Rapid diagnosis of pleural tuberculosis by polymerase chain reaction

Flow cytometry, molecular analysis, and other special techniques (in Serous Fluid Cytopathology)

Morphological and architectural pattern evaluations play a major role in the rpretation of hematopoietic neoplasms. However, confirmation of diagnosis, classification, prognosis, and risk stratification are highly dependent on the utilization of multiple ancillary studies. The importance of these ancillary studies increases in evaluating serous fluid samples, as these samples lack architecture and patterns. Likewise, the morphology can be disturbed by sample preparation. The most common ancillary studies utilized are flow cytometry, immunohistochemistry for immunophenotyping, Fluorescent In Situ Hybridization (FISH), cytogenetics for structural and gene rearrangements, and molecular studies for mutational analysis. Among them, flow cytometry analysis is the handiest test to perform with high diagnostic yield on serous fluid specimens. In this article we will discuss the use, caveat, and role of the most common ancillary studies on serous fluid specimen evaluation. This review article will be incorporated finally as one of the chapters in CMAS (CytoJournal Monograph/Atlas Series) #2. It is modified slightly from the chapter by the initial authors (Choladda Vejabhuti, MD and Chung-Che (Jeff) Chang, MD, PhD) in the first edition of Diagnostic Cytopathology of Serous Fluids.

Diagnostic Accuracy of Pleural Fluid Adenosine Deaminase for Diagnosing Tuberculosis. Meta-analysis of Spanish Studies

OBJECTIVE

To evaluate the usefulness of pleural fluid adenosine deaminase (ADA) for diagnosing tuberculous pleural effusions in the Spanish population, according to laboratory technique and cut-off point, and to compare the results with other populations.

METHODS

Meta-analysis of diagnostic studies on pleural fluid ADA in the Spanish population, extracted from the PubMed and Embase databases from inception until July 2017, with no language restrictions. The overall diagnostic accuracy of ADA and that of each of the measurement techniques (Giusti, manual and automated kinetic methods) and selected cut-offs were analyzed. The QUADAS-2 tool was used to evaluate the quality of studies. A bivariate random effects model was used. Results were compared with those obtained from previous meta-analyses in non-Spanish populations.

RESULTS

Sixteen studies in a total of 4,147 patients, 1,172 of whom had tuberculous pleural effusions, were included. ADA had 93% sensitivity, 92% specificity, positive likelihood ratio of 12, negative likelihood ratio of 0.08, and an area-under-the-curve of 0.968 for identifying tuberculosis. There were no differences in diagnostic accuracy between the techniques used for ADA measurement or the selected cut-offs. In 73 studies from non-Spanish populations a trend toward lower ADA sensitivity (88%, 95% CI:86%-90%) and specificity (88%, 95% CI: 86%-90%) was noted, but differences did not reach statistical significance.

CONCLUSIONS

Pleural fluid ADA in the Spanish population shows good diagnostic accuracy (regardless of the measurement technique or cut-off), similar to that reported in non-Spanish populations.

Evaluation of polymerase chain reaction for rapid diagnosis of clinically suspected tuberculous pleurisy

Pleural effusion is one of the commonest presentations of tuberculosis, the clinical manifestations being typically abrupt resembling bacterial pneumonia. Since delayed hypersensitivity is the underlying immune response, bacterial load is very low. Owing to these facts, tuberculous pleurisy as an extra-pulmonary disease poses a diagnostic dilemma. The conventional bacteriological methods rarely detect Mycobacterium tuberculosis in pleural fluid and are of limited use in diagnosis of tuberculous pleurisy. We evaluated the efficacy of polymerase chain reaction (PCR) in the diagnosis of tuberculous pleurisy by targeting the gene segment coding for MPB64 protein specific forMycobacterium tuberculosis. Based on the clinical criteria, 82 patients with lymphocytic exudative pleural effusion were included in the study. Patients were analyzed in two groups; one group consisting of 48 patients of tubercular pleural effusion confimed by various diagnostic procedures and another group of 34 patients comprising of non-tubercular pleural effusion. There were no false positive results by PCR and the specificity worked out to be 100%. Twenty two patients tested positive for Mantoux with a sensitivity of 45%. ZN-staining for AFB was found in samples from 15 patients (20% sensitivity). ADA was positive for 28 patients with a sensitivity of 53%. PCR was positive for 32/48 patients (67% sensitivity). Thus, PCR was found to be more sensitive than any other conventional method in diagnosis of clinically suspected tubercular pleurisy.

[Management of pleural disease]

In view of the presentations in the First National Forum of Trainee Pneumologists, the present article focuses on infectious pleural effusions and on the study of possible markers of malignant disease in asbestos-exposed individuals. The yield of the distinct techniques for the diagnosis of tuberculous pleural effusion is assessed, with emphasis on analysis of sputum and pleural samples (fluid and tissue) for Mycobacteriumtuberculosis. The utility of adenosine deaminase (ADA) (in the absence of empyema, ADA > 70 U/l is diagnostic of tuberculous pleurisy, while values of less than 40 U/l exclude this diagnosis) and interferon gamma in pleural fluid (cut off: 3.7 Ul/ml) is also discussed. The management of complicated parapneumonic pleural effusions is stratified in four categories, depending on the anatomical and morphological (size and eventual presence of loculations), bacteriological (positivity or negativity of pleural fluid culture) and biochemical (pH/glucose) characteristics of the effusion. Finally, recently developed markers for the evaluation and follow-up of asbestos-exposed individuals are described, with special emphasis on serum determination of mesothelin levels, which seem highly promising as a marker of the development of mesothelioma in these cases. A multicenter study currently being performed in Spain found that soluble mesothelin-related protein (SMRP) levels higher than 0.55 nmol/L showed a sensitivity and specificity of 72% for the diagnosis of epithelial malignant mesothelioma.

Evaluation of different primer sets for the rapid diagnosis of tuberculosis

Pleural fluid samples from patients with exudative effusion who were diagnosed with tuberculous pleuritis are examined using a new designed primer set based on IS1081 gene (IS1081-PCR) and rpoB-PCR. The PCR results are compared with the results of the sample cultures, using Loewenstein-Jensen (LJ) medium and Ziehl-Neelsen (ZN) staining. Of 78 cases that were confirmed as tuberculous pleuritis by histopathology, supported by sputum culture, biochemical markers (adenosine deaminase, gamma interferon and tumor necrosis factor), radiographic and clinical data, 61 (78.2%) were positive by IS1081-PCR, 43 (55.1%) by rpoB-PCR, 17 (21.7%) by culture and 3 (3.8%) by ZN stain. When IS1081-PCR test results were compared with the confirmed culture, the sensitivity, specificity, positive predictive value and negative predictive value for the IS1081-PCR were 94.1, 55.7, 37.2 and 97.1%, respectively. The corresponding values for the rpoB-PCR were 94.1, 26.2, 26.2 and 94.1%, respectively. When tests results were compare with the confirmed radiographic, histopathology, biochemical markers and clinical diagnosis of tuberculous pleuritis, the IS1081-PCR assay is more sensitive, specific and reliable than both rpoB-PCR assay and culture.

Improved diagnosis of pleural tuberculosis using the microscopic- observation drug-susceptibility technique

Tests for pleural tuberculosis are insensitive and expensive. We compared nonproprietary microscopic-observation drug-susceptibility (MODS) culture with Löwenstein-Jensen culture for evaluation of pleural specimens. MODS culture was associated with greatly increased diagnostic sensitivity and shorter time to diagnosis, compared with Löwenstein-Jensen culture (sensitivity of culture of biopsy specimens, 81% vs.51%; time to diagnosis, 11 days vs. 24 days; P < .001). The MODS technique is inexpensive, allows drug-susceptibility testing, and is a considerably improved diagnostic method for pleural tuberculosis.

Diagnostic accuracy of adenosine deaminase in tuberculous pleurisy: a meta-analysis

BACKGROUND

Conventional tests are not always helpful in making a diagnosis of tuberculous pleurisy. Many studies have investigated the usefulness of adenosine deaminase (ADA) in pleural fluid for the early diagnosis of tuberculous pleurisy. We conducted a meta-analysis to determine the accuracy of ADA measurements in the diagnosis of tuberculous pleurisy.

METHODS

After a systematic review of English language studies, sensitivity, specificity, and other measures of accuracy of ADA concentration in the diagnosis of pleural effusion were pooled using random effects models. Summary receiver operating characteristic curves were used to summarize overall test performance.

RESULTS

Sixty-three studies met our inclusion criteria. The summary estimates for ADA in the diagnosis of tuberculous pleurisy in the studies included were sensitivity 0.92 (95% confidence interval 0.90-0.93), specificity 0.90 (95% confidence interval 0.89-0.91), positive likelihood ratio 9.03 (95% confidence interval 7.19-11.35), negative likelihood ratio 0.10 (95% confidence interval 0.07-0.14), and diagnostic odds ratio 110.08 (95% confidence interval 69.96-173.20).

CONCLUSIONS

ADA determination is a relative sensitive and specific test for the diagnosis of tuberculous pleurisy. Measurement of ADA in pleural effusion is thus likely to be a useful diagnostic tool for tuberculous pleurisy. The results of ADA assays should be interpreted in parallel with clinical findings and the results of conventional tests.

Diagnosis and treatment of tuberculous pleural effusion in 2006

Tuberculous (TB) pleural effusion occurs in approximately 5% of patients with Mycobacterium tuberculosis infection. The HIV pandemic has been associated with a doubling of the incidence of extrapulmonary TB, which has resulted in increased recognition of TB pleural effusions even in developed nations. Recent studies have provided insights into the immunopathogenesis of pleural TB, including memory T-cell homing and chemokine activation. The definitive diagnosis of TB pleural effusions depends on the demonstration of acid-fast bacilli in the sputum, pleural fluid, or pleural biopsy specimens. The diagnosis can be established in a majority of patients from the clinical features, pleural fluid examination, including cytology, biochemistry, and bacteriology, and pleural biopsy. Measurement of adenosine deaminase and interferon-gamma in the pleural fluid and polymerase chain reaction for M tuberculosis has gained wide acceptance in the diagnosis of TB pleural effusions. Although promising, these tests require further evaluation before their routine use can be recommended. The treatment of TB pleural effusions in patients with HIV/AIDS is essentially similar to that in HIV-negative patients. At present, evidence regarding the use of corticosteroids in the treatment of TB pleural effusion is not clear-cut.

Clinical utility of polymerase chain reaction for diagnosis of smear-negative pleural tuberculosis

BACKGROUND

Polymerase chain reaction (PCR) is a molecular biology technique which can detect Mycobacterium tuberculosis (TB) genome in pleural fluid; however, the results are variable.

METHODS

Two hundred and twelve pleural fluid specimens suspected to be possibly associated with tuberculosis with negative acid-fast smears were sent to our laboratory to test for the presence of M. tuberculosis DNA using nested PCR, the target for the amplification being a segment of IS6110 in the genome of M. tuberculosis. The final diagnosis of TB pleurisy was based on combining clinical judgment with radiologic findings, microbiologic tests, and the histopathologic findings. Forty-nine patients were excluded due to incomplete or inconsistent clinical information.

RESULTS

Of 163 patients enrolled, PCR was positive in 23 (43.4%) of 53 patients with TB pleurisy and 5 (4.5%) of 110 patients with non-TB pleurisy, with a sensitivity and specificity of 43.4% and 95.5%, respectively. Positive culture of pleural fluid was found in 15 (28.3%) of the TB pleurisy group and none in the non-TB group. Fifteen (55.6%) of 27 with pleural biopsy demonstrated chronic granulomatous inflammation with or without caseous necrosis. Of these 27 patients, PCR was positive in 12 (44.4%). A higher proportion (70.4%) of patients with TB pleurisy was diagnosed when PCR was combined with biopsy results.

CONCLUSION

These data indicate that PCR alone has limited value in diagnosis of TB pleurisy with negative smear. However, when used in combination with pleural biopsy, it can be used to increase early detection of TB pleurisy in such patients.

Coleta e preservação do líquido pleural e biópsia pleural

As amostras de líquido pleural obtidas por toracocentese para o diagnóstico de transudatos e exsudatos devem obedecer a uma rotina de coleta e preservação para a realização de uma análise laboratorial adequada. Igualmente, fragmentos de biópsia de pleura obtidos para o diagnóstico diferencial dos exsudatos devem ser coletados de forma sistemática com o objetivo de otimizar o diagnóstico e facilitar a instituição da terapêutica adequada.

Molecular diagnostics in tuberculosis

Molecular diagnostics in tuberculosis has enabled rapid detection of Mycobacterium tuberculosis complex in clinical specimens, identification of mycobacterial species, detection of drug resistance, and typing for epidemiological investigation. In the laboratory diagnosis of tuberculosis, the nucleic acid amplification (NAA) test is rapid and specific but not as sensitive as culture of mycobacteria. The primary determinant of successful NAA testing for tuberculosis depends on the shedding of mycobacterial DNA in secretions from caseating granulomas and its dissemination into sterile body fluids or tissue biopsies. In multibacillary diseases with a high mycobacterial load, a positive Ziehl-Neelsen smear with a positive NAA test is diagnostic of active tuberculosis, whereas a positive Ziehl-Neelsen smear with a negative NAA test in the absence of inhibitors would indicate nontuberculous mycobacterial disease. The role of the NAA test is more important in paucibacillary diseases with low mycobacterial loads. The presence of polymerase chain reaction (PCR) inhibitors, however, especially in extrapulmonary specimens, may produce false-negative results. Although this problem can be overcome to some extent by extra extraction steps, the additional processing invariably leads to the loss of mycobacterial DNA. To circumvent this problem, a brief culture augmentation step is carried out before the NAA test is performed, which can enhance the mycobacterial load while concomitantly diluting inhibitors, thereby maintaining the sensitivity of the test without excessively increasing turnaround time.

Clinical suspicion as a primary guidance to use commercial amplification tests for rapid diagnosis of pulmonary tuberculosis

The Abbott LCx (Abbott Park, IL) Mycobacterium tuberculosis complex is a commercial amplification assay discontinued from the European market in 2002. A prospective clinical study was carried out to evaluate the clinical utility of the above test as applied by specialists for the rapid diagnosis of active pulmonary tuberculosis (PTB). According to the physician's clinical judgment, patients were classified into 3 groups (low, intermediate, and high) aiming to estimate the probability of active disease. The gold standard for final diagnosis was based on microbiologic and clinical information including data from a 6-month follow-up period. Sensitivities and specificities of rapid microbiologic tests were compared with those based on an integrated approach including clinical evaluation plus the above tests. The incidence of PTB in 214 patients was 13.1%. The basis for initial treatment of PTB was smear-positive results in 46%, positive LCx results in 29%, and clinical suspicion in 18%. For the remaining 7%, therapy was started upon receipt of culture results. The sensitivity, specificity, and positive and negative predictive values of the LCx assay were 68%, 99%, 95%, and 95%, respectively. In comparison, they were 93%, 99%, 96%, and 99%, respectively, for the combination of clinical evaluation plus the LCx test. It is concluded that in patients with high-to-moderate pretest probabilities, the combination of clinical judgment and amplification results strongly enhances a rapid and correct diagnosis of PTB.

Diagnosis of extrapulmonary tuberculosis by smear, culture, and PCR using universal sample processing technology

Definitive and rapid diagnosis of extrapulmonary tuberculosis is challenging since conventional techniques have limitations. We have developed a universal sample processing (USP) technology for detecting mycobacteria in clinical specimens. In this study, this technology was evaluated blindly on 99 extrapulmonary specimens collected from 87 patients. USP-processed specimens were submitted to smear microscopy for detection of acid-fast bacilli (AFB), culture, and two PCR tests targeting devR (Rv3133c) and IS6110 gene sequences. On the basis of clinical characteristics, histology and cytology, conventional microbiology results, and response to antitubercular therapy, 68 patients were diagnosed with tuberculosis. Although USP smear and culture were significantly superior to conventional microbiology, which was not optimized (P < 0.0001), these approaches fell short of PCR tests (P < 0.0001). The low yields by smear and culture are attributed to the paucibacillary load in the specimens. The highest sensitivity in PCR was achieved when devR and IS6110 test results were combined; the sensitivity and specificity values were 83 and 93.8%, 87.5 and 100%, and 66.7 and 75%, respectively, in pleural fluid, needle-biopsied pleural tissue, and lymph node specimens. In conclusion, the application of USP technology, together with clinicopathological characteristics, promises to improve the accuracy and confidence of extrapulmonary tuberculosis diagnosis.

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.

The Clinical Utility of Polymerase Chain Reaction for the Diagnosis of Pleural Tuberculosis

BACKGROUND

There is no exact consensus about the usefulness of the Mycobacterium tuberculosis polymerase chain reaction (PCR) testing for the diagnosis of tuberculous pleural effusion because of the diverse PCR methods and the different diagnostic criteria that are described in other studies.

METHODS

We analyzed pleural effusion specimens obtained from 111 patients for whom the exclusion of the possibility of tuberculous pleural effusion was necessary. We performed M. tuberculosis PCR testing using the Cobas Amplicor MTB test (Roche Diagnostic Systems), which is fully automated and commercially available.

RESULTS

Results of the M. tuberculosis PCR test of pleural effusion specimens were positive for 7 (17.1%) of the 41 patients with confirmed pleural tuberculosis and for 3 (18.8%) of the 16 patients with probable pleural tuberculosis. The overall sensitivity and specificity of M. tuberculosis PCR testing of pleural effusion were 17.5% and 98.1%, respectively. The sensitivity of M. tuberculosis PCR testing for each group of patients with tuberculous pleural effusion detected by smear-positive results, smear-negative and culture-positive results, and culture-negative and pleural biopsy-positive results, was 100.0%, 33.3%, and 3.7%, respectively. Of the 57 patients with pleural tuberculosis, only 3 (5.3%) had positive results of M. tuberculosis PCR testing along with negative results of smearing, negative results of pleural pathological analysis, and a low level of adenosine deaminase.

CONCLUSION

For specimens such as pleural effusion, in which the bacillary load is very low, the clinical utility of PCR testing seems highly limited.

Management of tuberculous pleuritis: Can we do better?

Management of patients with tuberculous pleuritis can be improved by establishing early diagnosis accurately, administering effective chemotherapy, and close monitoring of progress for early detection and prompt management of severe pleural inflammation in the hope of preventing or reducing subsequent residual pleural fibrosis. In addition to the conventional diagnostic tools, chemical markers, especially pleural fluid adenosine deaminase and interferon-gamma levels and new microbiological tests such as polymerase chain reaction and BACTEC culture of pleural biopsy specimens for Mycobacterium tuberculosis, can increase the diagnostic yield for tuberculous pleuritis. Indicators of the severity of pleural inflammation, including high pleural fluid tumour necrosis factor-alpha and lysozyme levels, and low pleural fluid glucose and pH, can help to predict residual pleural fibrosis. It is likely that patients will require surgery: (i) complete drainage of pleural fluid for prevention; and (ii) pleurectomy for the treatment of residual pleural fibrosis.

Molecular genetic methods for diagnosis and antibiotic resistance detection of mycobacteria from clinical specimens

Mycobacteria comprise a diverse group of bacteria that are widespread in nature, some of which cause significant disease in humans. Members of the Mycobacterium tuberculosis complex (MTBC) are the most important human pathogens of the genus Mycobacterium. Traditional methods for detection and identification of mycobacteria include microscopy, culture and phenotypic tests. These methods either lack sensitivity, specificity, or are time consuming. Advances in the field of molecular biology have provided rapid diagnostic tools that have reduced the turnaround times for detecting MTBC and drug resistance in cultures and directly in clinical specimens from weeks to days. This review discusses the molecular genetic techniques for detecting and identifying MTBC as well as drug resistance of mycobacteria in clinical specimens.

Useful clinical biological markers in diagnosis of pleural effusions in children

In a patient with an undiagnosed pleural effusion, the first question to answer is whether the fluid is an exudate or a transudate. This is usually determined by means of Light's criteria, which differentiate transudative effusions from exudative effusions by measuring the levels of total protein and lactate dehydrogenase in the pleural fluid (PF) and serum. In patients under diuretic treatment, Light's criteria misclassify transudates as exudates, but the serum to pleural fluid albumin gradient usually remains above 12 g/L. When tests are done only in PF, protein concentration >30 g/L performs at least as well as the other individual markers. To diagnose tuberculous pleuritis among exudates, PF adenosine deaminase and PF interferon-g exhibit high diagnostic accuracy. When malignancy is suspected the addition of tumour markers to the results of cytologic analysis increases the rate of detection. Other biochemical markers are useful in specific circumstances involving pleural effusion, such as amylase in effusions due to pancreatitis, or oesophageal rupture, and triglycerides in chylothorax. Several PF markers are associated with complicated parapneumonic effusion - e.g. low PF pH and glucose, and high PF LDH activity -- although PF pH appears to be the best biochemical aid in decisions regarding chest tube drainage. Recent reports suggest that neutrophil-derived enzymes (polymorphonuclear elastase and myeloperoxidase) can be useful as early indicators of the need of chest tube insertion; however these findings must be confirmed in large series. This review discusses the clinical usefulness of biochemical markers in the diagnosis and management of pleural effusions. The vast majority of prospective studies in this field have been conducted in adults and, although the mechanisms of pleural effusion production do not differ in children and adults, the prevalence of each etiologic cause does. Therefore it seems advisable to confirm or recalculate the predictive values of each marker in the paediatric population.

Clinical evaluation of the polymerase chain reaction for the rapid diagnosis of tuberculosis

AIMS

Use of the polymerase chain reaction for the detection of Mycobacterium tuberculosis (TB PCR) as a basis for making clinical decisions on the initiation of antituberculosis treatment was studied.

METHODS

A retrospective study involving a cohort of 155 patients being investigated for tuberculosis in an infectious disease consultation service was undertaken. TB PCR was performed on pulmonary and extrapulmonary specimens from these patients. The sensitivity of TB PCR was analysed.

RESULTS

Of the 155 patients, 144 fitted the clinical diagnosis of tuberculosis, and 112 of them were culture positive for M tuberculosis. Sixty (58.3%) patients with clinical features suggestive of tuberculosis received antituberculosis treatment based on positive TB PCR alone. Of 224 clinical specimens (138 pulmonary and 86 extrapulmonary) sent for TB PCR, 148 (99 pulmonary and 49 extrapulmonary) were positive in 117 patients. Of the 690 clinical specimens sent for culture, 279 were positive for M tuberculosis in 112 patients. The diagnostic sensitivity of TB PCR was 75.9% (85 of 112) and 81.3% (117 of 144) in patients with culture confirmed and clinically diagnosed tuberculosis, respectively. Using culture as the gold standard, the overall sensitivity of TB PCR was 78.3%, and for pulmonary and extrapulmonary specimens it was 82.3% and 72.0%, respectively.

CONCLUSIONS

TB PCR is a rapid and reliable test in the diagnosis and management of tuberculosis.

A simple C-reactive protein measurement for the differentiation between tuberculous and malignant pleural effusion

OBJECTIVE

The aim of this study was to determine the validity of pleural fluid C-reactive protein (CRP) concentrations and/or pleural fluid to serum CRP ratio for differentiating tuberculous pleuritis (TBP) from malignant pleural effusion (MPE) in patients presenting with lymphocytic exudative pleural effusions.

METHODOLOGY

A cross-sectional study was conducted on 161 patients with pleural effusion who underwent diagnostic evaluation at Siriraj Hospital, Bangkok, Thailand, between April 2001 and March 2002. The complete biochemical analysis of pleural fluid, cultures of pleural fluid, and pathological examinations of pleural fluid and pleural tissue were performed. The CRP concentrations were then measured in stored sera and pleural fluid samples from patients with a lymphocytic exudative pleural effusion and with a definite diagnosis.

RESULTS

Among the 148 patients with lymphocytic exudative pleural effusions, 55 were diagnosed with TBP, 60 with MPE, and 33 with non-specific pleuritis. Pleural fluid and serum CRP levels were significantly higher in the TBP group than in the MPE group (54.58 +/- 4.50 mg/L and 106.93 +/- 9.54 mg/L vs 12.66 +/- 3.52 mg/L and 49.66 +/- 8.84 mg/L, respectively, P < 0.001). The ratio of pleural fluid to serum CRP was significantly higher in the TBP group than in the MPE group (0.52 +/- 0.18 vs 0.30 +/- 0.16, P < 0.001). The optimum cut-off value for pleural fluid CRP level of > or =30 mg/dL had a sensitivity of 72% with 93% specificity, and the pleural fluid to serum CRP ratio cut-off value of 0.45 had a sensitivity of 60% with 89% specificity. A correlation between serum and pleural fluid CRP levels was observed in TBP patients but not in MPE patients.

CONCLUSION

In patients presenting with lymphocytic exudative pleural effusion, a simple marker of raised pleural fluid CRP level may be helpful in discriminating between TBP and MPE.

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.

Nucleic acid amplification tests in the diagnosis of tuberculous pleuritis: a systematic review and meta-analysis

Background

Conventional tests for tuberculous pleuritis have several limitations. A variety of new, rapid tests such as nucleic acid amplification tests – including polymerase chain reaction – have been evaluated in recent times. We conducted a systematic review to determine the accuracy of nucleic acid amplification (NAA) tests in the diagnosis of tuberculous pleuritis.

Methods

A systematic review and meta-analysis of 38 English and Spanish articles (with 40 studies), identified via searches of six electronic databases, hand searching of selected journals, and contact with authors, experts, and test manufacturers. Sensitivity, specificity, and other measures of accuracy were pooled using random effects models. Summary receiver operating characteristic curves were used to summarize overall test performance. Heterogeneity in study results was formally explored using subgroup analyses.

Results

Of the 40 studies included, 26 used in-house ("home-brew") tests, and 14 used commercial tests. Commercial tests had a low overall sensitivity (0.62; 95% confidence interval [CI] 0.43, 0.77), and high specificity (0.98; 95% CI 0.96, 0.98). The positive and negative likelihood ratios for commercial tests were 25.4 (95% CI 16.2, 40.0) and 0.40 (95% CI 0.24, 0.67), respectively. All commercial tests had consistently high specificity estimates; the sensitivity estimates, however, were heterogeneous across studies. With the in-house tests, both sensitivity and specificity estimates were significantly heterogeneous. Clinically meaningful summary estimates could not be determined for in-house tests.

Conclusions

Our results suggest that commercial NAA tests may have a potential role in confirming (ruling in) tuberculous pleuritis. However, these tests have low and variable sensitivity and, therefore, may not be useful in excluding (ruling out) the disease. NAA test results, therefore, cannot replace conventional tests; they need to be interpreted in parallel with clinical findings and results of conventional tests. The accuracy of in-house nucleic acid amplification tests is poorly defined because of heterogeneity in study results. The clinical applicability of in-house NAA tests remains unclear.

Polymerase Chain Reaction of Pleural Biopsy Is a Rapid and Sensitive Method for the Diagnosis of Tuberculous Pleural Effusion

BACKGROUND

Tuberculous pleural effusion occurs in 30% of patients with tuberculosis (TB). Rapid diagnosis of a tuberculous pleural effusion would greatly facilitate the management of many patients. Polymerase chain reaction (PCR) has been used to detect Mycobacterium tuberculosis in pleural fluid with highly variable sensitivity.

OBJECTIVE

To improve our laboratory diagnosis of tuberculous pleural effusion.

METHODS

We applied PCR to detect DNA specific for M tuberculosis in 33 of the studied pleural biopsy specimens using an IS986-based primer that was specific for mycobacterium complex, and compared it to the results of pleural fluid and biopsy cultures performed on either Lowenstein-Jensen (LJ) medium or BACTEC 12B liquid medium (Becton Dickinson Microbiology Systems; Cockeysville, MD), Ziehl-Neelsen (ZN) staining, and histopathology in 45 patients with pleural effusion.

RESULTS

Of the 45 patients with pleural effusion who were studied, 26 patients received diagnoses of tuberculous pleural effusion that had been confirmed by either culture and or histopathology, 10 patients received diagnoses of exudative effusion due to causes other than TB, and 9 patients received diagnoses of transudative effusion. Histopathology of the pleural biopsy specimen had a sensitivity of 53.8%. The sensitivity of the ZN staining of pleural fluid and biopsy specimens was 0.0% and 3.8%, respectively. The sensitivity of the culture on both BACTEC 12B liquid medium and LJ medium was higher in pleural biopsy specimens (92.3%) than in pleural fluid specimens (15.4%; p > 0.001). The improvements of the BACTEC culture system improved and shortened the detection time of M tuberculosis in pleural biopsy specimens. PCR of pleural biopsy specimens had 90% sensitivity and 100% specificity. The positive predictive value and the negative predictive value for pleural biopsy specimen cultures were 100% and 90.5% vs 100% and 86.7% for pleural biopsy specimen PCRs.

CONCLUSION

The overall accuracy of PCR of pleural biopsy was similar to the results of pleural biopsy culture, however, PCR of the pleural biopsy was much faster in reaching diagnosis. PCR of pleural biopsy is a useful method when used in combination with the BACTEC culture system and histopathologic examination of pleural biopsy to reach a rapid diagnosis of tuberculous pleural effusion.

Rapid diagnosis of extrapulmonary tuberculosis by PCR: impact of sample preparation and DNA extraction

In cases of suspected extrapulmonary tuberculosis, rapid and accurate laboratory diagnosis is of prime importance, since traditional techniques of detecting acid-fast bacilli have limitations. The major difficulty with mycobacteria is achieving optimal cell lysis. Buffers used in commercial kits do not allow this complete lysis in a number of clinical specimens. A comparison of two sample preparation methods, pretreatment with proteinase K (PK-Roche) and complete DNA purification (cetyltrimethylammonium bromide [CTAB]-Roche), was conducted on 144 extrapulmonary specimens collected from 120 patients to evaluate the impact on the Cobas-Amplicor method. Thirty patients were diagnosed with tuberculosis, with 15 patients culture positive for Mycobacterium tuberculosis. Amplification and detection of the amplicons were impaired by a high number of inhibitory specimens (39 to 52%). CTAB-Roche allowed the detection of more culture-positive specimens by PCR than PK-Roche. Comparison with the final diagnoses of tuberculosis confirmed that CTAB-Roche produced the best sensitivity (53.8%) compared to culture (43.3%), PK-Roche (16%), and smear (13%). However, the specificity of the PCR assay with CTAB-Roche-extracted material was always lower (78.8%) than those with culture (100%) and PK-Roche (96.5%). False-positive specimens were lung biopsy material, lymph node biopsy material and aspirate, or bone marrow aspirate, mainly from immunocompromised patients. Despite the efficiency of complete DNA extraction for the rapid diagnosis by PCR of extrapulmonary tuberculosis, the false-positive results challenge our understanding of PCR results.

Nested polymerase chain reaction for Mycobacterium tuberculosis DNA detection in aqueous and vitreous of patients with uveitis

BACKGROUND

Tuberculosis may be a lethal disease. Its ocular manifestations are commonly associated with severe difficulties in diagnosis and therapy; furthermore, it may cause blindness. DNA amplification methods may allow early detection of small amounts of Mycobacterium tuberculosis DNA to afford the possibility of prompt diagnosis. We evaluated a nested polymerase chain reaction (nPCR) assay for detection of Mycobacterium tuberculosis DNA in aqueous and vitreous.

METHODS

In a case-control study, 22 cases of diagnosed TB uveitis (three HIV-infected patients) and 38 controls (18 HIV-infected patients) with other types of uveitis (syphilis, nine; cytomegalovirus, seven; toxoplasmosis, five; herpes simplex, one; autoimmune vasculitis, eight; Vogt-Koyanagi-Harada, four; pars planitis, one; serpinginous choroiditis, one; Wegener granulomatosis, one; and Fuchs iridocyclitis, one studied). Samples from aqueous or vitreous were cultured and analyzed by nPCR for presence of M. tuberculosis nucleic acids. We used two sets of primers corresponding to IS6110 region coding for 219 bp and 123 bp DNA sequences.

RESULTS

Results were confirmed by Southern blot. All samples were tested by PCR simultaneously for Herpes simplex I, Herpes zoster, cytomegalovirus (CMV) and Toxoplasma gondii. nPCR was positive in 17 cases (77.2%) and only in three controls (8.8%) p = 0.022. All cultures were negative. Southern blot confirmed all positive nPCR tests. According to our definition of cases, there were five false negative results: two in patients with pulmonary tuberculosis; two in patients with tuberculous lymphadenitis, and one with positive skin test and hematuria. There were three cases considered false positives for nPCR: one with autoimmune vasculitis, and two with toxoplasmic uveitis.

CONCLUSIONS

nPCR for TB in ocular fluids was positive in the majority of cases of ocular TB. This method is useful in early confirmation of ocular tuberculosis.

Long-term results of Charnley low-friction arthroplasty in tuberculosis of the hip

We reported 8 to 13 years of follow-up of cases of tuberculosis of the hip previously. Now we report on 60 cases of hip tuberculosis treated with total hip arthroplasty. The results have been reasonably acceptable, with the longest follow-up >28 years. Prosthetic life was limited to at most 20 years in our longest cases mainly because of loss of fixation of the acetabular component. There were recurrences of tuberculosis in 5 hips. We confirmed that antituberculous chemotherapy is crucial in total hip arthroplasty reconstruction. Detection of Mycobacterium tuberculosis using polymerase chain reaction may provide rapid diagnosis and follow-up for treatment response.

Efficacy of Amplicor PCR for the diagnosis of tuberculosis in respiratory specimens other than sputum

A total of 832 respiratory specimens not including the sputum (402 bronchial lavages, 241 bronchial brushing specimens, 136 pumping lavages, 41 pleural effusions, and 12 others) from 462 patients were assayed using the Roche Amplicor Mycobacterium tuberculosis test for amplification and identification of M. tuberculosis, M. avium and M. intracellulare (Amplicor PCR). The results were compared with those obtained using conventional microscopy and cultivation methods. Each patient had little or no sputum and showed an abnormal chest X-ray shadowing of unknown cause. No patients had previously undergone antituberculous therapy. Of the specimens obtained, 24 were both PCR and culture positive, 786 were both PCR and culture negative, 11 were PCR positive and culture negative, and 11 were PCR negative and culture positive. Based on these results, the sensitivity and specificity of Amplicor PCR were determined to be 68.67% and 98.6%, respectively, when compared with culture of respiratory specimens not including the sputum. After correcting for discrepancies due to differences in patient clinical data, the sensitivity of Amplicor PCR was found to be 68.6%, and the specificity to be 99.9%; the corresponding values for culture were 66.7% and 100%, and those for smear were 9.8% and 100%. Thus, Amplicor PCR was shown to possess a similar sensitivity to culture and to be a highly specific technique for the diagnosis of tuberculosis in the respiratory system using non-sputum specimens within hours in patients showing little or no sputum and abnormal chest X-ray shadowing of an indeterminant cause.

Evaluation of polymerase chain reaction, adenosine deaminase, and interferon-gamma in pleural fluid for the differential diagnosis of pleural tuberculosis

STUDY OBJECTIVES

Pleural tuberculosis (TB) is a diagnostic challenge because of its nonspecific clinical presentation and paucibacillary nature. The inefficiency of conventional laboratory methods and the reliance on pleural biopsy have motivated the evaluation of alternative diagnostic strategies. We have evaluated polymerase chain reaction (PCR) directed to the IS6110 sequence of Mycobacterium tuberculosis, the determination of adenosine deaminase (ADA) activity, and measurement of interferon (IFN)-gamma levels in pleural fluid in the diagnosis of pleural TB.

PATIENTS

ADA activity, IFN-gamma levels, and PCR were evaluated in 140 cases of pleural effusion, 42 with confirmed pleural TB, 19 with probable pleural TB, 70 with a nontuberculous etiology, and 9 having an undetermined etiology.

RESULTS

ADA activity, IFN-gamma levels, and PCR were 88%, 85.7%, and 73.8% sensitive, respectively, and 85.7%, 97.1%, and 90% specific, respectively, for pleural TB that had been confirmed by either culture or pleural biopsy specimens. The combination of PCR, IFN-gamma measurement, and ADA activity determination allowed the selective increase of sensitivity and specificity for probable and confirmed cases compared to individual methods. Positive and negative predictive values for these individual or combined methods were maintained over a wide range of prevalence of pleural TB in the patient population presenting with pleural effusions. Fever and younger age were associated with tuberculous pleural effusion (p < 0. 0001), while blood in sputum and older age were associated with malignant etiology (p < 0.008).

CONCLUSIONS

These clinical variables together with the use of ADA activity determination, PCR, and measurement of IFN-gamma levels provide the basis for the rapid and efficient diagnosis of pleural TB in different clinical settings.

Detection of mycobacterium tuberculosis in paraffin-embedded pleural biopsy specimens by commercial ribosomal RNA and DNA amplification kits

STUDY OBJECTIVES

To evaluate the utility of two gene amplification systems in historical paraffin-embedded pleural biopsy (PEB) tissues from patients with pleural tuberculosis, and to compare the results to those obtained with conventional histologic and microbiological methods.

DESIGN

A retrospective study.

PATIENTS AND METHODS

Seventy-four formalin-fixed PEB tissues collected and stored over 12 years (1984 through 1995) were retrieved. Gene amplifications were performed in 57 tissues from patients with diagnoses of pleural tuberculosis and in 17 from patients with carcinoma as controls, using the first version of the Amplified Mycobacterium tuberculosis Direct Test (AMTDT; Gen-Probe; San Diego, CA) and the LCx Mycobacterium tuberculosis Assay (LCxMTB; Abbott Laboratories; Abbott Park, IL).

RESULTS

The sensitivities of the AMTDT and LCxMTB were 52.6% and 63.2%, respectively (p = not statistically significant). The specificity of both tests was 100%. Twenty tissue samples (35.1%) were positive by both systems, and 10 tissues (17.5%) were positive only by the AMTDT, while 16 tissues (28.1%) were positive only by the LCxMTB. Both tests gave negative results for 11 specimens (19.3%). When both tests were used, a positive diagnosis was achieved in 80.7% of the samples. Diagnosis of 73.7% of patient conditions had previously been made by smear examination of pleural biopsy and sputum, pleural liquid, or biopsy culture. The overall diagnostic yield with both culture and amplification techniques was 96.5% (55 of 57 patients) for pleural tuberculosis, with amplification techniques adding 22.8% of the diagnoses.

CONCLUSIONS

Amplification techniques are useful in archival PEB tissues, providing additional diagnoses beyond culturing, although the sensitivity should be improved, possibly by standardizing protocols.

The use of adenosine deaminase and adenosine deaminase isoenzymes in the diagnosis of tuberculous pleuritis

The bacillary population described in tuberculous pleuritis is small, and its most likely pathogenetic mechanism is essentially immunologic. This explains why, until now, the diagnostic identification of tuberculous pleuritis (TP) has been based on the presence of granulomas in pleural biopsy. Correcting this diagnostic deficiency through other parameters related to the specific pathogenetic mechanism has been widely studied. The determination of the levels of adenosine deaminase (ADA) in pleural fluid offers high performance in its discriminating capacity to identify TP (sensitivity 87 to 100%, specificity 81 to 97%). Adenosine deaminase expresses the sum of two isoenzymes (ADA1 and ADA2). ADA1 is ubiquitous in all cells, including lymphocytes and monocytes, whereas ADA2 is found only in monocytes. Analysis and determination of these isoenzymes have shown that ADA in TP increases particularly at the expense of ADA2 and that the ADA1 /ADAp activity ratio improves performance in terms of sensitivity, specificity, and efficacy (100%, 92 to 97%, and 98%, respectively) in correcting all false-negative and false-positive results except 1 to 9% of nonlymphoproliferative malignancies. Only the high performance of ADA in the identification of TP allows it to be assumed that pleural biopsy can be obviated, especially in patients aged less than 35 years of age or having a lymphocyte-to-neutrophil proportion of more than 0.75 in regions of high prevalence. Quick determination and low cost justify its routine use in exudates. The ADA1 /ADAp activity ratio improves performance even more and could be used in cases with uncertain diagnoses or in regions with low prevalence of tuberculosis.

Clinical management of the patient with pleural effusion

Pleural effusion is a frequent medical problem with a wide span of different causes. We wish to highlight the clinical management of the patient with pleural effusions but anatomic, physiologic and diagnostic management of the main pleural diseases will also be considered.

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.

[Usefulness of a gene amplification technique (LCx MTB) in the diagnosis of tuberculosis: preliminary results with different sputum samples]

OBJECTIVE

To evaluate the use in non-sputum samples of a commercial molecular amplification kit (LCx MTB, Abbott Diagnostica) (LCx) for the diagnosis of tuberculosis.

MATERIAL AND METHOD

Ninety-nine non-sputum samples from the same number of patients (bronchoalveolar, pleural and ascitic fluid, fecal samples, blood cultures, biopsies from different sites, cerebrospinal fluid, urine and gastric juices) and 14 sputum samples (10 from patients clinically suspected of having tuberculosis and 4 from patients diagnosed of tuberculosis and undergoing appropriate treatment for at least one month). All samples were LCx processed according to the manufacturer's instructions. The reference diagnosis was obtained by the Löwestein-jensen method and when results were inconsistent, we took into account the degree of clinical suspicion, response to treatment and histology.

RESULTS

Seven of the 99 samples were positive by the LCx technique, and 6 of the 7 were also LJ positive; 1 could not be evaluated because of culture contamination. One LJ positive culture was LCx negative. Only one sample was positive by Ziehl-Neelsen (ZN) staining. Ninety-two samples were LCx negative, with 91 showing no growth at all. Sensitivity was 86% and specificity 98%. Atypical mycobacteria were detected in 4 cases, all of which were LCx negative.

CONCLUSIONS

Diagnosis of tuberculosis by applying the LCx system to various types of samples other than sputum is simple, rapid, sensitive and specific.

IS6110 dot blot hybridization for the identification of Mycobacterium tuberculosis complex

To explore a simple, rapid, and inexpensive way to identify Mycobacterium tuberculosis complex culture, dot blot hybridization using IS6110 as the marker was performed against 2788 known clinical isolates of mycobacteria including M. tuberculosis (n = 721), M. kansasii (177), M. marinum (10), M. avium complex (700), M. terrae complex (203), M. fortuitum (476), M. chelonae (439), and other nonpigmented Runyon's Group IV mycobacteria (62). We found that the sensitivity and specificity of the test were 94.3% and 100%, respectively. When this method was evaluated in a laboratory blind study of 1253 initially unknown clinical isolates, its sensitivity and specificity were 91.2% and 100%, respectively. Because this identification test is technically simple, rapid, and can be done in batches, together with its high sensitivity and specificity, it is a cost-effective method for routine identification of M. tuberculosis complex in laboratories of areas with a high incidence of tuberculosis.

Rapid diagnosis of tuberculosis in various biopsy and body fluid specimens by the AMPLICOR Mycobacterium tuberculosis polymerase chain reaction test

STUDY OBJECTIVES

This study was undertaken to determine the usefulness of the AMPLICOR Mycobacterium tuberculosis (MTB) polymerase chain reaction (PCR) test (Roche Diagnostic Systems, Inc; Branchburg, NJ) in diagnosing TB in tissue and body fluid specimens other than respiratory secretions.

DESIGN AND SETTING

Prospective analysis of clinical and laboratory data in patients with suspected TB at the four divisional hospitals of Catholic Medical Center, located in New York.

PATIENTS AND MEASUREMENTS

A total of 1,090 tissue and body fluid specimens from 1,032 patients with suspected TB were subjected to acid-fast bacillus (AFB) smear, culture, and the AMPLICOR MTB PCR test.

RESULTS

Of the 1,090 specimens, 32 grew M tuberculosis complex and 8 specimens grew isolates belonging to the Mycobacterium avium complex (MAC). The AMPLICOR MTB PCR test was positive for 24 of the 32 specimens that grew M tuberculosis. It was also positive for four additional specimens that were culture-negative for M tuberculosis or MAC. Two of these specimens were from patients with a previously recorded positive sputum culture for M tuberculosis. The AMPLICOR test was negative for all eight specimens that yielded MAC only. When AMPLICOR MTB PCR test results were compared with the confirmed clinical diagnosis of TB, the sensitivity, specificity, positive predictive value, and negative predictive value for the AMPLICOR MTB PCR test were 76.4%, 99.8%, 92.8%, and 99.2%, respectively. PCR results were available within 6.5 hours, compared with an average of 3 weeks for culture of M tuberculosis.

CONCLUSIONS

These data establish the utility of the AMPLICOR MTB PCR test for the rapid detection of M tuberculosis in tissue and body fluid specimens other than respiratory secretions.