Predictors for false-negative QuantiFERON-TB Gold assay results in patients with extrapulmonary tuberculosis

The changes and its significance of peripheral blood NK cells in patients with tuberculous meningitis

Objective

Tuberculous meningitis (TBM) is the most severe form of tuberculosis (TB). The purpose of this study was to explore the relationship between the number of natural killer (NK) cells and adaptive immune status, and disease severity in TBM patients.

Methods

We conducted a retrospective study on 244 TB patients and 146 healthy control subjects in the 8th Medical Center of the PLA General Hospital from March 2018 and August 2023.

Results

The absolute count of NK cells in the peripheral blood of TBM patients was significantly lower than that in normal controls (NC), latent tuberculosis infection (LTBI), and non-severe TB (NSTB) patients (p < 0.05). The proportion of TBM patients (48.7%) with a lower absolute count of NK cells than the normal reference value was significantly higher than that in NC (5.2%) and LTBI groups (4.0%) (p < 0.05), and slightly higher than that in NSTB group (36.0%) (p > 0.05). The absolute counts of lymphocyte subsets in TBM combined with other active TB group, etiology (+) group, IGRA (-) group, and antibody (+) group were lower than that in simple TBM group, etiology (-) group, IGRA (+) group, and antibody (-) group, respectively. The CD3+ T, NK, and B cells in BMRC-stage III TBM patients were significantly lower than those in stage I and stage II patients (p < 0.05). The counts of CD3+ T, CD4+ T, and B cells in the etiology (+) group were significantly lower than those in the etiology (-) group (p < 0.05).

Conclusion

The absolute counts of lymphocyte subsets in the peripheral blood of TBM patients were significantly decreased, especially in NK cells. The reduction of these immune cells was closely related to the disease severity and had a certain correlation with cellular and humoral immune responses. This study helps to better understand the immune mechanism of TBM and provides reliable indicators for evaluating the immune status of TBM patients in clinical practice.

The tuberculous pleural effusion

Pleural tuberculosis (TB) is a common entity with similar epidemiological characteristics to pulmonary TB. It represents a spectrum of disease that can variably self-resolve or progress to TB empyema with severe sequelae such as chronic fibrothorax or empyema necessitans. Coexistence of and progression to pulmonary TB is high. Diagnosis is challenging, as pleural TB is paucibacillary in most cases, but every effort should be made to obtain microbiological diagnosis, especially where drug resistance is suspected. Much attention has been focussed on adjunctive investigations to support diagnosis, but clinicians must be aware that apparent diagnostic accuracy is affected both by the underlying TB prevalence in the population, and by the diagnostic standard against which the specified investigation is being evaluated. Pharmacological treatment of pleural TB is similar to that of pulmonary TB, but penetration of the pleural space may be suboptimal in complicated effusions. Evidence for routine drainage is limited, but evacuation of the pleural space is indicated in complicated disease.

Educational aims

To demonstrate that pleural TB incorporates a wide spectrum of disease, ranging from self-resolving lymphocytic effusions to severe TB empyema with serious sequelae.To emphasise the high coexistence of pulmonary TB with pleural TB, and the importance of obtaining sputum for culture (induced if necessary) in all cases.To explore the significant diagnostic challenges posed by pleural TB, and consequently the frequent lack of information about drug sensitivity prior to initiating treatment.To highlight the influence of underlying TB prevalence in the population on the diagnostic accuracy of adjunctive investigations for the diagnosis of pleural TB.To discuss concerns around penetration of anti-TB medications into the pleural space and how this can influence decisions around treatment duration in practice.

Low performance of interferon gamma release assay Quantiferon-TB gold coupled or not with Pst1/3/lipoglycan humoral detection to predict Mycobacterium tuberculosis complex disease in a low-burden area

Whole T cell interferon gamma release assays such as QuantiFERON-TB Gold Plus (QTF-TB) are used to evaluate Mycobacterium tuberculosis complex (MTC) exposure but fail to discriminate latent tuberculosis infection (LTBI) from active disease. In this study conducted in a low-burden area, 1215 patients presenting MTC risk and tested both for QTF-TB and mycobacterial infection (microscopy, culture, and/or PCR) were selected, as well as 1298 controls screened with QTF-TB before medical recruitment. The humoral response (LIODetect®TB-ST) was further evaluated in 199 selected patients. In patients with active disease, MTC positivity (culture and/or PCR with species identification) was associated with QTF-TB positivity (45/56, 80.4 %). Although QTF-TB1/TB2 peptides were not suitable for discriminating against active MTC disease from LTBI, the cut-off value of 4.4 IFN-γ IU/mL produced the best diagnostic performance for MTC detection. Lower levels of QTF-TB were reported among patients with isolated active pulmonary MTC as compared to a lymph-nodal location and a disseminated form. Next, antibodies were detected in 4/55 (7.3 %) active MTC disease cases, while negative in cases of LTBI and indeterminate/negative QTF-TB. In conclusion, the added value to combine cellular (QTF-TB) and humoral (LIODetect®TB-ST) assays to predict an active MTC disease is limited.

Tubercular Serpiginous-Like Choroiditis in Patients with Negative TB-Immunoreactivity Tests

BACKGROUND

Serpiginous-like choroiditis (SLC) denotes ocular tuberculosis (TB), in the presence of positive tuberculin skin test (TST) or interferon gamma release assay (IGRA).

METHODS

Retrospective review of SLC patients from a TB-endemic country, with negative TST and IGRA tests, but responsive to anti-TB therapy.

RESULTS

Fifteen patients (13 bilateral) with active SLC  were included.   Eleven (73.3%) patients had received corticosteroids ± immunosuppressive therapy prior to presentation. Chest radiographic abnormalities were found in four (26.7%) patients. We treated all patients with a combination of anti-TB therapy (ATT) and corticosteroids. Paradoxical worsening was noted in nine (60%) patients, complete resolution of lesions in 12 (80%), persistent inflammation (post-ATT) in one, while two were yet to complete ATT. None had recurrence after complete resolution of lesions (median follow-up of 71 weeks [range 15-676 weeks]).

CONCLUSIONS

TB-SLC may present with negative TST and IGRA tests but may still have clinical appearance, and treatment response, like test-positive disease.

Diagnostic Performance of Different Laboratory Methods for the Detection of Extrapulmonary Tuberculosis

Accurate and appropriate extrapulmonary tuberculosis (EPTB) diagnosis remains challenging due to its paucibacillary nature, requirement of invasive collection procedures, and lack of sensitive tests. This study investigated the diagnostic performance of different methods for the diagnosis of EPTB. A total of 1340 EPTB specimens were collected from presumptive EPTB patients from four different hospitals between November 2015 and March 2017. The collected specimens were tested with AFB microscopy, culture, Xpert MTB/RIF assay (Xpert), and MTBDRplus assay. Among the 1340 EPTB specimens, 49 (3.66%), 141 (10.52%), 166 (12.39%), and 154 (11.49%) were positive in AFB microscopy, culture, Xpert MTB/RIF, and MTBDRplus assay, respectively. A total of 194 (14.9%) cases were found positive in at least one of these methods. Using culture as a reference standard, the sensitivity and specificity of AFB microscopy, Xpert MTB/RIF, and MTBDRplus assay were: 27.0%/99.1%, 83.7%/96.0%, and 79.4%/96.5%, respectively. Compared to the composite reference standard, the sensitivity of culture, AFB microscopy, Xpert MTB/RIF, and MTBDRplus assay was 72.7%, 25.3%, 85.6%, and 79.4%, respectively, with a specificity of 100% for all the methods. The Xpert MTB/RIF assay showed the highest sensitivity compared to other methods. Considering the short turnaround time and promising findings, Xpert MTB/RIF assay should be integrated into national TB guidelines as a routine diagnostic test.

You Have Gut TB Kidding Me

Tuberculosis is a disease that affects millions of individuals worldwide every year.1 Most cases present as pulmonary tuberculosis, though there are rare reports of abdominal tuberculosis. These presentations make up only 1-3% of all tuberculosis cases worldwide.1 Symptoms are often vague, presenting as abdominal pain, discomfort, or weight changes.2 These symptoms can be misdiagnosed for other more common gastrointestinal disorders. Unfortunately, misdiagnosis or a prolongation in diagnosis can lead to worsened patient outcome due to delay of initiation of anti-tubercular therapy.3 It is therefore imperative that providers understand the spectrum of symptoms associated with this illness as well as having a high clinical suspicion for patients at risk. Incorporating this knowledge and using a thorough diagnostic work up to confirm this disease is crucial, as delay of care can lead to poor patient prognosis or death.3.

Predictors for False-Negative Interferon-Gamma Release Assay Results in Hemodialysis Patients with Latent Tuberculosis Infection

The present study aimed to clinically evaluate the effect of T-cell dysfunction in hemodialysis (HD) patients with latent tuberculosis (TB) infection (LTBI) who were false-negatives in the QuantiFERON-TB Gold In-Tube (QFT-GIT) test. Whole blood samples from a total of 20 active TB patients, 83 HD patients, and 52 healthy individuals were collected, and the QFT-GIT test was used for measuring Mycobacterium tuberculosis (MTB)-specific interferon gamma (IFN-γ) level. The positive rate of the IFN-γ release assays (IGRAs) in HD patients was lower than the negative rate. The mean value of MTB-specific IFN-γ level, which determines the positive rate of the IGRA test, was highest in active TB, followed by HD patients and healthy individuals. Among HD patients, phytohemagglutinin A (PHA)-stimulated IFN-γ levels of approximately 40% were 10.00 IU/mL or less. However, there was no low level of PHA-stimulated IFN-γ in the healthy individuals. This reveals that T-cell function in HD patients was reduced compared to healthy individuals, which leads to the possibility that QFT-GIT results in HD patients are false-negative. The clinical manifestations of TB in patients on HD are quite non-specific, making timely diagnosis difficult and delaying the initiation of curative treatment, delay being a major determinant of outcome.

Factors Influencing False-Negative Results of QuantiFERON-TB Gold In-Tube (QFT-GIT) in Active Tuberculosis and the Desirability of Resetting Cutoffs for Different Populations: A Retrospective Study

Objectives The value of QuantiFERON-TB Gold In-Tube (QFT-GIT) in the diagnosis of TB varies by population, comorbidities, and other factors. In this study, we aimed to investigate factors that influence false-negative results of QFT-GIT test in the diagnosis of TB as well as the impact of different cutoffs on the diagnostic value. Methods A total of 3562 patients who underwent QFT-GIT tests at Shanghai Pulmonary Hospital were enrolled retrospectively between May 2016 and May 2017. False-negative and false-positive results were analyzed using different clinical stratifications. The optimal cutoff values were established under different clinical conditions. Results Positive QFT-GIT results greatly shortened the time taken to diagnose smear-negative TB. The factors of age, smear and culture results, site of TB, comorbidity with tumors, white blood cell count, neutrophil count, and CD4/CD8 ratio were significantly correlated with false-negative QFT-GIT results (p < 0.05). Personalized cutoff values were established according to different influencing factors. The results showed high consistency between the smear-negative and total populations. Conclusion QFT-GIT can facilitate the early diagnosis of smear-negative TB. The diagnostic performance of the QFT-GIT test in the diagnosis of active TB was shown to be affected by many clinical factors. Personalized cutoff values may have superior value in the identification of active tuberculosis under different conditions.

Miliary Tuberculosis: A Case Report Highlighting the Diagnostic Challenges Associated With the Condition

End-stage renal disease requiring chronic dialysis is an immunocompromised state which increases the risk of tuberculosis development and its spread. Due to the high frequency of non-specific or “decoy” symptoms at presentation and frequent extrapulmonary involvement, diagnosis of tuberculosis is a significant challenge. Therefore, it is correctly labeled as ‘Tuberculosis; the great imitator’ as it can mimic various other disease processes, causing confusion and testing of subsystems involved in the disease process, which come back as abnormal, leading to a vicious cycle. Missing the diagnosis leads to grave consequences, especially in a patient with a miliary form of tuberculosis, as the prognosis with any delay in treatment is poor. High diagnostic suspicion is required to promptly diagnose and treat the condition, especially in a resource-rich setting where tuberculosis is uncommon. Here, we report a patient with miliary tuberculosis who presented with a chief complaint of chronic diarrhea and fecal continence, with prior recent negative interferon-gamma release assay testing. Due to every organ system involved, multiple subspecialties were on board, with a broad differential in mind, including malabsorption syndromes, neoplasia, infections, amyloidosis, and autoimmune disorders, and therefore, numerous tests were performed. However, despite all efforts, the diagnosis was delayed significantly, leading to the unfortunate demise of the patient. The case report sheds light on unique clinical features of miliary tuberculosis, diagnostic findings, and a reminder to always keep tuberculosis high in the differential in an appropriate clinical setting.

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.

Mycobacterium tuberculosis-specific CD4 T-cell scoring discriminates tuberculosis infection from disease

Background

Rapid and reliable diagnostic work-up of tuberculosis (TB) remains a major healthcare goal. In particular, discrimination of TB infection from TB disease with currently available diagnostic tools is challenging and time consuming. This study aimed at establishing a standardised blood-based assay that rapidly and reliably discriminates TB infection from TB disease based on multiparameter analysis of TB antigen-reactive CD4⁺ T-cells acting as sensors for TB stage-specific immune status.

Methods

157 HIV-negative subjects with suspected TB infection or TB disease were recruited from local tertiary care hospitals in Berlin (Germany). Peripheral blood mononuclear cells were analysed for CD4⁺ T-cells reactive to the Mycobacterium tuberculosis antigens purified protein derivative and early secretory antigenic target 6 kDa/culture filtrate protein 10. The activation state of TB antigen-reactive T-cells, identified by surface expression of CD154, was evaluated according to the expression profile of proliferation marker Ki-67 and activation markers CD38 and HLA-DR. Using data from 81 subjects with clinically confirmed TB infection (n=34) or culture-proven pulmonary or extrapulmonary TB disease (n=47), 12 parameters were derived from the expression profile and integrated into a scoring system.

Results

Using the scoring system, our assay (TB-Flow Assay) allowed reliable discrimination of TB infection from both pulmonary and extrapulmonary TB disease with high sensitivity (90.9%) and specificity (93.3%) as was confirmed by Monte-Carlo cross-validation.

Conclusion

With low time requirement, ease of sample collection, and high sensitivity and specificity both for pulmonary and extrapulmonary TB disease, we believe this novel standardised TB-Flow Assay will improve the work-up of patients with suspected TB disease, supporting rapid TB diagnosis and facilitating treatment decisions.

In a prospective study, a scoring system based on analysis of the activation state of tuberculosis (TB)-specific CD4⁺ T-cells was developed that allows reliable discrimination of TB infection and TB disease with high sensitivity and specificityhttps://bit.ly/3EFG4KX

Absence of Evidence as The Evidence Of Absence: The Curious Case of Latent Infection Causing Ocular Tuberculosis

Ocular tuberculosis (TB) is frequently considered as intraocular inflammation in the setting of latent TB, owing mainly to the absence of microbiological evidence of Mycobacterium tuberculosis in ocular fluid samples. Even though such lack of microbiological evidence, and of systemic signs of active TB disease, are suggestive of latent TB infection, molecular and rare histopathologic evidence of mycobacteria in the eye, and favourable response of ocular inflammation to anti-TB therapy point to the presence of active infection in ocular TB. Here, we discuss how intraocular inflammation in ocular TB is not merely an immunologic response to bacilli, but an active tuberculosis infection. We will discuss the reason for the frequent absence of microbiological evidence of TB in the eye in ocular TB and the diagnostic hierarchy to arrive at the diagnosis of this infectious uveitis entity.

Diagnostic role of internal mammary lymph node involvement in tuberculous pleurisy: a multicenter study

BACKGROUND AND OBJECTIVES

Diagnosis of tuberculous pleurisy (TP) may be challenging and it often requires pleural biopsy. A tool able to increase pre-test probability of TP may be helpful to guide diagnostic work-up and enlargement of internal mammary lymph node (IMLN) has been suggested to play a potential role. The aim of the present investigation was to assess role of IMLN involvement in TP in a multi-centric case-control study, by comparing its prevalence and test performance to those observed in patients with infectious, non-tuberculous pleurisy (NTIP), and in controls free from respiratory diseases (CP).

METHODS

A total of 419 patients, from 14 Pulmonology Units across Italy were enrolled (127 patients affected by TP, 163 affected by NTIP and 129 CP). Prevalence, accuracy and predictive values of ipsilateral IMLN involvement between cases and control groups were assessed, as well as concordance between chest computed tomography (CT scan) and thoracic ultrasound (TUS) measurements.

RESULTS

The prevalence of ipsilateral IMLN involvement in TP was significantly higher than that observed in NTIP and CP groups (respectively 77.2%, 39.3% and 14.7%). Results on test performance, stratified by age, revealed a high positive predictive value in patients aged ≤50 years, while a high negative predictive value in patients aged >50 years. The comparison between CT scan and ultrasound showed moderate agreement (Kappa=0.502).

CONCLUSIONS

Evaluation of IMLN involvement plays a relevant role in assessing the pre-test probability of TP. Considering the increasing global prevalence of mycobacterial infections, a tool able to guide diagnostic work-up of suspected TP is crucial, especially where local sources are limited.

Calvarial tuberculosis in a paediatric patient: a diagnosis not to forget

We report the case of a 10-year-old boy that presented with a palpable, painless, frontal lesion. Laboratory assessments were unremarkable and the patient was asymptomatic. Initial investigation, with a skull radiograph and unenhanced CT scan, showed a lytic midline frontal lesion involving the inner and outer tables of the skull and a large subgaleal hypodense component. MRI further depicted communication with the epidural space and contact with the superior sagittal sinus (SSS). Subsequent evaluation by Doppler ultrasound and MR angiography excluded a sinus pericranii and showed normal patency of the SSS. Surgical biopsy revealed chronic granulomatous inflammation; PCR was positive for Mycobacterium sp. One year after surgical resection and antitubercular therapy, there are no signs of recurrence. Primary calvarial involvement by tuberculosis is rare, even in developing countries. Familiarity with the expected clinical and imaging features is required to avoid diagnostic delay.

Fine-needle aspiration cytology-based accurate and rapid diagnosis of breast tuberculosis mimicking an abscess

A case of breast tuberculosis was initially misdiagnosed as a breast abscess and diagnosed definitively by minimally invasive fine-needle aspiration cytology. This definitive diagnosis enabled us to prevent widespread infection by early initiation of the standard anti-tuberculosis regimen. The patient recovered, and no disease recurrence was noted during follow-ups.

Neurologic Complications of Tuberculosis

PURPOSE OF REVIEW

This article describes the current epidemiology, common clinical characteristics, and up-to-date evidence-based approaches to the diagnosis and management of the most common neurologic complications of tuberculosis (TB): tuberculous meningitis, intracranial tuberculoma, and spinal TB.

RECENT FINDINGS

Central nervous system (CNS) TB remains common and associated with significant mortality and neurologic sequelae worldwide. Human immunodeficiency virus (HIV) co-infection is strongly associated with both the development of and mortality due to CNS TB. Strongyloides co-infection is associated with reduced CNS inflammation and improved outcomes in the setting of tuberculous meningitis. Stroke remains a common complication of tuberculous meningitis, and emerging evidence suggests aspirin may be used in this context. Although a recent nucleic acid amplification test has demonstrated suboptimal sensitivity in the diagnosis of CNS TB, emerging diagnostic techniques include cell-free DNA, peripheral blood microRNA, metagenomic next-generation sequencing, and advanced imaging techniques, but these are not yet well validated. CNS TB is associated with high mortality even with current treatment regimens, although novel, promising strategies for treatment are under investigation, including a combination of IV isoniazid and ethambutol and high-dose rifampicin.

SUMMARY

TB can affect the nervous system in various ways and is associated with high mortality. Diagnosis remains challenging in endemic settings, with empiric treatment often initiated without a definitive diagnosis. Furthermore, optimal treatment regimens remain uncertain because current treatment for all forms of CNS TB is extrapolated from trials of tuberculous meningitis whereas the role of steroids in people with HIV and tuberculous meningitis remains controversial.

Tuberculosis Screening, Testing, and Treatment of US Health Care Personnel: ACOEM and NTCA Joint Task Force on Implementation of the 2019 MMWR Recommendations

: On May 17, 2019, the US Centers for Disease Control and Prevention and National Tuberculosis Controllers Association issued new Recommendations for Tuberculosis Screening, Testing, and Treatment of Health Care Personnel, United States, 2019, updating the health care personnel-related sections of the Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Settings, 2005. This companion document offers the collective effort and experience of occupational health, infectious disease, and public health experts from major academic and public health institutions across the United States and expands on each section of the 2019 recommendations to provide clarifications, explanations, and considerations that go beyond the 2019 recommendations to answer questions that may arise and to offer strategies for implementation.

Gastrointestinal and Abdominal Tuberculosis

Gastrointestinal (GI) tuberculosis (TB) remains a significant problem worldwide, and may involve the luminal GI tract from oral cavity to perianal area in addition to associated viscera and peritoneum. Although GI TB more commonly affects immunocompromised hosts, it can also occur in immunocompetent people. Diagnosis is difficult because it usually mimics a malignancy or inflammatory bowel disease. A high index of clinical suspicion and appropriate use of combined investigative methods help in early diagnosis, and reduce morbidity and mortality. Anti-TB therapy is the same as for pulmonary disease, and invasive and specialized interventions are reserved for selected complications.

IL-1RA in the supernatant of QuantiFERON-TB Gold In-Tube and QuantiFERON-TB Gold Plus is useful for discriminating active tuberculosis from latent infection

INTRODUCTION

The new-generation QuantiFERON (QFT)-TB Gold Plus (QFT-Plus) is expected to be useful because it includes a new peptide that is supposed to induce a CD8⁺ T cell response. There is a need for a new marker with sensitivity higher than that of the conventional IFN-γ release assays owing to false-negative results in the latter. This study aimed to compare cytokines in QFT-plus and QuantiFERON-Gold In-Tube (QFT-GIT) supernatants to discriminate between active tuberculosis and latent tuberculosis infection (LTBI).

METHODS

A cross-sectional study was conducted at Tokyo National Hospital, wherein 21 LTBI patients and age and sex-matched active TB patients were randomly selected. The levels of various cytokines were measured and compared using the MAGPIX System, and receiver operating characteristic (ROC) curves were generated.

RESULTS

IL-1RA, IFN-γ, CXCL10/IP-10, and CCL4/MIP-1β levels were higher in the active TB group than in the LTBI group in QFT-GIT antigen (GIT Ag) tubes. In QFT-plus tubes, IL-1RA was higher in TB1 and TB2 tubes, while CCL2/MCP-1 was higher only in TB2 tubes. In Nil tubes, CCL5/RANTES, TNF-α, PDGF-BB, and IL-2 levels were significantly higher in the active TB group. IL-1RA in GIT Ag tubes showed the highest area under the curve of 0.8367. The sensitivity and specificity of IL-1RA were 66.7% (95% confidence interval [CI]: 43.0-85.4) and 90.5% (95% CI: 69.6-98.8), respectively, which were the highest among the cytokines.

CONCLUSIONS

IL-1RA level in the QFT-GIT supernatant can be a good marker for discriminating active TB from LTBI.

Tubercular subretinal abscess in a pediatric intermediate uveitis patient on methotrexate

Pediatric intermediate uveitis (IU), usually idiopathic, can also be associated with tuberculosis (TB) and sarcoidosis. A 14-year-old girl was diagnosed with idiopathic IU after ruling out TB and sarcoid. She was treated with oral steroids and methotrexate (MTX) with good inflammation control. One year later, she presented with subretinal (SR) abscess. Lab tests were still negative but aqueous polymerase chain reaction confirmed TB. With antituberculosis treatment, complete resolution of the lesion was noted. The likelihood of a change in phenotype of ocular TB, from an IU to TB SR abscess or a possible reactivation of latent TB due to MTX are discussed.

A Critically Ill Patient With Central Nervous System Tuberculosis and Negative Initial Workup

Empiric anti-tuberculous therapy should not be delayed in patients with a strong clinical suspicion for TB. Because confirmatory TB testing may be difficult to obtain, early and empiric treatment, when there is concern for central nervous system TB, may result in improved outcomes for patients. GeneXpert is currently an area of active research, and the test returns diagnostic results within hours, which would make it the preferred test for investigating TB meningitis.

Factors associated with false negative interferon-γ release assay results in patients with tuberculosis: A systematic review with meta-analysis

Which factors are related to false negative results of the interferon-γ release assay (IGRA) is unclear. This systematic review described the risk factors associated with false negative IGRA results. Two authors independently identified studies designed to evaluate risk factors for false negative IGRA results from PubMed, the Cochrane Register of Control Trial database, and EMBASE, accessed on October 22, 2018. Meta-analyses were conducted with random-effect models, and heterogeneity was calculated with the I² method. Of 1,377 titles and abstracts screened, 47 full texts were selected for review, and we finally included 17 studies in this systematic review. The most commonly studied risk factor (14 studies) was advanced age, followed by low peripheral lymphocyte counts (7 studies), and these factors were associated with false negative results even with different tuberculosis incidences (pooled odds ratio 2.06; 95% CI, 1.68–2.52 in advanced age and 2.68; 95% CI, 2.00–3.61 in low peripheral lymphocyte counts). Advanced age and low peripheral lymphocyte counts may be common risk factors for false negative IGRA results, suggesting that people with these factors need to be carefully followed, even if they have negative IGRA results.

Coats-like response in tubercular subretinal abscess masquerading as melanoma as the initial manifestation of miliary tuberculosis

Ocular neoplasia can masquerade as an inflammatory condition and vice-versa, which if untreated, can lead to loss of vision or even life. We present a young immunocompetent adult male referred to us as choroidal melanoma. He had a large atypical choroidal mass and exudative retinal detachment. He had no systemic complaints and ocular lesions were the first manifestation of disseminated disease. Aqueous polymerase chain reaction for Mycobacterium tuberculosis (MTB) was negative, but Mantoux, chest radiology, acid-fast bacilli, and caseation necrosis on pleural nodule histopathology confirmed tuberculosis (TB). While on antitubercular therapy, a rare “Coats'-like response” was noted which eventually resolved completely with treatment.

Clinical application of QuantiFERON-TB Gold in-tube in the diagnosis and treatment of tuberculosis

At present, although it has made great progress in the diagnosis and treatment of tuberculosis, tuberculosis is still an important cause of morbidity and mortality. There were approximately 8.6 million new cases of tuberculosis in 2012, and approximately 1.3 million people died from tuberculosis. Early diagnosis and timely treatment are essential for controlling the spread of tuberculosis infection and reducing mortality. Conventional methods of Mycobacterium tuberculosis detection such as acid-fast staining microscopy and tuberculin skin test are widely used, but with low sensitivity or specificity. In recent years, a newly developed quantitative test, γ-interferon release test (IGRA), has been recognized and widely applied to the early diagnosis and monitoring of tuberculosis. QuantiFERON-TB Gold in-tube (QFT-GIT) is one of the mature IGRA methods. This paper summarizes the researches on QFT-GIT in recent years and introduces its principles, methodology, clinical application, and factors of uncertain results for the diagnosis and treatment of tuberculosis.

Atypical Laryngeal Infections: Localized Lesions from Unusual Organisms May Simulate Malignancy

Objective:

The identification of rare sources of laryngeal infection in immunocompetent patients. Recovered organisms were Mycobacterium tuberculosis (laryngeal tuberculosis [LTB]), Mycobacterium fortuitum (laryngeal Mycobacterium fortuitum [LMF]), and Blastomyces dermatiditis (laryngeal blastomycosis [LB]).

Method:

Single institution retrospective case series of three patients over a 2.5-year period and review of the literature on laryngeal infections by three atypical organisms.

Results:

Three patients presented with hoarseness and cough; one additionally had throat pain (LTB). Indirect laryngoscopy demonstrated diffuse laryngeal ulceration (LTB, LMF) and an exophytic, contiguous glottic mass (LB). Direct microlaryngoscopic biopsies and cultures established the diagnoses, including a frozen section in one case (LB), which prevented a simultaneously planned surgical resection. Appropriate antimicrobial therapy yielded dramatic laryngeal and corresponding vocal improvement, for which we provide unique photo and audio documentation. In the last 10 years, fewer than 500 cases of LTB have been reported in the English language medical literature, principally outside the United States. To date, there have been reports of only 34 LB and no cases of LMF.

Conclusion:

Atypical infections of the larynx may be localized and mimic laryngeal cancer on endoscopy. Tissue examination as well as microbiologic samples are diagnostic and complementary.

Tuberculous pleural effusion

Tuberculous effusion is a common disease entity with a spectrum of presentations from a largely benign effusion, which resolves completely, to a complicated effusion with loculations, pleural thickening and even frank empyema, all of which may have a lasting effect on lung function. The pathogenesis is a combination of true pleural infection and an effusive hypersensitivity reaction, compartmentalized within the pleural space. Diagnostic thoracentesis with thorough pleural fluid analysis including biomarkers such as adenosine deaminase and gamma interferon achieves high accuracy in the correct clinical context. Definitive diagnosis may require invasive procedures to demonstrate histological evidence of caseating granulomas or microbiological evidence of the organism on smear or culture. Drug resistance is an emerging problem that requires vigilance and extra effort to acquire a complete drug sensitivity profile for each tuberculous effusion treated. Nucleic acid amplification tests such as Xpert MTB/RIF can be invaluable in this instance; however, the yield is low in pleural fluid. Treatment consists of standard anti-tuberculous therapy or a guideline-based individualized regimen in the case of drug resistance. There is low-quality evidence that suggests possible benefit from corticosteroids; however, they are not currently recommended due to concomitant increased risk of adverse effects. Small studies report some short- and long-term benefit from interventions such as therapeutic thoracentesis, intrapleural fibrinolytics and surgery but many questions remain to be answered.

Sensitivity and characteristics associated with positive QuantiFERON-TB Gold-Plus assay in children with confirmed tuberculosis

Background

Although QuantiFERON-TB Gold Plus (QFT-Plus), a new interferon-gamma release assay, has shown good performance in adults, little data is available in children.

Methods

De-identified data from TB-suspected patients age <18 years with QFT-Plus results, who were admitted or screened at the National Lung Hospital (NLH) in Ha Noi, Vietnam in 2017, were assessed. Logistic regression analyses were performed to determine the characteristics associated with having a positive QFT-Plus result. Sensitivity, both overall and in subgroups of pulmonary TB only (PTB), extra-pulmonary TB (EPTB) only, and both PTB and EPTB were calculated.

Results

Of 222 children with available QFT-Plus results, 33 were classified as confirmed TB, of whom 18 had QFT-Plus (+) and 15 had QFT-Plus (-). Multiple logistic regression modeling suggested that age, history of TB, and confirmed TB were significantly associated with having a positive QFT-Plus result with an area under the ROC curve of 0.77. QFT-Plus sensitivity in PTB only, EPTB, and both PTB and EPTB patients was 84.2%, 14.3% and 14.3%, respectively. The overall sensitivity of the QFT-Plus assay (regardless PTB or EPTB) in children was 54.5%.

Conclusion

Although QFT-Plus had a good sensitivity in children having exclusive PTB, it had poor sensitivity in EPTB.