Cerebrospinal fluid concentrations of antituberculosis agents in adults and children

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.

The Role of Efflux Pumps in Tuberculosis Treatment and Their Promise as a Target in Drug Development: Unraveling the Black Box

Insight into drug transport mechanisms is highly relevant to the efficacious treatment of tuberculosis (TB). Major problems in TB treatment are related to the transport of antituberculosis (anti-TB) drugs across human and mycobacterial membranes, affecting the concentrations of these drugs systemically and locally. Firstly, transporters located in the intestines, liver, and kidneys all determine the pharmacokinetics and pharmacodynamics of anti-TB drugs, with a high risk of drug-drug interactions in the setting of concurrent use of antimycobacterial, antiretroviral, and antidiabetic agents. Secondly, human efflux transporters limit the penetration of anti-TB drugs into the brain and cerebrospinal fluid, which is especially important in the treatment of TB meningitis. Finally, efflux transporters located in the macrophage and Mycobacterium tuberculosis cell membranes play a pivotal role in the emergence of phenotypic tolerance and drug resistance, respectively. We review the role of efflux transporters in TB drug disposition and evaluate the promise of efflux pump inhibition from a novel holistic perspective.

Cerebrospinal fluid matrix metalloproteinase 9 levels, blood-brain barrier permeability, and treatment outcome in tuberculous meningitis

Objectives

Tuberculous meningitis is characterized by elevated levels of matrix metalloproteinase 9 (MMP9) in the cerebrospinal fluid (CSF). However, it is unclear whether elevated MMP9 levels are associated with poor treatment outcome. We tested the hypothesis that pretreatment MMP9 levels in the CSF would be higher in tuberculous meningitis patients experiencing a poor treatment outcome.

Methods

We prospectively assessed the treatment outcome in a consecutive sample of human immunodeficiency virus-negative patients with tuberculous meningitis. We defined good outcome as survival without severe neurological disability (modified Rankin scale scores 0–2). We estimated levels of MMP9 and its tissue inhibitor (TIMP1) on pretreatment CSF samples. We used albumin index to assess blood-brain barrier permeability.

Results

We studied 40 patients (23 males [58%]) with tuberculous meningitis. Sixteen patients (40%) had stage 3 disease. On follow-up, 18 (45%) patients had a poor treatment outcome—15 patients died and 3 had severe neurological disability. Pretreatment MMP9 levels were not associated with treatment outcome (median [interquartile range], 254 [115–389] vs. 192 [60–383] ng/mL in good vs. poor outcome groups; P = 0.693). MMP9 levels did not correlate with the albumin index (Spearman’s rho = 0.142; P = 0.381). However, MMP9 levels significantly correlated with CSF glucose levels (rho = −0.419; P = 0.007) and admission Glasgow coma scale score (rho = 0.324; P = 0.032). Likewise, TIMP1 levels also did not differ by treatment outcome (1239 [889–1511] vs. 1522 [934–1949] ng/mL; P = 0.201). MMP9/TIMP1 ratio that reflects net proteolytic activity was also not different between the two groups (0.191 [0.107–0.250] vs. 0.163 [0.067–0.34]; P = 0.625).

Conclusion

Our findings do not support the hypothesis that pretreatment levels of MMP9 would be higher in tuberculous meningitis patients experiencing a poor treatment outcome. Further, MMP9 levels in the CSF did not correlate with blood-brain barrier permeability in patients with tuberculous meningitis.

The importance of clinical pharmacokinetic-pharmacodynamic studies in unraveling the determinants of early and late tuberculosis outcomes

Tuberculosis remains a major infectious cause of morbidity and mortality worldwide. Current antibiotic regimens, constructed prior to the development of modern pharmacokinetic-pharmacodynamic (PK–PD) tools, are based on incomplete understanding of exposure–response relationships in drug susceptible and multidrug resistant tuberculosis. Preclinical and population PK data suggest that clinical PK–PD studies may enable therapeutic drug monitoring for some agents and revised dosing for others. Future clinical PK–PD challenges include: incorporation of PK methods to assay free concentrations for all active metabolites; selection of appropriate early outcome measures which reflect therapeutic response; elucidation of genetic contributors to interindividual PK variability; conduct of targeted studies on special populations (including children); and measurement of PK–PD parameters at the site of disease.

Long-term Mortality of Patients With Tuberculous Meningitis in New York City: A Cohort Study

Background

Tuberculous meningitis (TBM) is the most devastating clinical presentation of infection with Mycobacterium tuberculosis; delayed initiation of effective antituberculosis therapy is associated with poor treatment outcomes. Our objective was to determine the relationship between drug resistance and 10-year mortality among patients with TBM.

Methods

We conducted a retrospective cohort study of 324 patients with culture-confirmed TBM, susceptibility results reported for isoniazid and rifampin, and initiation of at least 2 antituberculosis drugs, reported to the tuberculosis registry in New York City between 1 January 1992 and 31 December 2001. Date of death was ascertained by matching the tuberculosis registry with death certificate data for 1992-2012 from the New York Office of Vital Statistics. Human immunodeficiency virus (HIV) status was ascertained by medical records review, matching with the New York City HIV Surveillance registry, and review of cause of death.

Results

Among 257 TBM patients without rifampin-resistant isolates, isoniazid resistance was associated with mortality after the first 60 days of treatment when controlling for age and HIV infection (adjusted hazard ratio, 1.94 [95% confidence interval, 1.08-3.94]). Death occurred before completion of antituberculosis therapy in 63 of 67 TBM patients (94%) with rifampin-resistant disease.

Conclusions

Among patients with culture-confirmed TBM, we observed rapid early mortality in patients with rifampin-resistant isolates, and an independent association between isoniazid-resistant isolates and death after 60 days of therapy. These findings support the continued evaluation of rapid diagnostic techniques and the empiric addition of second-line drugs for patients with clinically suspected drug-resistant TBM.

Chemotherapy of Tuberculosis

The management of tuberculosis (TB) can be a challenging process that has implications both for the affected patient and public health. Effective anti-TB chemotherapy both cures and renders the patient noncontagious. Biological factors specific to M. tuberculosis necessitate the use of multiple drugs for prolonged durations to adequately eradicate infection. Recommended regimens address the complexities of eliminating organisms from diverse reservoirs while preventing the emergence of drug resistance. First-line anti-TB therapy for drug susceptible disease effectively cures almost all patients within 6-9 months. The loss of first-line agents, due to resistance or intolerance, necessitates lengthy treatment courses, frequently 12-18 months or longer. Due to the long treatment times and the implications of missed doses, directly-observed therapy (DOT) is considered the standard of care. Drugs used for the treatment of TB have serious potential toxicities that require close monitoring and prompt response. A strong public health infrastructure and robust social supports are important elements to assure successful treatment. These numerous factors compel public health entities to take a lead role in the management of TB, either through the direct management of TB treatment or by assuring the activities of partner organizations.

A High-throughput Compatible Assay to Evaluate Drug Efficacy against Macrophage Passaged Mycobacterium tuberculosis

The early drug development process for anti-tuberculosis drugs is hindered by the inefficient translation of compounds with in vitro activity to effectiveness in the clinical setting. This is likely due to a lack of consideration for the physiologically relevant cellular penetration barriers that exist in the infected host. We recently established an alternative infection model that generates large macrophage aggregate structures containing densely packed M. tuberculosis (Mtb) at its core, which was suitable for drug susceptibility testing. This infection model is inexpensive, rapid, and most importantly BSL-2 compatible. Here, we describe the experimental procedures to generate Mtb/macrophage aggregate structures that would produce macrophage-passaged Mtb for drug susceptibility testing. In particular, we demonstrate how this infection system could be directly adapted to the 96-well plate format showing throughput capability for the screening of compound libraries against Mtb. Overall, this assay is a valuable addition to the currently available Mtb drug discovery toolbox due to its simplicity, cost effectiveness, and scalability.

The epidemiology, pathogenesis, transmission, diagnosis, and management of multidrug-resistant, extensively drug-resistant, and incurable tuberculosis

Global tuberculosis incidence has declined marginally over the past decade, and tuberculosis remains out of control in several parts of the world including Africa and Asia. Although tuberculosis control has been effective in some regions of the world, these gains are threatened by the increasing burden of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis. XDR tuberculosis has evolved in several tuberculosis-endemic countries to drug-incurable or programmatically incurable tuberculosis (totally drug-resistant tuberculosis). This poses several challenges similar to those encountered in the pre-chemotherapy era, including the inability to cure tuberculosis, high mortality, and the need for alternative methods to prevent disease transmission. This phenomenon mirrors the worldwide increase in antimicrobial resistance and the emergence of other MDR pathogens, such as malaria, HIV, and Gram-negative bacteria. MDR and XDR tuberculosis are associated with high morbidity and substantial mortality, are a threat to health-care workers, prohibitively expensive to treat, and are therefore a serious public health problem. In this Commission, we examine several aspects of drug-resistant tuberculosis. The traditional view that acquired resistance to antituberculous drugs is driven by poor compliance and programmatic failure is now being questioned, and several lines of evidence suggest that alternative mechanisms-including pharmacokinetic variability, induction of efflux pumps that transport the drug out of cells, and suboptimal drug penetration into tuberculosis lesions-are likely crucial to the pathogenesis of drug-resistant tuberculosis. These factors have implications for the design of new interventions, drug delivery and dosing mechanisms, and public health policy. We discuss epidemiology and transmission dynamics, including new insights into the fundamental biology of transmission, and we review the utility of newer diagnostic tools, including molecular tests and next-generation whole-genome sequencing, and their potential for clinical effectiveness. Relevant research priorities are highlighted, including optimal medical and surgical management, the role of newer and repurposed drugs (including bedaquiline, delamanid, and linezolid), pharmacokinetic and pharmacodynamic considerations, preventive strategies (such as prophylaxis in MDR and XDR contacts), palliative and patient-orientated care aspects, and medicolegal and ethical issues.

Neurological complications after tuberculous meningitis in a multi-state cohort in the United States

BACKGROUND AND PURPOSE

To assess the rate of neurological complications and mortality after tuberculous meningitis in the United States.

METHODS

The authors performed a retrospective cohort study of all patients 18years or older hospitalized for tuberculous meningitis in California between 2005 and 2010, New York between 2006 and 2012, and Florida between 2005 and 2012. Outcomes of interest were mortality and the following neurological complications: stroke, seizure, hydrocephalus requiring a ventriculoperitoneal shunt, vision impairment, and hearing impairment. Kaplan-Meier survival statistics were used to assess the cumulative rate of neurological complications and death. Cox proportional hazards regression was used to compare rates of complications in patients with and without human immunodeficiency virus (HIV) after adjustment for comorbidities.

RESULTS

806 patients with tuberculous meningitis were identified, among whom the cumulative rate of any complication or death was 55.4% (95% CI, 51.5-59.3%). More than two-thirds of complications occurred during the initial hospitalization for tuberculous meningitis. Individual neurological complications were not uncommon: the cumulative rate of stroke was 16.8% (95% CI, 14.0-20.0%), the rate of seizure was 18.8% (95% CI, 15.4-22.8%), and the rate of ventriculoperitoneal shunting was 8.4% (95% CI, 6.4-10.9%). Vision impairment occurred in 21.6% (95% CI, 18.5-25.1%) of patients and hearing impairment occurred in 6.8% (95% CI, 4.9-9.4%). The mortality rate was 21.5% (95% CI, 18.4-24.9%). Patients with HIV infection were not at increased risk of complications compared to patients without HIV (hazard ratio, 1.2; 95% CI, 0.9-1.6).

CONCLUSIONS

Tuberculous meningitis is associated with significant risk of neurological complications and death in the United States.

Mycobacterium tuberculosis exploits the PPM1A signaling pathway to block host macrophage apoptosis

The ability to suppress host macrophage apoptosis is essential for M. tuberculosis (Mtb) to replicate intracellularly while protecting it from antibiotic treatment. We recently described that Mtb infection upregulated expression of the host phosphatase PPM1A, which impairs the antibacterial response of macrophages. Here we establish PPM1A as a checkpoint target used by Mtb to suppress macrophage apoptosis. Overproduction of PPM1A suppressed apoptosis of Mtb-infected macrophages by a mechanism that involves inactivation of the c-Jun N-terminal kinase (JNK). Targeted depletion of PPM1A by shRNA or inhibition of PPM1A activity by sanguinarine restored JNK activation, resulting in increased apoptosis of Mtb-infected macrophages. We also demonstrate that activation of JNK by subtoxic concentrations of anisomycin induced selective apoptotic killing of Mtb-infected human macrophages, which was completely blocked in the presence of a specific JNK inhibitor. Finally, selective killing of Mtb-infected macrophages and subsequent bacterial release enabled rifampicin to effectively kill Mtb at concentrations that were insufficient to act against intracellular Mtb, providing proof of principle for the efficacy of a "release and kill" strategy. Taken together, these findings suggest that drug-induced selective apoptosis of Mtb-infected macrophages is achievable.

Tuberculous Meningitis in an Immunocompetent Host: A Case Report

Patient: Male, 57

Final Diagnosis: Tuberculous meningitis

Symptoms: Altered mental state • headache

Medication: —

Clinical Procedure: Lumbar puncture

Specialty: Infectious Diseases

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.

Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis

The American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America jointly sponsored the development of this guideline for the treatment of drug-susceptible tuberculosis, which is also endorsed by the European Respiratory Society and the US National Tuberculosis Controllers Association. Representatives from the American Academy of Pediatrics, the Canadian Thoracic Society, the International Union Against Tuberculosis and Lung Disease, and the World Health Organization also participated in the development of the guideline. This guideline provides recommendations on the clinical and public health management of tuberculosis in children and adults in settings in which mycobacterial cultures, molecular and phenotypic drug susceptibility tests, and radiographic studies, among other diagnostic tools, are available on a routine basis. For all recommendations, literature reviews were performed, followed by discussion by an expert committee according to the Grading of Recommendations, Assessment, Development and Evaluation methodology. Given the public health implications of prompt diagnosis and effective management of tuberculosis, empiric multidrug treatment is initiated in almost all situations in which active tuberculosis is suspected. Additional characteristics such as presence of comorbidities, severity of disease, and response to treatment influence management decisions. Specific recommendations on the use of case management strategies (including directly observed therapy), regimen and dosing selection in adults and children (daily vs intermittent), treatment of tuberculosis in the presence of HIV infection (duration of tuberculosis treatment and timing of initiation of antiretroviral therapy), as well as treatment of extrapulmonary disease (central nervous system, pericardial among other sites) are provided. The development of more potent and better-tolerated drug regimens, optimization of drug exposure for the component drugs, optimal management of tuberculosis in special populations, identification of accurate biomarkers of treatment effect, and the assessment of new strategies for implementing regimens in the field remain key priority areas for research. See the full-text online version of the document for detailed discussion of the management of tuberculosis and recommendations for practice.

Six months therapy for tuberculous meningitis

BACKGROUND

Tuberculous meningitis (TBM) is the main form of tuberculosis that affects the central nervous system and is associated with high rates of death and disability. Most international guidelines recommend longer antituberculous treatment (ATT) regimens for TBM than for pulmonary tuberculosis disease to prevent relapse. However, longer regimens are associated with poor adherence, which could contribute to increased relapse, development of drug resistance, and increased costs to patients and healthcare systems.

OBJECTIVES

To compare the effects of short-course (six months) regimens versus prolonged-course regimens for people with tuberculous meningitis (TBM).

SEARCH METHODS

We searched the following databases up to 31 March 2016: the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; MEDLINE; EMBASE; LILACS; INDMED; and the South Asian Database of Controlled Clinical Trials. We searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov for ongoing trials. We also checked article reference lists and contacted researchers in the field.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and prospective cohort studies of adults and children with TBM treated with antituberculous regimens that included rifampicin for six months or longer than six months. The primary outcome was relapse, and included studies required a minimum of six months follow-up after completion of treatment.

DATA COLLECTION AND ANALYSIS

Two review authors (SJ and HR) independently assessed the literature search results for eligibility, and performed data extraction and 'Risk of bias' assessments of the included studies. We contacted study authors for additional information when necessary. Most data came from single arm cohort studies without a direct comparison so we pooled the findings for each group of cohorts and presented them separately using a complete-case analysis. We assessed the quality of the evidence narratively, as using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was inappropriate with no direct comparisons between short- and prolonged-course regimens.

MAIN RESULTS

Four RCTs and 12 prospective cohort studies met our inclusion criteria, and included a total of 1881 participants with TBM. None of the included RCTs directly compared six months versus longer regimens, so we analysed all data as individual cohorts to obtain relapse rates in each set of cohorts.We included seven cohorts of participants treated for six months, with a total of 458 participants. Three studies were conducted in Thailand, two in South Africa, and one each in Ecuador and Papua New Guinea between the 1980s and 2009. We included 12 cohorts of participants treated for longer than six months (ranging from eight to 16 months), with a total of 1423 participants. Four studies were conducted in India, three in Thailand and one each in China, South Africa, Romania, Turkey and Vietnam, between the late 1970s and 2011.The proportion of participants classified as having stage III disease (severe) was higher in the cohorts treated for six months (33.2% versus 16.9%), but the proportion with known concurrent HIV was higher in the cohorts treated for longer (0/458 versus 122/1423). Although there were variations in the treatment regimens, most cohorts received isoniazid, rifampicin, and pyrazinamide during the intensive phase.Investigators achieved follow-up beyond 18 months after completing treatment in three out of the seven cohorts treated for six months, and five out of the 12 cohorts treated for eight to 16 months. All studies had potential sources of bias in their estimation of the relapse rate, and comparisons between the cohorts could be confounded.Relapse was an uncommon event across both groups of cohorts (3/369 (0.8%) with six months treatment versus 7/915 (0.8%) with longer), with only one death attributed to relapse in each group.Overall, the proportion of participants who died was higher in the cohorts treated for longer than six months (447/1423 (31.4%) versus 58/458 (12.7%)). However, most deaths occurred during the first six months in both treatment cohorts, which suggested that the difference in death rate was not directly related to duration of ATT but was due to confounding. Clinical cure was higher in the group of cohorts treated for six months (408/458 (89.1%) versus longer than six months (984/1336 (73.7%)), consistent with the observations for deaths.Few participants defaulted from treatment with six months treatment (4/370 (1.1%)) versus longer treatment (8/355 (2.3%)), and adherence was not well reported.

AUTHORS' CONCLUSIONS

In all cohorts most deaths occurred in the first six months; and relapse was uncommon in all participants irrespective of the regimen. Further inferences are probably inappropriate given this is observational data and confounding is likely. These data are almost all from participants who are HIV-negative, and thus the inferences will not apply to the efficacy and safety of the six months regimens in HIV-positive people. Well-designed RCTs, or large prospective cohort studies, comparing six months with longer treatment regimens with long follow-up periods established at initiation of ATT are needed to resolve the uncertainty regarding the safety and efficacy of six months regimens for TBM.

Adverse effects of oral second-line antituberculosis drugs in children

INTRODUCTION

Increasing numbers of children with drug-resistant tuberculosis are accessing second-line antituberculosis drugs; these are more toxic than first-line drugs. Little is known about the safety of new antituberculosis drugs in children. Knowledge of adverse effects, and how to assess and manage these, is important to ensure good adherence and treatment outcomes.

AREAS COVERED

A Pubmed search was performed to identify articles addressing adverse effects of second-line antituberculosis drugs; a general search was done for the new drugs delamanid and bedaquiline. This review discusses adverse effects associated with oral second-line antituberculosis drugs. The spectrum of adverse effects caused by antituberculosis drugs is wide; the majority are mild or moderate, but these are important to manage as it could lead to non-adherence to treatment. Adverse effects may be more common in HIV-infected than in HIV-uninfected children.

EXPERT OPINION

Although children may experience fewer adverse effects from oral second-line antituberculosis drugs than adults, evidence from prospective studies of the incidence of adverse events in children is limited. Higher doses of second-line drugs, new antituberculosis drugs, and new drug regimens are being evaluated in children: these call for strict pharmacovigilance in children treated in the near future, as adverse effect profiles may change.

Pharmacokinetics and safety/tolerability of higher oral and intravenous doses of rifampicin in adult tuberculous meningitis patients

High-dose intravenous (i.v.) rifampicin improved the outcome of tuberculous meningitis (TBM) in a previous study. Unfortunately, i.v. rifampicin is not available in many high-endemic settings. This study examined exposures to and safety of higher oral rifampicin doses compared with i.v. rifampicin. Thirty adult Indonesian TBM patients were randomised to rifampicin 750 mg (ca. 17 mg/kg) orally, 900 mg (ca. 20 mg/kg) orally or 600 mg (ca. 13 mg/kg, as used previously) i.v. over 1.5 h for 14 days, combined with other TB drugs. The pharmacokinetics of rifampicin was assessed in the critical phase of TBM treatment (≤3 days after treatment initiation) and at ≥9 days. In the first days of treatment, the geometric mean (range) plasma AUC0-24 values following rifampicin 750 mg orally, 900 mg orally and 600 mg i.v. were 131.4 (38.1-275.1), 164.8 (66.9-291.2) and 145.7 (77.7-430.2) mg⋅h/L, respectively; Cmax values were 14.3 (6.1-22.2), 16.2 (5.7-28.3) and 24.7 (13.9-37.8) mg/L. CSF concentrations correlated with plasma exposures. After ≥9 days, AUC0-24 values had decreased to 100.1, 101.2 and 94.9 mg⋅h/L. Transient grade 3 ALT increases (8/30 patients) and one grade 4 ALT increase occurred, not related to rifampicin exposure. Higher oral rifampicin doses resulted in approximately similar plasma AUC0-24 but lower plasma Cmax values compared with 600 mg i.v. over 1.5 h. Exposures to rifampicin varied substantially and decreased due to autoinduction. Liver function disturbances occurred in this severely ill population. Future studies should examine even higher rifampicin doses in TBM treatment.

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.

A Macrophage Infection Model to Predict Drug Efficacy Against Mycobacterium Tuberculosis

In the last 40 years, only a single new antituberculosis drug was FDA approved. New tools that improve the drug development process will be essential to accelerate the development of next-generation antituberculosis drugs. The drug development process seems to be hampered by the inefficient transition of initially promising hits to candidate compounds that are effective in vivo. In this study, we introduce an inexpensive, rapid, and BSL-2 compatible infection model using macrophage-passaged Mycobacterium tuberculosis (Mtb) that forms densely packed Mtb/macrophage aggregate structures suitable for drug efficacy testing. Susceptibility to antituberculosis drugs determined with this Mtb/macrophage aggregate model differed from commonly used in vitro broth-grown single-cell Mtb cultures. Importantly, altered drug susceptibility correlated well with the reported ability of the respective drugs to generate high tissue and cerebrospinal fluid concentrations relative to their serum concentrations, which seems to be the best predictors of in vivo efficacy. Production of these Mtb/macrophage aggregates could be easily scaled up to support throughput efforts. Overall, its simplicity and scalability should make this Mtb/macrophage aggregate model a valuable addition to the currently available Mtb drug discovery tools.

Mortality in HIV-infected patients with tuberculosis treated with streptomycin and a two-week intensified regimen: data from an HIV cohort study using inverse probability of treatment weighting

Background. Despite the dramatic scale-up of antiretroviral therapy in low- and middle-income countries, tuberculosis (TB) is still the main cause of death among HIV-infected patients in resource-limited settings. Previous studies in patients with TB meningitis suggest that the use of higher doses of common anti-TB drugs could reduce mortality.

Methods. Using clinical data from an HIV cohort study in India, we compared the mortality among HIV-infected patients diagnosed with TB according to the regimen received during the first two weeks of treatment: standard anti-tuberculosis therapy (ATT) (N = 847), intensified ATT (N = 322), and intensified ATT with streptomycin (N = 446). The intensified ATT comprised double dose of rifampicin and substitution of ethambutol with levofloxacin. Multivariate analysis was performed using Cox proportional hazard models and inverse probability of treatment weighting (IPTW) based on propensity scores. Patients with TB meningitis were excluded.

Results. The use of intensified ATT alone did not improve survival. However, when streptomycin was added, the use intensified ATT was associated with reduced mortality in Cox models (adjusted hazard ratio 0.72, 95% CI [0.57–0.91]) and after IPTW (hazard ratio 0.77, 95% CI [0.67–0.96]). Other factors associated with improved survival were high serum albumin concentration, high CD4 lymphocyte cell-counts, and high glomerular filtration rates. Factors associated with increased mortality were high urea concentrations, being on antiretroviral therapy at the time of ATT initiation and high BUN/creatinine ratio. In an effect modification analysis, the survival benefits of the intensified ATT with streptomycin disappeared in patients with severe hypoalbuminemia.

Conclusion. The results of this study are in accordance with a previous study from our cohort involving patients with TB meningitis, and suggest that an intensified 2-week ATT with streptomycin could reduce mortality in HIV infected patients with TB. As this is an observational study, we should be cautious about our conclusions, but given the high mortality of HIV-related TB, our findings deserve further research.

Naïve-pooled pharmacokinetic analysis of pyrazinamide, isoniazid and rifampicin in plasma and cerebrospinal fluid of Vietnamese children with tuberculous meningitis

BACKGROUND

Among the various forms of TB, tuberculous meningitis (TBM) is the most severe, with about 30% mortality and 50% of survivors left with neurological sequelae. Children suffer more frequently from TBM than adults and outcomes are often poor due to difficulties in making the diagnosis and uncertainty regarding the best anti-tuberculosis drug regimen. The aim of this prospective study was to describe the pharmacokinetics of pyrazinamide, isoniazid and rifampicin in plasma and cerebrospinal fluid of children with tuberculous meningitis treated with the standard TBM regimen.

METHODS

We performed a prospective observational study of 100 consecutively treated children (≤ 15 years of age) with tuberculous meningitis in Ho Chi Minh City, Vietnam. Children were treated according to the 2006 WHO recommended pediatric treatment regimen consisting of isoniazid (5 mg/kg), rifampicin (10 mg/kg) and ethambutol (15 mg/kg) for 8 months, with the addition of pyrazinamide (25 mg/kg) for the first 3 months and streptomycin (15 mg/kg) for the first 2 months. Pyrazinamide, isoniazid and rifampicin concentrations were measured in plasma at day 14 and in cerebrospinal fluid (CSF) at 1 month by HPLC-UV. A naïve-pooled non-compartmental data analysis was used to describe the pharmacokinetic properties of drugs in the two-age groups of children ≤ 4 years or > 4 years of age.

RESULTS

Younger children, when compared to older children, presented a higher body weight-normalized clearance and volume of distribution, and lower median total plasma exposures for the three studied drugs with -14%, -22% and -16% for Pyrazinamide, Isoniazid and Rifampicin, respectively. In CSF, individual concentrations of isoniazid and pyrazinamide were comparable to that in plasma in both age groups; but rifampicin concentrations were lower than the minimum inhibitory concentration of susceptible bacteria in all but two children.

CONCLUSIONS

There is an age-dependent variation in the plasma and cerebrospinal fluid pharmacokinetics of rifampicin, isoniazid and pyrazinamide. The safety and efficacy of higher doses of rifampicin should be investigated for the treatment of childhood tuberculous meningitis.

Intensified Antituberculosis Therapy in Adults with Tuberculous Meningitis

BACKGROUND

Tuberculous meningitis is often lethal. Early antituberculosis treatment and adjunctive treatment with glucocorticoids improve survival, but nearly one third of patients with the condition still die. We hypothesized that intensified antituberculosis treatment would enhance the killing of intracerebral Mycobacterium tuberculosis organisms and decrease the rate of death among patients.

METHODS

We performed a randomized, double-blind, placebo-controlled trial involving human immunodeficiency virus (HIV)-infected adults and HIV-uninfected adults with a clinical diagnosis of tuberculous meningitis who were admitted to one of two Vietnamese hospitals. We compared a standard, 9-month antituberculosis regimen (which included 10 mg of rifampin per kilogram of body weight per day) with an intensified regimen that included higher-dose rifampin (15 mg per kilogram per day) and levofloxacin (20 mg per kilogram per day) for the first 8 weeks of treatment. The primary outcome was death by 9 months after randomization.

RESULTS

A total of 817 patients (349 of whom were HIV-infected) were enrolled; 409 were randomly assigned to receive the standard regimen, and 408 were assigned to receive intensified treatment. During the 9 months of follow-up, 113 patients in the intensified-treatment group and 114 patients in the standard-treatment group died (hazard ratio, 0.94; 95% confidence interval, 0.73 to 1.22; P=0.66). There was no evidence of a significant differential effect of intensified treatment in the overall population or in any of the subgroups, with the possible exception of patients infected with isoniazid-resistant M. tuberculosis. There were also no significant differences in secondary outcomes between the treatment groups. The overall number of adverse events leading to treatment interruption did not differ significantly between the treatment groups (64 events in the standard-treatment group and 95 events in the intensified-treatment group, P=0.08).

CONCLUSIONS

Intensified antituberculosis treatment was not associated with a higher rate of survival among patients with tuberculous meningitis than standard treatment. (Funded by the Wellcome Trust and the Li Ka Shing Foundation; Current Controlled Trials number, ISRCTN61649292.).

Clinical features, Outcomes and Molecular Profiles of Drug Resistance in Tuberculous Meningitis in non-HIV Patients

Tuberculous meningitis continues to be a serious problem for physicians because it is difficult to make an early diagnosis and the consequences of delaying treatment are severe. The objective of this study is to provide data for the optimization of diagnostic and timely treatment of tuberculous meningitis. Of the 401 human immunodeficiency virus (HIV)-negative tuberculous meningitis patients in our study, 332 were found to have an impaired blood brain barrier (82.8%). Nearly 17.0% of patients failed to be timely diagnosed. Headache (53.6%) and fever (48.6%) were the most common features, and Computed Tomography/Magnetic Resonance Imaging (CT/MRI) detected 96 patients (23.9%) with abnormal meningeal imaging. Cerebrospinal fluid real-time polymerase chain reaction was positive in 73.8% of the tuberculous meningitis patients, whereas, smears and cultures detected only 6.7% and 5.2%, respectively. Further analysis identified striking differences between drug-resistant and drug-susceptible tuberculous meningitis. Patients with drug resistance correlated with grave prognosis. Tuberculous meningitis diagnosis should overall embody clinical symptoms, laboratory and cerebral imaging findings, and more sensitive diagnostic approaches are still warranted. Our data suggest cerebrospinal fluid polymerase chain reaction for mycobacterial DNA and molecular drug susceptibility testing as routine assays for suspected tuberculous meningitis patients, and observation of the blood brain barrier function could be performed for individual management.

Safety and tolerability profile of second-line anti-tuberculosis medications

Tuberculosis (TB) remains a major public health problem, representing the second leading cause of death from infectious diseases globally, despite being nearly 100 % curable. Multidrug-resistant (MDR)-TB, a form of TB resistant to isoniazid and rifampicin (rifampin), two of the key first-line TB drugs, is becoming increasingly common. MDR-TB is treated with a combination of drugs that are less effective but more toxic than isoniazid and rifampicin. These drugs include fluoroquinolones, aminoglycosides, ethionamide, cycloserine, aminosalicyclic acid, linezolid and clofazimine among others. Minor adverse effects are quite common and they can be easily managed with symptomatic treatment. However, some adverse effects can be life-threatening, e.g. nephrotoxicity due to aminoglycosides, cardiotoxicity due to fluoroquinolones, gastrointestinal toxicity due to ethionamide or para-aminosalicylic acid, central nervous system toxicity due to cycloserine, etc. Baseline evaluation may help to identify patients who are at increased risk for adverse effects. Regular clinical and laboratory evaluation during treatment is very important to prevent adverse effects from becoming serious. Timely and intensive monitoring for, and management of adverse effects caused by, second-line drugs are essential components of drug-resistant TB control programmes; poor management of adverse effects increases the risk of non-adherence or irregular adherence to treatment, and may result in death or permanent morbidity. Treating physicians should have a thorough knowledge of the adverse effects associated with the use of second-line anti-TB drugs, and routinely monitor the occurrence of adverse drug reactions. In this review, we have compiled safety and tolerability information regarding second-line anti-TB drugs in both adults and children.

Pediatric tuberculous meningitis: Model-based approach to determining optimal doses of the anti-tuberculosis drugs rifampin and levofloxacin for children

Pediatric tuberculous meningitis (TBM) is a highly morbid, often fatal disease. Standard treatment includes isoniazid, rifampin, pyrazinamide, and ethambutol. Current rifampin dosing achieves low cerebrospinal fluid (CSF) concentrations, and CSF penetration of ethambutol is poor. In adult trials, higher-dose rifampin and/or a fluoroquinolone reduced mortality and disability. To estimate optimal dosing of rifampin and levofloxacin for children, we compiled plasma and CSF pharmacokinetic (PK) and outcomes data from adult TBM trials plus plasma PK data from children. A population PK/pharmacodynamic (PD) model using adult data defined rifampin target exposures (plasma area under the curve (AUC)0-24 = 92 mg*h/L). Levofloxacin targets and rifampin pediatric drug disposition information were literature-derived. To attain target rifampin exposures, children require daily doses of at least 30 mg/kg orally or 15 mg/kg intravenously (i.v.). From our pediatric population PK model, oral levofloxacin doses needed to attain exposure targets were 19-33 mg/kg. Our results provide data-driven guidance to maximize pediatric TBM treatment while we await definitive trial results.

A review of the use of ethionamide and prothionamide in childhood tuberculosis

Ethionamide (ETH) and prothionamide (PTH), both thioamides, have proven efficacy in clinical studies and form important components for multidrug-resistant tuberculosis treatment regimens and for treatment of tuberculous meningitis in adults and children. ETH and PTH are pro-drugs that, following enzymatic activation by mycobacterial EthA inhibit InhA, a target shared with isoniazid (INH), and subsequently inhibit mycolic acid synthesis of Mycobacterium tuberculosis. Co-resistance to INH and ETH is conferred by mutations in the mycobacterial inhA promoter region; mutations in the ethA gene often underlie ETH and PTH monoresistance. An oral daily dose of ETH or PTH of 15-20 mg/kg with a maximum daily dose of 1000 mg is recommended in children to achieve adult-equivalent serum concentrations shown to be efficacious in adults, although information on optimal pharmacodynamic targets is still lacking. Gastrointestinal disturbances, and hypothyroidism during long-term therapy, are frequent adverse effects observed in adults and children, but are rarely life-threatening and seldom necessitate cessation of ETH therapy. More thorough investigation of the therapeutic effects and toxicity of ETH and PTH is needed in childhood TB while child-friendly formulations are needed to appropriately dose children.

Successful Treatment of a Child With Extensively Drug-Resistant Tuberculous Meningitis

Unlike in pulmonary multidrug-resistant (MDR) tuberculosis, the clinical outcome of MDR tuberculous meningitis (TBM) in children, including extensively drug-resistant tuberculosis, is poor and management is challenging. We report the successful treatment of a case of extensively drug-resistant TBM in a 4-year-old girl, and we discuss implications for tuberculosis diagnosis and chemotherapy.

Adding Streptomycin to an Intensified Regimen for Tuberculous Meningitis Improves Survival in HIV-Infected Patients

In low- and middle-income countries, the mortality of HIV-associated tuberculous meningitis (TM) continues to be unacceptably high. In this observational study of 228 HIV-infected patients with TM, we compared the mortality during the first nine months of patients treated with standard antituberculosis therapy (sATT), intensified ATT (iATT), and iATT with streptomycin (iATT + STM). The iATT included levofloxacin, ethionamide, pyrazinamide, and double dosing of rifampicin and isoniazid and was given only during the hospital admission (median 7 days, interquartile range 6–9). No mortality differences were seen in patients receiving the sATT and the iATT. However, patients receiving the iATT + STM had significant lower mortality than those in the sATT group (hazard ratio [HR] 0.47, 95% confidence interval [CI] 0.24 to 0.93). After adjusting for other covariates, the mortality hazard of the iATT + STM versus the sATT remained statistically significant (adjusted HR 0.2, 95% CI 0.09 to 0.46). Other factors associated with mortality were previous ATT and low albumin concentrations. The mortality risk increased exponentially only with CD4+ lymphocyte concentrations below 100 cells/μL. In conclusion, the use of iATT resulted in a clinically important reduction in mortality compared with the standard of care only if associated with STM. The results of this study deserve further research.

Determination of [11C]rifampin pharmacokinetics within Mycobacterium tuberculosis-infected mice by using dynamic positron emission tomography bioimaging

Information about intralesional pharmacokinetics (PK) and spatial distribution of tuberculosis (TB) drugs is limited and has not been used to optimize dosing recommendations for new or existing drugs. While new techniques can detect drugs and their metabolites within TB granulomas, they are invasive, rely on accurate resection of tissues, and do not capture dynamic drug distribution in the tissues of interest. In this study, we assessed the in situ distribution of (11)C-labeled rifampin in live, Mycobacterium tuberculosis-infected mice that develop necrotic lesions akin to human disease. Dynamic positron emission tomography (PET) imaging was performed over 60 min after injection of [(11)C]rifampin as a microdose, standardized uptake values (SUV) were calculated, and noncompartmental analysis was used to estimate PK parameters in compartments of interest. [(11)C]rifampin was rapidly distributed to all parts of the body and quickly localized to the liver. Areas under the concentration-time curve for the first 60 min (AUC0-60) in infected and uninfected mice were similar for liver, blood, and brain compartments (P > 0.53) and were uniformly low in brain (10 to 20% of blood values). However, lower concentrations were noted in necrotic lung tissues of infected mice than in healthy lungs (P = 0.03). Ex vivo two-dimensional matrix-assisted laser desorption ionization (MALDI) imaging confirmed restricted penetration of rifampin into necrotic lung lesions. Noninvasive bioimaging can be used to assess the distribution of drugs into compartments of interest, with potential applications for TB drug regimen development.

Pharmacokinetic/pharmacodynamic analysis of an intensified regimen containing rifampicin and moxifloxacin for tuberculous meningitis

Recent data suggest that intensified antimicrobial treatment may improve the outcome of tuberculous meningitis (TBM). Considering that drug exposure is the intermediate link between dose and effect, we examined the concentration-response relationship for rifampicin and moxifloxacin in TBM patients. In an open-label, phase 2 clinical trial performed in Indonesia (ClinicalTrials.gov NCT01158755), 60 TBM patients were randomised to receive standard-dose (450mg oral) or high-dose rifampicin (600mg intravenous) plus either oral moxifloxacin (400mg or 800mg) or ethambutol (750mg). After 14 days, all patients continued with standard tuberculosis treatment. Pharmacokinetic sampling was performed once in every patient during the first three critical days. Differences in exposure between patients who died or survived were tested with independent samples t-tests. The relationship between drug exposure and mortality was examined using Cox regression. Compared with patients who died during the 2 weeks of intensified treatment, surviving patients had significantly higher rifampicin plasma AUC0-6h, plasma Cmax and CSF Chighest. Additionally, patients had a 32-43% lower relative likelihood of dying with an interquartile range increase in rifampicin exposure. Moxifloxacin exposure did not show a clear relationship with survival. From exposure-response curves, a rifampicin plasma AUC0-6h of ∼70mg·h/L (AUC0-24h of ∼116mgh/L) and a Cmax of ∼22mg/L were deduced as minimum target values for treatment. A strong concentration-effect relationship was found, with higher rifampicin exposure leading to better TBM survival. The current treatment dose of rifampicin is suboptimal; higher doses of rifampicin should be evaluated.

Extrapulmonary tuberculosis presenting as a cavernous sinus syndrome: Case report with review of existing literature

Tuberculoma involving the cavernous sinus is a rare presentation of CNS disease, with only twelve cases reported in previous literature. We report a case of a 48 year old woman who presented with a right cavernous sinus syndrome of 2 months duration. MRI showed a mass in the right cavernous sinus, and serologic workup revealed an elevated sedimentation rate and positive Quantiferon^®-GOLD testing. 18-FDG PET-CT demonstrated a hypermetabolic 3 cm subcarinal lymph node, and lymph node biopsy showed caseating granuloma. Culture of lymphatic tissue grew drug-sensitive M. tuberculosis. The patient was treated with a non-standard 4-drug regimen and prednisone, with rapid improvement of symptoms and radiologic abnormalities. Total length of treatment was 12 months. In addition, we review the 12 cases found in literature, and discuss clinical features, diagnostic dilemmas, and approaches to treatment.

Understanding pharmacokinetics to improve tuberculosis treatment outcome

INTRODUCTION

Tuberculosis (TB) remains the leading cause of death from a curable infectious disease; drug-resistant TB threatens to dismantle all prior gains in global control. Suboptimal circulating anti-TB drug concentrations can lead to lack of cure and acquired drug resistance.

AREAS COVERED

This review will introduce pharmacokinetic parameters for key anti-TB drugs, as well as the indications and limitations of measuring these parameters in clinical practice. Current and novel methodologies for delivering anti-TB pharmacokinetic-pharmacodynamic data are highlighted and gaps in operational research described.

EXPERT OPINION

Individual pharmacokinetic variability is commonplace, underappreciated and difficult to predict without therapeutic drug monitoring (TDM). Pharmacokinetic thresholds associated with poor TB treatment outcome in drug-susceptible TB have recently been described and may now guide the application of TDM, but require validation in a variety of settings and comorbidities. Dried blood spots for TDM and prepackaged multidrug plates for minimum inhibitory concentration testing will overcome barriers of accessibility and represent areas for innovation. Operationalizing pharmacokinetics has the potential to improve TB outcomes in the most difficult-to-treat forms of the disease such as multidrug resistance. Clinical studies in these areas are eagerly anticipated and we expect will better define the rational introduction of novel therapeutics.

Short intensified treatment in children with drug-susceptible tuberculous meningitis

BACKGROUND

The World Health Organization recommends 12-month treatment (2RHZE/10RH) for children with tuberculous meningitis (TBM). Studies evaluating length of antituberculous treatment for TBM report similar completion and relapse rates comparing 6-month treatment with 12-month treatment.

METHODS

A prospective evaluation to determine whether short-course intensified treatment (6 RHZEth for HIV-infected and 9RHZEth for HIV-infected) is sufficient and safe in children with drug-susceptible TBM.

RESULTS

Of 184 children with TBM, median age 58 months and 90 (49%) male, 98 children (53%) presented at stage II TBM, 64 (35%) at stage III TBM and only 22 (12%) at stage I TBM. Ninety (49%) children were treated at home after the first month of therapy; all others received their full treatment in hospital. The HIV prevalence was 14% (22/155 children tested). Anti-TB drug-induced hepatotoxicity occurred in 5% (8 of 143 children tested), all tested negative for viral hepatitis; in all 8 cases, the original regimen was restarted without recurrence. After treatment completion, 147 (80%) children had a good outcome, 7 (3.8%) died. There was no difference in outcome between HIV-infected and HIV-uninfected children who completed treatment (P = 0.986) nor between TBM-hydrocephalic children who were medically treated or shunted (P = 0.166).

CONCLUSION

Short intensified treatment is safe and effective in both HIV-infected and HIV-uninfected children with drug-susceptible TBM.

Therapy duration and long-term outcomes in extra-pulmonary tuberculosis

BACKGROUND

Tuberculosis is classified as either pulmonary or extra-pulmonary (EPTB). While much focus has been paid to pulmonary tuberculosis, EPTB has received scant attention. Moreover, EPTB is viewed as one wastebasket diagnosis, as "the other" which is not pulmonary.

METHODS

This is a retrospective cohort study of all patients treated for EPTB in the state of Texas between January 2000 and December 2005, who had no pulmonary disease. Clinical and epidemiological factors were abstracted from electronic records of the Report of Verified Case of Tuberculosis. The long-term outcome, which is death by December 2011, was established using the Social Security Administration Death Master File database. Survival in EPTB patients was compared to those with latent tuberculosis, as well as between different types of EPTB, using Cox proportional hazard models. A hybrid of the machine learning method of classification and regression tree analyses and standard regression models was used to identify high-order interactions and clinical factors predictive of long-term all-cause mortality.

RESULTS

Four hundred and thirty eight patients met study criteria; the median study follow-up period for the cohort was 7.8 (inter-quartile range 6.0-10.1) years. The overall all-cause mortality rate was 0.025 (95% confidence interval [CI]: 0.021-0.030) per 100 person-year of follow-up. The significant predictors of poor long-term outcome were age (hazard ratio [HR] for each year of age-at-diagnosis was 1.05 [CI: 1.04-1.06], treatment duration, type of EPTB and HIV-infection (HR = 2.16; CI: 1.22, 3.83). Mortality in genitourinary tuberculosis was no different from latent tuberculosis, while meningitis had the poorest long-term outcome of 46.2%. Compared to meningitis the HR for death was 0.50 (CI: 0.27-0.91) for lymphatic disease, 0.42 (CI: 0.21-0.81) for bone/joint disease, and 0.59 (CI: 0.27-1.31) for peritonitis. The relationship between mortality and therapy duration for each type of EPTB was a unique "V" shaped curve, with the lowest mortality observed at different therapy durations for each, beyond which mortality increased.

CONCLUSIONS

EPTB is comprised of several different diseases with different outcomes and durations of therapy. The "V" shaped relationship between therapy duration and outcome leads to the hypothesis that longer duration of therapy may lead to higher patient mortality.

Initial Antituberculous Regimen with Better Drug Penetration into Cerebrospinal Fluid Reduces Mortality in HIV Infected Patients with Tuberculous Meningitis: Data from an HIV Observational Cohort Study

Tuberculous meningitis (TM) is the deadliest form of tuberculosis. Nearly two-thirds of HIV infected patients with TM die, and most deaths occur within one month. Current treatment of TM involves the use of drugs with poor penetration into the cerebro-spinal fluid (CSF). In this study, we present the mortality before and after implementing a new antituberculous regimen (ATR) with a higher drug penetration in CSF than the standard ATR during the initial treatment of TM in an HIV cohort study. The new ATR included levofloxacin, ethionamide, pyrazinamide, and a double dose of rifampicin and isoniazid and was given for a median of 7 days (interquartile range 6-9). The new ATR was associated with an absolute 21.5% (95% confidence interval (CI), 7.3-35.7) reduction in mortality at 12 months. In multivariable analysis, independent factors associated with mortality were the use of the standard ATR versus the new ATR (hazard ratio 2.05; 95% CI, 1.2-3.5), not being on antiretroviral therapy, low CD4 lymphocyte counts, and low serum albumin levels. Our findings suggest that an intensified initial ATR, which likely results in higher concentrations of active drugs in CSF, has a beneficial effect on the survival of HIV-related TM.

Isoniazid- and streptomycin-resistant miliary tuberculosis complicated by intracranial tuberculoma in a Japanese infant

In Japan, the incidence of severe pediatric tuberculosis (TB) has decreased dramatically in recent years. However, children in Japan can still have considerable opportunities to contract TB infection from adult TB patients living nearby, and infants infected with TB may develop severe disseminated disease. A 3-month-old girl was admitted to our hospital with dyspnea and poor feeding. After admission, miliary TB and multiple brain tuberculomas were diagnosed. Anti-tuberculous therapy was initiated with streptomycin (SM), isoniazid (INH), rifampicin and pyrazinamide. Symptoms persisted after starting the initial treatment and mycobacterial cultures of gastric fluid remained positive. Drug sensitivity testing revealed the TB strain isolated on admission as completely resistant to INH and SM. Treatments with INH and SM were therefore stopped, and treatment with ethambutol and ethionamide was started in addition to rifampicin and pyrazinamide. After this change to the treatment regimen, symptoms and laboratory data gradually improved. The patient was treated with these four drugs for 18 months, and then pyrazinamide was stopped. After another 2 months, ethambutol was stopped. Treatment of tuberculosis was completed in 24 months. No adverse effects of these anti-TB drugs were observed. The patient achieved a full recovery without any sequelae. On the other hand, the infectious source for this patient remained unidentified, despite the extensive contact investigations. The incidence of drug-resistant TB is increasing in many areas of the world. Continuous monitoring for pediatric patients with drug-resistant TB is therefore needed.