Polymerase Chain Reaction For Mycobacterium Tuberculosis Research Articles

Diagnostic value of bronchoscopy in sputum‑negative presumptive pulmonary tuberculosis patients and its clinicoradiological profile

Abstract: CONTEXT: Tuberculosis (TB) remains endemic in India. Little local data have been reported on bronchoscopic evaluation of sputum‑negative pulmonary TB patients, which poses a significant diagnostic and therapeutic challenge. AIMS: To determine the diagnostic value of bronchoscopy and bronchoalveolar lavage (BAL) and its clinical and radiological profile in sputum‑negative, pulmonary TB patients. METHODS: We performed an analysis of patients with probable pulmonary TB with overall negative (smear and/or polymerase chain reaction [PCR]) or scanty sputum that had undergone bronchoscopy with BAL over a period of 11 months. Patients’ symptoms, radiological features, lung lobe lavaged, BAL acid‑fast bacilli (AFB) stain, Mycobacterium TB (MTB)‑PCR, and mycobacterial cultures were analyzed. Mycobacterial culture was used as a reference standard. RESULTS: 54 patients underwent a diagnostic bronchoscopy. Dry cough and fever were the most common symptoms. Uncontrolled diabetes mellitus was the most frequent comorbidity identified in 15 (28%) patients. Fifty‑nine percent of the patients had diffuse lung infiltrates, with consolidation being the most common abnormality (41%), followed by cavitation (39%). Right upper lobe was the most frequent lung lobe lavaged (31%). BAL mycobacterial culture and MTB Polymerase Chain Reaction (PCR) were positive in 43 (80%) and 41 (76%) patients and BAL AFB was positive in 5 patients respectively. Using BAL culture as reference, male gender, predominant upper lobe disease, upper lobe lavage, and presence of cavities on chest imaging had the highest diagnosticyield (82%, 100%, 63%, and 89%, respectively) (P = 0.02,0.006, 0.03, and 0.02, respectively).There was 100% concordance among the three diagnostic modalities. CONCLUSIONS: An overall diagnostic yield of 80% was achieved with combined use of BAL MTB PCR, culture, and AFB staining. Keywords: Broncho alveolar lavage, bronchoscopy, Mycobacterium tuberculosis polymerase chain reaction, sputum negative, tuberculosis

Rapid Diagnosis of Disseminated Tuberculosis Using Cell-free DNA Sequencing in a Kidney Transplant Recipient.

Here, we report a case of smear-negative disseminated tuberculosis (TB) in a kidney transplant recipient diagnosed using plasma cell-free DNA (cfDNA). A 68-y-old woman presented with 2 mo of fevers and a 15-pound weight loss. Six years earlier, she received a living donor kidney transplant from her husband for adult polycystic kidney disease. She received standard induction with antithymocyte globulin and maintenance immunosuppression with tacrolimus, mycophenolate mofetil, and low-dose prednisone. Her posttransplant course was uncomplicated. She was born and lived in Massachusetts and had not traveled internationally in many years. She worked in finance until she retired a few years prior. She had no history of incarceration or homelessness. Her hobbies included volunteering at a local food bank. On presentation, she was febrile to 38.8 °C and diaphoretic but otherwise appeared well. Her laboratory values were notable for a leukocytosis of 16 000 K/µL and a urinalysis with >100 white blood cells per high power field. There was no growth in the urine or blood cultures. Her nasopharyngeal multiplex polymerase chain reaction (PCR) was negative for common respiratory viruses. She had negative test results for Epstein-Barr virus DNA, cytomegalovirus DNA, HIV 1/2 antigen/antibody, cryptococcal and Histoplasma antigens. Chest computed tomography showed innumerable 1- to 3-mm bilateral nodules (Figure 1A) and lytic lesions of the T6 and T7 vertebral bodies. Spine magnetic resonance imaging demonstrated enhancing lesions involving the entire T6 and T7 bodies (Figure 1B).FIGURE 1.: Abnormal imaging findings. A, Chest CT scan with diffuse bilateral pulmonary nodules in a miliary pattern. B, MRI of the thoracic spine with enhancing lesions of the T6 and T7 vertebral bodies. CT, computed tomography.Further workup included bronchoalveolar lavage with multiple negative studies: bacterial cultures, Pneumocystis direct fluorescent antibody, galactomannan antigen, acid-fast bacilli (AFB) and modified AFB smear, and Mycobacterium tuberculosis PCR. Transbronchial biopsy was nondiagnostic, with negative AFB and fungal stains. Mycobacterial blood and urine cultures were also obtained. A biopsy of her T7 vertebral body noted chronic inflammation and 1 nonnecrotizing granuloma. On hospital day (HD) 13, while she remained febrile and without a definitive diagnosis, we sent a quantitative cfDNA test (Karius, Inc, Redwood City, CA). On HD 15, the Karius cfDNA test returned positive for M tuberculosis. Subsequently, the mycobacterial blood, urine, and bronchoalveolar lavage cultures grew M tuberculosis on HD 17, 17, and 21, respectively. Bone cultures grew M tuberculosis at 34 d after biopsy after the patient had been discharged from the hospital. Cell-free DNA tests have become increasingly prevalent in recent years, including donor-derived cfDNA, which is routinely used to detect allograft rejection. The Karius cfDNA test uses metagenomic next-generation sequencing to specifically detect microbial nucleic acid from over a thousand clinically relevant species in plasma.1 This was the first case of TB diagnosed by plasma cfDNA sequencing in our institution. The turnaround time of 48 h is a promising characteristic of this test, especially when slow-growing pathogens are suspected. Had it been obtained earlier in the course, this test would have not only expedited diagnosis and treatment initiation but also eliminated the need for invasive diagnostics. Nevertheless, like other molecular tests, cfDNA sequencing does not provide antimicrobial susceptibilities to guide antimicrobial therapy and thus does not eliminate the need for cultures. In a recent meta-analysis, cfDNA sequencing showed excellent specificity but poor pooled sensitivity for the diagnosis of TB.2 The very low-risk epidemiologic history for TB and disease onset in the late posttransplant period were other interesting features of this case. Her pretransplant T spot TB was negative. We considered donor-derived TB, but this was deemed unlikely because her donor was her husband, who was healthy and had a negative TB screening. She had no known exposures to TB, and her exposure to higher-risk populations via volunteerism was her only epidemiologic risk factor.

Multicenter Testing of a Simple Molecular Diagnostic System for the Diagnosis of Mycobacterium Tuberculosis

Mycobacterium tuberculosis (MTB) is a communicable disease and still remains a threat to common health. Thus, early diagnosis and treatment are required to prevent the spread of infection. Despite the recent advances in molecular diagnostic systems, the commonly used MTB diagnostic tools are laboratory-based assays, such as mycobacterial culture, MTB PCR, and Xpert MTB/RIF. To address this limitation, point-of-care testing (POCT)-based molecular diagnostic technologies capable of sensitive and accurate detection even in environments with limited sources are needed. In this study, we propose simple tuberculosis (TB) molecular diagnostic assay by combining sample preparation and DNA-detection steps. The sample preparation is performed using a syringe filter with amine-functionalized diatomaceous earth and homobifunctional imidoester. Subsequently, the target DNA is detected by quantitative PCR (polymerase chain reaction). The results can be obtained within 2 h from samples with large volumes, without any additional instruments. The limit of detection of this system is 10 times higher than those of conventional PCR assays. We validated the clinical utility of the proposed method in 88 sputum samples obtained from four hospitals in the Republic of Korea. Overall, the sensitivity of this system was superior to those of other assays. Therefore, the proposed system can be useful for MTB diagnosis in limited-resource settings.

Usefulness of Mycobacterium tuberculosis-polymerase chain reaction with bronchial washing samples in predicting discontinuation of airborne infection isolation in patients hospitalized with suspected pulmonary tuberculosis.

In-hospital tuberculosis (TB) transmission remains a concern. Airborne infection isolation (AII) can be discontinued in hospitalized patients with suspected active pulmonary TB when the results of three consecutive sputum acid-fast bacilli (AFB) smears are negative. However, fiberoptic bronchoscopy can be performed in patients who may have difficulty in producing sputum samples. This study aimed to investigate the usefulness of Mycobacterium tuberculosis-polymerase chain reaction (MTB-PCR) with bronchial washing specimens in predicting AII discontinuation in hospitalized patients with suspected active pulmonary TB. We reviewed the medical charts of patients admitted to a tertiary hospital who were isolated and underwent fiberoptic bronchoscopy for suspicious pulmonary TB from January 2016 to December 2019. Patients with positive MTB-PCR results in the initial sputum examination were excluded. Criteria for discontinuing AII were defined as negative results for three consecutive AFB smears from respiratory specimens, or cases diagnosed other than TB. The study patients were divided into two groups: TB group and non-TB group. In total, 166 patients were enrolled in the study. Of them, 35 patients were diagnosed with TB. There was no significant difference between the number of males in the TB (81; 61.8%) and non-TB (21; 60.0%) group. Though 139 patients had negative results on MTB-PCR using washing specimens, eight showed positive AFB culture. Of the 139 patients with negative MTB-PCR results, 138 had negative results for three consecutive AFB smears or were established to not have pulmonary TB. Therefore, the predictive accuracy of MTB-PCR with bronchial washing samples for discontinuing AII was 99.2%. Although a negative result from MTB-PCR with bronchial washing samples cannot exclude pulmonary TB, it can predict AII discontinuation in hospitalized patients with suspected active pulmonary TB.

HIDING IN PLAIN SIGHT: DISSEMINATED PULMONARY TB

HIDING IN PLAIN SIGHT: DISSEMINATED PULMONARY TB

Analysis of Clinical Features and Risk Factors in Pregnant Women With Miliary Pulmonary Tuberculosis After In Vitro Fertilization Embryo Transfer.

PurposeMiliary pulmonary tuberculosis (TB) among pregnant women after in vitro fertilization embryo transfer (IVF-ET) causes poor outcomes but is rarely reported. This study analyzed the clinical characteristics and risk factors of these patients to provide hints for further studies.MethodThe demographic characteristics, clinical manifestations, radiologic features, treatment, and outcomes of six patients diagnosed from May 2012 to August 2021 in Xiangya Hospital and 69 patients that were reported in English or Chinese literature from January 1980 to August 2021 were retrospectively analyzed. Continuous variables were compared between groups by t-test or Mann–Whitney U test, and categorical variables were compared between groups by chi-square test or Fisher exact test. Univariate and multiple logistic regression analyses were used to determine the predictors of respiratory failure.ResultsA total of 75 patients were included. The average age of patients was about 30 years. All patients had tubal obstruction; 5 of them were diagnosed with pelvic TB before. Thirteen cases had a history of pulmonary or extrapulmonary TB, six out of them without any antituberculosis treatment history. All patients were in their first or second trimester during the onset of symptoms. The average interval between onset of symptoms and radiologic examination was about 21 days. The most common abnormalities on chest computed tomography scan were multiple nodules, pulmonary infiltrate, and consolidation. Merely 10 patients obtained bacteriological diagnosis by Mycobacterium tuberculosis culture or polymerase chain reaction test. The other patients were clinically diagnosed. All the patients received antituberculosis treatment. Although 44% of patients had fatal complications, all cases were cured or improved after antituberculosis treatment. Unfortunately, only eight fetuses survived (10.6%). The most frequent and severe complication was type I respiratory failure (20%). Patients with expectoration, dyspnea, coarse breath sounds, ground-glass opacity, and pulmonary infiltrate or consolidation were more likely to have respiratory failure (P < 0.05). Ground-glass opacity (OR = 48.545, 95% CI = 2.366–995.974, P = 0.012) and pulmonary infiltrate or consolidation (OR = 19.943, 95% CI = 2.159–184.213, P = 0.008) were independent predictors for respiratory failure.ConclusionTube infertility with underscreened or untreated TB is a risk factor for miliary TB during pregnancy after IVF-ET. Ground-glass opacity and pulmonary infiltrate or consolidation are predictors of respiratory failure. We demonstrate risk factors for incidence and complications to supply clues for future intervention and improve patient prognosis.

Polymicrobial spontaneous pyogenic spondylodiscitis: A very rare entity!

Spontaneous pyogenic spondylodiscitis (SPS) is an uncommon disease. The most common causative organism of SPS is Staphylococcus aureus, followed by Gram-negative bacilli in 4%–30% of the cases. Polymicrobial SPS is very rare, with only a few cases reported in the literature. We report a case of polymicrobial SPS in a 43-year-old male who was recently diagnosed with autoimmune hepatitis with cirrhosis of the liver and presented with a 1-month history of progressive low backache with radiation to both the legs. Initially, he was managed as a case of Pott's spine with antitubercular therapy on the basis of immunocompromised status with positive ascitic fluid Mycobacterium tuberculosis polymerase chain reaction. However, due to lack of clinical and radiological response after 6 weeks, he underwent computed tomography-guided biopsy of the affected region. The culture from the biopsy specimen yielded Klebsiella oxytoca and Proteus vulgaris. He was managed with culture-sensitive antimicrobials. To the best of our knowledge, this is the first case of polymicrobial SPS caused by K. oxytoca, P. vulgaris, and M. tuberculosis.

Delayed hypersensitivity to the Comirnaty coronavirus disease 2019 vaccine presenting with pneumonitis and rash

Delayed hypersensitivity to the Comirnaty coronavirus disease 2019 vaccine presenting with pneumonitis and rash

AN UNUSUAL CAUSE OF SECONDARY SPONTANEOUS PNEUMOTHORAX

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Secondary spontaneous pneumothorax (SSP) is defined as a non-traumatic pneumothorax in patients with underlying lung disease. They are commonly seen in patients with conditions such as chronic obstructive pulmonary disease, cystic fibrosis, infection, and cancer. While it is widely recognized that tuberculosis (TB) can cause SSP, estimates suggest less than 1% of TB cases are complicated by SSP. This case describes a rare initial presentation of TB. CASE PRESENTATION: A 41-year-old woman from Mexico presented with acute onset sharp left-sided chest pain. She had been having pneumonia symptoms (cough, chills, sputum production) for four months and took several courses of oral antibiotics with no improvement. She had no prior episodes of pneumonia, tuberculosis or other infections, and had no sick contacts. On presentation, she was afebrile, tachycardic, tachypneic and mildly hypoxic with decreased breath sounds on the left. A chest radiograph showed a large left-sided pneumothorax, and a 14-French pigtail chest tube was placed. Computed tomography of the chest showed bronchiectasis and cystic changes with large cavitation. Sputum acid-fast bacilli staining as well as mycobacterium tuberculosis (MTB) polymerase chain reaction returned positive. She was diagnosed with secondary spontaneous pneumothorax, and RIPE therapy was initiated. The chest tube was connected to suction which produced a continuous air leak which improved when the tube was connected to water seal, raising concern for a bronchopleural fistula. The air leak persisted for 14 days, and thus she was evaluated by thoracic surgery who ultimately performed a lobectomy. DISCUSSION: This case illustrates an unusual initial presentation of tuberculosis – this patient had an SSP from underlying bronchiectasis as well as a bronchopleural fistula. Mycobacterial infections (classically, non-tuberculous mycobacterium) often complicate pre-existing bronchiectasis. MTB itself can cause bronchiectasis from longstanding tuberculous bronchitis, post-obstructive damage secondary to post-tuberculous bronchial wall stenosis, and extraluminal bronchial obstruction by enlarged tuberculous lymph nodes. This patient had no symptoms of longstanding lung disease, and a basic workup for other causes of bronchiectasis returned normal, leaving MTB as the most likely reason for her abnormal lung architecture. The acute onset SSP triggered her eventual presentation to the hospital. It is estimated that SSP complicates between 0.6% and 1.5% of cases of tuberculosis. In one series, patients with SSP from MTB were safely treated with pleural drainage for an average of 13 days (ranging from 4 - 54 days). 28% of patients required surgery for persistent air leak, as did this patient. CONCLUSIONS: SSP is a potentially fatal complication of MTB that typically responds well to pleural drainage and RIPE therapy. Surgery may be needed for continuous air leaks. REFERENCE #1: Freixinet JL, Caminero JA, Marchena J, Rodríguez PM, Casimiro JA, Hussein M. Spontaneous pneumothorax and tuberculosis: long-term follow-up. Eur Respir J. 2011;38(1):126-131. doi:10.1183/09031936.00128910 REFERENCE #2: Doucette K, Cooper R. Tuberculosis. In: Grippi MA, Elias JA, Fishman JA, Kotloff RM, Pack AI, Senior RM, Siegel MD. eds. Fishman's Pulmonary Diseases and Disorders, Fifth Edition. McGraw-Hill; Accessed April 22, 2021. https://accessmedicine.mhmedical.com/content.aspx?bookid=1344§ionid=81199723 REFERENCE #3: Burguete S, DeArmond DT, Soni NJ, Peters J. Pneumothorax. In: Grippi MA, Elias JA, Fishman JA, Kotloff RM, Pack AI, Senior RM, Siegel MD. eds. Fishman's Pulmonary Diseases and Disorders, Fifth Edition. McGraw-Hill; Accessed April 29, 2021. https://accessmedicine.mhmedical.com/content.aspx?bookid=1344§ionid=81193412 DISCLOSURES: No relevant relationships by Ethan Loftspring, source=Web Response No relevant relationships by Dharani Kumari Narendra, source=Web Response No relevant relationships by Divya Verma, source=Web Response

Circulating MicroRNA 29a: An Evolving Biomarker for Diagnosis of Pulmonary Tuberculosis

Introduction: Tuberculosis (TB) is global health problem threatening millions every year. There is urgent need of effective biomarkers for its diagnostics and circulating microRNAs (miRNAs) have recently emerged as novel and non-invasive molecular markers in blood. Aim: This study was done to evaluate serum miRNAs as a potential biomarker for the diagnosis of pulmonary mycobacterium tuberculosis infection. Materials and Methods: In this prospective cross-sectional study, acute pulmonary TB patients were recruited based on positive Mycobacterium tuberculosis Polymerase Chain Reaction (PCR) in sputum samples and Microarray expression profiling was performed on blood of these patients to study differentially expressed miRNAs. The results were validated by Real-Time Polymerase Chain Reaction (RT-PCR) on pulmonary TB cases and healthy controls. Student’s t-tests and analysis variance tests were used for statistical analysis. The p-value &lt;0.05 was considered statistically significant. Results: Results of microarray expression profiling showed 75 differentially expressed miRNAs in cases of pulmonary TB; among these 5 upregulated and 2 downregulated miRNAs were evaluated by RT-PCR. miRNA 29a exhibited good distinguishing efficiency; followed by miRNA 384. ROC plot of expression data for miRNA in cases and control groups showed that AUC of miRNA-29a was 0.8268 (sensitivity=80%, specificity=82%) . Conclusion: This study suggests that altered levels of serum miRNAs have great potential to serve as non-invasive biomarkers for detection of Mycobacterium tuberculosisinfection. miRNA-29a can be used as an effective biomarker for diagnosis of pulmonary TB.

Role of Laparoscopy in the Diagnosis of Genital TB in Infertile Females in the Era of Molecular Tests

To assess diagnostic value of polymerase chain reaction (PCR) in endometrial aspirates (EAs) in comparison with conventional tests for diagnosis of female genital tuberculosis (TB) and to find agreement between EA PCR done for endometrial TB and laparoscopic findings of pelvic TB in women with unexplained infertility. Prospective observational cohort study. Tertiary care hospital. A total of 732 infertile females screened and 385 enrolled to undergo procedure to obtain EAs. EAs were tested by conventional tests (histopathology, acid-fast bacilli, Lowenstein-Jensen staining, liquid culture) and PCR for Mycobacterium tuberculosis. Patients with positive conventional tests were started on antitubercular treatment (ATT). Patients with negative conventional tests underwent laparohysteroscopy irrespective of PCR results to assess changes of tubercular infection in the pelvis. Peritoneal washings were also sent for liquid culture and PCR for TB, and suspicious lesions were biopsied at laparohysteroscopy. Findings at laparoscopy upgraded the diagnosis in these women. EAPCR results were analyzed to find agreement with the findings at laparoscopy. Conventional tests were positive in 8 of 385 (2%) patients. PCR was positive in 58.1% (n = 224) of endometrial samples, with sensitivity of 62.5% (95% confidence interval [CI], 24.49-91.48), specificity of 41.91% (95% CI, 36.88-47.07), positive predictive value of 2.23% (95% CI, 1.31-3.78), negative predictive value of 98.14% (95% CI, 95.53-99.24), and a diagnostic accuracy of 42.34% (95% CI, 37.35-47.45) with conventional tests. A total of 265 patients underwent laparoscopy, of whom 165 were PCR positive and 100 were PCR negative. Laparoscopic findings suggestive of TB were found in 39.3% of patients who were PCR positive and 9% of patients who were PCR negative. Kappa agreement was 0.25, suggesting fair agreement between PCR and laparoscopy. PCR as a stand-alone diagnostic test for endometrial TB is not justified to confirm diagnosis and initiate ATT. The addition of laparohysteroscopy improves diagnostic yield for genital TB. Referring patients with a suspicion of female genital TB to tertiary care for 1-time laparoscopy is better than initiating ATT solely on the basis of PCR results.

A case of autoimmune hepatitis with tuberculosis caused by prednisolone from undeterminable enzyme-linked immunospot assay

An 88-year-old woman was referred to our hospital for autoimmune hepatitis in 2016. She was treated with prednisolone. In 2018, she was rehospitalized owing to hepatitis relapse. Steroid pulse therapy was performed. She exhibited good recovery of hepatitis, but was transferred to a convalescent ward in a general hospital because of decreased activity of daily life. After a month later, she had high fever and cough. She was diagnosed as having tuberculosis because of positive Mycobacterium tuberculosis polymerase chain reaction. At our first medical examination in 2016, we performed enzyme-linked immunospot and the result was undeterminable. There is an increase in the opportunities to use immunosuppressant and biologic agents for elderly patients. Our case report should contribute to future medical care for elderly patients who are at risk of latent tuberculosis infection.

Isolation and deisolation of patients admitted with presumptive pulmonary tuberculosis. Can it be shortened?

Objectives:To determine the ideal number of sputum acid-fast bacilli (AFB) smears and polymerase chain reaction (PCR) required for discontinuing tuberculosis (TB) isolation among patients with suspected pulmonary TB.Methods:This was a single-center, record-based retrospective study of all admitted patients diagnosed with culture-proven pulmonary TB between 2010 and 2018. The study was conducted at Prince Sultan Military Medical City (PSMMC) in Riyadh, Saudi Arabia, a large tertiary care center consisting of 1,200 beds. Data were obtained from our TB notification records. Patients with smear-positive TB were investigated. Only the first 3 sputum smears for AFB were included in the analysis. The PCR results for Mycobacterium tuberculosis (MTB) were also included in the study. The incremental yield of the second and third smears was assessed.Results:Overall, 240 patients were MTB-culture positive. A total of 126 (52.5%) patients were smear and culture positive, whereas 114 were culture positive but smear negative. Of 126 patients who were AFB smear positive, 98 (77.8%) were detected in the first specimen, 13 (10.3%) in the second specimen, and only 9 (7.1%) in the third specimen. Polymerase chain reaction for MTB was positive in 122 (96.8%) smear-positive patients. Four patients did not undergo a PCR test.Conclusion:A single Xpert MTB/resistance to rifampicin test detected all smear-positive patients, whereas the third smear did not significantly contribute to MTB isolation.

Clinical usefulness of routine AFB culture and MTB PCR of EBUS-TBNA needle rinse fluid.

We evaluated the usefulness of acid-fast bacilli (AFB) culture and Mycobacterium tuberculosis (MTB) polymerase chain reaction (PCR) of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) needle rinse fluid for diagnosing tuberculous lymphadenitis. EBUS-TBNA needle rinse fluid was routinely used for AFB culture and MTB PCR. The patients were categorized according to the pre-procedural diagnosis (Group A, suspected/histology-confirmed lung cancer; Group B, extrapulmonary malignancy; and Group C, other benign diseases). Of the 4672 subjects, 104 (2.2%) were diagnosed with tuberculous lymphadenitis; 1.0%, 4.6% and 12.7% of Group A, B and C, respectively. Tuberculous lymphadenitis was diagnosed in 0.2%, 1.0% and 4.5% Group A, B and C patients, respectively, by histopathology. On addition of AFB culture to histopathology, tuberculous lymphadenitis was diagnosed in 1.0%, 4.4% and 10.3% of Group A, B and C patients, respectively (P < 0.001, P = 0.001 and P = 0.005, respectively). On addition of MTB PCR to histopathology, tuberculous lymphadenitis was diagnosed in 0.4%, 1.9% and 8.8%, respectively (Group C; P = 0.029). Routine AFB culture of needle rinse fluid was useful to increase the diagnostic yield of tuberculous lymphadenitis for all subjects who underwent EBUS-TBNA regardless of pre-procedural diagnosis in an intermediate tuberculosis (TB)-burden country. However, MTB PCR was only useful in subjects with pre-procedural diagnosis of benign pulmonary diseases.

Pooled analysis of 163 published tuberculous peritonitis cases from Turkey

Background/aim: Tuberculous peritonitis may be difficult to diagnose due to its insidious and variable clinical manifestations as well as characteristics similar to malignancy. In this study, case reports from Turkey over the last 10 years were reviewed systematically using pooled analysis. Materials and methods: Thirty-four suitable articles were found and 163 tuberculous peritonitis cases were included in the study. Results: The mean age was 34.1 years (17–79 years), and 146 (98.6%) of the patients were female and 17 (10.4%) were male. The most common complaints of these patients were abdominal pain (77.4%) and abdominal distention (73.5%). Ascites in the abdomen (75%), fever (42%), abdominal tenderness (33%), and abdominal distention (30.7%) were the most common physical examination findings. The mean adenosine deaminase level was 120.3 IU/L. In the subsets of patients with relevant data, acid-fast bacilli were found in 23.3%, culture was positive in 22.2%, and Mycobacterium tuberculosis polymerase chain reaction was positive in 20%. In abdominal imaging, ascites was reported in 92%. Elevated serum CA-125 was reported in 96.7% of the patients. Of 105 patients with data available following the antituberculous therapy prognosis, four (3.8%) died and the other 101 (96.2%) showed good treatment response. Conclusion: Tuberculous peritonitis should be kept in mind during the differential diagnosis of patients admitted with the triad of ascites, fever, and abdominal distention.

Orbital tuberculosis: Clinicopathological correlation and diagnosis using PCR in formalin-fixed tissues

ABSTRACTThis article describes the clinicopathological correlation and challenges encountered in the diagnosis of orbital tuberculosis (TB). Retrospective, interventional case series. A chart review of six patients who underwent biopsy for an orbital mass between January 2012 and December 2013 was performed. Institutional review board approval was obtained for the study. Clinical, radiological, and laboratory findings were documented, and response to antitubercular therapy (ATT) was noted. Age at presentation ranged from 18 to 64 years and duration of complaints varied from 2 weeks to 2 months. Pain, redness, and swelling with an orbital mass on computerized tomography (CT) were the common features. None of the patients was clinically suspected to have orbital TB at presentation. History of prior contact with a patient of TB and history of prior TB were present in one case each. Chest radiography (CXR) showed pulmonary consolidation in one case. Tuberculin skin test (TST) readings ranged from nonreactive to 23 mm. The presence of sputum acid fast bacilli (AFB) was tested in three cases and was negative. Polymerase chain reaction (PCR) for MPB64 gene was positive in all six cases. All cases responded to ATT. Clinical presentation of orbital TB can be variable and can simulate conditions like inflammatory disease and malignancy. Biopsy with histopathology plays a key role in diagnosis. Supportive laboratory investigations are necessary to clinch the diagnosis in cases where histopathology is suggestive of TB. In this regard, PCR for Mycobacterium tuberculosis (MTB) on tissue biopsy specimens may be a sensitive diagnostic tool.

The new frontier of diagnostics: Molecular assays and their role in infection prevention and control.

Recent advances in technology over the last decade have propelled the microbiology laboratory into a pivotal role in infection prevention and control. The rapid adaptation of molecular technologies to the field of clinical microbiology now greatly influences infectious disease management and significantly impacts infection control practices. This review discusses recent developments in molecular techniques in the diagnosis of infectious diseases. It describes the basic concepts of molecular assays, discusses their advantages and limitations, and characterizes currently available commercial assays with respect to cost, interpretive requirements, and clinical utility.

Evaluation of polymerase chain reaction in space-occupying lesions of liver reported as granulomatous inflammation/tuberculosis on fine-needle aspiration cytology.

Background:Tubercular involvement of the liver is uncommon, but is a serious consideration in differential diagnosis of granulomatous conditions, especially in endemic regions like India.Objective:To assess the role of polymerase chain reaction (PCR) done on archival cytological material in diagnosing tuberculosis (TB) in cases reported as granulomatous inflammation/TB in liver lesions.Materials and Methods:This was a retrospective study including a total of 17 cases of liver space-occupying lesions (SOLs) reported as granulomatous inflammation (n = 12) and TB (n = 5). The smears were retrieved from the archives of the department and were reviewed for the cytomorphologic features. Air-dried smears stained with May–Grünwald–Giemsa (MGG) stain were assessed for the representative material in the form of epithelioid granulomas and giant cells. One/two MGG smears from each case were destained and the material was used for performing PCR for Mycobacterium tuberculosis by amplification of 123 bp fragment of the IS6110 insertion element.Results:The age of the patients ranged from 3 to 61 years. There were 12 females and 5 males. The patients presented with solitary/multiple liver SOLs. DNA could be extracted from 10/17 cases from archival MGG smears. PCR positivity was noted in 8/10 cases (including four acid-fast bacilli smear-positive cases), confirming a diagnosis of TB.Conclusion:Cytomorphology alone may not be sufficient for differentiating various granulomatous lesions reported in liver SOLs. DNA can be extracted from the archival cytological MGG-stained smears. PCR should be carried out if Ziehl–Neelsen staining is negative in granulomatous lesions, especially when material has not been submitted for culture.

The diagnostic value of polymerase chain reaction for Mycobacterium tuberculosis to distinguish intestinal tuberculosis from crohn's disease: A meta-analysis.

Background/Aim:Intestinal tuberculosis (ITB) and Crohn's disease (CD) are important differential diagnoses that can be difficult to distinguish. Polymerase chain reaction (PCR) for Mycobacterium tuberculosis (MTB) is an efficient and promising tool. This meta-analysis was performed to systematically and objectively assess the potential diagnostic accuracy and clinical value of PCR for MTB in distinguishing ITB from CD.Materials and Methods:We searched PubMed, Embase, Web of Science, Science Direct, and the Cochrane Library for eligible studies, and nine articles with 12 groups of data were identified. The included studies were subjected to quality assessment using the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool.Results:The summary estimates were as follows: sensitivity 0.47 (95% CI: 0.42–0.51); specificity 0.95 (95% CI: 0.93–0.97); the positive likelihood ratio (PLR) 10.68 (95% CI: 6.98–16.35); the negative likelihood ratio (NLR) 0.49 (95% CI: 0.33–0.71); and diagnostic odds ratio (DOR) 21.92 (95% CI: 13.17–36.48). The area under the curve (AUC) was 0.9311, with a Q* value of 0.8664. Heterogeneity was found in the NLR. The heterogeneity of the studies was evaluated by meta-regression analysis and subgroup analysis.Conclusions:The current evidence suggests that PCR for MTB is a promising and highly specific diagnostic method to distinguish ITB from CD. However, physicians should also keep in mind that negative results cannot exclude ITB for its low sensitivity. Additional prospective studies are needed to further evaluate the diagnostic accuracy of PCR.

抗酸菌症診断における気管支洗浄液, 喀痰での MTD 法, PCR 法の有用性についての検討

抗酸菌症診断における気管支洗浄液, 喀痰での MTD 法, PCR 法の有用性についての検討