 females) or as tuberculous (49 males/27 females), neoplastic (50 males/39 females), parapneumonic (36 males/19 females), empyematous (11 males/3 females), or miscellaneous (25 males/13 females) exudates. Total ADA, ADA-2 and 2'-deoxyadenosine deaminase activities were, respectively, 127.5 +/- 2.9, 103 +/- 29.5 and 42.8 +/- 14 U.L-1 in tuberculous exudates. With diagnostic thresholds of 47, 40 and 22 U.L-1 respectively, the sensitivities of ADA, ADA-2 and 2'-deoxyadenosine deaminase for tuberculosis were 100, 100 and 95%; their specificities 91, 96 and 92%; and their efficiencies 93, 97 and 93%, respectively. One hundred and one effusions (all 76 tuberculous, 12 neoplastic, 4 parapneumonic and 9 empyematous exudates) had total ADA levels > 47 U.L-1; of these, 8 neoplastic, 1 parapneumonic and all the tuberculous exudates had a 2'-deoxyadenosine deaminase/ADA activity ratio < 0.49. The criterion of simultaneously having ADA > 47 U.L-1, ADA-2 > 40 U.L-1 and a 2'-deoxyadenosine deaminase/ADA activity ratio < 0.49 was satisfied by all the tuberculous effusions but only eight others (all neoplastic) (sensitivity 100%, specificity 97%, efficiency 98%). We conclude that: 1) high total ADA activity in tuberculous pleural effusions is due mainly to an increase in ADA-2, and, therefore, originated from the only known source monocytes and macrophages; 2) ADA-2 was a more efficient diagnostic marker of tuberculous pleurisy than total ADA activity, although the difference was not statistically significant; and 3) among effusions with high total ADA the 2'-deoxyadenosine deaminase/ADA activity ratio differentiates tuberculous effusions from empyemas and parapneumonic effusions, but fails to discriminate well between tuberculous and neoplastic effusions.

Tumour necrosis factor, interleukin-1 and adenosine deaminase in tuberculous pleural effusion

Tumour necrosis factor (TNF) and interleukin-1 (IL-1) are powerful mediators with a key role in inflammation. This study was undertaken to study the presence of TNF and IL-1 in tuberculous effusion where there is marked inflammation and where examination of the pleural fluid may give information about the local inflammatory reaction. Adenosine deaminase activity (ADA, a marker of TB pleurisy) was also tested. Tumour necrosis factor, IL-1 and ADA levels were measured in the pleural fluid and serum of 97 patients; 33 with tuberculous effusion, 33 with malignant effusion, and 31 patients with benign non-tuberculous effusion. Pleural fluid TNF and ADA levels were higher in tuberculous (TB) patients than in patients with benign disorders or cancer (P < 0.01). Serum TNF levels were also higher in TB patients than other benign (P < 0.01) or malignant (P < 0.05) effusions. There was a positive correlation between serum and pleural fluid values (r = 0.998-0.999, P < 0.001) although pleural fluid concentration was higher (P < 0.001), possibly suggesting local production in the pleural cavity. Pleural fluid IL-1 levels were not raised in any patient group but there was a positive correlation between TNF and IL-1. In addition, a positive correlation was found between TNF and ADA levels, probably indicating some common production mechanism. Furthermore, ADA sensitivity in the diagnosis of tuberculous effusion was augmented by the combined use of TNF and ADA. The use of both these markers may prove useful in the differential diagnosis of TBC pleurisy.