Diagnostic value of bronchoalveolar lavage in suspected pulmonary tuberculosis

Aerosolization of viable Mycobacterium tuberculosis bacilli by tuberculosis clinic attendees independent of sputum-Xpert Ultra status

Potential Mycobacterium tuberculosis (Mtb) transmission during different pulmonary tuberculosis (TB) disease states is poorly understood. We quantified viable aerosolized Mtb from TB clinic attendees following diagnosis and through six months' follow-up thereafter. Presumptive TB patients (n=102) were classified by laboratory, radiological, and clinical features into Group A: Sputum-Xpert Ultra-positive TB (n=52), Group B: Sputum-Xpert Ultra-negative TB (n=20), or Group C: TB undiagnosed (n=30). All groups were assessed for Mtb bioaerosol release at baseline, and subsequently at 2 wk, 2 mo, and 6 mo. Groups A and B were notified to the national TB program and received standard anti-TB chemotherapy; Mtb was isolated from 92% and 90% at presentation, 87% and 74% at 2 wk, 54% and 44% at 2 mo and 32% and 20% at 6 mo, respectively. Surprisingly, similar numbers were detected in Group C not initiating TB treatment: 93%, 70%, 48% and 22% at the same timepoints. A temporal association was observed between Mtb bioaerosol release and TB symptoms in all three groups. Persistence of Mtb bioaerosol positivity was observed in ~30% of participants irrespective of TB chemotherapy. Captured Mtb bacilli were predominantly acid-fast stain-negative and poorly culturable; however, three bioaerosol samples yielded sufficient biomass following culture for whole-genome sequencing, revealing two different Mtb lineages. Detection of viable aerosolized Mtb in clinic attendees, independent of TB diagnosis, suggests that unidentified Mtb transmitters might contribute a significant attributable proportion of community exposure. Additional longitudinal studies with sputum culture-positive and -negative control participants are required to investigate this possibility.

The Added Value of Bronchoalveolar Lavage for Pulmonary Tuberculosis Diagnosis in High-Risk Hospitalized Patients with Negative Sputum Samples

Hospitalized patients with a high suspicion of pulmonary tuberculosis (HS-PTB) are isolated until a definite diagnosis can be determined. If doubt remains after negative sputum samples, bronchoscopy with bronchoalveolar lavage (BAL) is often sought. Still, evidence of the added value of BAL in this patient population is scarce. To address this issue, we included consecutive HS-PTB patients with negative sputum samples who underwent BAL between 2017 and 2018. Chest X-rays (CXR) and CT scans were evaluated by a chest radiologist blind to the final diagnosis. Independent predictors for PTB were assessed by multivariate regression, using all positive PTB patients between 2017 and 2019 (by sputum or BAL) as a control group (n = 41). Overall, 42 HS-PTB patients were included (mean age 51 ± 9, 36% female). BAL was a viable diagnostic for PTB in three (7%) cases and for other clinically relevant pathogens in six (14%). Independent predictors for PTB were ≥2 sub-acute symptoms (adjusted OR 3.18, 95% CI 1.04-9.8), CXR upper-lobe consolidation (AOR 8.70, 95% CI 2.5-29), and centrilobular nodules in chest CT (AOR 3.96, 95% CI 1.20-13.0, p = 0.02). In conclusion, bronchoscopy with BAL in hospitalized patients with HS-PTB had a 7% added diagnostic value after negative sputum samples. Our findings highlight specific predictors for PTB diagnosis that could be used in future controlled studies to personalize the diagnostic evaluation.

Bronchial Washing Using a Thin Versus a Thick Bronchoscope to Diagnose Pulmonary Tuberculosis: A Randomized Trial

BACKGROUND

This study was performed to evaluate the efficacy of using a thin bronchoscope for the diagnosis of pulmonary tuberculosis (PTB).

METHODS

Between March 2019 and November 2021, we prospectively enrolled participants with suspected PTB whose sputum acid-fast bacilli (AFB) smear and tuberculosis (TB) polymerase chain reaction (PCR) tests were negative or who could not produce self-expectorated sputum. Participants were randomized to a control group (bronchial washing [BW] using a 5.9-mm conventional bronchoscope guided by chest computed tomography) or an investigational group (BW using a 4.0-mm thin bronchoscope under virtual bronchoscopic navigation guidance). The primary outcome was detection of TB in BW fluid, defined as a positive result in the Xpert MTB/RIF assay. The secondary outcomes included AFB smear and Mycobacterium tuberculosis culture positivity, time to treatment initiation, and bronchoscopy-related complications.

RESULTS

In total, 85 participants were included in the final analysis (43 in the control group and 42 in the investigational group). Twenty-three and 29, respectively, were finally diagnosed with PTB. The TB detection rate in BW fluid was higher in the investigational group (72.4% vs 43.5%, P = .035). Mycobacterium tuberculosis culture positivity was also higher in the investigational group (79.3% vs 52.2%, P = .038). No participants required premature bronchoscopy termination because of complications. Of the participants with PTB, the time to treatment initiation was shorter in the investigational group (median, 2.0 days vs 4.0 days, P = .001).

CONCLUSIONS

BW using a thin bronchoscope increases the TB detection rate in patients with PTB compared to conventional bronchoscopy. Clinical Trials Registration.ȃNCT03802812.

Diagnostic value of bronchoalveolar lavage and bronchial washing in sputum-scarce or smear-negative cases with suspected pulmonary tuberculosis: a randomized study

OBJECTIVES

Bronchoalveolar lavage (BAL) and bronchial washing (BW) are two major methods used to obtain high-quality respiratory specimens from patients with suspected pulmonary tuberculosis (TB) but a sputum-scarce or smear-negative status. We aimed to compare the value of BAL and BW in the diagnosis of TB in such patients.

METHODS

We enrolled patients with suspected pulmonary TB but with a sputum-scarce or smear-negative status who were referred for bronchoscopy between October 2013 and January 2016. Participants were randomized into the BAL and BW groups for evaluation. The primary outcome was the diagnostic yield for TB detection. Secondary outcomes included culture positivity, positivity of nucleic acid amplification tests (NAATs) for Mycobacterium tuberculosis and procedure-related complications.

RESULTS

A total of 94 patients were assessed and 91 (43 in the BAL group, 48 in the BW group) were analysed. Twenty-one patients (48.8%) in the BAL group and 30 (62.5%) in the BW group had a final diagnosis of pulmonary TB. The detection rate of M. tuberculosis by culture or NAAT was significantly higher in BAL specimens than in BW specimens (85.7% vs 50.0%, p 0.009). The procedure-related complications were hypoxic events, 2/43 (4.7%) in the BAL group and 5/48 (10.4%) in the BW group; and post-bronchoscopic fever, 3/43 (7.0%) in the BAL group and 4/48 (8.3%) in the BW group.

DISCUSSION

As long as it is tolerable, BAL rather than BW, should be used to obtain specimens for the diagnosis of pulmonary TB in sputum-scarce or smear-negative cases.

A Comprehensive Evaluation of Xpert MTB/RIF Assay With Bronchoalveolar Lavage Fluid as a Single Test or Combined With Conventional Assays for Diagnosis of Pulmonary Tuberculosis in China: A Two-Center Prospective Study

Introduction: The Xpert MTB/RIF is recommended by the World Health Organization as a first line rapid test for the diagnosis of pulmonary tuberculosis (TB); however, China does not routinely use this test, partially due to the lack of a sufficient number of systematic evaluations of this assay in local patients. The aims of this study were to comprehensively assess the diagnostic performance of Xpert MTB/RIF, either alone or in combination with conventional assays for the diagnosis of pulmonary TB in adult Chinese patients. Methods: Xpert MTB/RIF tests were performed in 190 adult patients with suspected pulmonary TB, using bronchoalveolar lavage fluid (BALF) as test specimens. In parallel, conventional tests were carried out using the same BALF samples. Using two different reference standards, the performance of Xpert MTB/RIF, conventional assays and their combinations were evaluated. Results: Using mycobacterial culture as the reference comparator, Xpert MTB/RIF was found to be superior to smear-microscopy in detecting Mycobacterium tuberculosis. When final diagnosis, based on clinical criteria, was employed as the reference standard, Xpert MTB/RIF showed an even higher accuracy of 72.1%, supported by a sensitivity of 61.1% and specificity of 96.6%. Xpert MTB/RIF also demonstrated a powerful capability to identify pulmonary TB cases undetected by culture or smear-microscopy. Combining smear-microscopy and Xpert MTB/RIF was found to be the most accurate early predictor for pulmonary TB. Rifampicin resistance reported by Xpert MTB/RIF slightly deviated from that by phenotypic antibiotic susceptibility testing and requires further study with a larger sample size. Conclusion: This two-center prospective study highlights the value of Xpert MTB/RIF with BALF in diagnosing pulmonary TB in adult Chinese patients. These findings might contribute to the optimization of current diagnostic algorithms for pulmonary TB in China.

A Comparative Study of Induced Sputum and Bronchial Washings in Diagnosing Sputum Smear Negative Pulmonary Tuberculosis

INTRODUCTION

Tuberculosis is one of the most important public health problem worldwide. Detecting patients with active pulmonary Koch's disease is an important component of tuberculosis control programs. However, at times in patients even with a compatible clinical picture, sputum smears do not reveal acid-fast bacilli and smear-negative pulmonary tuberculosis remains a common problem.

AIM

The present study is aimed to compare the results of induced sputum and bronchial washings smear in patients suspected to have sputum smear negative pulmonary tuberculosis.

MATERIALS AND METHODS

A prospective study conducted from August 2014 to July 2015, comprising 120 patients fulfilling study criteria. Patients with respiratory symptoms and chest roentgenogram suspicious of pulmonary tuberculosis with no previous history of anti-tuberculosis treatment and two spontaneous sputum smear samples negative for acid fast bacilli were included. Patients with active haemoptysis and sputum positive were excluded from the study. Sputum induction was done by using 5-10 ml of 3% hypertonic saline through ultrasonic nebulizer taking safety precautions. All the patient underwent fibreoptic bronchoscopy after six hours fasting on the same day. About 20 ml of normal saline instilled into the suspected pathology area and washings were taken with gentle suction. The sample processing and fluorescent staining for acid fast bacilli was done in a designated microscopy lab.

RESULTS

Out of 120 sputum smear negative pulmonary tuberculosis patients, induced sputum smear examination detected acid fast bacilli in 76 patients (63.3%) and acid fast bacilli detected from bronchial washings in 94 patients (78.3%). Smear positivity was higher in cavitary and infiltrative lesions as compared to consolidation and infrahilar pattern disease.

CONCLUSION

Even though both induced sputum and bronchial washings procedures were valuable for the diagnosis of sputum smear negative, sputum induction with hypertonic saline should be the initial procedure of choice, which can be repeated twice / thrice in a day or two consecutive days. If the patient still remains induced sputum smear negative and if the clinical probability of tuberculosis is high, starting anti-tuberculosis treatment and closely monitoring patient and reserving bronchoscopy to those patients who do not improve and to exclude alternative diagnosis seems to be a practically useful approach.

Induced sputum versus bronchial washings in the diagnosis of sputum negative pulmonary tuberculosis

Introduction:

Tuberculosis (TB) is one of the most important public health problems worldwide. Detecting patients with active pulmonary TB (PT) is an important component of TB control programs. However, at times in patients even with a compatible clinical picture, sputum smears do not reveal acid-fast bacilli (AFB) and smear-negative PT remains a common problem. This study compares the results of induced sputum (IS) and bronchial washings (BWs) in detecting sputum negative PT.

Materials and Methods:

A prospective study conducted from June 2014 to June 2015, comprising 120 patients fulfilling study criteria. Patients with respiratory symptoms and chest roentgenogram suspicious of PT with no previous history of antiTB treatment (ATT) and two spontaneous sputum smear samples negative for AFB were included in the study. Patients with active hemoptysis and sputum positive were excluded from the study. Sputum induction was done using 5–10 ml of 3% hypertonic saline through ultrasonic nebulizer taking safety precautions. All the patients underwent fiberoptic bronchoscopy after 6 h fasting on the same day. About 20 ml of normal saline instilled into the suspected pathology area and washings were taken with gentle suction. The sample processing and fluorescent staining for AFB were done in a designated microscopy laboratory.

Results:

Of 120 smear-negative PT patients, IS smear examination detected AFB in 76 patients (63.3%) and AFB detected from BWs in 94 patients (78.5%). Smear positivity higher in cavitary and infiltrative lesions compared to consolidation and infrahilar pattern disease.

Conclusions:

Even though both IS and BWs procedures were valuable for the diagnosis of smear-negative TB, sputum induction with hypertonic saline should be the initial procedure of choice, which can be repeated twice/thrice in a day or 2 consecutive days. If the patient remains IS smear-negative and if the clinical probability of TB is high, starting ATT and closely monitoring patient and reserving bronchoscopy to those patients who do not improve and to exclude alternative diagnosis seems to be a practically useful approach.

Role of bronchoscopy in evaluation of cases with sputum smear negative pulmonary tuberculosis, interstitial lung disease and lung malignancy: A retrospective study of 712 cases

BACKGROUND

The introduction of flexible bronchoscope has revolutionized the field of pulmonary medicine and is a standard instrument used for diagnostic purpose. A retrospective analysis of the clinico-radiological profile, indication, biopsy procedure and complications, for patients undergoing bronchoscopy at one of the respiratory unit at a tertiary care center in India.

METHODS

Retrospective analysis of 712 bronchoscopies was done in regard to demographic profile, clinical and radiological presentation and diagnostic indication. The results were analyzed on basis of bronchoscopy inspection and histopathological specimen obtained from transbronchial (TBLB), endobronchial biopsy (EBLB) and cytology specimen by transbronchial needle aspiration (TBNA). Furthermore, diagnostic yield of each biopsy procedure and their combination was evaluated.

RESULTS

Of 712 patients undergoing bronchoscopy, the pathological diagnosis was achieved in 384 (53.93%). Of 384 diagnosed cases, the clinic-radio-pathological diagnosis of pulmonary tuberculosis in 88 (22.19%), interstitial lung disease (ILDs) in 226 (58.85%), and lung cancer in 70 (18.22%) cases. Of 116 sputum smear negative tuberculosis patients, 88 (75.86%) were diagnosed to be pulmonary tuberculosis; the contribution of BAL being 71.59%. Of 226 ILDs, sarcoidosis was most common 148/226 (65.48%). Among 70 lung cancer diagnosed cases, squamous cell carcinoma was most common (54.28%).

CONCLUSION

The results from current study reemphasizes on the diagnostic utility as well as safety of the bronchoscopy procedure.

Retrospective observational study of diagnostic accuracy of the Xpert® MTB/RIF assay on fiberoptic bronchoscopy sampling for early diagnosis of smear-negative or sputum-scarce patients with suspected tuberculosis

Background

Fiberoptic bronchoscopy (FOB) is a useful diagnosis tool in low-burden countries for patients with suspected pulmonary tuberculosis (TB) who are smear-negative or sputum-scarce. This study sought to determine the accuracy of the Xpert® MTB/RIF (XP) assay using FOB samples.

Methods

We retrospectively reviewed clinical, radiological, and microbiological characteristics of 175 TB-suspected patients requiring diagnostic FOB (bronchial aspirate or bronchoalveolar lavage) with XP assay. Polymerase chain reaction (PCR) and smear microscopy (SM) performances were first compared to culture, then to the final diagnosis, established based on clinical or radiological evolution when cultures were negative.

Results

Of the total 162 included patients, 30 (18.5%) had a final diagnosis of pulmonary TB, with positive cultures reported in 23. As compared to culture, sensitivity and specificity values were 80.0% and 98.6% for the XP assay, and 25.0% and 95.8% for SM, respectively. As compared to final diagnosis, the corresponding performance values were 60.0% and 100.0% for the XP assay, and 16.7% and 95.5% for SM, respectively. The sensitivity of the XP assay was significantly higher than that of SM in both cases (p = 0.003 and p = 0.001). Concerning the final diagnosis, both XP assay and culture sensitivities were similar (60% vs. 66.7%). PCR assay enabled pulmonary TB to be diagnosed earlier in 13 more cases, compared to SM.

Conclusion

Our study has confirmed the clinical benefits provided by XP assay compared to SM for the early diagnosis of suspected pulmonary TB cases requiring FOB, on per procedure samples, especially in a low TB-burden country.

Bacterial yield from quantitative cultures of bronchoalveolar lavage fluid in patients with pneumonia on antimicrobial therapy

BACKGROUND/AIMS

Early diagnosis and appropriate antimicrobial choice are crucial when managing pneumonia patients, and quantitative culture of bronchoalveolar lavage (BAL) fluid is considered a useful method for identifying pneumonia pathogens. We evaluated the quantitative yield of BAL fluid bacterial cultures in patients being treated with antimicrobials and attempted to identify factors predictive of positive BAL cultures.

METHODS

Patients over 18 years old and whose BAL fluid was subjected to quantitative culture to identify the organism causative of pneumonia between January 1, 2005, and December 31, 2009, were included. We reviewed the results of BAL fluid bacterial cultures and the clinical records, laboratory tests, and radiographic findings of the patients.

RESULTS

BAL was performed on 340 patients with pneumonia. A positive BAL culture, defined as isolation of more than 10(4) colony forming units/mL bacteria, was documented in 18 (5.29%) patients. Of these, 9 bacteria isolated from 10 patients were classified as probable pathogens. The most frequently isolated bacteria were methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa. No independent predictive factor for positive BAL cultures was identified.

CONCLUSIONS

The yield of quantitative BAL fluid bacterial culture in patients already on antimicrobials was low. Clinicians should be cautious when performing a BAL culture in patients with pneumonia who are already on antimicrobials.

Screening and rapid molecular diagnosis of tuberculosis in prisons in Russia and Eastern Europe: a cost-effectiveness analysis

BACKGROUND

Prisons of the former Soviet Union (FSU) have high rates of multidrug-resistant tuberculosis (MDR-TB) and are thought to drive general population tuberculosis (TB) epidemics. Effective prison case detection, though employing more expensive technologies, may reduce long-term treatment costs and slow MDR-TB transmission.

METHODS AND FINDINGS

We developed a dynamic transmission model of TB and drug resistance matched to the epidemiology and costs in FSU prisons. We evaluated eight strategies for TB screening and diagnosis involving, alone or in combination, self-referral, symptom screening, mass miniature radiography (MMR), and sputum PCR with probes for rifampin resistance (Xpert MTB/RIF). Over a 10-y horizon, we projected costs, quality-adjusted life years (QALYs), and TB and MDR-TB prevalence. Using sputum PCR as an annual primary screening tool among the general prison population most effectively reduced overall TB prevalence (from 2.78% to 2.31%) and MDR-TB prevalence (from 0.74% to 0.63%), and cost US$543/QALY for additional QALYs gained compared to MMR screening with sputum PCR reserved for rapid detection of MDR-TB. Adding sputum PCR to the currently used strategy of annual MMR screening was cost-saving over 10 y compared to MMR screening alone, but produced only a modest reduction in MDR-TB prevalence (from 0.74% to 0.69%) and had minimal effect on overall TB prevalence (from 2.78% to 2.74%). Strategies based on symptom screening alone were less effective and more expensive than MMR-based strategies. Study limitations included scarce primary TB time-series data in FSU prisons and uncertainties regarding screening test characteristics.

CONCLUSIONS

In prisons of the FSU, annual screening of the general inmate population with sputum PCR most effectively reduces TB and MDR-TB prevalence, doing so cost-effectively. If this approach is not feasible, the current strategy of annual MMR is both more effective and less expensive than strategies using self-referral or symptom screening alone, and the addition of sputum PCR for rapid MDR-TB detection may be cost-saving over time.

Post-bronchoscopy sputum: improving the diagnostic yield in smear negative pulmonary TB

INTRODUCTION

Patients with suspected active Pulmonary Tuberculosis (PTB) who are Acid-Fast Bacilli (AFB) smear negative or non-productive of sputum may undergo bronchoalveolar lavage. However, post-bronchoscopy sputum (PBS) sampling is not routine. The aim of this study was to establish the potential diagnostic value of PBS sampling.

METHODS

A retrospective study of patients attending a London University hospital with microbiologically confirmed PTB between January 2004 and December 2010. Patients who were AFB smear negative or non-productive of sputum were eligible if sputum sampling was performed within 7 days of bronchoscopy.

RESULTS

Over the study period, 236 patients had microbiologically confirmed smear negative PTB of which 57 patients were eligible for the study. 15 patients (26.3%) were infected with HIV. 19 patients (33.3%) converted to AFB sputum smear positivity post-bronchoscopy and 5 patients (8.8%) were exclusively AFB sputum smear positive on PBS microscopy. Mycobacterium tuberculosis was cultured from the PBS of 43 patients (75.4%) and of these, 4 (7.0%) were exclusively PBS culture positive.

CONCLUSION

PBS analysis can provide a simple method of rapidly diagnosing pulmonary tuberculosis. In this cohort, M. tuberculosis culture yield was increased by 7% through PBS sampling. This study has important infection control implications with nearly one third of patients becoming more infectious after bronchoscopy.

Bronchoscopy in suspected pulmonary TB with negative induced-sputum smear and MTD(®) Gen-probe testing

INTRODUCTION

In our institution, patients with suspected pulmonary TB undergo multiple induced-sputum sampling for microscopy, culture and nucleic acid amplification (NAA) with the MTD(®) Gen-probe assay. Those with negative induced-sputum results still suspected with TB are then referred for bronchoscopy. We sought to determine the diagnostic yield of bronchoscopy in these patients with negative initial induced-sputum results both via smear and NAA testing.

METHODS

We identified 30 consecutive cases of suspected pulmonary TB between 2001 and 2007, who had undergone a diagnostic bronchoscopy after negative results on induced-sputum smears and the MTD(®) Gen-probe on at least 2 samples.

RESULTS

The cohort (M = 20 & F = 10) had a median age of 37 (range 16-85 yrs); were predominantly foreign born (27/30); HIV-negative (29/30) individuals with strongly positive TST's (mean 18 + 5 mm). Induced-sputum cultures were negative for M-TB in all patients after a full 60-day incubation period. BAL was culture positive for M-TB in 3/30 cases (10%) with 2 strains being pan-sensitive and the third being INH resistant. BAL microscopy with acid-fast smear (n = 30) and BAL Gen-probe (n = 23) were negative in all cases. A third of the patients (9/27, 33%) with negative bronchoscopy results were treated for culture negative TB. Treatment for latent TB was initiated in 5/27 (18%) individuals whereas 13/27 (48%) received no further treatment.

CONCLUSION

Bronchoscopy provided diagnostic confirmation of pulmonary TB in 10% of subjects at least 2 negative induced-sputum samples by smear microscopy and NAA testing.

The value of fiberoptic bronchoscopy in culture-positive pulmonary tuberculosis patients whose pre-bronchoscopic sputum specimens were negative both for smear and PCR analyses

OBJECTIVE

This study assessed the diagnostic rate of pulmonary tuberculosis (PTB) using fiberoptic bronchoscopy (FBS) in patients with suspected PTB, and negative pre-bronchoscopy smear and polymerase-chain reaction (PCR) in sputum.

PATIENTS AND METHODS

We retrospectively reviewed 201 culture-positive PTB patients that underwent FBS because both smear and PCR results in sputum were negative. The positive rates of smear for acid fast bacilli, PCR for Mycobacterium tuberculosis, the presence of granuloma in transbronchial biopsy (TBB), and culture of M. tuberculosis were analyzed. In addition, the radiographic features, contribution of FBS to rapid and/or definitive diagnosis of PTB, and drug susceptibility results of M. tuberculosis were also reviewed.

RESULTS

There were 136 males and 102 patients under the age of 40 years; non-cavitary (156 cases) and minimal disease (119 cases) on radiographs predominated. The positive rates of FBS were: 44% (smear), 62% (PCR), 61% (TBB), and 87% (culture). These rates increased in smear and PCR examinations when taken from wider spread shadows on radiographs. The combination of the various bronchoscopy samples increased the diagnostic rate to 92% when all examinations were combined. Positive culture results depended on FBS procedures in 80 cases. Twenty-one cases showed resistance to at least one of the major anti-tuberculous agents.

CONCLUSION

This analysis revealed high positive rates of PTB from bronchoscopy samples, providing rapid and definitive ability for PTB diagnosis, and details of drug susceptibility. Therefore, FBS is an important diagnostic procedure in patients with suspected PTB whose sputum specimens were negative both for smear and PCR analyses.

Diagnostic yield of sputum, induced sputum, and bronchoscopy after radiologic tuberculosis screening

RATIONALE

To assess feasibility and yield of diagnostic procedures after active case finding for tuberculosis with radiologic screening at the three main entry points for asylum seekers to Switzerland.

METHOD

Prospective multicenter study on the value of symptoms, spontaneous and induced sputum, and bronchoscopy for the confirmation of tuberculosis in radiologically selected cases.

RESULTS

Among 101 asylum seekers examined, spontaneous sputum was collected "on the spot" in 83 and yielded 7 (54%) of 13 smear-positive and 13 (39%) of 33 culture-positive cases. Morning sputum, collected in 84, yielded 8 (62%) and 16 (49%), and the two spontaneous sputa combined 9 (69%) and 20 (61%), respectively. Two additional induced sputa, collected in 91 persons, yielded no additional smear-positive, but yielded seven culture-positive cases (yield, 82%). Bronchoscopy, performed in 87 of 92 sputum smear-negative cases, yielded four additional smear-positive and six culture-positive cases. Culture confirmation was independently and significantly predicted by obtaining a specimen using bronchoscopy (adjusted odds ratio, 11.0; 95% confidence interval, 1.9-62) and a prior decision to treat (adjusted odds ratio, 3.0; confidence interval, 1.1-8.1).

CONCLUSION

Radiographic anomalies compatible with tuberculosis found during screening are a poor guide to initiation of treatment. Respiratory and systemic symptoms correlated weakly with culture confirmation of tuberculosis. All radiologically selected cases must be examined with on-the-spot and early-morning sputum, regardless of symptoms. If both specimens are smear negative, the yield is increased by bronchoscopy and, to a lesser extent, by two samples of induced sputum. The examination of any single specimen has a low yield of 36 to 63% and is insufficient to exclude active tuberculosis.

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 blood mononuclear cells (PBMCs) and mononuclear cells from the BAL fluid (BALMCs).

MEASUREMENTS AND MAIN RESULTS

Of 37 patients, 12 were found to have smear-negative pTB and 25 were found to have an alternative diagnosis. Patients with tuberculosis had a median number of 17 ESAT-6-specific cells and 24.5 CFP-10-specific cells per 200,000 PBMCs and 37.5 ESAT-6-specific cells and 49.5 CFP-10-specific cells per 200,000 cells in the BAL fluid. Control patients had a median of 1 ESAT-6-specific cell and 1 CFP-10-specific cell per 200,000 PBMCs and no ESAT-6- and CFP-10-specific cells per 200,000 cells in the BAL fluid (p < 0.0001). All patients with TB but none of the control subjects had more than 5 spot-forming cells per 200,000 BALMCs with either peptide in the BAL fluid ELISPOT.

CONCLUSION

Smear-negative pulmonary tuberculosis can be diagnosed rapidly by identification of MTB-specific cells in the BAL fluid.

The diagnosis of tuberculosis

Diagnostic testing for tuberculosis has remained unchanged for nearly a century, but newer technologies hold the promise of a true revolution in tuberculosis diagnostics. New tests may well supplant the tuberculin skin test in diagnosing latent tuberculosis infection in much of the world. Tests such as the nucleic acid amplification assays allow more rapid and accurate diagnosing of pulmonary and extrapulmonary tuberculosis. The appropriate and affordable use of any of these tests depends on the setting in which they are employed.

[Acute forms of diffuse interstitial hypoxemic pneumonia in immunocompetent patients]

The large majority of patients with acute respiratory failure present diffuse pulmonary opacities resulting from pulmonary embolism, intra-alveolar hemorrhage, or a classical cause of ARDS. In a small number of patients however, these opacities correspond to diffuse interstitial pneumonia. This should be suspected in light of the context, the time of formation, and the unusual respiratory and/or extrarespiratory signs. If there is a clinical doubt, thoracic scan and bronchoalveolar lavage should be performed together with infectious and immunology tests. Treatment depends on the cause and/or the type of lesion.

Tuberculosis in Lung Transplant Recipients

BACKGROUND

Post-lung transplant infection is one of the leading causes of morbidity and mortality. The cause and incidence are similar in many series; however, infections such as Mycobacterium tuberculosis are influenced by the epidemiologic situation. The authors present a prospective and observational study to define the incidence, clinical presentation, and course of tuberculosis in a cohort of lung transplant patients at a single center in Spain.

METHODS

Between 1990 and 2002, cutaneous delayed-type hypersensitivity testing and pathologic and microbiologic study of explanted lungs were conducted in 187 lung transplant patients. Serial bronchoscopies with transbronchial biopsy and bronchioalveolar lavage were performed during follow-up. The diagnosis of tuberculosis was established only when M. tuberculosis was identified in any sample or when histopathologic study was conclusive.

RESULTS

Forty-eight patients were classified as anergic (25.6%) and 61 (32.6%) were classified as having a positive tuberculin skin test. Of the 109 patients, 95 received latent tuberculosis infection prophylaxis. Tuberculosis was diagnosed in 12 patients (6.41%); in six of them, diagnosis was determined from the explanted lungs. The remainder were diagnosed during follow-up. Fever and dyspnea were the most common symptoms. Chest radiographic findings presented an alveolar pattern. All patients responded well to antituberculous therapy; no deaths were attributable to tuberculosis.

CONCLUSIONS

In the authors' experience, tuberculosis is not rare in lung transplant patients and can be managed successfully with antituberculous therapy without rifampin. A systematic protocol for diagnosing tuberculosis of the explanted lung is useful for reducing tuberculous complications of the implanted lung.

Diagnostic Value of Fiberoptic Bronchoscopy in Suspected Pulmonary Tuberculosis in the State of Qatar

To assess the diagnostic value of fiberoptic bronchoscopy (FOB) in patients with abnormal chest radiographs suggestive of pulmonary tuberculosis (PTB) but with negative sputum smears for acid fast bacilli (AFB), a retrospective study was made of all such cases referred to the Pulmonary Diseases Service at Hamad Medical Corporation between July 1997 and June 2000. It included patients unable to produce any sputum sample. From 193 FOB procedures, active pulmonary tuberculosis was diagnosed in 58 patients (30 %). The diagnosis was confirmed either by finding acid fast bacilli in a smear or by culture of bronchial washings or bronchoalveolar lavage (BAL), or by demonstrating caseating granulomata on transbronchial or endobronchial biopsy. In 19 of58 (33%) positive cases, the diagnosis was rapidly established by demonstrating AFB in smears of bronchial aspirate or by positive histopathology. It is concluded that FOB is still the gold-standard procedure in the diagnosis of pulmonary tuberculosis in those patients in whom the diagnosis cannot be established by sputum examination, thus allowing early diagnosis in a significant proportion of them. The results are in agreement with similar studies.

Culturing bronchial washings obtained during bronchoscopy fails to add diagnostic utility to culturing the bronchoalveolar lavage fluid alone

A retrospective analysis was performed to determine whether cultures of bronchial washings (BW) obtained during bronchoscopy added to the diagnostic efficiency of cultures of bronchoalveolar lavage fluid (BAL) alone. Results of BW and BAL cultures submitted from 268 patients over a 7-month period were compared. The isolation of an organism from the BW but not from the BAL occurred in only 17.4% of cases. Moreover, the vast majority of those organisms consisted of yeasts or molds of questionable clinical significance that did not prompt a change in antimicrobial therapy. Culturing the BAL specimen alone would have resulted in an efficiency of 97.0% (95% confidence interval 94.2-98.7%) for the isolation of clinically relevant pathogens identified from bronchoscopic specimens. These results suggest that the submission of BW obtained during the BAL procedure for culture evaluation not only fails to add diagnostic value, but may also result in unnecessary laboratory evaluations and provide misleading information to clinicians.

[Acute alveolo-interstitial pneumopathies in HIV-negative patients treated with antineoplastic chemotherapy]

INTRODUCTION

Treatment of malignant tumors can delay some opportunistic infections. In this paper, we report three cases of alveolo-interstitial pneumonia among HIV negative patients who received chemotherapy.

EXEGESIS

All three patients received corticotherapy for a long time. In two cases, it was pneumocystis-tuberculosis coinfection. Evolution was favourable for two patients with sulfaméthoxazole-triméthoprime (one with corticotherapy).

CONCLUSION

The possible role of chemotherapy, corticotherapy and malignant tumor in the pathogenesis of opportunistic infections will be discussed.

Role of bronchoscopy in AIDS

The differential diagnosis of pulmonary disorders in the HIV-infected individual is broad. Clinical features and chest radiographs may point towards a diagnosis but cannot reliably establish one. It is important to know the conditions in which bronchoscopy, BAL, and TBB are likely to be diagnostic, just as it is to know when other invasive or noninvasive procedures may be more useful. Finally, the incidence of transmission of infections such as tuberculosis during bronchoscopy and cross-contamination of patients with an improperly sterilized bronchoscope, cannot be overemphasized.

Issues in the management of contacts of patients with active pulmonary tuberculosis

The evidence regarding the transmission of tuberculosis and risk of infection and disease in several specific clinical situations has been reviewed. There is considerable epidemiologic evidence that contagiousness is not an all-or-nothing phenomenon and is affected by several factors, only one of which is the bacteriologic status of the patient's sputum. Although untreated smear negative, culture positive patients are less contagious on average, they still may transmit infection to their close and casual contacts. Compared with contacts with tuberculin conversion, persons who are already tuberculin positive have much lower risk of developing active tuberculosis after exposure, and persons with prior BCG vaccination are at somewhat lower risk. Preventive therapy will be of less benefit, but should still be recommended for contacts who are heavily exposed or are immune compromised. Epidemiologic studies using RFLP techniques could provide more precise answers to the questions in this review.

Empiric treatments impair the diagnostic yield of BAL in HIV-positive patients

OBJECTIVE

To investigate the influence of empiric treatments prior to fiberoptic bronchoscopy (FOB) on the diagnostic yield of BAL in HIV-positive patients with respiratory symptoms.

METHOD

We studied 123 consecutive FOBs with BAL in HIV-positive patients; 101 of these patients (82%) had received previous antimicrobial treatment from 1 to 60 days. Diagnostic yield of BAL for Pneumocystis carinii, Mycobacterium tuberculosis, and bacterial pneumonia was compared between patients with and without previous empiric treatments.

RESULTS

A diagnosis was obtained in 85 patients (69%), of whom 17 (20%) had multiple infections. Diagnostic yield was higher in patients without previous treatment, 91% (20/22) compared with 64% (65/101), p < 0.03. Diagnostic yield was also higher for bacterial pneumonia: seven isolations from 22 patients not receiving previous empiric treatment (32%), compared with 11 of those who had (11%; p < 0.02). The duration of empiric treatment against P carinii in patients in whom it was isolated was significantly shorter than in those in whom P carinii was not detected (3.5 +/- 1.8 days compared with 5.2 +/- 2.4 days; p = 0.003). FOB permitted a change in treatment in 62% of patients with a final diagnosis.

CONCLUSION

This study demonstrates that empiric treatments prior to FOB significantly impair the diagnostic yield of BAL in detecting common pathogens in HIV-infected patients with respiratory symptoms.

Incidence and significance of acid-fast bacilli in sputum smears at the end of antituberculous treatment

OBJECTIVE

A group of patients with pulmonary tuberculosis (PT) who received and correctly completed antituberculous therapy were studied to determine the incidence and significance of positive acid-fast bacilli (AFB) in sputum smears at the end of this treatment.

DESIGN

Retrospective chart review of persons with bacteriologically proved PT.

PATIENTS

Of 1,052 patients diagnosed as having PT between 1988 and 1992, 453 who fulfilled the following criteria were included in the study: (1) diagnosis established by positive AFB and positive culture in sputum smears; (2) no previous antituberculous treatment had been received; (3) HIV serologic test results were negative; (4) treatment was correctly completed; (5) they were followed up throughout the period of treatment; and (6) expectoration was still present at the end of treatment and at least two spontaneous sputum samples could be obtained.

RESULTS

Positive AFB of sputum smears were found at the end of treatment in 10 (2.2%) of the 453 patients studied. Five patients had only one positive smear, and the other five had more than one. Of these ten cases, sputum culture was negative in eight, which were considered to be unviable bacilli, and positive for nontuberculous mycobacteria in two. Clinical symptoms or worsening on chest radiograph were observed only in one patient with unviable bacilli, but they were caused by a concomitant nonspecific respiratory tract infection.

CONCLUSIONS

Positive AFB smear results at the end of completed treatment regimens analyzed in this study have occurred because of unviable bacilli and nontuberculous mycobacteria colonization. The presence of more than one positive smear seems not to increase the probability of treatment failure and is more frequently due to nontuberculous mycobacteria. Results of culture can thus be awaited without the need to prolong or modify antituberculous therapy.

Bronchoscopic diagnosis of pneumonia

Lower respiratory tract infections are characterized by significant morbidity and mortality but also by a relative inability to establish a specific etiologic agent on clinical grounds alone. With the recognized shortcomings of expectorated or aspirated secretions toward establishing an etiologic diagnosis, clinicians have increasingly used bronchoscopy to obtain diagnostic samples. A variety of specimen types may be obtained, including bronchial washes or brushes, protected specimen brushings, bronchoalveolar lavage, and transbronchial biopsies. Bronchoscopy has been applied in three primary clinical settings, including the immunocompromised host, especially human immunodeficiency virus-infected and organ transplant patients; ventilator-associated pneumonia; and severe, nonresolving community- or hospital-acquired pneumonia in nonventilated patients. In each clinical setting, and for each specimen type, specific laboratory protocols are required to provide maximal information. These protocols should provide for the use of a variety of rapid microscopic and quantitative culture techniques and the use of a variety of specific stains and selective culture to detect unusual organism groups.

[The efficacy of bronchoalveolar lavage in the diagnosis of pulmonary tuberculosis]

In order to analyze the usefulness of bronchoalveolar lavage (BAL) for conventional microbiological diagnosis of tuberculosis (TB) and other mycobacteria, and to assess the need to use it or not as a routine diagnostic technique in these diseases, we studied 30 patients with mycobacteria (26 TB and 4 Mycobacterium avium-intracellulare infections) by bronchoscopy, with BAL and bronchoaspirate (BAS) bacteriological analyses also available. The results were compared with those obtained for sputum taken before and after bronchoscopy when these specimens were available. The overall yield for BAL and BAS cultures was 90%, with BAL (83.3%) specimens being more productive than BAS (73.3%) specimens. Both performed far better than the 53.8% recorded for cultures of pre-bronchoscopy sputum and 60% for post-bronchoscopy sputum. BAL was the only diagnostic specimen from 7 patients, while BAS the only one from 4. Sensitivity was similar for the two mycobacteria studied. The results for direct bacilloscopy, however, at 30% for the two specimens, rose to 36.6% when they were analyzed together with BAS and BAL. We conclude that bronchoscopy should be performed on all patients suspected of mycobacterial infection when sputum bacilloscopy is negative and patients have no expectoration. Performance of BAL should be routine since this simple and usually uncomplicated technique produces the most productive specimens.

Bronchoalveolar lavage fluid profiles in sarcoidosis, tuberculosis, and non-Hodgkin's and Hodgkin's disease. An evaluation of differences

The aim of this study was to identify characteristic features in bronchoalveolar lavage fluid (BALF) samples of patients with tuberculosis, non-Hodgkin's or Hodgkin's disease and to investigate whether these differences facilitate the distinction of those disorders from sarcoidosis presenting with a similar clinical picture. Nonsmoker patients with histologically verified sarcoidosis (n = 29), tuberculosis (n = 6) proven by positive culture, non-Hodgkin's disease, (n = 6) or Hodgkin's disease (n = 7), both histologically verified, were investigated by BAL. A control group consisted of subjects without any pulmonary history. The presence of CD4+ and CD8+ T lymphocytes, as well as the CD4/CD8 ratio in BALF, aided in the differentiation between the various groups. Patients with malignant lymphomas had the lowest CD4/CD8 ratio in BALF, as well as in peripheral blood, and occasionally, plasma cells were present in BALF samples. The most important feature of BALF analysis in tuberculosis was detection of the causal microbial agent. In conclusion, although malignant lymphomas and tuberculosis require histologic evaluation and a positive culture, respectively, for diagnosis, BALF analysis may be of additional value in distinguishing those disorders from sarcoidosis.

Bronchoscopic diagnosis of pulmonary infections in a heterogeneous, nonselected group of patients

Fiberoptic bronchoscopy with bronchoalveolar lavage and protected specimen brush technique has become an established method for etiologic diagnosis in severe forms of pulmonary infections during recent years. In this study, including 62 bronchoscopies in 53 patients, a standardized program, covering all important pulmonary pathogens, has been evaluated in a heterogeneous group of patients. Results providing therapeutic guidelines were obtained in 53 percent (16/30) of the immunocompromised patients (including 5 bronchoscopies on HIV-positive patients), but only 19 percent (6/32) of the immunocompetent patients (p < 0.001). We conclude that bronchoscopy is of great value for diagnosing pulmonary infections in immunocompromised patients. In immunocompetent patients, the diagnostic yield is lower and the indication for bronchoscopy must be established for each individual patient based on clinical importance, resources, and risk. When bronchoscopy is performed, we believe that a standardized program like ours reduces the risk of missing important pathogens.

Diagnostic value of bronchoalveolar lavage in peripheral lung cancer

A prospective study has been performed to assess the value of the addition of bronchoalveolar lavage (BAL) to the routine bronchoscopic exploration with bronchial washing (BW) and postbronchoscopy sputum (PBS) procedures in the diagnosis of peripheral primary lung cancer not visible through bronchoscope when fluoroscopic guidance is not available. BW, BAL, and PBS were performed in 67 patients with suspected primary lung cancer by peripheral lung lesion on chest radiograph (39 nodules and 28 infiltrates) and nonendoscopically visible lesion. The sequence of procedures was in all cases BW, BAL, and post-bronchoalveolar lavage bronchoaspirate (PBBA). An attempt was made to collect early morning postbronchoscopy samples of sputum (PBS) on 3 consecutive days. BW and PBBA were collected in the same test tube, and the cytologic result was considered as BW diagnostic yield. If there were negative bronchoscopic results, either percutaneous fine-needle aspiration or open-lung biopsy were performed for diagnosis. Fifty-five patients were found to have malignant disease (23 adenocarcinomas, 22 squamous cell carcinomas, six small cell carcinomas, and four bronchioloalveolar cell carcinomas). BAL was positive in 18 of the 55 (33%) carcinomas, and it gave the only positive result in six (11%). BW was also positive in 18 of the 55 (33%), but it gave positive results in only 3 (5%). PBS was positive in 13 of the 43 (30%) patients from whom samples could be spontaneously obtained and were suitable for cytologic examination (not consisting of saliva), and gave the only positive result in three (7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrasound guided aspiration biopsy for pulmonary tuberculosis with unusual radiographic appearances

BACKGROUND

Pulmonary tuberculosis can produce unusual radiographic appearances and negative results of sputum and bronchoscopic examinations are common. This study assessed the value of ultrasound guided aspiration biopsy in the diagnosis of pulmonary tuberculosis with unusual radiographic appearances.

METHODS

Thirteen patients, ultimately diagnosed as having tuberculosis, underwent a chest ultrasonographic examination between June 1984 and August 1991. All had sputum available for examination and nine were also examined by bronchoscopy. Ten patients who had a negative sputum smear and negative bronchoscopic brushing smears underwent ultrasound guided aspiration or biopsy. Percutaneous aspiration was performed with a 22 gauge needle. If the smear did not reveal acid fast bacilli, a biopsy sample was taken with a 16 gauge Tru-cut needle to obtain a histological diagnosis.

RESULTS

The ultrasonographic examination delineated the more complex nature of the lesions better than the chest radiograph. Ultrasound guided aspiration biopsy provided the diagnosis in nine of 10 patients, while the sputum smear and culture provided diagnosis in five of 13, and bronchoscopy in four of nine. In terms of rapid diagnosis, ultrasound guided aspiration biopsy gave the diagnosis in eight of 10 cases. No patient developed a major complication.

CONCLUSION

Ultrasonography can direct the needle to the most suitable part of a lesion to obtain the relevant specimens. The diagnostic yield is high and the procedure is relatively safe. It is especially helpful in patients with negative results of sputum and bronchoscopic examinations.

The value of flexible bronchoscopy in childhood pulmonary tuberculosis

The value of 121 flexible bronchoscopy (FB) procedures was evaluated in 54 children, aged three months to 14 years, suspected of having pulmonary tuberculosis. Specimens from FB were culture-positive for Mycobacterium tuberculosis in seven of the 13 bacteriologically confirmed cases. Bronchial abnormalities consistent with the diagnosis were found in 31 of 54 cases. Separate or coexistent findings at initial FB included airway compression (20 cases), granulation tissue (ten cases), and obstructive caseum (four cases). Chest roentgenograms underestimated bronchial involvement in 14 children. Further FB monitoring documented disease evolution. The FB was important in the management of patients, as it (1) guided the use of prednisone therapy, especially in the children with a chest roentgenogram not suggestive of bronchial involvement; (2) indicated a need for resection of granulation tissue by rigid bronchoscopy (three cases); and (3) guided the surgical decision (two children with persistent bronchial obstruction). Thus, FB is a safe and valuable procedure in the management of childhood pulmonary tuberculosis.

Protected bronchoalveolar lavage. A new bronchoscopic technique to retrieve uncontaminated distal airway secretions

We tested the effectiveness of protected bronchoalveolar lavage (PBAL), performed through a protected transbronchoscopic balloon-tipped (PBT) catheter, in collecting distal airway secretions with a minimal degree of contamination. The PBAL had less than or equal to 1% squamous epithelial cells in 91% of specimens and an absence of bacterial growth in 59% of patients without pneumonia. Using a threshold of 10(4) cfu/ml we had one false positive result in 33 patient without pneumonia and one false negative in 13 patients with pneumonia. Quantitative bacterial cultures of the PBAL specimens had a diagnostic sensitivity of 97% and a specificity of 92%, with a positive predictive value of 97% and a negative predictive value of 92%. The diagnostic efficiency was 96%. The presence of intracellular organisms in much greater than or equal to 2% of the recovered alveolar cells (Giemsa stain) was seen in all but two patients with pneumonia (on corticosteroids) and in none of the patients without pneumonia. Gram stains of the PBAL specimens were positive in all but one patient with pneumonia and negative in all but one patient without infection (patient with endobronchial narrowing secondary to neoplasm with false positive cultures). Either the Giemsa or the Gram stain was positive in all patients with pneumonia, allowing early and accurate diagnosis of lower respiratory tract infection before the results of cultures were available. The time off antibiotic therapy before bronchoscopy did not affect the result of PBAL cultures, contrary to what we observed for the protected brush specimen.

The diagnostic yield of bronchoscopy

The endoscopic examination of the tracheobronchial tree is most helpful in the diagnosis and staging of bronchial carcinoma. Tumors that are endoscopically visible may be confirmed in more than 95% of the cases. In localized peripheral tumors, the diagnostic yield of bronchoscopy is significantly lower; for peripheral metastases, only about 10%. In diffuse interstitial pulmonary diseases other than malignancies, some infections, and histiocytosis X, bronchoscopy including transbronchial biopsy is less successful.

Bronchoscopic aspiration and bronchoalveolar lavage in the diagnosis of sputum smear-negative pulmonary tuberculosis

The ability to make a definitive diagnosis in sputum smear-negative pulmonary tuberculosis by bronchoscopic aspiration, bronchoalveolar lavage (BAL), and examination of postbronchoscopy sputum were compared. Thirty-four patients with lesions on chest x-rays suspected of being pulmonary tuberculosis were entered into the study. The diagnosis of pulmonary tuberculosis was subsequently confirmed in 28 patients and the method of arriving at the final diagnosis was analyzed. A positive acid-fast bacilli (AFB) smear result was obtained in 4/28 (14%) of cases by a combination of bronchoscopic techniques and postbronchoscopy sputum examination. Prebronchoscopy sputum culture was positive in 12/28 (43%). Combined with bronchoscopy specimens, a positive AFB culture result was obtained in 26/28 (93%). Sputum examination, bronchoscopic aspiration, and BAL are complementary techniques and together they give a high yield of definitive diagnosis of pulmonary tuberculosis.