Intractable intracranial tuberculous infection responsive to thalidomide: report of four cases

Tumor necrosis factor-alpha antagonists in patients with complicated spinal tuberculosis: A case series and literature review

INTRODUCTION

Spinal tuberculosis is often associated with poor outcomes; host-directed inflammation involving the spine contributes to this disability.

METHODS

A retrospective review of patients with complicated spinal tuberculosis having received tumor necrosis factor-alpha (TNF-α) antagonists at a referral hospital in South Africa. A literature review was performed to identify all published cases of complicated spinal tuberculosis that received a TNF-α antagonist as part of their treatment.

RESULTS

We describe 23 cases, of which 19 were previously reported in the literature. All patients were treated with either thalidomide (n=6) or infliximab (n=16), except for one who received both. All in all, 21 (91%) cases improved neurologically and, at the end of follow-up, 18 could walk.

CONCLUSION

There is accumulating experience to confer the efficacy and safety of TNF-α antagonists in treating complicated spinal tuberculosis cases. Evidence from randomized controlled trials is urgently required to substantiate these findings.

The Neuro-Ophthalmology of Tuberculosis

Tuberculosis (TB) is a global health concern and central nervous system (CNS) TB leads to high mortality and morbidity. CNS TB can manifest as tubercular meningitis, tuberculoma, myelitis, and arachnoiditis. Neuro-ophthalmological involvement by TB can lead to permanent blindness, ocular nerve palsies and gaze restriction. Visual impairment is a dreaded complication of tubercular meningitis (TBM), which can result from visual pathway involvement at different levels with varying pathogenesis. Efferent pathway involvement includes cranial nerve palsies and disorders of gaze. The purpose of this review is to outline the various neuro-ophthalmological manifestations of TB along with a description of their unique pathogenesis and management. Optochiasmatic arachnoiditis and tuberculomas are the most common causes of vision loss followed by chronic papilloedema. Abducens nerve palsy is the most commonly seen ocular nerve palsy in TBM. Gaze palsies with deficits in saccades and pursuits can occur due to brainstem tuberculomas. Corticosteroids are the cornerstone in the management of paradoxical reactions, but other immunomodulators such as thalidomide and infliximab are being explored. Toxic optic neuropathy caused by ethambutol necessitates careful monitoring and immediate drug discontinuation. Cerebrospinal fluid diversion through ventriculo-peritoneal shunting may be required in patients with hydrocephalus in stage I and II of TBM to prevent visual impairment. Early diagnosis and prompt management are crucial to prevent permanent disability. Prevention strategies, public health initiatives, regular follow-up and timely intervention are essential in reducing the burden of CNS TB and its neuro-ophthalmological complications.

Bacterial meningitis in Africa

Bacterial meningitis differs globally, and the incidence and case fatality rates vary by region, country, pathogen, and age group; being a life-threatening disease with a high case fatality rate and long-term complications in low-income countries. Africa has the most significant prevalence of bacterial meningitis illness, and the outbreaks typically vary with the season and the geographic location, with a high incidence in the meningitis belt of the sub-Saharan area from Senegal to Ethiopia. Streptococcus pneumoniae (pneumococcus) and Neisseria meningitidis (meningococcus) are the main etiological agents of bacterial meningitis in adults and children above the age of one. Streptococcus agalactiae (group B Streptococcus), Escherichia coli, and Staphylococcus aureus are neonatal meningitis's most common causal agents. Despite efforts to vaccinate against the most common causes of bacterial neuro-infections, bacterial meningitis remains a significant cause of mortality and morbidity in Africa, with children below 5 years bearing the heaviest disease burden. The factors attributed to this continued high disease burden include poor infrastructure, continued war, instability, and difficulty in diagnosis of bacterial neuro-infections leading to delay in treatment and hence high morbidity. Despite having the highest disease burden, there is a paucity of African data on bacterial meningitis. In this article, we discuss the common etiologies of bacterial neuroinfectious diseases, diagnosis and the interplay between microorganisms and the immune system, and the value of neuroimmune changes in diagnostics and therapeutics.

Management of Pediatric Stroke - Challenges and Perspectives from Resource-limited Settings

Childhood stroke is not as common as adult stroke, but it is underrecognized the world over. Diagnosis is often delayed due to lack of awareness not only by the lay public but also by emergency and front-line health care workers. Despite the relative rarity of childhood stroke, the impact on morbidity, mortality and the economic burden for families and society is high, especially in poorly resourced settings. The risk factors for stroke in children differ from the adult population where lifestyle factors play a more important role. The developmental aspects of the pediatric cerebral vasculature and hematological maturational biology affects the clinical presentation, investigation, management and outcomes of childhood stroke in a different way compared to adults. The management of childhood stroke is currently based on expert guidelines and evidence extrapolated from adult studies. Hyperacute therapies that have revolutionized the treatment of stroke in adults cannot be easily applied to children at this stage due to the diagnostic delays, diverse risk factors and developmental considerations mentioned above. Much has been achieved in the understanding of genetic, acquired, preventable and recurrent stroke risk factors in the past decade through international collaborative efforts like the International Pediatric Stroke Study. Evidence for the prevention and treatment of childhood stroke remains elusive. Even more elusive are relevant and achievable management guidelines for pediatric stroke in resource-limited settings. This narrative review focusses on the current management practices globally, emphasizing the challenges, and gaps in knowledge of pediatric stroke in low- and middle-income countries and other areas with limited resources. Priorities and some potential solutions at national and local level are suggested for these settings.

The use of thalidomide to treat children with tuberculosis meningitis: A review

Much of the morbidity and mortality caused by tuberculous meningitis (TBM) is mediated by a dysregulated immune response. Effective host-directed therapy is therefore critical to improve survival and clinical outcomes. Currently only one host-directed therapy (HDT), corticosteroids, is proven to improve mortality. However, there is no evidence that corticosteroids reduce morbidity and the mechanism of action for mortality reduction is uncertain. Further, it has no proven benefit in HIV co-infected individuals. One promising host-directed therapy approach is to restrict the immunopathology arising from tumour necrosis factor (TNF)-α excess is via TNF-α inhibitors. There are accumulating data on the role of thalidomide, anti-TNF-α monoclonal antibodies (infliximab, adalimumab) and the soluble TNF-α receptor (etanercept) in TBM treatment. Thalidomide was developed nearly seventy years ago and has been a highly controversial drug. Birth defects and toxic adverse effects have limited its use but an improved understanding of its immunological mechanism of action suggest that it may have a crucial role in regulating the destructive host response seen in inflammatory conditions such as TBM. Observational studies at our institution found low dosage adjunctive thalidomide safe in treating tuberculous mass lesions and blindness related to optochiasmatic arachnoiditis, with good clinical and radiological response. In this review, we discuss possible mechanisms of action for thalidomide, based on our clinico-radiologic experience and post-mortem histopathological work. We also propose a rationale for its use in the treatment of certain TBM-related complications.

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.

Risk factors for ischemic stroke in children with tuberculous meningitis

PURPOSE

Cerebrovascular complications are commonly observed in children with tuberculous meningitis. We aimed to determine which clinical factors were associated with stroke at admission in children with tuberculous meningitis and, in children stroke-free at admission, which factors were associated with development of stroke on treatment.

METHODS

We analysed a cohort of 474 children diagnosed with 'definite' and 'probable' tuberculous meningitis, with prospectively collected data, at Tygerberg Hospital, Cape Town, South Africa from 1985 to 2005. We considered either hemiparesis or radiological arterial ischemic infarction as evidence of stroke.

RESULTS

At admission, 339 (71.5%) children presented with stroke. Features associated with stroke at admission included age <3 years (odds ratio (OR) 3.70; 95% confidence interval (CI): 2.44-5.63; p < 0.01), convulsions (OR: 2.25; 95% CI: 1.46-3.45; p < 0.01) and hydrocephalus (OR: 1.63; 95% CI: 1.05-2.53; p = 0.03). In the group of children without stroke at admission (n = 135), 33 (24.4%) developed stroke by 1 month. Similar factors predicted stroke and included age <3 years (OR: 2.60; 95% CI: 1.17-5.80; p = 0.02), convulsions (OR: 2.25; 95% CI: 1.46-3.45; p < 0.01), CSF cell count <10 or >500/L (OR: 3.12; 95% CI: 1.03-9.43; p = 0.04) and hydrocephalus (OR: 2.99; 95% CI: 1.30-6.89; p = 0.01).

CONCLUSION

A large proportion of children with tuberculous meningitis present with stroke at admission. Of those with no evidence of stroke at admission, a quarter develop stroke by 1 month, suggesting that there could be a brief window in which to give preventive therapy.

Host Directed Therapies for Tuberculous Meningitis

A dysregulated host immune response significantly contributes to morbidity and mortality in tuberculous meningitis (TBM). Effective host directed therapies (HDTs) are critical to improve survival and clinical outcomes. Currently only one HDT, dexamethasone, is proven to improve mortality. However, there is no evidence dexamethasone reduces morbidity, how it reduces mortality is uncertain, and it has no proven benefit in HIV co-infected individuals. Further research on these aspects of its use, as well as alternative HDTs such as aspirin, thalidomide and other immunomodulatory drugs is needed. Based on new knowledge from pathogenesis studies, repurposed therapeutics which act upon small molecule drug targets may also have a role in TBM. Here we review existing literature investigating HDTs in TBM, and propose new rationale for the use of novel and repurposed drugs. We also discuss host variable responses and evidence to support a personalised approach to HDTs in TBM.

Host Directed Therapies for Tuberculous Meningitis

A dysregulated host immune response significantly contributes to morbidity and mortality in tuberculous meningitis (TBM). Effective host directed therapies (HDTs) are critical to improve survival and clinical outcomes. Currently only one HDT, dexamethasone, is proven to improve mortality. However, there is no evidence dexamethasone reduces morbidity, how it reduces mortality is uncertain, and it has no proven benefit in HIV co-infected individuals. Further research on these aspects of its use, as well as alternative HDTs such as aspirin, thalidomide and other immunomodulatory drugs is needed. Based on new knowledge from pathogenesis studies, repurposed therapeutics which act upon small molecule drug targets may also have a role in TBM. Here we review existing literature investigating HDTs in TBM, and propose new rationale for the use of novel and repurposed drugs. We also discuss host variable responses and evidence to support a personalised approach to HDTs in TBM.

Thalidomide Use for Complicated Central Nervous System Tuberculosis in Children: Insights From an Observational Cohort

BACKGROUND

Much of the neurological sequelae of central nervous system (CNS) tuberculosis (TB) is due to an excessive cytokine-driven host-inflammatory response. Adjunctive corticosteroids, which reduce cytokine production and thus dampen the inflammation, improve overall survival but do not prevent morbidity. This has prompted investigation of more targeted immunomodulatory agents, including thalidomide.

METHODS

We describe a retrospective cohort of 38 children consecutively treated with adjunctive thalidomide for CNS TB-related complications over a 10-year period.

RESULTS

The most common presenting symptom was focal motor deficit (n = 16), followed by cranial nerve palsies and cerebellar dysfunction. Three of the 38 children presented with large dural-based lesions, manifesting as epilepsia partialis continua (EPC), 4 presented with blindness secondary to optochiasmatic arachnoiditis, and 2 children developed paraplegia due to spinal cord TB mass lesions. Duration of adjunctive thalidomide therapy (3-5 mg/kg/day) varied according to complication type. In children compromised by TB mass lesions, the median treatment duration was 3.9 months (interquartile range [IQR], 2.0-5.0 months), whereas in children with optic neuritis it was 2.0 months (IQR, 1.3-7.3 months) and in EPC it was 1.0 months (IQR, 1-2.5 months). Satisfactory clinical and radiological response was observed in 37 of the children. None of the children experienced rashes, hepatitis, or hematologic derangements or complained of leg cramps.

CONCLUSIONS

This study is the largest cohort of adult or pediatric patients treated with adjunctive thalidomide for CNS TB-related complications. The drug has proved to be safe and well tolerated and appears to be clinically efficacious. The potential role of thalidomide or analogues in the treatment of other tuberculous meningitis-related complications requires further exploration.

Recurrent tuberculous cerebellar abscess: A case study and review of the literature

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Recurrent tubercular brain abscess is a rare pathology in immunocompetent children.

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Recurrence is possible despite a well-managed treatment such as surgery and anti-tuberculosis therapy.

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Early management and careful monitoring are important.

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The addition of corticosteroid therapy and readjustment of the dose of anti-tuberculosis drugs are necessary to achieve a cure.

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Our treatment was based on several punctures of the abscess associated with a shunt, a readjustment of doses of antituberculosis drugs and additional corticosteroid therapy which led to a clinical improvement.

Introduction and importance

Tuberculous cerebellar abscess is a rare form of extra-pulmonary tuberculosis. The outcome is often favorable with well-managed treatment; however, they can continue to develop. We share in this article our experience on the management of this rare pathologie.

Case presentation

A 10-year-old boy with a medical history of tuberculous meningitis after 3 months of tuberculosis treatment. He presented to the hospital with acute obstructive hydrocephalus due to a large tuberculous cerebellar abscess. A puncture of the abscess was initially performed, followed by placement of a ventriculoperiotoneal shunt, which resulted in some clinical improvement. However, the child subsequently presented with neurological deterioration due to the massive enlargement of the tuberculous abscess despite adequate antituberculosis chemotherapy. The initiation of corticosteroid therapy associated with a readjustment of the dose of anti-tuberculosis drugs and a repeated puncture ultimately led to clinical improvement.

Clinical discussion

Tuberculous brain abscess is an extra-pulmonary location of tuberculosis rarely seen in immunocompetent children. The treatment consists of surgery associated with antituberculosis chemotherapy and rigorous clinico-radiological monitoring. Recurrence is possible despite well-conducted treatment. Additional corticosteroid therapy is necessary with readjustment of the anti-tuberculosis treatment for an effective cure.

Conclusion

Rarely, the tuberculous abscess of the cerebellum continues to evolve despite proper treatment. This pattern does not necessarily mean treatment failure. Close clinical and imaging monitoring is crucial in the management of these cases.

Tuberculosis IRIS: Pathogenesis, Presentation, and Management across the Spectrum of Disease

Antiretroviral therapy (ART), while essential in combatting tuberculosis (TB) and HIV coinfection, is often complicated by the TB-associated immune reconstitution inflammatory syndrome (TB-IRIS). Depending on the TB disease site and treatment status at ART initiation, this immune-mediated worsening of TB pathology can take the form of paradoxical TB-IRIS, unmasking TB-IRIS, or CNS TB-IRIS. Each form of TB-IRIS has unique implications for diagnosis and treatment. Recently published studies have emphasized the importance of neutrophils and T cell subtypes in TB-IRIS pathogenesis, alongside the recognized role of CD4 T cells and macrophages. Research has also refined our prognostic understanding, revealing how the disease can impact lung function. While corticosteroids remain the only trial-supported therapy for prevention and management of TB-IRIS, increasing interest has been given to biologic therapies directly targeting the immune pathology. TB-IRIS, especially its unmasking form, remains incompletely described and more data is needed to validate biomarkers for diagnosis. Management strategies remain suboptimal, especially in the highly morbid central nervous system (CNS) form of the disease, and further trials are necessary to refine treatment. In this review we will summarize the current understanding of the immunopathogenesis, the presentation of TB-IRIS and the evidence for management recommendations.

Tumor necrosis factor antagonists for paradoxical inflammatory reactions in the central nervous system tuberculosis: Case report and review

RATIONALE

Paradoxical reaction/immune reconstitution inflammatory syndrome is common in patients with central nervous system tuberculosis. Management relies on high-dose corticosteroids and surgery when feasible.

PATIENT CONCERN

We describe 2 cases of HIV-negative patients with corticosteroid-refractory paradoxical reactions of central nervous system tuberculosis.

DIAGNOSES

The 2 patients experienced clinical impairment shortly after starting therapy for TB, and magnetic resonance imaging showed the presence of tuberculomas, leading to the diagnosis of a paradoxical reaction.

INTERVENTIONS

We added infliximab, an anti-tumor necrosis factor (TNF)-alpha monoclonal antibody, to the dexamethasone.

OUTCOMES

Both patients had favorable outcomes, 1 achieving full recovery but 1 suffering neurologic sequelae.

LESSONS

Clinicians should be aware of the risk of paradoxical reactions/immune reconstitution inflammatory syndrome when treating patients with tuberculosis of the central nervous system and should consider the prompt anti-TNF-α agents in cases not responding to corticosteroids.

Thalidomide in the treatment of human immunodeficiency virus-negative tuberculous meningitis: A case report

INTRODUCTION

Tuberculous meningitis (TBM) is the most fatal type of tuberculosis in which corticosteroids are added with antitubercular therapy to prevent permanent brain damage. However, this treatment may produce paradoxical reactions. In such cases, thalidomide use might reduce central nervous system inflammation and improve the outcome. We present the case of a human immunodeficiency virus-negative patient with TBM who developed paradoxical reactions manifesting as multiple intracranial tuberculomas that were resistant to standard care (antitubercular drugs and corticosteroids) but responded well to thalidomide.

PATIENT'S MAIN CONCERN AND CLINICAL FINDINGS

The patient was a 40-year-old Chinese female, who was admitted with a 10-day history of headaches, night sweats, and cough. She was healthy before contracting the infection and had no history of contact with tuberculosis patients.

DIAGNOSES, INTERVENTION, AND OUTCOME

We diagnosed the patient with TBM complicated by the occurrence of pulmonary tuberculosis. Positive results were obtained from Gram and Ziehl-Neelsen staining of the sputum and acid-fast bacilli sputum culture. Standard treatment was initiated with antitubercular drugs (daily isoniazid, rifampicin, ethionamide, and pyrazinamide) and corticosteroids (dexamethasone). However, 3 months later the magnetic resonance imaging of the head revealed some new tuberculoma lesion. Thus, a specific therapy of antitubercular drugs and thalidomide was introduced. On completion of a 12-month course of antitubercular drugs with 2 months of thalidomide, the patient showed favorable outcomes without neurologic sequelae. Moreover, thalidomide appeared safe and well tolerated in the patient.

CONCLUSION

In addition to the specific anti-tubercular and adjuvant corticosteroid therapies for TBM, thalidomide can be used as a "salvage" antitubercular drug in cases that are unresponsive to corticosteroids.

Challenges in the diagnosis of tuberculous meningitis

Tuberculosis (TB) continues to pose a significant public health problem. Tuberculous meningitis (TBM) is the most severe form of extra-pulmonary TB. TBM carries a high mortality rate, including for those receiving treatment for TB. Diagnosis of TBM is difficult for clinicians as it can clinically present similarly to other forms of meningitis. The difficulty in diagnosis often leads to a delay in treatment and subsequent mortality. Those who survive are left with long-term sequelae leading to lifelong disability. The microbiologic diagnosis of TBM requires the isolation of Mycobacterium tuberculosis from the cerebrospinal fluid (CSF) of an infected patient. The diagnosis of tuberculous meningitis continues to be challenging for clinicians. Unfortunately, many cases of TBM cannot be confirmed based on clinical and imaging findings as the clinical findings are nonspecific, while laboratory techniques are largely insensitive or slow. Until recently, the lack of accessible and timely tests has contributed to a delay in diagnosis and subsequent morbidity and mortality for many patients, particularly those in resourcelimited settings. The availability of Xpert Ultra and point-of-care lipoarabinomannan (LAM) testing could represent a new era of prompt diagnosis and early treatment of tuberculous meningitis. However, clinicians must be cautious when ruling out TBM with Xpert Ultra due to its low negative predictive value. Due to the limitations of current diagnostics, clinicians should utilize a combination of diagnostic modalities in order to prevent morbidity in patients with TBM.

[Parardoxical reaction following tuberculosis treatment in non HIV-infected patients]

A paradoxical reaction is the worsening of prior existing, or the appearance of, new tuberculous lesions, following the initiation of treatment with anti-tuberculous drugs, after the exclusion of poor compliance, malabsorption, drug interaction or multiresistant mycobacteria. Well known and well managed in the context of HIV coinfection, it is not well known outside this context. An increasing number of publications have described this syndrome. This review aims to describe the pathogenic, epidemiological, clinical, prognostic and therapeutic elements of non-HIV-associated paradoxical reactions. It involves a reversal of the Mycobacterium tuberculosis-induced immunodepression along with a heightened detrimental pro-inflammatory profile caused by efficient drug treatment. Extra-thoracic locations, especially lymph nodes and neurological, malnutrition and initial lymphopenia are the principal risk factors. The median delay is 40±20 days after the onset of treatment. Corticosteroids are the mainstay of the management. Anti-TNF-α drugs show good results in corticosteroid refractory cases. The prognosis is good overall except in neurological forms. The place of preventive methods remains to be established.

Management of intracranial tuberculous mass lesions: how long should we treat for?

Tuberculous intracranial mass lesions are common in settings with high tuberculosis (TB) incidence and HIV prevalence. The diagnosis of such lesions, which include tuberculoma and tuberculous abscesses, is often presumptive and based on radiological features, supportive evidence of TB elsewhere and response to TB treatment. However, the treatment response is unpredictable, with lesions frequently enlarging paradoxically or persisting for many years despite appropriate TB treatment and corticosteroid therapy. Most international guidelines recommend a 9-12 month course of TB treatment for central nervous system TB when the infecting Mycobacterium tuberculosis ( M.tb) strain is sensitive to first-line drugs. However, there is variation in opinion and practice with respect to the duration of TB treatment in patients with tuberculomas or tuberculous abscesses. A major reason for this is the lack of prospective clinical trial evidence. Some experts suggest continuing treatment until radiological resolution of enhancing lesions has been achieved, but this may unnecessarily expose patients to prolonged periods of potentially toxic drugs. It is currently unknown whether persistent radiological enhancement of intracranial tuberculomas after 9-12 months of treatment represents active disease, inflammatory response in a sterilized lesion or merely revascularization. The consequences of stopping TB treatment prior to resolution of lesional enhancement have rarely been explored. These important issues were discussed at the 3 rd International Tuberculous Meningitis Consortium meeting. Most clinicians were of the opinion that continued enhancement does not necessarily represent treatment failure and that prolonged TB therapy was not warranted in patients presumably infected with M.tb strains susceptible to first-line drugs. In this manuscript we highlight current medical treatment practices, benefits and disadvantages of different TB treatment durations and the need for evidence-based guidelines regarding the treatment duration of patients with intracranial tuberculous mass lesions.

Management of intracranial tuberculous mass lesions: how long should we treat for?

Tuberculous intracranial mass lesions are common in settings with high tuberculosis (TB) incidence and HIV prevalence. The diagnosis of such lesions, which include tuberculoma and tuberculous abscesses, is often presumptive and based on radiological features, supportive evidence of TB elsewhere and response to TB treatment. However, the treatment response is unpredictable, with lesions frequently enlarging paradoxically or persisting for many years despite appropriate TB treatment and corticosteroid therapy. Most international guidelines recommend a 9-12 month course of TB treatment for central nervous system TB when the infecting Mycobacterium tuberculosis ( M.tb) strain is sensitive to first-line drugs. However, there is variation in opinion and practice with respect to the duration of TB treatment in patients with tuberculomas or tuberculous abscesses. A major reason for this is the lack of prospective clinical trial evidence. Some experts suggest continuing treatment until radiological resolution of enhancing lesions has been achieved, but this may unnecessarily expose patients to prolonged periods of potentially toxic drugs. It is currently unknown whether persistent radiological enhancement of intracranial tuberculomas after 9-12 months of treatment represents active disease, inflammatory response in a sterilized lesion or merely revascularization. The consequences of stopping TB treatment prior to resolution of lesional enhancement have rarely been explored. These important issues were discussed at the 3 rd International Tuberculous Meningitis Consortium meeting. Most clinicians were of the opinion that continued enhancement does not necessarily represent treatment failure and that prolonged TB therapy was not warranted in patients presumably infected with M.tb strains susceptible to first-line drugs. In this manuscript we highlight current medical treatment practices, benefits and disadvantages of different TB treatment durations and the need for evidence-based guidelines regarding the treatment duration of patients with intracranial tuberculous mass lesions.

Neurotuberculosis: Control of Steroid-Refractory Paradoxical Inflammatory Reaction With Ruxolitinib

Paradoxical inflammatory reactions associated with treatment of neurotuberculosis can lead to severe morbidity and mortality and may not be controlled by steroids alone. We report the use of the Janus kinase inhibitor ruxolitinib to treat a steroid-refractory neurotuberculosis paradoxical reaction.

Management of intracranial tuberculous mass lesions: how long should we treat for?

Tuberculous intracranial mass lesions are common in settings with high tuberculosis (TB) incidence and HIV prevalence. The diagnosis of such lesions, which include tuberculoma and tuberculous abscesses, is often presumptive and based on radiological features, supportive evidence of TB elsewhere and response to TB treatment. However, the treatment response is unpredictable, with lesions frequently enlarging paradoxically or persisting for many years despite appropriate TB treatment and corticosteroid therapy. Most international guidelines recommend a 9-12 month course of TB treatment for central nervous system TB when the infecting Mycobacterium tuberculosis (M.tb) strain is sensitive to first-line drugs. However, there is variation in opinion and practice with respect to the duration of TB treatment in patients with tuberculomas or tuberculous abscesses. A major reason for this is the lack of prospective clinical trial evidence. Some experts suggest continuing treatment until radiological resolution of enhancing lesions has been achieved, but this may unnecessarily expose patients to prolonged periods of potentially toxic drugs. It is currently unknown whether persistent radiological enhancement of intracranial tuberculomas after 9-12 months of treatment represents active disease, inflammatory response in a sterilized lesion or merely revascularization. The consequences of stopping TB treatment prior to resolution of lesional enhancement have rarely been explored. These important issues were discussed at the 3rd International Tuberculous Meningitis Consortium meeting. Most clinicians were of the opinion that continued enhancement does not necessarily represent treatment failure and that prolonged TB therapy was not warranted in patients presumably infected with M.tb strains susceptible to first-line drugs. In this manuscript we highlight current medical treatment practices, benefits and disadvantages of different TB treatment durations and the need for evidence-based guidelines regarding the treatment duration of patients with intracranial tuberculous mass lesions.

Clinical Management of Drug-resistant Mycobacterium tuberculosis Strains: Pathogen-targeted Versus Host-directed Treatment Approaches

Background:

Despite exerted efforts to control and treat Mycobacterium tuberculosis (MTB) strains, Tuberculosis (TB) remains a public health menace. The emergence of complex drug-resistant profiles, such as multi-drug resistant and extensively drug-resistant MTB strains, emphasizes the need for early diagnosis of resistant cases, shorter treatment options, and effective medical interventions.

Objective:

Solutions for better clinical management of drug-resistant cases are either pathogencentered (novel chemotherapy agents) or host-directed approaches (modulating host immune response to prevent MTB invasion and pathogenesis).

Results:

Despite the overall potentiality of several chemotherapy agents, it is feared that their effectiveness could be challenged by sequential pathogen adaptation tactics. On the contrary, host-directed therapy options might offer a long-term conceivable solution.

Conclusion:

This review discusses the main suggestions proposed so far to resolve the clinical challenges associated with drug resistance, in the context of TB. These suggestions include novel drug delivery approaches that could optimize treatment outcome and increase patients’ compliance to the treatment.

The pathogenesis of tuberculous meningitis

Tuberculosis (TB) remains a leading cause of death globally. Dissemination of TB to the brain results in the most severe form of extrapulmonary TB, tuberculous meningitis (TBM), which represents a medical emergency associated with high rates of mortality and disability. Via various mechanisms the Mycobacterium tuberculosis (M.tb) bacillus disseminates from the primary site of infection and overcomes protective barriers to enter the CNS. There it induces an inflammatory response involving both the peripheral and resident immune cells, which initiates a cascade of pathologic mechanisms that may either contain the disease or result in significant brain injury. Here we review the steps from primary infection to cerebral disease, factors that contribute to the virulence of the organism and the vulnerability of the host and discuss the immune response and the clinical manifestations arising. Priorities for future research directions are suggested.

Clinical perspectives into the use of thalidomide for central nervous system tuberculosis

BACKGROUND AND PURPOSE

Central nervous system (CNS) tuberculosis (TB) accounts for over 4% of all TB notifications in the UK and causes death or significant disability in over half of those affected. Tumour necrosis factor alpha is a critical cytokine involved in the neuropathogenesis of CNS TB. Thalidomide has been trialled in CNS TB due to its immunomodulatory and immune reconstitution effects through the inhibition of tumour necrosis factor alpha. Despite animal models demonstrating dramatic improvement in survival, studies in paediatric patients have been associated with higher levels of mortality. The effects of thalidomide have not yet been studied in adults with CNS TB. This narrative case series guides clinicians through a range of CNS TB clinical cases seen in a large London teaching hospital, serving a region with a high incidence of TB (32 per 100 000) with 55% of TB cases manifesting as extrapulmonary disease. We aimed to illustrate our experiences of using thalidomide to treat a range of severe CNS TB complications.

METHODS

Five inpatients at The Royal London Hospital, London, UK treated with thalidomide in addition to standard TB treatment are described in detail. The rationale for treatment initiation with thalidomide is explained.

RESULTS

The case examples are used to guide our reflections and lessons learnt regarding the use of thalidomide. Responses to treatment and functional outcomes suggest that thalidomide may be a useful adjunct to standard TB therapy in selected adult cases.

CONCLUSIONS

The experience gained from using thalidomide in this small case series may provide evidence leading to more research into using thalidomide to treat severe CNS TB.

Late-onset paradoxical reactions 10 years after treatment for tuberculous meningitis in an HIV-negative patient: a case report

Background

Although paradoxical reactions (PRs) to anti-tuberculosis (anti-TB) therapy during treatment are well-established occurrences, PRs presenting as a new lesion after the completion of treatment are extremely rare, and little is known about the management of such cases, particularly of central nervous system (CNS) tuberculosis.

Case presentation

A 27-year-old female, with a past medical history of tuberculous meningitis 10 years ago and who completed the anti-TB treatment with asymptomatic remnant tuberculomas in the basal cistern, was admitted to our hospital because of a headache and the worsening of pre-existing visual disturbance. Contrast-enhanced T1-weighted brain magnetic resonance imaging (MRI) revealed new tuberculomas in the left sylvian fissure with a diffuse low signal around it. Because repeated polymerase chain reaction and Mycobacterium tuberculosis culture presented negative results and the patient had no laboratory data suggestive of a relapse of tuberculous meningitis, she was diagnosed with late-onset post-treatment PRs and treated with oral corticosteroids, tapered off over 1 year. Eventually, the symptoms were relieved, and the tuberculomas disappeared.

Conclusions

Clinicians should consider the possibility of PRs long after the completion of tuberculous meningitis treatment. Hence, a precise MRI-based examination is imperative for the follow-up of CNS tuberculosis, and the unnecessary administration of anti-TB drugs should be avoided. The use of corticosteroids as a treatment option for post-treatment PRs is seemingly safe when the isolated M. tuberculosis is sensitive to the first-line anti-TB therapy.

Intracranial tuberculous mass lesions treated with thalidomide in an immunocompetent child from a low tuberculosis endemic country: A case report

RATIONALE

Tuberculous meningitis is a highly morbid, often fatal disease.

PATIENT CONCERN

We describe a case of an Italian child. DIAGNOSES:: we diagnosed early a Tuberculous meningitis complicated by the occurrence of hydrocephalus, stroke, and paradoxical reaction with brain pseudo-abscesses.

INTERVENTIONS

The child started readily a specific therapy associated with steroids and thalidomide was introduced few month later.

OUTCOMES

the patient had a favorable outcome without neurologic sequelae.

LESSONS

Despite the prompt specific anti-tubercular and adjuvant corticosteroid therapies, only the addition of thalidomide to the treatment allow to a favorable clinical outcome.

Treatment of Tuberculous Meningitis and Its Complications in Adults

PURPOSE OF REVIEW

Tuberculous meningitis (TBM) is a global health problem. In this review, we systematically evaluate the evidence for current and emerging antimicrobials, host-directed therapies and supportive managements.

RECENT FINDINGS

Current antimicrobial regimes do not factor the differing ability of drugs to cross the blood-brain barrier. Rifampicin may be more effective at higher doses yet the most recent clinical trial failed to demonstrate survival benefit at 15 mg/kg/day. Dose finding studies suggest that higher doses still may be safe and more effective. Fluoroquinolones are currently listed as important second-line agents in drug-resistant TBM; however, a survival benefit as a first-line agent has yet to be shown. Linezolid may be a promising antimicrobial with good central nervous system penetrance. Dexamethasone reduces mortality in HIV-uninfected individuals yet evidence for its use in HIV co-infection is lacking. Aspirin has anti-inflammatory and anti-thrombotic properties. Small studies have demonstrated efficacy in reducing stroke but further research is required to better understand its effect on controlling the host inflammatory response. Discovery of genetic polymorphisms may direct individualized immune therapies and mediators of the innate immune response may provide targets for the development of novel therapies. There is at present no significant evidence base to guide management of hydrocephalus in HIV co-infection. Further clinical trial data is required to improve treatment outcomes in TBM in particularly in regard to the value of high-dose rifampicin, newer antimicrobials with improved central nervous system penetration and host-directed therapies. Supportive measures in particular the management of hydrocephalus in HIV co-infection should be an area for future research.

Efficacy of thalidomide therapy in pediatric Crohn’s disease with evidence of tuberculosis

AIM

To evaluate the efficacy of thalidomide for treating troublesome cases of pediatric Crohn’s disease (CD) with tuberculosis infection.

METHODS

A retrospective study of clinical outcome among children treated with thalidomide was conducted. All patients had evidence of tuberculosis infection with a failure of anti-tuberculosis treatment for more than one year, and were subsequently diagnosed with CD. All the patients received thalidomide treatment with a starting dose of 1.2-2.5 mg/kg per day. Remission was defined as pediatric CD activity index less than or equal to 10.

RESULTS

Ten patients with CD were treated with thalidomide at an average age of 7.2 years and followed up for a median of 22.2 mo. Clinical remission rate was 60% after 9-12 mo of thalidomide treatment. One patient with no response had an interleukin-10 receptor alpha gene mutation. Erythrocyte sedimentation rate, C-reactive protein and platelet count showed a dramatic decrease; hemoglobin level and weight improved significantly after thalidomide treatment when compared with the baseline values.

CONCLUSION

Thalidomide is an effective and safe drug for remission of CD in pediatric patients who have been treated for tuberculosis.

Tuberculous meningitis

Tuberculosis remains a global health problem, with an estimated 10.4 million cases and 1.8 million deaths resulting from the disease in 2015. The most lethal and disabling form of tuberculosis is tuberculous meningitis (TBM), for which more than 100,000 new cases are estimated to occur per year. In patients who are co-infected with HIV-1, TBM has a mortality approaching 50%. Study of TBM pathogenesis is hampered by a lack of experimental models that recapitulate all the features of the human disease. Diagnosis of TBM is often delayed by the insensitive and lengthy culture technique required for disease confirmation. Antibiotic regimens for TBM are based on those used to treat pulmonary tuberculosis, which probably results in suboptimal drug levels in the cerebrospinal fluid, owing to poor blood-brain barrier penetrance. The role of adjunctive anti-inflammatory, host-directed therapies - including corticosteroids, aspirin and thalidomide - has not been extensively explored. To address this deficit, two expert meetings were held in 2009 and 2015 to share findings and define research priorities. This Review summarizes historical and current research into TBM and identifies important gaps in our knowledge. We will discuss advances in the understanding of inflammation in TBM and its potential modulation; vascular and hypoxia-mediated tissue injury; the role of intensified antibiotic treatment; and the importance of rapid and accurate diagnostics and supportive care in TBM.

Tuberculous tales: an East London experience

Tuberculous meningitis presents a diagnostic and therapeutic challenge, and considering its long history and increasing global incidence, the evidence base for its treatment is relatively scanty. Many UK neurologists will have little first-hand experience of this deadly condition, and if faced with a patient with possible tuberculous meningitis will find decision making less than straightforward. In parts of East London (UK) the rates of tuberculosis and tuberculous meningitis are among the highest in Western Europe, and so the neurologists and respiratory physicians at the Royal London Hospital have encountered many such patients over the years. We have found experience to be a valuable teacher and so would like to share five cases that illustrate the complexities of diagnosis and management of the disease, and complications of its treatment.

Brainstem tuberculous abscesses successfully treated by microsurgical excision: A case report and review of the literature

In patients without systemic manifestations of tuberculosis, isolated brainstem tuberculous abscesses are infrequently observed. The present study reports a rare case of two cystic tuberculous abscesses involving the dorsal aspect of the medulla oblongata in an otherwise healthy 14-year-old Chinese girl, whose primary complaint was respiratory distress. These lesions were successfully treated using a microsurgical excision approach and anti-tuberculosis therapy. Although rare, tuberculous abscesses should be considered in the differential diagnosis of isolated cystic brainstem lesions. The results of the present study indicate that microsurgery, when combined with anti-tuberculosis therapy, is an effective and safe method to treat brainstem tuberculous abscesses.

Inflammatory bowel disease in Chinese children: A retrospective analysis of 49 cases

To present study reports the clinical characteristics, diagnosis and management of pediatric patients with inflammatory bowel disease (IBD) in China. Clinical records of 49 pediatric patients with IBD at Fudan University Children's Hospital (Shanghai, China) between July 2001 and May 2012 were reviewed. Of 49 patients (30 males and 19 females), 8 patients had ulcerative colitis (UC) and 41 patients had Crohn's disease (CD). The mean age was 10.4 years in patients with UC and 10.1 years in patients with CD. The percentages of patients with UC with abdominal pain, diarrhea or rectal bleeding were 62.5, 100 and 87.5%, respectively, and that of CD patients were 75.6, 61 and 39%, respectively. Patients with UC were underweight (37.5%), and had oral ulcers (12.5%) and arthritis (12.5%), and patients with CD were underweight (34.1%), and had oral ulcers (26.8%), anal fistulas (22%) and arthritis (19.5%). Patients with CD had a higher proportion of immunoglobulin G, C-reactive protein and erythrocyte sedimentation rate compared with patients with UC. Histologic lesions of patients with UC were primarily located in the sigmoid colon (75%), transverse colon (50%) or pan-colon (50%), and in patients with CD they were located in the distal ileum (51.2%), ileocecum (58.5%) or upper gastrointestinal tract (41.5%). All patients underwent colonoscopies and 13 underwent double-balloon enteroscopies. Standard treatment for IBD, including corticosteroids, 5-aminosalicylate, and immunosuppressants (6-mercaptopurine and azathioprine), were administered to all patients. In addition 3 patients were treated with infliximab and 10 patients were treated with thalidomide. Comprehensive assessment of clinical, laboratory, endoscopic, and pathohistological data will benefit the timely diagnosis of IBD.

Drug-resistant tuberculosis and advances in the treatment of childhood tuberculosis

Over the last 10 years, interest in pediatric tuberculosis (TB) has increased dramatically, together with increased funding and research. We have a better understanding of the burden of childhood TB as well as a better idea of how to diagnose it. Our appreciation of pathophysiology is improved and with it investigators are beginning to consider pediatric TB as a heterogeneous entity, with different types and severity of disease being treated in different ways. There have been advances in how to treat both TB infection and TB disease caused by both drug-susceptible as well as drug-resistant organisms. Two completely novel drugs, bedaquiline and delamanid, have been developed, in addition to the use of older drugs that have been re-purposed. New regimens are being evaluated that have the potential to shorten treatment. Many of these drugs and regimens have first been investigated in adults with children an afterthought, but increasingly children are being considered at the outset and, in some instances studies are only conducted in children where pediatric-specific issues exist.

Recent Developments and Future Opportunities in the Treatment of Tuberculosis in Children

Tuberculosis in children accounts for a significant proportion of the overall burden of disease, and yet for many years research into pediatric treatment has been neglected. Recently, there have been major developments in our understanding of pediatric tuberculosis, and a large number of studies are under way or planned. New drugs and regimens are being evaluated, and older drugs are being repurposed. Shorter regimens with potentially fewer side effects are being assessed for the treatment and prevention of both drug-susceptible and drug-resistant tuberculosis. It may be possible to tailor treatment so that children with less severe disease are given shorter regimens, and weekly dosing is under investigation for preventive therapy and for the continuation phase of treatment. The interaction with human immunodeficiency virus and the management of tuberculosis meningitis are also likely to be better understood. Exciting times lie ahead for pediatric tuberculosis, but much work remains to be done.

Sharpening nature's tools for efficient tuberculosis control: A review of the potential role and development of host-directed therapies and strategies for targeted respiratory delivery

Centuries since it was first described, tuberculosis (TB) remains a significant global public health issue. Despite ongoing holistic measures implemented by health authorities and a number of new oral treatments reaching the market, there is still a need for an advanced, efficient TB treatment. An adjunctive, host-directed therapy designed to enhance endogenous pathways and hence compliment current regimens could be the answer. The integration of drug repurposing, including synthetic and naturally occurring compounds, with a targeted drug delivery platform is an attractive development option. In order for a new anti-tubercular treatment to be produced in a timely manner, a multidisciplinary approach should be taken from the outset including stakeholders from academia, the pharmaceutical industry, and regulatory bodies keeping the patient as the key focus. Pre-clinical considerations for the development of a targeted host-directed therapy are discussed here.

Repurposing drugs for treatment of tuberculosis: a role for non-steroidal anti-inflammatory drugs

INTRODUCTION

The number of cases of drug-resistant Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), has risen rapidly in recent years. This has led to the resurgence in repurposing existing drugs, such as non-steroidal anti-inflammatory drugs (NSAIDs), for anti-TB treatment.

SOURCES OF DATA

Evidence from novel drug screening in vitro, in vivo, pharmacokinetic/pharmacodynamics analyses and clinical trials has been used for the preparation of this systematic review of the potential of NSAIDs for use as an adjunct in new TB chemotherapies.

AREAS OF AGREEMENT

Certain NSAIDs have demonstrated inhibitory properties towards actively replicating, dormant and drug-resistant clinical isolates of M. tuberculosis cells.

AREAS OF CONTROVERSY

NSAIDs are a diverse class of drugs, which have reported off-target activities, and their endogenous antimicrobial mechanism(s) of action is still unclear.

GROWING POINTS

It is essential that clinical trials of NSAIDs continue, in order to assess their suitability for addition to the current TB treatment regimen. Repurposing molecules such as NSAIDs is a vital, low-risk strategy to combat the trend of rapidly increasing antibiotic resistance.

Repurposing-a ray of hope in tackling extensively drug resistance in tuberculosis

Tuberculosis (TB) remains a serious concern more than two decades on from when the World Health Organization declared it a global health emergency. The alarming rise of antibiotic resistance in Mycobacterium tuberculosis, the etiological agent of TB, has made it exceedingly difficult to control the disease with the existing portfolio of anti-TB chemotherapy. The development of effective drugs with novel mechanism(s) of action is thus of paramount importance to tackle drug resistance. The development of novel chemical entities requires more than 10 years of research, requiring high-risk investment to become commercially available. Repurposing pre-existing drugs offers a solution to circumvent this mammoth investment in time and funds. In this context, several drugs with known safety and toxicity profiles have been evaluated against the TB pathogen and found to be efficacious against its different physiological states. As the endogenous targets of these drugs in the TB bacillus are most likely to be novel, there is minimal chance of cross-resistance with front-line anti-TB drugs. Also, reports that some of these drugs may potentially have multiple targets means that the possibility of the development of resistance against them is minimal. Thus repurposing existing molecules offers immense promise to tackle extensively drug-resistant TB infections.

Therapeutics targeting inflammation in the immune reconstitution inflammatory syndrome

Immune reconstitution inflammatory syndrome (IRIS) is characterized by improvement in a previously incompetent human immune system manifesting as worsening of clinical symptoms secondary to the ability of the immune system to now mount a vigorous inflammatory response. IRIS was first recognized in the setting of human immunodeficiency virus, and this clinical setting continues to be where it is most frequently encountered. Hallmarks of the pathogenesis of IRIS, independent of the clinical presentation and the underlying pathogen, include excessive activation of the immune system, with increased circulating effector memory T cells, and elevated levels of serum cytokines and inflammatory markers. Patients with undiagnosed opportunistic infections remain at risk for unmasking IRIS at the time of active antiretroviral therapy (ART) initiation. Systematic screening for opportunistic infections before starting ART is a key element to prevent this phenomenon. Appropriate management of IRIS requires prompt recognition of the syndrome and exclusion of alternative diagnoses, particularly underlying infections and drug resistance. Controlled studies supporting the use of pharmacologic interventions in IRIS are scare, and recommendations are based on case series and expert opinions. The only controlled trial published to date, showed reduction in morbidity in patients with paradoxical tuberculosis-related IRIS with the use of oral corticosteroids. There are currently limited data to recommend other anti-inflammatory or immunomodulatory therapies that are discussed in this review, and further research is needed. Ongoing research regarding the immune pathogenesis of IRIS will likely direct future rational therapeutic approaches and clinical trials.

HIV-1 tuberculosis-associated immune reconstitution inflammatory syndrome

Patients co-infected with HIV-1 and tuberculosis (TB) are at risk of developing TB-associated immune reconstitution inflammatory syndrome (TB-IRIS) following commencement of antiretroviral therapy (ART). TB-IRIS is characterized by transient but severe localized or systemic inflammatory reactions against Mycobacterium tuberculosis antigens. Here, we review the risk factors and clinical management of TB-IRIS, as well as the roles played by different aspects of the immune response in contributing to TB-IRIS pathogenesis.

Advancing host-directed therapy for tuberculosis

Improved treatments are needed for nearly all forms of Mycobacterium tuberculosis infection. Adjunctive host-directed therapies have the potential to shorten tuberculosis treatment duration, prevent resistance and reduce lung injury by promoting autophagy, antimicrobial peptide production and other macrophage effector mechanisms, as well as by modifying specific mechanisms that cause lung inflammation and matrix destruction. The range of candidates is broad, including several agents approved for other clinical indications that are ready for evaluation in Phase II clinical trials. The promise of new and existing host-directed therapies that could accelerate response and improve tuberculosis treatment outcomes is discussed in this Opinion article.

Clinicoradiologic response of neurologic tuberculous mass lesions in children treated with thalidomide

Neurologic tuberculous pseudoabscesses that clinically progress despite conventional antituberculosis therapy may be responsive to adjuvant thalidomide, a potent tumor necrosis factor-α inhibitor. In this study, the addition of thalidomide provided substantial clinical benefit in the majority of patients, and magnetic resonance imaging evolution of lesions from early-stage "T2 bright" with edema to "T2 black" represented a marker of cure.

Paradoxical evolution of a cerebellar tuberculosis abscess after surgical drainage and antibiotic therapy

Background:

Involvement of the central nervous system (CNS) by a tuberculosis abscess is a rare form of extra-pulmonary tuberculosis. With proper treatment, the abscess most commonly follows a pattern of continued reduction in size.

Case Description:

A 71-year-old male with a past medical history of kidney transplant on immunosuppressive therapy, presented to the hospital with a 1-day history of headache. On physical examination, the patient had no focal neurological symptoms. Initial laboratory reports were unremarkable. Contrast enhanced magnetic resonance imaging (MRI) was performed, which showed a ring enhancing mass and perilesional edema in the left cerebellar hemisphere. The patient underwent a left posterior fossa biopsy and drainage. The lesion was encapsulated with a purulent center. Cultures revealed pan-sensitive mycobacterium tuberculosis and the patient was started on rifampicin, isoniazid, pyrazinamide, ethambutol, and B6. The patient was monitored carefully and brain MRIs were obtained at 1, 4, 9, 11, and 14 months. It was noted that the tuberculosis abscess had grown in size from month 4 to month 9 of treatment. Since the patient's neurologic examination and symptoms were stable at that time, the drug regimen was not changed. The 14-month follow up MRI showed that the abscess had nearly resolved.

Conclusion:

Rarely, the pattern of CNS tuberculosis abscess evolution may include growth, even with proper treatment. This pattern does not necessarily signify treatment failure, as our abscess resolved without change in treatment. Given the possibility of asymptomatic abscess enlargement, close clinical and imaging follow up are crucial in management of these cases.

Modeling tuberculous meningitis in zebrafish using Mycobacterium marinum

Tuberculous meningitis (TBM) is one of the most severe extrapulmonary manifestations of tuberculosis, with a high morbidity and mortality. Characteristic pathological features of TBM are Rich foci, i.e. brain- and spinal-cord-specific granulomas formed after hematogenous spread of pulmonary tuberculosis. Little is known about the early pathogenesis of TBM and the role of Rich foci. We have adapted the zebrafish model of Mycobacterium marinum infection (zebrafish-M. marinum model) to study TBM. First, we analyzed whether TBM occurs in adult zebrafish and showed that intraperitoneal infection resulted in granuloma formation in the meninges in 20% of the cases, with occasional brain parenchyma involvement. In zebrafish embryos, bacterial infiltration and clustering of infected phagocytes was observed after infection at three different inoculation sites: parenchyma, hindbrain ventricle and caudal vein. Infection via the bloodstream resulted in the formation of early granulomas in brain tissue in 70% of the cases. In these zebrafish embryos, infiltrates were located in the proximity of blood vessels. Interestingly, no differences were observed when embryos were infected before or after early formation of the blood-brain barrier (BBB), indicating that bacteria are able to cross this barrier with relatively high efficiency. In agreement with this observation, infected zebrafish larvae also showed infiltration of the brain tissue. Upon infection of embryos with an M. marinum ESX-1 mutant, only small clusters and scattered isolated phagocytes with high bacterial loads were present in the brain tissue. In conclusion, our adapted zebrafish-M. marinum infection model for studying granuloma formation in the brain will allow for the detailed analysis of both bacterial and host factors involved in TBM. It will help solve longstanding questions on the role of Rich foci and potentially contribute to the development of better diagnostic tools and therapeutics.

Paradoxical reaction in HIV negative tuberculous meningitis

This review focusses on paradoxical reactions occurring during the treatment of tuberculous meningitis (TBM) in human immunodeficiency virus-negative cases. A paradoxical reaction is defined as the worsening of a pre-existing lesion or the appearance of new lesion in a patient whose clinical symptoms initially improved with anti-tuberculosis treatment. A number of different paradoxical reactions have been reported in patients with TBM including expansion of existing cerebral tuberculomas, and appearance of new tuberculomas, hydrocephalus, and optochiasmatic and spinal arachnoiditis. While the exact mechanism of paradoxical reactions is uncertain, an exaggerated immune reaction against Mycobacterium tuberculosis-associated antigens is currently the most accepted theory for tuberculous paradoxical reaction. Corticosteroids are considered to have a beneficial effect in the management of paradoxical reactions. Immuno-modulatory drugs, including tumor necrosis factor-α antagonists, thalidomide and interferon-γ have been used in isolated cases with more severe forms of paradoxical reactions.

Update on the diagnosis and management of tuberculous meningitis in children

Tuberculous meningitis (TBM), the most devastating manifestation of tuberculosis, is often missed or overlooked because of nonspecific symptoms and difficulties in diagnosis. It continues to be an important cause of neurologic handicap in resource-poor countries. Owing to the suboptimal performance of diagnostic tests of TBM, diagnosis relies on thorough history, clinical examination, and relevant investigations. The development of affordable, accurate diagnostic tests for TBM in resource-poor settings remains a priority. Short intensified treatment is safe and effective in both human immunodeficiency virus (HIV)-infected and HIV-uninfected children. Treatment of tuberculous hydrocephalus depends on the level of the cerebrospinal fluid obstruction. Corticosteroids reduce risk of neurodisability and death in HIV-uninfected children. Thalidomide should be considered in children compromised by tuberculosis abscesses and tuberculous-related optochiasmic arachnoiditis. In resource-poor countries, home-based TBM treatment after initial in-hospital stabilization is feasible in carefully selected patients. Early diagnosis and treatment of TBM is the single most important factor determining outcome.

Clinical review: tuberculosis on the intensive care unit

Rates of tuberculosis (TB) are increasing in most west European nations. Patients with TB can be admitted to an ICU for a variety of reasons, including respiratory failure, multiorgan failure and decreased consciousness associated with central nervous system disease. TB is a treatable disease but the mortality for patients admitted with TB to an ICU remains high. Management challenges exist in establishing a prompt diagnosis and administering effective treatment on the ICU with potentially poor gastric absorption and high rates of organ dysfunction and drug toxicity. In this review reasons for ICU admission, methods of achieving a confident diagnosis through direct and inferred methods, anti-tuberculosis treatment (including steroid and other adjuvant therapies) and specific management problems with particular relevance to the intensivist are discussed. The role of therapeutic drug monitoring, judicious use of alternative regimes in the context of toxicity or organ dysfunction and when to suspect paradoxical tuberculosis reactions are also covered. Diagnostic and therapeutic algorithms are proposed to guide ICU doctors in the management of this sometimes complicated disease.

Tuberculous meningitis: more questions, still too few answers

Tuberculous meningitis is especially common in young children and people with untreated HIV infection, and it kills or disables roughly half of everyone affected. Childhood disease can be prevented by vaccination and by giving prophylactic isoniazid to children exposed to infectious adults, although improvements in worldwide tuberculosis control would lead to more effective prevention. Diagnosis is difficult because clinical features are non-specific and laboratory tests are insensitive, and treatment delay is the strongest risk factor for death. Large doses of rifampicin and fluoroquinolones might improve outcome, and the beneficial effect of adjunctive corticosteroids on survival might be augmented by aspirin and could be predicted by screening for a polymorphism in LTA4H, which encodes an enzyme involved in eicosanoid synthesis. However, these advances are insufficient in the face of drug-resistant tuberculosis and HIV co-infection. Many questions remain about the best approaches to prevent, diagnose, and treat tuberculous meningitis, and there are still too few answers.

Poor prognostic significance of Mycobacterium tuberculosis infection during bortezomib-containing chemotherapy in patients with multiple myeloma

Background

Bortezomib administration leads to a transient decrease in CD4⁺ T cells, increasing the susceptibility to opportunistic infections. The activation and proliferation of CD4⁺ T cells are particularly important in the host's defense against tuberculosis infection. The aim of this study was to determine the incidence and clinical significance of tuberculosis infection in patients with multiple myeloma (MM) treated with a bortezomib-containing regimen.

Methods

We retrospectively investigated the incidence of Mycobacterium tuberculosis in 115 patients with MM who were given a bortezomib-containing regimen and studied the disease prognosis.

Results

All patients received chemotherapy prior to bortezomib administration, and the median duration from diagnosis to bortezomib administration was 12.4 months (range, 0.2-230). We diagnosed tuberculosis in 8 patients (8/115, 7%): 7 patients had a pulmonary granulomatous lesion prior to chemotherapy and 1 developed reactivation of tuberculosis, but none of them died of uncontrolled tuberculosis infection. In 50% of patients with tuberculosis, bortezomib-containing therapy was interrupted. This resulted in significantly lower response rates to the bortezomib-containing therapy (P<0.05) and significantly shorter overall survival times amongst tuberculosis vs. non-tuberculosis patients (P=0.017).

Conclusion

Tuberculosis infection was not uncommon among the patients with MM who were treated with bortezomib-containing therapy, and tuberculosis infection in these patients resulted in an interruption of bortezomib administration, which significantly affected patient outcomes. Therefore, early diagnosis and treatment of tuberculosis infection are critical to avoid worsening outcomes in such patients.

The dual face of central nervous system tuberculosis: a new Janus Bifrons?

Tuberculosis (TB) is still a common infectious disease in developing countries, but it is also re-emerging in industrialized nations due to the HIV/AIDS pandemic. In addition to bacillary virulence, the host immune response plays a major role in the development of an active disease (either as a primary infection or reactivation) and in controlling the infection. Even though several mechanisms are involved in regulating the human immune response, biological environment seems to be determinant. In this context, the integrated neuro-immune-endocrine system strongly influences TB clinical outcome. One of the most important clinical aspects of TB is shown when the infection locates in the central nervous system (CNS), in which a very different set of immune responses is induced. Herein we review several aspects of the paradoxical immune response triggered during CNS-TB infection, and discuss the implications of this response in the cerebral infection outcome.

HIV-1 and the immune response to TB

TB causes 1.4 million deaths annually. HIV-1 infection is the strongest risk factor for TB. The characteristic immunological effect of HIV is on CD4 cell count. However, the risk of TB is elevated in HIV-1 infected individuals even in the first few years after HIV acquisition and also after CD4 cell counts are restored with antiretroviral therapy. In this review, we examine features of the immune response to TB and how this is affected by HIV-1 infection and vice versa. We discuss how the immunology of HIV-TB coinfection impacts on the clinical presentation and diagnosis of TB, and how antiretroviral therapy affects the immune response to TB, including the development of TB immune reconstitution inflammatory syndrome. We highlight important areas of uncertainty and future research needs.

Tuberculous meningitis

Tuberculous (TB) meningitis is common in resource-poor communities but also occurs in developed countries where the diagnosis is frequently delayed because of unfamiliarity with the disease. TB meningitis develops whenever a small intracranial tuberculoma (Rich focus) ruptures causing predominantly basal meningitis. This results in hydrocephalus, cranial nerve palsies, and ischemic brain injury secondary to tuberculous vasculitis. The primary source of TB is usually the lung. Early diagnosis is difficult because patients tend to present subacutely with nonspecific symptoms such as fever, cough, vomiting, listlessness, and failure to thrive. Lumbar puncture typically shows clear and colorless CSF with a low, predominantly lymphocytic, leukocytosis and raised protein and low glucose levels. Decision to treat is mostly clinical because of difficulty in demonstrating TB bacilli on routine smear and time needed for culture. A positive TB contact, Mantoux skin test, chest radiograph, CT/MRI brain scan, PCR for tuberculosis on CSF, and demonstration of TB bacilli from extraneural sources are invaluable in supporting a diagnosis of TB meningitis. Current World Health Organization guidelines recommend treatment with a four-drug regimen for 2 months, followed by a two-drug regimen for 10 months, the total duration of treatment being 12 months. Corticosteroids reduce mortality without changing neurological morbidity. Outcome relates closely to age and stage of disease.