Comparison of polymerase chain reaction with histopathologic features for diagnosis of tuberculosis in formalin-fixed, paraffin-embedded histologic specimens

Treatment of primary nasal tuberculosis with anti-tumor necrosis factor immunotherapy: A case report

BACKGROUND

Primary nasal tuberculosis (TB) is a rare form of extrapulmonary TB, particularly in patients receiving anti-tumor necrosis factor (TNF) immunotherapy. As a result, its diagnosis remains challenging.

CASE SUMMARY

A 58-year-old male patient presented to the ear, nose, and throat department with right-sided nasal obstruction and bloody discharge for 1 month. He was diagnosed with psoriatic arthritis and received anti-TNF immunotherapy for 3 years prior to presentation. Biopsy findings revealed chronic granulomatous inflammation and a few acid-fast bacilli, suggestive of primary nasal TB. He was referred to our TB management department for treatment with oral anti-TB agents. After 9 months, the nasal lesions had disappeared. No recurrence was noted during follow-up.

CONCLUSION

The diagnosis of primary nasal TB should be considered in patients receiving TNF antagonists who exhibit thickening and crusting of the nasal septum mucosa or inferior turbinate, particularly when pathological findings suggest granulomatous inflammation.

Aural tuberculosis at the start of the 21st century. Literature review according to SWiM guidelines. Part 1: Clinical and diagnostic data

OBJECTIVES

Review of the scientific literature dedicated to clinical data and diagnosis modalities for aural tuberculosis published since the start of the 21st century.

MATERIAL AND METHODS

Search of the Medline, Cochrane and Embase databases for the period 2000-2020. Selection of articles in English, French and Spanish devoted to clinical cases and series documenting clinical data and diagnosis for aural tuberculosis of articles by two authors. Analysis performed according to SWiM guidelines. Extraction of data on pre-established files documenting clinical and diagnostic data.

RESULTS

In total, 173 articles: 163 case reports (228 patients) and 10 cohorts (177 patients) from 49 countries were analyzed. Female/male sex ratio was 1.05, with ages ranging from less than 1 month to 87 years. Tuberculosis involved another site in 35.1% of cases. Aural involvement was bilateral in 19.7% of cases. Clinical presentation corresponded to otitis media (prior antibiotic treatment and auricular surgery in 41.4% and 10.1% of cases, respectively) without any pathognomonic symptoms or signs. Associated severe locoregional complications were seen in 32% of cases, with 23.2% and 13% incidence of peripheral facial palsy and severe intracranial complications, respectively. Time to diagnosis ranged from less than 1 month to 384 months, and was longer than 12 months in 26.5% of case reports, without significant correlation (P=0.29) with severe revelatory locoregional complications. Incidence of Mycobacterium tuberculosis detection ranged from 33.4% of documented cases in auricular secretions to 64.6% in polyps, granulomas, and/or biopsies. In the case reports, diagnosis with certainty was done in 58.3% of cases, while it was based on involvement of another site and on indirect criteria or positive clinical progression after treatment in the other 10.1% and 31.6%, respectively.

CONCLUSION

Aural tuberculous must always be considered in case of unfavorable progression of otitis. Definitive diagnosis is based on multiple auricular sample sites, polymerase chain reaction, and γ interferon blood assay.

Understanding the tuberculosis granuloma: the matrix revolutions

Mycobacterium tuberculosis (Mtb) causes the human disease tuberculosis (TB) and remains the top global infectious pandemic after coronavirus disease 2019 (COVID-19). Furthermore, TB has killed many more humans than any other pathogen, after prolonged coevolution to optimise its pathogenic strategies. Full understanding of fundamental disease processes in humans is necessary to successfully combat this highly successful pathogen. While the importance of immunodeficiency has been long recognised, biologic therapies and unbiased approaches are providing unprecedented insights into the intricacy of the host-pathogen interaction. The nature of a protective response is more complex than previously hypothesised. Here, we integrate recent evidence from human studies and unbiased approaches to consider how Mtb causes human TB and highlight the recurring theme of extracellular matrix (ECM) turnover.

Agreement Test of Histopathology in the Diagnosis of Extrapulmonary Tuberculosis with Gold Standard Polymerase Chain Reaction Technique: A Step to Overcome False Diagnosis

BACKGROUND: Tuberculosis (TB) is global health problem which is caused by Mycobacterium tuberculosis (M. tuberculosis) bacteria. One-quarter of the world’s populations is infected by M. tuberculosis and only 10–15% of those develop the disease, while the remaining 85–95% of the population are carrying the bacteria and cannot transmit the disease to the others. M. tuberculosis bacteria affects the lungs, but any organ in the body can be affected by the bacteria. About 15% of M. tuberculosis infections are of in the extrapulmonary type. The diagnosis of extrapulmonary TB (EPTB) is very challenging because most sites are inaccessible and paucibacillary nature of the bacteria in these sites. The need for rapid and more sensitive and specific tests for the diagnosis of EPTB in comparison to culture and histopathology is increasing. The molecular methods for the detection of M. tuberculosis gene(s) in the provided sample are now promising. PATIENT AND METHODS: A cross-sectional descriptive study at AL-Kindy Teaching Hospital at Al-Resaffa part of Baghdad city, Iraq. Data collection has been done in three months duration (July, August, and September) 2015. A total of 74 formalin-fixed paraffin-embedded samples from suspected EPTB cases was collected, both Polymerase Chain reaction test for M. tuberculosis and histopathological examination was done for each sample. RESULTS: A total of 74 patients (18 males, 56 females), mean age 29.72 suspected to had extrapulmonary TB underwent biopsies from different tissue types. The biopsies from the 74 patients were taken from different tissues according to the site of lesion, 49 (66.2%) biopsies were taken from lymph node, 12 biopsies (16.2%) was taken from mass in the axilla, 6 (8.1%) from abscess, 4 (5.4%) from the intestine, 3 (4.1%) from fistula. Of the 74 studied patients 57 (77%) showed positive polymerase chain reaction (PCR) and 17 (23%) showed negative PCR results. Regarding to the histopathological reports of the biopsies, there were 54 (73%) patients had positive histopathological (granuloma) result and 20 (27%) patients had negative results (nongranuloma). The sensitivity of histopathological examination of the biopsies was 91.02%, the specificity 88.2%, and the kappa was 0.748 (p = 0.00) which is mean good agreement between histopathological examination of the biopsies and the polymerase chain reaction test. CONCLUSIONS: The sensitivity, specificity, and the positive predictive value of histopathology examination of biopsies were 91.02%, 88.2%, and 96%, respectively. The kappa was 0.748 (p = 0.00) which is mean good agreement between histopathological examination of the biopsies and the polymerase chain reaction test.

Evaluation of effectiveness of pathology reports in active surveillance of tuberculosis

OBJECTIVE

Despite advancing technology, national TB surveillance systems are still inadequate in terms of patient detection around the world. It was aimed to investigate suspicious cases detected by active surveillance method in pathology laboratories and to evaluate the effectiveness of this method in terms of finding new TB cases.

METHODS

This is a descriptive cross-sectional study. It was administrated in Samsun, Turkey, between January 2012-December 2017. Within the scope of active surveillance, pathology laboratories were regularly visited and reported cases with granulomatous inflammation were assessed. The obtained patient list was compared with the records of the Electronic Tuberculosis Management System (ETMS). Patients who were not included in these records were invited to the dispensary and evaluated for TB. They were also referred to the relevant hospitals for diagnosis if necessary. Frequency values and descriptive statistics were calculated using SPSS method.

RESULTS

It was found that 35.6% of 703 patients with the diagnosis of granulomatous inflammation were previously diagnosed, treated or currently undergoing treatment in the ETMS registry. As a result of the assessment of remaining 453 cases, 46 patients (10.1%) were newly diagnosed with TB. Newly diagnosed TB patients were reported, and their treatment started.

CONCLUSION

As a result, active surveillance method conducted in pathology laboratories are used to detect unknown or late reported TB cases and allows to start treatment without further delay.

A case of postoperative tubercular spondylitis following microdiscectomy for lumbar disc herniation

Background:

Postoperative infections are one of the most common complications of spine surgery. However, following a lumbar microdiscectomy, a postoperative infection involving Mycobacterium tuberculosis (MTB) is extremely rare.

Case Description:

One and half months after a L4-5 microdiscectomy, a 47-year-old immunocompromised male with hepatitis B infection presented with low back and bilateral gluteal pain. The MRI revealed a large intraspinal/paraspinal fluid collection spanning from L4 to S1 along with an anterior epidural collection at L5. The patient underwent a L4 lumbar laminectomy for abscess drainage and wound debridement. After obtaining a positive culture for MTB, four antitubercular drug therapies (ATTs) were started, that is, isoniazid (H), rifampicin (R), ethambutol (E), a. One month later, the patient had minimal pain and no residual neurological deficit.

Conclusion:

MTB infection, although rare, should be considered among the differential diagnoses of postoperative infections following lumbar spine surgery in immunocompromised patients living in areas where tuberculosis is endemic.

A rare case of primary sinonasal tuberculosis presented with phlyctenular keratoconjunctivitis in a pediatric patient: A case report and literature review

RATIONALE

Tuberculosis is a common cause of phlyctenular keratoconjunctivitis, especially for patients who live in a high endemic area of tuberculosis. We report a rare case of pediatric phlyctenular keratoconjunctivitis associated with primary sinonasal tuberculosis.

PATIENT CONCERNS

A 7-year-old boy presented with a 5-month history of redness of the left eye accompanied by mild visual impairment. Physical examination revealed elevated pinkish-white nodules with a circumcorneal hypervascularized lesion on the left conjunctiva.

DIAGNOSIS

Computed tomography revealed an enhancing soft tissue mass in the left maxillary sinus with bone destruction. Histopathology of maxillary tissue showed chronic inflammation without granuloma. Special stain, culture and polymerase chain reaction for mycobacterium were initially negative. Left maxillary sinus tuberculosis was diagnosed by positive Mycobacterium tuberculosis polymerase chain reaction from formalin-fixed paraffin-embedded maxillary tissue.

INTERVENTIONS

Two month of oral isoniazid, rifampicin, pyrazinamide, and ethambutol, followed by 10 months of oral isoniazid and rifampicin without topical eye drops agent were prescribed.

OUTCOMES

Two months after initiation of treatment, the phlyctenular lesion had significantly improved. A follow-up computed tomography showed a significant reduction in the size of the maxillary sinus lesion and the extent of adjacent bone destruction.

LESSONS

Primary sinonasal tuberculosis is an uncommon cause of phlyctenular keratoconjunctivitis in children. When microbiological and histopathological evidences are absent, polymerase chain reaction analysis has a crucial role in the diagnosis of tuberculosis, especially in patient with uncommon presentation.

Pathogenesis of ocular tuberculosis: New observations and future directions

Ocular tuberculosis (OTB) encompasses all forms of intra- and extra-ocular inflammation associated with Mycobacterium tuberculosis (Mtb) infection. However, the organism is rarely found in ocular fluid samples of diseased eyes, rendering the pathomechanisms of the disease unclear. This confounds clinical decision-making in diagnosis and treatment of OTB. Here, we critically review existing human and animal data related to ocular inflammation and TB pathogenesis to unravel likely pathomechanisms of OTB. Broadly there appear to be two fundamental mechanisms that may underlie the development of TB-associated ocular inflammation: a. inflammatory response to live/replicating Mtb in the eye, and b. immune mediated ocular inflammation induced by non-viable Mtb or its components in the eye. This distinction is significant as in direct Mtb-driven mechanisms, diagnosis and treatment would be aimed at detection of Mtb-infection and its elimination; while indirect mechanisms would primarily require anti-inflammatory therapy with adjunctive anti-TB therapy. Further, we discuss how that most clinical phenotypes of OTB likely represent a combination of both mechanisms, with one being predominant than the other.

Uncommon Complications after Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament reconstruction (ACL-R) is a common surgical procedure, with good outcome in 75 to 97% of the cases. However, different complications have been described including infection, hemarthrosis, deep vein thrombosis (DVT), and pulmonary embolism (PE) with a rate ranging from 1 to 15%. There are few case reports in the literature describing rare complications after ACL-R and they can be divided into: (1) complications related to the fixation device (rupture, migration); (2) fractures (tibial or femoral side); (3) infections due to uncommon bacteria, mycobacterium, and mycosis; (4) rare vascular injuries; (5) nerve injuries; and (6) other rare complications. In case of fixation device rupture or migration, device removal can be easy but the diagnosis may be challenging. Patellar fracture after ACL-R may be related to harvesting and it is not uncommon. Conversely, femoral or tibial fractures are most frequently due to bone weakness related to bone tunnels. Some rare infections related to uncommon bacteria or mycosis are also described with potentially devastating joint damage. Popliteal artery injuries are uncommon in ACL-R but minor vessels damages are described with possible severe consequences for patients. Injuries to the infrapatellar branch of the saphenous nerve are not uncommon in ACL-R. However, there are few case reports also describing injuries to the saphenous nerve, the common peroneal nerve and the sciatic nerve. The aim of this paper is to review the literature describing uncommon complications after ACL-R, giving some more information about diagnosis and treatment.

Potential Value of Qiagen and PrepIT•MAX Kits in Extraction of Mycobacterial DNA From Presumptive Tuberculosis Archived Formalin-Fixed Paraffin-Embedded Tissues

BACKGROUND

DNA analysis has potential for screening for and diagnosing a variety of conditions as well as the characterization of various pathogens for many purposes including to identify genetic disorders and mutations, study genetic diversity, and establish evolutional trends.

METHODS

Our study compared the performance of 2 DNA extraction kits: Qiagen and prepIT•MAX. The study tested 160 formalin-fixed paraffin-embedded (FFPE) human tissue samples that had been collected at Muhimbili National Hospital (MNH) between 2010 and 2016. For each sample, DNA extraction was performed using both the Qiagen and prepIT•MAX kits followed by polymerase chain reaction (PCR) tests to target the RNA polymerase gene and gel electrophoresis.

RESULTS

The findings showed that the Qiagen was 3 times superior to the prepIT•MAX kit in successfully extracting mycobacterial DNA from presumptive tuberculosis (TB) FFPE tissues. Of the 160 previously Ziehl-Neelsen stain-negative Mycobacterium tuberculosis suspicious tissue samples, 12 (7.5%) tested positive with the PCR. Of the 12 PCR-detected positive samples, 8 (66.7%) yielded positive results with the Qiagen kit only and 4 (33.3%) yielded positive results with both Qiagen and prepIT•MAX kits. Additionally, 10 (83.3%) came from well-formed granuloma, 1 (8%) from caseous necrosis, and 1 (8.3%) Langhans-type giant cells endorsing their potential for housing infection such as TB adenitis.

CONCLUSIONS

A combination of molecular techniques, microscopy, and pathological features increases detection of M. tuberculosis from FFPE tissues. Both the Qiagen and the prepIT•MAX DNA extraction kits have shown a remarkable capability for extracting DNA from M. tuberculosis, although examination of FFPE tissues is not an intended use for the prepIT MAX, according to the manufacturer. In resource-limited countries, however, these kits may complement each other. We recommend further studies for validation and optimization, which includes the cost effectiveness of prepIT•MAX extraction kit to advocate for its use in extraction of mycobacterial DNA from FFPE tissues.

Lung Infections

A review of pulmonary infections of all types with diagnostic and morphological features.

Histological Examination in Obtaining a Diagnosis in Patients with Lymphadenopathy in Lima, Peru

The differential diagnosis for lymphadenopathy is wide and clinical presentations overlap, making obtaining an accurate diagnosis challenging. We sought to characterize the clinical and radiological characteristics, histological findings, and diagnoses for a cohort of patients with lymphadenopathy of unknown etiology. 121 Peruvian adults with lymphadenopathy underwent lymph node biopsy for microbiological and histopathological evaluation. Mean patient age was 41 years (Interquartile Range 26–52), 56% were males, and 39% were HIV positive. Patients reported fever (31%), weight loss (23%), and headache (22%); HIV infection was associated with fever (P < 0.05) and gastrointestinal symptoms (P < 0.05). Abnormalities were reported in 40% of chest X-rays (N = 101). Physicians suspected TB in 92 patients (76%), lymphoma in 19 patients (16%), and other malignancy in seven patients (5.8%). Histological diagnoses (N = 117) included tuberculosis (34%), hyperplasia (27%), lymphoma (13%), and nonlymphoma malignancy (14%). Hyperplasia was more common (P < 0.001) and lymphoma less common (P = 0.005) among HIV-positive than HIV-negative patients. There was a trend toward reduced frequency of caseous necrosis in samples from HIV-positive than HIV-negative TB patients (67 versus 93%, P = 0.055). The spectrum of diagnoses was broad, and clinical and radiological features correlated poorly with diagnosis. On the basis of clinical features, physicians over-diagnosed TB, and under-diagnosed malignancy. Although this may not be inappropriate in resource-limited settings where TB is the most frequent easily treatable cause of lymphadenopathy, diagnostic delays can be detrimental to patients with malignancy. It is important that patients with lymphadenopathy undergo a full diagnostic work-up including sampling for histological evaluation to obtain an accurate diagnosis.

Tuberculous otitis media: a resurgence?

Objective:

Tuberculosis is a global health problem that is especially prevalent in developing countries such as India. Recently, atypical presentation has become more common and a high index of suspicion is essential. This study analysed the various presenting symptoms and signs of tuberculous otitis media and the role of diagnostic tests, with the aim of formulating criteria for the diagnosis.

Methods:

A total of 502 patients underwent tympanomastoidectomy over a two-year period. Microbiological and histopathological examinations and polymerase chain reaction analysis of tissue taken during tympanomastoidectomy were performed.

Results:

A total of 25 patients (5 per cent) were diagnosed with tuberculous otitis media. Severe mixed hearing loss, facial palsy, labyrinthine fistula, post-aural fistula, perichondritis and extradural abscess were noted.

Conclusion:

There seems to be a resurgence in tuberculous otitis media in India. Microbiological, histopathological and polymerase chain reaction tests for tuberculosis are helpful for its diagnosis.

Mycobacterium tuberculosis subverts negative regulatory pathways in human macrophages to drive immunopathology

Tuberculosis remains a global pandemic and drives lung matrix destruction to transmit. Whilst pathways driving inflammatory responses in macrophages have been relatively well described, negative regulatory pathways are less well defined. We hypothesised that Mycobacterium tuberculosis (Mtb) specifically targets negative regulatory pathways to augment immunopathology. Inhibition of signalling through the PI3K/AKT/mTORC1 pathway increased matrix metalloproteinase-1 (MMP-1) gene expression and secretion, a collagenase central to TB pathogenesis, and multiple pro-inflammatory cytokines. In patients with confirmed pulmonary TB, PI3Kδ expression was absent within granulomas. Furthermore, Mtb infection suppressed PI3Kδ gene expression in macrophages. Interestingly, inhibition of the MNK pathway, downstream of pro-inflammatory p38 and ERK MAPKs, also increased MMP-1 secretion, whilst suppressing secretion of TH1 cytokines. Cross-talk between the PI3K and MNK pathways was demonstrated at the level of eIF4E phosphorylation. Mtb globally suppressed the MMP-inhibitory pathways in macrophages, reducing levels of mRNAs encoding PI3Kδ, mTORC-1 and MNK-1 via upregulation of miRNAs. Therefore, Mtb disrupts negative regulatory pathways at multiple levels in macrophages to drive a tissue-destructive phenotype that facilitates transmission.

Does Polymerase Chain Reaction of Tissue Specimens Aid in the Diagnosis of Tuberculosis?

Background

Mycobacterial culture is the gold standard test for diagnosing tuberculosis (TB), but it is time-consuming. Polymerase chain reaction (PCR) is a highly sensitive and specific method that can reduce the time required for diagnosis. The diagnostic efficacy of PCR differs, so this study determined the actual sensitivity of TB-PCR in tissue specimens.

Methods

We retrospectively reviewed 574 cases. The results of the nested PCR of the IS6110 gene, mycobacterial culture, TB-specific antigen-induced interferon-γ release assay (IGRA), acid-fast bacilli (AFB) staining, and histological findings were evaluated.

Results

The positivity rates were 17.6% for PCR, 3.3% for the AFB stain, 22.2% for mycobacterial culture, and 55.4% for IGRA. PCR had a low sensitivity (51.1%) and a high specificity (86.3%) based on the culture results of other studies. The sensitivity was higher (65.5%) in cases with necrotizing granuloma but showed the highest sensitivity (66.7%) in those with necrosis only. The concordance rate between the methods indicated that PCR was the best method compared to mycobacterial culture, and the concordance rate increased for the methods using positive result for PCR or histologic features.

Conclusions

PCR of tissue specimens is a good alternative to detect tuberculosis, but it may not be as sensitive as previously suggested. Its reliability may also be influenced by some histological features. Our data showed a higher sensitivity when specimens contained necrosis, which indicated that only specimens with necrosis should be used for PCR to detect tuberculosis.

Cesarean scar caseating granuloma: a case of vesicouterine fistula 30 years after cesarean section

A mass developing in operating scar part with fistula should raise concern for caseating granuloma even if many years after operation.

Diagnosis of Ocular Tuberculosis

Ocular tuberculosis remains a presumptive clinical diagnosis, as the gold standard tests for diagnosing ocular tuberculosis are often not useful: Mycobacterium tuberculosis cultures require weeks to process on Lowenstein-Jenson media and have low yield from ocular samples; while acid-fast bacilli smears or polymerase chain reaction detection of M. tuberculosis DNA have low sensitivities. Thus, diagnosis is often based on suggestive clinical signs, which are supported by positive investigations: tuberculin skin test or interferon-gamma release assays; chest X-ray findings suggestive of pulmonary tuberculosis, and/or evidence of associated systemic tuberculosis infections in the absence of other underlying disease. The aim of this review is to provide an update on the methods of diagnosing ocular tuberculosis, and discuss the challenges of its diagnosis. We also suggest a step-ladder approach to a more accurate diagnosis of ocular tuberculosis by combining the available diagnostic tests.

Nontuberculous mycobacteria in fistula-in-ano: A new finding and its implications

OBJECTIVE/BACKGROUND

Nontuberculous mycobacteria (NTM) are not known to be associated with fistula-in-ano. NTM was detected in three fistula-in-ano patients in our series. In this study, related data was reviewed to find the mycobacterial disease in patients in our database.

METHODS

In this study, 311 consecutive fistula-in-ano patients operated over 2years were analyzed. The histopathology of anal fistula tract epithelial lining of every operated patient was analyzed and other tests (real-time-polymerase chain reaction [RT-PCR], GeneXpert, and mycobacterial culture) were conducted in patients with high index of suspicion of having mycobacterial disease.

RESULTS

Two patients had histopathological features suggestive of mycobacterial disease. Of these, one patient had NTM and the other had Mycobacterium tuberculosis (MTB) on RT-PCR. Four patients had normal histopathology features but tested positive on RT-PCR (2 each for NTM and MTB). Therefore, a total of six patients were tested for mycobacterial disease (3 each for NTM and MTB). Mycobacterium culture was performed in two patients (both NTM) but the result was negative. Five of six patients (NTM=2, MTB=3) presented with delayed recurrences after operation (6-18months after complete healing).

CONCLUSION

NTM can cause fistula-in-ano. It could be an undiagnosed contributory factor in fistula recurrence. Mycobacterial disease (both tuberculous and nontuberculous) may be associated with delayed recurrence of fistula. RT-PCR is highly sensitive and can differentiate between NTM and MTB. It should perhaps be performed in all recurrent and refractory cases.

Development and Diagnostic Evaluation of Loop-Mediated Isothermal Amplification Using a New Gene Target for Rapid Detection of Helicobacter pylori

BACKGROUND

Helicobacter pylori cause chronic gastritis and subsequent diseases like gastric and duodenal ulcers and gastric adenocarcinoma. Current methods for detecting H. pylori have several disadvantages and it is of utmost importance to develop a simple, quick, accurate, and cost-effective diagnostic test.

OBJECTIVES

The aim of this study was to set up and evaluate a diagnostic value of loop- mediated isothermal amplification (LAMP) for detecting H. pylori.

PATIENTS AND METHODS

The analytical sensitivity values (limit of detection) of LAMP and polymerase chain reaction (PCR) were determined using serial dilutions of H. pylori DNA. Analytical specificity of the methods using new designed primers targeted ureC gene was also determined.

RESULTS

The detection limits of the LAMP and PCR assay were similar and were 10 fg of pure DNA of H. pylori, which is equal to 6 copy numbers of H. pylori genome. Analytical specificity of the tests was 100% because the tests were positive only with H. pylori DNA.

CONCLUSIONS

The analytical sensitivity of LAMP and PCR methods, using the designed primers, was 8 times more than any other reported methods. The designed methods are specific and sensitive for detection of H. pylori in different clinical and environmental samples.

Membrane Type 1 Matrix Metalloproteinase Regulates Monocyte Migration and Collagen Destruction in Tuberculosis

Tuberculosis (TB) remains a global pandemic and drug resistance is rising. Multicellular granuloma formation is the pathological hallmark of Mycobacterium tuberculosis infection. The membrane type 1 matrix metalloproteinase (MT1-MMP or MMP-14) is a collagenase that is key in leukocyte migration and collagen destruction. In patients with TB, induced sputum MT1-MMP mRNA levels were increased 5.1-fold compared with matched controls and correlated positively with extent of lung infiltration on chest radiographs (r = 0.483; p < 0.05). M. tuberculosis infection of primary human monocytes increased MT1-MMP surface expression 31.7-fold and gene expression 24.5-fold. M. tuberculosis-infected monocytes degraded collagen matrix in an MT1-MMP-dependent manner, and MT1-MMP neutralization decreased collagen degradation by 73%. In human TB granulomas, MT1-MMP immunoreactivity was observed in macrophages throughout the granuloma. Monocyte-monocyte networks caused a 17.5-fold increase in MT1-MMP surface expression dependent on p38 MAPK and G protein-coupled receptor-dependent signaling. Monocytes migrating toward agarose beads impregnated with conditioned media from M. tuberculosis-infected monocytes expressed MT1-MMP. Neutralization of MT1-MMP activity decreased this M. tuberculosis network-dependent monocyte migration by 44%. Taken together, we demonstrate that MT1-MMP is central to two key elements of TB pathogenesis, causing collagen degradation and regulating monocyte migration.

The relevance of biopsy in tuberculosis patients without human immunodeficiency virus infection

Although chronic granulomatous inflammation (CGI) with concomitant caseous necrosis (CN) is a characteristic histological feature of tuberculosis (TB), few studies have investigated its frequency or various pathologic findings. The medical records of 227 human immunodeficiency virus (HIV) -negative, culture-positive TB patients who underwent biopsy were studied. After the frequency of characteristic pathological findings of TB was determined, a pathologist reanalyzed the pathological findings with particular focus on necrosis and reclassified CGI, CN, or possible CN into possible TB pathologic findings. The initial biopsy interpretation revealed that 63 (34.8%) of 181 patients with pulmonary TB had caseating granulomas, 36 (19.9%) patients had only CGI, and 6 (3.3%) patients had only CN. Among 46 patients with extrapulmonary TB, 16 (34.8%) patients had only caseating granulomas, and 14 (30.4%) patients had only CGI. More patients who underwent percutaneous lung biopsy had CGI or CN (76.3%) than patients who underwent transbronchial lung biopsy (53.6%). The reanalysis confirmed all CN cases identified by the first interpretation, and 20 (95.2%) of 21 non-CN cases were reclassified as possible CN. Ten cases (three pulmonary and seven extrapulmonary) were reclassified as possible TB pathologic findings from just necrosis. Caseating granuloma was present in only one-third of TB cases. Even in cases where only necrosis was identified, CN may be present.

The Extracellular Matrix Regulates Granuloma Necrosis in Tuberculosis

A central tenet of tuberculosis pathogenesis is that caseous necrosis leads to extracellular matrix destruction and bacterial transmission. We reconsider the underlying mechanism of tuberculosis pathology and demonstrate that collagen destruction may be a critical initial event, causing caseous necrosis as opposed to resulting from it. In human tuberculosis granulomas, regions of extracellular matrix destruction map to areas of caseous necrosis. In mice, transgenic expression of human matrix metalloproteinase 1 causes caseous necrosis, the pathological hallmark of human tuberculosis. Collagen destruction is the principal pathological difference between humanised mice and wild-type mice with tuberculosis, whereas the release of proinflammatory cytokines does not differ, demonstrating that collagen breakdown may lead to cell death and caseation. To investigate this hypothesis, we developed a 3-dimensional cell culture model of tuberculosis granuloma formation, using bioelectrospray technology. Collagen improved survival of Mycobacterium tuberculosis-infected cells analyzed on the basis of a lactate dehydrogenase release assay, propidium iodide staining, and measurement of the total number of viable cells. Taken together, these findings suggest that collagen destruction is an initial event in tuberculosis immunopathology, leading to caseous necrosis and compromising the immune response, revealing a previously unappreciated role for the extracellular matrix in regulating the host-pathogen interaction.

The relevance of biopsy in tuberculosis patients without human immunodeficiency virus infection

Although chronic granulomatous inflammation (CGI) with concomitant caseous necrosis (CN) is a characteristic histological feature of tuberculosis (TB), few studies have investigated its frequency or various pathologic findings. The medical records of 227 human immunodeficiency virus (HIV) -negative, culture-positive TB patients who underwent biopsy were studied. After the frequency of characteristic pathological findings of TB was determined, a pathologist reanalyzed the pathological findings with particular focus on necrosis and reclassified CGI, CN, or possible CN into possible TB pathologic findings. The initial biopsy interpretation revealed that 63 (34.8%) of 181 patients with pulmonary TB had caseating granulomas, 36 (19.9%) patients had only CGI, and 6 (3.3%) patients had only CN. Among 46 patients with extrapulmonary TB, 16 (34.8%) patients had only caseating granulomas, and 14 (30.4%) patients had only CGI. More patients who underwent percutaneous lung biopsy had CGI or CN (76.3%) than patients who underwent transbronchial lung biopsy (53.6%). The reanalysis confirmed all CN cases identified by the first interpretation, and 20 (95.2%) of 21 non-CN cases were reclassified as possible CN. Ten cases (three pulmonary and seven extrapulmonary) were reclassified as possible TB pathologic findings from just necrosis. Caseating granuloma was present in only one-third of TB cases. Even in cases where only necrosis was identified, CN may be present.

Using ATP-driven bioluminescence assay to monitor microbial safety in a contemporary human cadaver laboratory

INTRODUCTION

The objective of this study was to utilize a cost-effective method for assessing the levels of bacterial, yeast, and mold activity during a human dissection laboratory course. Nowadays, compliance with safety regulations is policed by institutions at higher standards than ever before. Fear of acquiring an unknown infection is one of the top concerns of professional healthcare students, and it provokes anti-laboratory anxiety. Human cadavers are not routinely tested for bacteria and viruses prior to embalming. Human anatomy dissecting rooms that house embalmed cadavers are normally cleaned after the dissected cadavers have been removed. There is no evidence that investigators have ever assessed bacterial and fungal activities using adenosine triphosphate (ATP)-driven bioluminescence assays.

METHODS

A literature search was conducted on texts, journals, and websites regarding bacterial, yeast, and mold activities in an active cadaver laboratory. Midway into a clinical anatomy course, ATP bioluminescence assays were used to swab various sites within the dissection room, including entrance and exiting door handles, water taps, cadaver tables, counter tops, imaging material, X-ray box switches, and the cadaver surfaces.

RESULTS

The results demonstrated very low activities on cadaver tables, washing up areas, and exiting door handles. There was low activity on counter tops and X-ray boxes. There was medium activity on the entrance door handles.

CONCLUSION

These findings suggest an inexpensive and accurate method for monitoring safety compliance and microbial activity. Students can feel confident and safe in the environment in which they work.

Genital tuberculosis: Comparative study of the diagnostic modalities

BACKGROUND

Genital tuberculosis (GTB) is one of the major causes for severe tubal disease leading to infertility. Unlike pulmonary tuberculosis (TB), the clinical diagnosis of GTB is difficult because in the majority of cases the disease is either asymptomatic or has varied clinical presentation. Routine laboratory tests are of little value in the diagnosis. The objective of this study was to compare the modalities of polymerase chain reaction (PCR) technique, acid fast bacilli (AFB) culture and AFB staining.

MATERIALS AND METHODS

The women visiting in vitro fertility center during December 2012 and May 2013 were included in this study. A total of 227 aseptically collected endometrial tissue samples were processed. AFB staining, AFB culture and PCR were carried out using standard procedures.

RESULT

Out of 227 patients suspected of GTB, 133 were found to be positive either by AFB smear microscopy, culture or PCR. Out of 133 samples, two samples (1.5%) were found to be positive by all three methods, i.e. microscopy, culture and PCR, 11 (4.8%) were found to be positive by both PCR and culture, whereas 126 (86%) samples were found to be positive only by PCR. The PCR has failed to detect seven cases that were positive by conventional culture method.

CONCLUSION

Our study showed that the conventional methods of diagnosis like microscopy and culture are less sensitive when compared with PCR. PCR also helped in early diagnosis of infection. However simultaneously, false negative results were an important limitation of this method. PCR negative samples were found to be positive by culture methods. Deoxyribose nucleic acid PCR is not reliable for TB due to false positive or negative result. Thus, we suggest both culture and PCR as important diagnostic methods for detection of GTB.

Tuberculous spondylitis after percutaneous vertebroplasty: misdiagnosis or complication?

So far, there have been few previous reports of tuberculous spondylitis occurring after percutaneous vertebroplasty. We report an unusual case of tuberculous spondylitis diagnosed after percutaneous vertebroplasty in a patient who had a history of pulmonary tuberculosis for the first time. A 58-year-old woman, who had a history of complete recovery from pulmonary tuberculosis six years previously, was hospitalized due to severe back pain after a fall. Radiological studies revealed a fresh compression fracture at the T12 thoracic vertebra. The back pain improved dramatically, and the patient was discharged two days after the vertebroplasty. However, cold sweats and a low grade fever with severe back pain developed four weeks after the procedure. Magnetic resonance imaging revealed a severe kyphosis and the T11-T12 disc space had collapsed with heterogeneous signal intensity. The results of the culture of the biopsy specimens were negative, and did not lead to identification of the causative micro-organism. However, the polymerase chain reaction for Mycobacterium tuberculosis was positive. Treatment for tuberculous spondylitis was started and she underwent posterior fusion and instrumentation from T9-L2 after the markers for infection returned to normal. After surgical intervention, the pain improved and the kyphotic deformity was corrected.

Detection of microorganisms in granulomas that have been formalin-fixed: review of the literature regarding use of molecular methods

Granuloma is an organized aggregate of immune cells that under the microscope appear as epithelioid macrophages. A granuloma can only be diagnosed when a pathologist observes this type of inflammation under the microscope. If a foreign body or a parasite is not observed inside the granuloma, stains for acid-fast bacilli and fungi are ordered since mycobacteria and fungi are frequently the cause of this type of inflammation. It is calculated that 12 to 36% of granulomas do not have a specific etiology and many have wondered if with new molecular methods we could reduce this number. This paper will summarize the frequently known causes of granulomas and will present the recent literature regarding the use of molecular techniques on tissue specimens and how these have helped in defining causative agents. We will also briefly describe new research regarding formation and function of granulomas and how this impacts our ability to find an etiologic agent.

Pathologic basis of central nervous system infections

Radiology provides valuable gross pathologic information about central nervous system (CNS) infections. Major categories of infectious lesions of the brain and spinal cord are recognized by imaging such as diffuse, focal, or multifocal. This article discusses the pathologic basis of these radiographic findings. It illustrates examples with gross and microscopic photographs of CNS infections, and the tissue reactions to these infections. Where the organism can spread within the CNS, and cellular responses to the organism underlie both the radiographic and pathologic findings.

Histopathological spectrum of cutaneous tuberculosis and non-tuberculous mycobacterial infections

The non-specific clinical findings and variable histopathological features of cutaneous tuberculosis and non-tuberculous mycobacterial infections often make it difficult to establish a diagnosis and initiate appropriate therapy. We investigated 25 patients diagnosed with mycobacterial infections of the skin in Hanyang University Hospital between 2001 and 2011. Skin biopsy specimens were re-evaluated by various histopathological criteria and molecular studies. To identify the mycobacteria, we performed staining for acid-fast bacilli and also completed polymerase chain reaction analysis. The non-tuberculous mycobacterium species were identified by genetic sequencing of formalin-fixed, paraffin-embedded tissues. Immunocompromised status was more frequent in non-tuberculous mycobacterial infections than in tuberculosis (p = 0.017) while disease duration was longer in tuberculosis (p = 0.026). Microscopically, neutrophil infiltration, interstitial granuloma, small vessel proliferation and increased numbers of bacilli were found to be associated with non-tuberculous mycobacterial infections (all p < 0.05). In contrast, giant cells, plasma cells, tuberculoid granulomas and necrosis were associated with tuberculosis (all p < 0.05). There were no species-specific histopathological findings in non-tuberculous mycobacterial infections. The significant histopathological differences between cutaneous tuberculous and non-tuberculous mycobacterial infections are helpful in considering differential diagnoses. In addition, molecular techniques together with clinico-pathological findings may assist in making accurate diagnoses of cutaneous non-tuberculous mycobacterial infections.

Tuberculosis prevalence at autopsy: a study from North India

Tuberculosis (TB) is an important cause of morbidity and mortality. This study attempts to determine the prevalence of TB in autopsies. Of 768 autopsies, 39 cases were diagnosed as TB. These were retrieved and re-examined. It was noted that in a significant number of patients with TB was only revealed after autopsy. This has important implications as they may well have been a source of transmission to the general public and health-care providers.

An unusual case of post-operative spondylitis caused by mycobacterium intracellulare in an immunosuppressed patient

There are few reported cases of post-operative spondylitis caused by Mycobacterium intracellulare. A 75-year-old female presented to our hospital with low back pain and paraparesis after a fall. The radiologic examination revealed compression fractures of L1, L3 and L4 and an epidural hematoma compressing the spinal cord. The dark-red epidural hematoma was urgently evacuated. Four weeks post-operatively, neurologic deficits recurred with fever. On magnetic resonance image, an epidural abscess and osteomyelitis were detected in the previous operative site. Five weeks post-operatively, revision was performed with multiple biopsies. The specimen were positive for acid-fast bacilli and traditional anti-tuberculous medications were started. Because the Polymerase Chain Reaction for non-tuberculous mycobacterium (NTM) was positive, the anti-tuberculous medications were changed to anti-NTM drugs. However, the neurologic deficits did not improve and persistent elevation of erythrocyte sedimentation rate and C-reactive protein were noted. Eight weeks after the revision, Mycobacterium intracellulare was detected in the specimen cultures. Despite supportive care with medication, the patient died due to multiple organ failure.

Intestinal Tuberculosis with Hoarseness as a Chief Complaint due to Mediastinal Lymphadenitis

A 68-year-old woman was admitted to our hospital complaining of hoarseness. A chest X-ray detected an abnormal shadow on the upper right lung. Bronchoscopic examination revealed that the left vocal cord was fixed in the paramedian position, and therefore left recurrent nerve paralysis was suspected. Lymphadenopathy was found in the left supraclavicular area. Chest computed tomography showed that the pretracheal and subaortic lymph nodes were swollen. Gastroendoscopy showed a 2-cm protruding lesion with ulceration on the upper esophagus. Histological examination of the supraclavicular lymph nodes and biopsy specimens from the esophagus revealed non-specific inflammation. PET-CT showed abnormal accumulations not only on the upper right lung but also on the lower right of the abdomen. Colonoscopy was performed and multiple erosions on the terminal ileum were found. Polymerase chain reaction analysis of a specimen biopsied from the erosion of the terminal ileum was positive for Mycobacterium tuberculosis and intestinal tuberculosis was diagnosed. The patient was then treated with anti-tuberculous therapy. After treatment, the erosions on the terminal ileum, the swelling of the mediastinal lymphadenopathy, and the esophageal ulcer were all improved. The hoarseness was subsequently relieved. This is the first report of intestinal tuberculosis with hoarseness as a chief complaint due to mediastinal lymphadenitis.

Strengths and weaknesses of diagnostic tools for tuberculous uveitis

Diagnostic criteria for tuberculous uveitis encompass exclusion of other known etiologies of uveitis, suggestive clinical history and signs, supportive systemic investigations, positive response to empiric antituberculosis treatment and evidence of Mycobacterium tuberculosis or its DNA in ocular fluids/tissues. Recent advances in diagnostic tools for tuberculous infection, including molecular biology techniques for detection of M. tuberculosis DNA and interferon-gamma release assays, have improved the specificity of the diagnosis and the ability to ascertain exposure to the infectious agent. However even with such advances, establishing the diagnosis of tuberculous uveitis remains a challenging issue because each of these available investigations has its strengths and limitations and tuberculous infection can present with clinical features of any type of extraocular or intraocular inflammation. This article critically analyzes the role of these tests in supporting the diagnosis of tuberculous uveitis and proposes a practical diagnostic approach, based on a judicious combination of these tests.

Frequency of bacille Calmette-Guerin (BCG) and Mycobacterium tuberculosis in tissue biopsy specimens of children vaccinated with BCG

Vaccination of all newborns with bacille Calmette-Guérin (BCG) vaccine is a standard practice in developing countries. Disseminated mycobacterial infection in an immunocompromised child can be caused by BCG and other mycobacteria. A total of 21 patients with a histopathologic diagnosis of mycobacterial infection were studied in a period of 4 years. DNA was extracted from formalin-fixed, paraffin-embedded tissues. Real-time polymerase chain reaction was performed to determine the mycobacterial species. The overall sensitivity of the assay was 71.5%. The prevalence rates of BCG, Mycobacterium tuberculosis, and other mycobacteria in the positive results were 80% (12/15), 13% (2/15), and 7% (1/15), respectively.

Rapid differential diagnosis between extrapulmonary tuberculosis and focal complications of brucellosis using a multiplex real-time PCR assay

BACKGROUND

Arduous to differ clinically, extrapulmonary tuberculosis and focal complications of brucellosis remain important causes of morbidity and mortality in many countries. We developed and applied a multiplex real-time PCR assay (M RT-PCR) for the simultaneous detection of Mycobacterium tuberculosis complex and Brucella spp.

METHODOLOGY

Conventional microbiological techniques and M RT-PCR for M. tuberculosis complex and Brucella spp were performed on 45 clinical specimens from patients with focal complications of brucellosis or extrapulmonary tuberculosis and 26 control samples. Fragments of 207 bp and 164 bp from the conserved region of the genes coding for an immunogenic membrane protein of 31 kDa of B. abortus (BCSP31) and the intergenic region SenX3-RegX3 were used for the identification of Brucella and M. tuberculosis complex, respectively.

CONCLUSIONS

The detection limit of the M RT-PCR was 2 genomes per reaction for both pathogens and the intra- and inter-assay coefficients of variation were 0.44% and 0.93% for Brucella and 0.58% and 1.12% for Mycobacterium. M RT-PCR correctly identified 42 of the 45 samples from patients with tuberculosis or brucellosis and was negative in all the controls. Thus, the overall sensitivity, specificity, PPV and NPV values of the M RT PCR assay were 93.3%, 100%, 100% and 89.7%, respectively, with an accuracy of 95.8% (95% CI, 91.1%-100%). Since M RT-PCR is highly reproducible and more rapid and sensitive than conventional microbiological tests, this technique could be a promising and practical approach for the differential diagnosis between extrapulmonary tuberculosis and focal complications of brucellosis.

A case of postoperative tuberculous spondylitis with a bizarre course

Postoperative infections following spine surgery are usually attributable to bacterial organisms. Staphylococcus aureus is known to be the most common single pathogen leading to this infection, and the number of infections caused by methicillin-resistant Staphylococcus aureus is increasing. However, there is a paucity of literature addressing postoperative infection with Mycobacterium tuberculosis. We encountered a case of tuberculous spondylitis after spine surgery. A man had fever with low back pain three weeks after posterior interbody fusion with instrumentation for a herniated intervertebral disc at the L4-L5 level. He had been treated with antibiotics for an extended period of time under the impression that he had a bacterial infection, but his symptoms and laboratory data had not improved. Polymerase chain reaction for Mycobacterium tuberculosis turned out to be positive. The patient's symptoms finally improved when he was treated with antituberculosis medication.

Tubercular infection after arthroscopic anterior cruciate ligament reconstruction

PURPOSE

Tubercular infection has not been described, to our knowledge, in the literature after anterior cruciate ligament (ACL) reconstruction, and, hence, the purpose of our case series was to describe our experience, evaluate the clinical and laboratory findings, and assess the treatment outcome.

METHODS

We performed a retrospective analysis of 1,152 cases of arthroscopic ACL reconstruction with autografts performed at our institution between January 1998 and May 2007. Tubercular infection was considered to be present in the setting of recurrent negative bacterial cultures but a positive result on microscopy, culture, histopathology, or polymerase chain reaction (PCR). All patients underwent arthroscopic lavage and synovectomy, followed by antitubercular therapy for 12 months.

RESULTS

We identified 8 patients (0.69%) with infection. Bone-patellar tendon-bone graft was used in 1 and hamstring graft in 7. All patients were immunocompetent. The mean time from surgery to presentation was 64.4 days (range, 23 to 152 days). Aspirate fluid staining and culture for acid-fast bacilli was negative in all cases, synovial tissue culture was positive in 3, characteristic histopathology was positive in 7, and PCR was positive in 6. A mean of 1.25 surgeries (range, 1 to 2) were performed. The mean length of follow-up in our series was 43.6 months (range, 25 to 73 months), with no reinfections. The mean postoperative Lysholm knee score was 80.

CONCLUSIONS

Tubercular infection as a complication after arthroscopic ACL reconstruction, though rare, should be kept in mind as a possible cause of infection in immunocompetent patients in zones endemic for tuberculosis. It should also be kept in mind in nonendemic areas, among immigrants from endemic areas, and in cases with persistent swelling and discharge, effusion with minimal inflammatory signs, and negative cultures. We recommend deoxyribonucleic acid-PCR testing for early diagnosis of tuberculosis. Arthroscopic debridement and antitubercular chemotherapy together are the mainstay of treatment.