Diagnosis Of PTB Research Articles

Rapid Diagnosis of Smear-negative Tuberculosis by Bronchoalveolar Lavage Enzyme-linked Immunospot

Rationale: In a large proportion of patients with active pulmonary tuberculosis (pTB), acid-fast bacilli smear results for sputum and bronchial secretions are negative. Detectable growth of Mycobacterium tuberculosis (MTB) in cultures takes several weeks and MTB-specific DNA amplification results on sputum and bronchial secretions are variable in these patients.Objective: We investigated whether a rapid diagnosis of pTB can be established by enumeration of MTB-specific mononuclear cells from bronchoalveolar lavage (BAL) fluid in routine clinical practice.Methods: Patients presenting to a tertiary hospital with medical histories and pulmonary infiltrates compatible with tuberculosis, and negative acid-fast bacilli smear results (three) from sputum, were prospectively enrolled in this study. An MTB-specific enzyme-linked immunospot assay (ELISPOT [T-SPOT.TB; Oxford Immunotec, Abingdon, UK]) with early antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) peptides was performed on peripheral b...

Level of antibodies against mycobacterial glycolipid in the effusion for diagnosis of tuberculous pleural effusion

Diagnosing tuberculous pleural effusion (pTB) is often difficult because the culturing of tubercle bacilli results in a negative test in the majority of cases. Serological tests for the detection of antibodies to tuberculous glycolipid (TBGL) and lipoarabinomannan (LAM) have been introduced for the diagnosis of pulmonary tuberculosis. We examined the levels of these antibodies, adenosine deaminase (ADA) and interferon-gamma (IFN-gamma) in the pleural effusion and compared their diagnostic values in pTB. We studied 65 patients with pleural effusion. Of those, 19 patients were diagnosed as having pTB according to our broad case definition. The etiologies in the other 46 patients were malignant effusion, transdative effusion and miscellaneous diseases. Determiner TBGL antibody (D-TBGL-Ab) and MycoDot were used for the detection of anti-LAM and anti-TBGL antibodies, respectively, in the pleural effusion. The sensitivity of ADA was 78.9% (15/19) and the specificity 97.8% (45/46). The sensitivity of IFN-gamma was 84.2% (16/19) and the specificity 93.5% (43/46). The sensitivities of D-TBGL-Ab and MycoDot were both 52.6% (10/19) and their specificities were 95.7% (44/46) and 97.8% (45/46), respectively. When DTBGL-Ab (cutoff point: 2.0 U/ml) and ADA activity (cutoff point: 57 IU/l) were combined, the sensitivity was 94.7% (18/19) and the specificity 93.5% (43/46). In the diagnosis of pTB, D-TBGL-Ab and MycoDot each have low sensitivity but high specificity. When D-TBGL-Ab is used in combination with ADA, the sensitivity and specificity are both >90%. We conclude that D-TBGL-Ab and ADA in combination are useful in the diagnosis of pTB.

Combined Use of the Polymerase Chain Reaction and Detection of Adenosine Deaminase Activity on Pleural Fluid Improves the Rate of Diagnosis of Pleural Tuberculosis

Evaluation of the combined use of polymerase chain reaction (PCR) and adenosine deaminase (ADA) activity on the diagnosis of pleural tuberculosis (pTB) in a region of high prevalence of tuberculosis. PCR and determination of ADA activity were performed on the pleural fluid of every patient presenting with pleural effusion suspected to be associated with tuberculosis. The case definition of pTB involved parameters including the combination of clinical and radiologic findings; biochemical, microbiologic, and cytologic examination of the pleural fluid; and the histopathologic findings of pleural fragments obtained by biopsy. The diagnosis of pTB was confirmed in any patient presenting with positive culture findings of Mycobacterium tuberculosis, either on the pleural fluid or other biological material, or the presence of histopathologic findings suggestive of pTB on pleural biopsy, and also, in the absence of negative laboratory results, those patients with clinical improvement after empirical treatment. We studied 45 patients with pleural effusion. Of these, 16 patients met the diagnosis of pTB by our broad case definition. PCR findings were positive in six patients. The reaction was also positive in a patient whose diagnosis of tuberculosis could not be confirmed. ADA activity was considered positive in 11 patients with pTB. The combined use of PCR and ADA activity confirmed pTB in 14 patients; however, when analyzed in combination with the conventional methods, diagnosis of pTB was achieved in all 16 patients. Our results show that, even in a highly endemic area, neither PCR nor ADA activity should be relied on as a single test that substitutes for the diagnostic methods already available, but rather they should be used as an extra tool in the diagnosis of pTB. The combined analysis of PCR and ADA activity, however, is a very useful diagnostic approach to achieve a more rapid and precise diagnosis in the cases of pTB.

Noninvasive Imaging of cerebrovascular disease

<h3>Abstract</h3> There has been a lot of debate about the use of the Adenosine Deaminase (ADA) for tuberculosis (TB) diagnosis. In the present study, to overcome this debate, we have planned a large scale study in all forms of TB to access the performance of ADA for diagnosis of TB. we have also studied the performance of the ADA in the Tb prognosis. ADA activity was evaluated using Guisti and Galanti method. The sensitivity of the ADA test is impressive in all forms of TB clinical samples analysed for the study (PTB [82%], TBM [85%] TBAR [85%]), and (ATB) [84%]. However, the specificity was variable in pulmonary TB, but satisfactory in extrapulmonary TB (EPTB) cases (i.e TBM [89%], (ATB) [88%], TBAR [88%]). In the follow-up samples, ADA value declined drastically after the anti TB medication (ATT). Our study, which consists of a large number of samples, suggests that the ADA has very limited value in the diagnosis of PTB, and hence it is not recommended for PTB diagnosis. We recommend, ADA test is quite useful for EPTB diagnosis along with other clinical correlations and in absence of other advanced diagnostic tests. However, on the other ADA can be used as a prognostic test for all forms of TB.

Comparison of Different Diagnostic Method for Mycobacteria Tuberculosis in Suspected Patients

Background: Microbial examination of smear of AFB by Z-N stain is currently the most rapid method for the detection of M. tuberculosis but its sensitivity is low i.e. required at least 10,000 bacterial cells per ml of sputum and also none specific, but auramine staining method has higher sensitivity than that of the Z-N stain but there are chances of false positive. Objective of this study was to find the correlation between chest X-ray, direct sputum smear examination by Ziehl-Neelsen stain, Auramine fluorochrome stain and sputum culture for M. tuberculosis. Methods: During that study period 250 x 3 samples were taken three each from 250 patients and divided into two groups A and B by performing Auramine fluorochrome stain in all samples . In group A, there were 150 fluorochrome stain positive samples. One each from 150 patient for comparative study of direct sputum smear examination by Ziehl-Neelsen stain, , culture on LJ medium and chest X-ray. Similarly in group B, next 100 fluorochrome stain negative specimens one each from 100 patients were taken for the comparative study of direct sputum smear examination by Ziehl-Neelsen stain, culture and chest X-ray. Results: In the study group A (n=150) all the specimens were positive in Auramine fluorochrome stain and all of them show positive in X-ray but only 134 showed positive in Ziehl-Neelsen stain and 136 showed positive in culture. In the study group B (n=100), all the specimens were negative in Auramine fluorochrome stain and all of them show negative in Ziehl-Neelsen stain but 14 of them were positive in culture and 24 were positive in chest X-ray. Conclusions: The diagnosis of PTB could be made by Auramine fluorochrome microscopy and culture. Key words: auramine fluorochrome stain; culture; mycobacterium tuberculosis; x-ray; ziehl-neelsen. DOI: 10.3126/jnhrc.v7i2.3012 Journal of Nepal Health Research Council Vol.7(2) Apr 2009 84-88