Diagnostic yield of post-bronchoscopy sputum for diagnosing pauci-bacillary pulmonary tuberculosis

BackgroundA few studies have mentioned that post-bronchoscopy sputum (PBS) could improve the diagnostic yield in pauci-bacillary pulmonary tuberculosis (PTB). Therefore, we evaluated the diagnostic yield of PBS for diagnosing pauci-bacillaryPTB.MethodsClinical data of immunocompromised adult patients with pauci-bacillary PTB were retrospectively retrieved at a tertiary hospital in Seoul, South Korea over a 5-year period. We analyzed patients who underwent bronchoscopy examinations for diagnosing pauci-bacillary PTB.ResultsNinety patients were finally analyzed. Of these patients, 76 patients were tested with PBS. Six (8%) of these patients had positive results on AFB smear of PBS alone. Additionally, 52 patients (68%) had positive results on mycobacterial culture and 12 (16%) had positive results on mycobacterial culture of PBS exclusively. Therefore, in this study population, a total of 18 patients (20%) were finally diagnosed as having PTB with PBS results only, even though AFB smear microscopy and culture of other specimens had negative results.ConclusionsPBS could improve the diagnostic yield by 20% when diagnosing pauci-bacillary PTB. In addition, about 8% of the patients could be diagnosed rapidly because of AFB smear microscopy positivity for PBS. Therefore, PBS use should be considered as a complementary diagnostic approach in patients with suspected pauci-bacillary PTB.     

纤维支气管镜检查在抗酸杆菌阴性肺结核诊断中的应用价值

目的:评价纤维支气管镜(纤支镜)检查在痰涂片抗酸杆菌阴性(菌阴)肺结核诊断中的作用.方法:对应用纤支镜检查确诊的92例菌阴且临床表现不典型肺结核病例资料进行回顾性分析.结果:本组39例纤支镜下见支气管黏膜有异常改变,其中29例(74.4%)刷检涂片找抗酸杆菌阳性,活检有结核病理改变23例(59.0%);另外53例病灶位于外周部位,纤支镜下未见明显异常,经支气管肺活检(TBLB)抗酸杆菌阳性42例(79.2%),刷检涂片抗酸杆菌阳性24例(45.3%),支气管肺泡灌洗液涂片检查抗酸杆菌阳性15例(28.3%).结论:对痰涂片抗酸杆菌阴性肺结核,尤其是临床表现不典型者,纤支镜检查有助于明确诊断.     

Usefulness of induced sputum and fibreoptic bronchoscopy specimens in the diagnosis of pulmonary tuberculosis

We investigated the diagnostic value of induced sputum (IS) and bronchial lavage (BL) specimens in patients with suspected pulmonary tuberculosis who had negative spontaneous sputum specimens or who were unable to produce sputum spontaneously. IS specimens and BL specimens obtained using flexible fibreoptic bronchoscopy from 55 patients were evaluated for the presence of acid-fast bacilli (AFB) and cultured for Mycobacterium tuberculosis. Positive results were found with IS smear in 23 patients, BL smear in 26 patients, and IS or BL culture in 42 patients. Culture of BL specimens had a higher sensitivity than IS or BL smears or culture of IS specimens. The highest sensitivity rate was obtained with a positive BL or IS culture (86%). For early diagnosis (a positive IS or BL smear), the sensitivity was 57%. IS has a higher sensitivity rate than spontaneous sputum for the detection of tuberculosis, and fibreoptic bronchoscopy is useful for the early diagnosis of tuberculosis when AFB are not detected in spontaneous or induced sputum specimens.     

Molecular detection of Mycobacterium tuberculosis: impact on patient care

BACKGROUND: Nucleic acid amplification technologies such as PCR are revolutionizing the detection of infectious pathogens such as tuberculosis (TB). Amplification technology offers the potential for the diagnosis of TB in a few hours with a high degree of sensitivity and specificity. However, molecular assays neither replace nor reduce the need for conventional smear and culture, speciation, and antibiotic sensitivity assays. METHODS: We undertook prospective studies of sputum samples to assess the performance of two PCR-based assays for the detection of TB as well as the impact of more rapid availability of test results on patient care. RESULTS: The sensitivity of both the in-house and Amplicor PCR assays was 100% for smear-positive sputa. For smear-negative sputa (two sputum samples collected during the first 24 h of hospitalization), the sensitivity was 85% for our in-house PCR assay and 74% for the Roche PCR assay. Approximately 10% of the smear- and culture-negative sputa yielded positive PCR results; however, more than one-half of these were positive with both the in-house and Amplicor assays, suggesting the presence of TB DNA or organisms. Several of these came from patients whose other samples grew Mycobacterium tuberculosis during the same admission, and others came from patients who had previously treated TB. Overall, the specificities of the in-house and Amplicor PCR assays in smear-negative patients were 86% and 93%, respectively. CONCLUSIONS: Molecular detection of slow-growing pathogens such as M. tuberculosis have the potential to improve clinical care through a dramatic reduction in the time required for detection and may provide substantial savings in the overall cost of care of a patient compared with conventional smear, culture, and speciation alone, despite the fact that conventional assays must still be performed for speciation of nontuberculous mycobacteria and for full assessment of antibiotic sensitivity.     

Comparison of quantitative polymerase chain reaction,acid fast bacilli smear,and culture results in patients receiving therapy for pulmonary tuberculosis

Quantitative-competitive polymerase chain reaction (QPCR) was performed on serial sputum samples from 22 consecutive cases of acid fast bacilli (AFB) smear-positive pulmonary tuberculosis. Of 94 specimens, 55, 72, and 83% were positive by culture, AFB smear, and QPCR, respectively. Of 52 culture-positive specimens, 6% were negative by PCR, and 13% were negative by AFB smear. Of 42 culture-negative specimens, AFB smear and QPCR were positive in 55 and 61%, respectively. AFB smear and QPCR results were strongly correlated (r = 0.75, p < 0.001), but each correlated less strongly with culture (r = 0.54, p < 0.005 for smear and r = 0.52, p < 0.005 for QPCR). When patients were classified by microbiologic response, responders tended to have less DNA in their sputum and shorter time to a negative PCR result compared to nonresponders. These data do not suggest a great advantage of QPCR over AFB smear for predicting culture results in patients with pulmonary tuberculosis.     

Utility of B-cell epitopes based peptides of RD1 and RD2 antigens for immunodiagnosis of pulmonary tuberculosis

Tuberculosis (TB) continues to be a major health problem due to lack of accurate, rapid, and cost-effective diagnostic tests. Serodiagnostic tests incorporating highly specific region of difference (RD) antigens (early secretory antigenic target 6 [ESAT-6], culture filtrate protein 10 [CFP-10], culture filtrate protein 21 [CFP-21], and mycobacterial protein from species tuberculosis 64 [MPT-64]) have recently been shown to be promising for specific diagnosis of TB in our lab. However, only few studies have reported the use of synthetic peptides of RD antigens, and none has used them to differentiate TB from sarcoidosis, a close mimic of smear-negative pulmonary TB (PTB) with entirely different management. The present study was conducted with an aim to study the utility of B-cell epitopes based peptides of RD1 (ESAT-6, CFP-10) and RD2 (CFP-21, MPT-64) antigens for immunodiagnosis of PTB for which sputum smear-positive PTB patients, sputum smear-negative PTB patients, sarcoidosis patients, and healthy controls (n = 24/group) were recruited. Bioinformatic software Bcepred was used to predict linear B-cell epitopes, using physico-chemical properties on a non-redundant dataset. Seven peptides as representative B-cell epitopes of ESAT-6, CFP-10, CFP-21, and MPT-64 were evaluated as targets of the antibody responses in TB patients and controls by enzyme-linked immunosorbent assay (ELISA). The current study showed sensitivity with individual peptides ranging from 37.5% to 83.3% for smear positive, 25% to 58.3% for smear negative as compared to 4.16% to 20.8% for sarcoidosis. Four out of 7 peptides that showed higher reactivity with TB patients and better discrimination from sarcoidosis patients representing ESAT-6, CFP-10, CFP-21, and MPT-64 were selected for multiepitope ELISA. The combination of peptides yielded 83.3% sensitivity for smear positive, 62.5% for smear negative, and only 4.16% for sarcoidosis. The specificity, however, for all the peptides/combination was 100%. Combination of peptides has proven to be better than individual peptides as per the latest criteria of the World Health Organization according to which a test that can replace smear microscopy with sensitivity of >90% for smear-positive patients and >65% for smear-negative TB patients with a specificity >95%, and thus, the present study suggests that a test based on combination of peptides selected from mycobacterial RD1 and RD2 antigens could be important for promoting an early diagnosis and management of otherwise difficult to diagnose smear-negative PTB patients. Moreover, it can also be used to discriminate sarcoidosis from PTB, thus preventing the misdiagnosis and mismanagement.     

The evaluation of FASTPlaqueTB test for the rapid diagnosis of tuberculosis

FASTPlaqueTB (Biotec Laboratories Ltd., Ipswich, UK) is a rapid test which utilizes bacteriophage amplification technology for the detection of viable Mycobacterium tuberculosis in clinical specimens. We evaluated performance of the FASTPlaqueTB test by comparing with BACTEC 460 TB culture system (Becton Dickinson Co., Maryland, USA), polymerase chain reaction (PCR) and acid fast bacilli (AFB) smear methods. We investigated 192 sputum specimens collected from the patients suspected of having pulmonary TB by AFB smear, BACTEC 460 TB culture system, PCR and FASTPlaqueTB test. The sensitivity of AFB smear, PCR and FASTPlaqueTB test were 57.8%, 84.4% and 87.5% respectively when we accepted BACTEC 460 TB culture system as gold standard. We conclude that FASTPlaqueTB test has a good potential for rapid diagnosis of Mycobacterium tuberculosis as a result of the evaluation of these three tests by comparison to the BACTEC 460 TB culture system.     

结核分枝杆菌检测方法临床应用的对比研究

目的用涂片、聚合酶链反应(PCR)法检测结核分枝杆菌,探讨其临床应用价值。方法对169例临床确诊的肺结核患者、可疑肺结核患者和非结核患者痰标本用涂片、PCR两种方法进行检测,对结果进行对比分析。结果 169例痰标本中,痰涂片检查阳性率为7.1%(12/169),PCR检测阳性率为32.54%(55/169);痰涂片、PCR法检测42例临床确诊的肺结核患者痰标本阳性率分别为11.9%(5/42)、57.1%(24/42);检测82例临床可疑肺结核患者痰标本阳性率分别为8.54%(7/82)、37.8%(31/82)。比较两种方法的阳性检测率,差异有统计学意义(χ2=19.729,P<0.01),检测45例非结核患者痰标本,涂片及PCR检测均为阴性。结论 PCR法检测结核分枝杆菌具有较高的敏感性和特异性,可作为临床结核病检测诊断的有效方法之一。     

纤维支气管镜检查对痰菌阴性下肺野结核的诊断价值

目的提高结核病的及时诊断。方法利用纤维支气管镜（纤支镜）诊断痰菌阴性的下肺野结核57例。纤支镜下表现为溃疡性肉芽肿、气管黏膜充血水肿和纤维性狭窄。结果经纤支镜活检病理诊断7例（7／57），刷检涂片诊断20例（20／57），吸检涂片18例（18／54），灌洗液涂片诊断14例（14／27）。结论利用纤支镜检查可提高痰菌阴性的下肺野结核的诊断率和了解支气管内膜病变情况，从而指导临床治疗。     

Usefulness of gastric aspirate for the diagnosis of smear-negative pulmonary tuberculosis

IntroductionGastric aspirate can be useful for the diagnosis of pulmonary tuberculosis (TB) in patients with smear-negative pulmonary TB or without sputum production. The gastric aspirate smear technique has low sensitivity, and a previous report demonstrated that no patient was diagnosed by only gastric aspirate analysis. However, some patients with TB have been negative on sputum examination but positive on gastric aspirate examination, and the incidence of such cases is uncertain. Therefore, this study investigated the usefulness of gastric aspirate in the diagnosis of pulmonary TB.MethodsTo analyze the diagnostic accuracy of gastric aspirate examination, the data of 513 patients with negative sputum smears or a lack of sputum production, including 203 patients with pulmonary TB (39.6%) and 93 patients with nontuberculous mycobacteriosis who underwent gastric aspiration at Fukujuji Hospital from January 2016 to March 2021, were collected retrospectively.ResultsThe accuracy rates of gastric aspirate examination for the diagnosis of pulmonary TB were as follows: 21.2% sensitivity and 91.9% specificity for smear positivity, 55.8% sensitivity and 99.6% specificity for nucleic acid amplification test positivity, and 71.4% sensitivity and 100% specificity for culture positivity. Twenty-three patients (11.2%) were diagnosed by gastric aspirate examination alone. Among the 356 patients who underwent three repeated sputum examinations in addition to gastric aspirate examination, the cumulative diagnostic rate for the 3 mycobacterial examinations plus gastric aspirate examination was higher than that for only three sputum examinations.ConclusionsGastric aspirate is useful for the diagnosis of TB in patients with smear-negative pulmonary TB or without sputum production.     

Ligase chain reaction assay is clinically useful in the discrimination of smear-positive pulmonary tuberculosis from atypical mycobacterioses

We evaluated the usefulness of the ligase chain reaction (LCR) (Abbott LCx Mycobacterium tuberculosis assay) during the initial diagnosis of tuberculosis. LCx was carried out in parallel with conventional methods for the analysis of clinical samples. Out of 86 patients who were examined clinically, 53 were suspected of having pulmonary tuberculosis, eight had residual X-ray scars from previous tuberculosis and 25 served as asymptomatic controls. Ten bronchoscopy samples and 237 sputum samples were analysed by direct microscopy, culture and LCx. All 11 smear-positive and two of three smear-negative tuberculosis patients had at least one LCx-positive specimen. All samples that were both LCx- and smear-positive were culture-positive for M. tuberculosis. The smear-positive samples from the five patients with atypical mycobacteriosis were LCx-negative. There were three false-positive results: one in a smear-negative sample from a patient with M. malmoense infection and two from two pneumonia patients. All samples from controls and patients with previous tuberculosis were LCx-negative. The sensitivity, specificity and the positive and negative predictive values of LCx in patient analysis were 92.9%, 95.8%, 81.3% and 98.6%, respectively. LCx assay of M. tuberculosis is useful in rapid confirmation of tuberculosis or atypical mycobacteriosis from a smear-positive sample and may aid in diagnosing smear-negative tuberculosis.     

Fiberoptic bronchoscopy in the diagnosis of pulmonary tuberculosis

We reviewed the records of 80 patients with culture-positive pulmonary tuberculosis. Forty (50%) had their diagnoses established by sputum smears and cultures alone, 20 (25%) by brush/wash specimens from fiberoptic bronchoscopy alone, 18 (22.5%) from both sources, and two (2.5%) by gastric smears. The average age of the patients was 71.3 years, and only 20% had symptoms typical of pulmonary tuberculosis. Our data reveal that findings in smears from fiberoptic bronchoscopy were of comparable sensitivity (80%) to those of sputum (72.5%); in 25/80 (31.25%), diagnosis was made exclusively by fiberoptic bronchoscopy. Such a high sensitivity of fiberoptic bronchoscopy in the diagnosis of pulmonary tuberculosis indicates a threefold rise (P = .018) in the number of diagnoses made in this manner compared to our figures from 1983 (10% of diagnoses made by fiberoptic bronchoscopy). Forty-three of the 80 patients (53.8%) had either a negative sputum smear or no sputum available. Thirty of the 43 patients (69.8%) had diagnostic bronchoscopy, which provided an immediate diagnosis (smear positivity) in 18 patients (60%). Transbronchial biopsy was most useful in excluding associated malignancy. Fiberoptic bronchoscopy is playing an increasingly significant role in the diagnosis of pulmonary tuberculosis. Further studies are essential to evaluate cost effectiveness, specificity of fiberoptic bronchoscopy, and the influence of the procedure on morbidity and mortality in pulmonary tuberculosis.     

痰液切片与涂片联合检查对提高肺癌诊断的价值

对１８３例怀疑肺癌者的痰液，应用石蜡包埋连续切片与涂片进行了联合检查，共检出肺癌９２例，其中切片涂片均阳性者４８例；切片阳性涂片阴性者２８例，涂片阳性切片阴性者１６例，假阴生４例，可疑癌细胞者７例，从中可见痰液肿瘤脱落细胞学检查，石蜡包埋连续切片阳性率高于涂片，而切片与涂片联合检查的阳性率又高于单独切片或涂片。同时应用石蜡包埋切片做了特色，免疫组织化学，电子显微镜检查，为痰液肿瘤脱落细胞学的深入研     

2177例痰结核菌涂片抽检结果分析

[目的]评价我院结核实验室结核菌涂片制作质量,结果符合率,减少假阳性和假阴性的发生,保证检验质量。[方法]收集2008年12月～2009年11月天津市海河医院结核门诊和住院病人的痰涂片5587例,抽取阳性片450例,阴性片1727例,共计2177例,由高级检验技师进行复检。[结果]涂片质量优良及合格率达88．7％,抽查450例阳性片,发现假阳性5例（1．1％）,阳性445例（98．9％）。1727例阴性片抽查,发现阴性1593例（92．24％）,再发现阳性134例,再发现率为7．76％,其中增加镜检至300～400个视野数,再发现率为3．94％。[结论]规范涂片制作质量,加强涂片镜检后的抽查,增加显微镜视野检查数量,提高检验者对查痰意义的认识和镜检技术水平,就可以使结核菌涂片检出率有所改善和提高,降低和减少肺结核假阴性病例的出现。     

Bronchoalveolar lavage in pulmonary tuberculosis: a decision analysis approach

We assessed the utility of bronchoalveolar lavage (BAL) in thediagnosis of pulmonary tuberculosis (PTB) in 50 consecutiveHIV-negative patients with clinical and radiographic findingssuggestive of PTB, but with negative microscopy for acid-fastbacilli (AFB) on sputum smear. Patients were grouped, usinga scoring system, into relative likelihoods of having PTB (I—IV,in descending probability). Patients were started on anti-tuberculosistreatment according to the BAL results. Bacteriological diagnosisof PTB was confirmed in 22/50 BAL; 11 (91.6%), seven (37%) andfour (40%) of groups I–III, respectively. In 13 cases,an early diagnosis of PTB was made by positive microscopy forAFB on BAL; an alternative diagnosis was made in six cases (bacterialpneumonia 4, carcinoma 2). A decision analysis model was createdto assess the overall utility of BAL. This suggested that ina region of high PTB prevalence, and when the clinical diagnosisof PTB is likely, empirical treatment is the best course ofaction, with BAL being reserved for further investigation ofnon-responders. Early BAL should be considered when the diagnosisof PTB is uncertain.     

Direct identification of mycobacteria from smear-positive sputum samples using an improved multiplex polymerase chain reaction assay

The rapid identification of mycobacteria from smear-positive sputum samples is very important. To identify the Mycobacterium tuberculosis complex (MTBC) and frequently isolated nontuberculous mycobacteria strains directly from smear-positive sputum samples, an improved multiplex polymerase chain reaction (PCR) assay was developed. Nine pairs of primers targeting the 16S-23S rDNA internal transcribed spacer-1, hsp65, and the early secretory antigen (ESAT-6) gene sequences were developed, and their efficacy was evaluated in comparison to traditional culturing and 16S rRNA gene sequencing methods. A total of 200 smear- and culture-positive sputum specimens collected between November 2005 and May 2006 were used for the analysis. The results of the assay showed an accurate identification rate for acid-fast bacilli (AFB) 3+, AFB 2+, and AFB rare/1+ samples of 98%, 95%, and 53%, respectively. The improved multiplex PCR method saves time and has advantages for identifying mycobacteria from AFB 2+ and 3+ sputum samples. The method is suitable for use in countries with a high MTBC prevalence rate.     

支气管结核48例临床诊断分析

目的探讨提高支气管结核患者临床诊断水平的方法。方法回顾性分析我院2004年至2009年收治的48例支气管结核患者的临床资料。结果所有患者均有咳嗽、咳痰病史;X线检查有2例考虑为结核病,确诊率为4.17%(2/48);有30例患者行CT检查,12例确诊,确诊率为40%(12/30);48例行纤维支气管镜检,32例确诊,确诊率为66.67%(32/48);常规痰抗酸染色涂片有12例发现结核杆菌,阳性率为25%(12/48),结合支气管镜取材39例抗酸染色涂片阳性,阳性率为81.25%(39/48);确诊率为81.25%(39/48);病理检查38例确诊,确诊率为79.17%(38/48)。结论 X线、胸部CT、PPD检查、常规痰涂片检查及纤维支气管镜检查对支气管结核的诊断都存在盲区,但纤维支气管镜镜检联合镜下取材行痰抗酸杆菌培养及涂片检查或者联合病理学检查能大大提高诊断水平。     

Usefulness of bronchial lavage for the diagnosis of pulmonary disease caused by Mycobacterium avium-intracellulare complex (MAC) infection

To evaluate the usefulness of bronchial lavage for the diagnosis of pulmonary disease due to Mycobacterium avium-intracellulare complex (MAC) infection, we examined the clinical records and bacteriologic findings of patients admitted to our hospital between 1999 and 2002 who fulfilled the 1997 American Thoracic Society (ATS) criteria for MAC pulmonary infection. Bronchoscopic examinations were performed in those patients with MAC pulmonary disease who showed negative sputum smears for mycobacteria on 3 consecutive days (n = 14) or who could not expectorate sputum (n = 2). The bronchial lavage sample was smear-positive for acid-fast bacilli in 8 of the 16 patients (50.0%), polymerase chain reaction (PCR)-positive for MAC in 10 of 15 (66.7%), and culture-positive for MAC in 15 of 16 (93.7%). The brushing sample was positive for MAC in 5 of 14 patients (35.7%), and transbronchial lung biopsy (TBLB)-positive for MAC in 2 of 5 (40.0%). MAC was isolated by culture of bronchial lavage samples in a higher percentage of patients than that in whom MAC was isolated by sputum culture, and we could make an early diagnosis of MAC pulmonary disease based on the smear and PCR results for bronchial lavage samples. Bronchial lavage is useful to screen sputum smear-negative patients suspected of having MAC pulmonary disease.     

手工判读MGIT法检测分枝杆菌的效果评价

目的 应用手工荧光判读仪对MGIT液体培养基进行快速检测分枝杆菌的效果评价.方法 收集2011年3月至2011年4月杭州市红十字会医院临床诊断为结核病的患者临床标本230份,其中涂片法抗酸染色阳性标本57份,阴性标本173份.分别对同份标本做L-J固体和MGIT液体培养法分离培养效果比较,结果统计学分析采用x2检验...     

支气管镜多指标联合检测对菌阴肺结核的诊断价值探讨

目的探讨支气管镜多指标联合检测对菌阴肺结核的诊断价值。方法138例菌阴肺结核患者治疗前进行支气管镜检查行病理活检、刷检涂片、支气管肺泡灌洗液（BALF）涂片、BALF培养以及术后连续3d痰涂片检查，了解不同取材方法对肺结核诊断的阳性率。结果43例患者镜下有异常改变，其中28例行活检19例病理为典型结核结节，活检阳性率为67．8％，刷检涂片、BALF涂片、BALF培养、术后痰涂片的阳性率分别为32．6％、36．996、12．3％和21．0％，四者联合检测的阳性率为52．1％，活检与细菌学联合检测阳性率为63．0％。结论支气管镜检查直接观察气道有无内膜结核而诊断是否肺结核，多项指标联合检测可提高肺结核的诊断率。