Hepatotoxicity from antituberculous therapy in the elderly: a systematic review

Global, regional, and national age-specific progress towards the 2020 milestones of the WHO End TB Strategy: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND

Global evaluations of the progress towards the WHO End TB Strategy 2020 interim milestones on mortality (35% reduction) and incidence (20% reduction) have not been age specific. We aimed to assess global, regional, and national-level burdens of and trends in tuberculosis and its risk factors across five separate age groups, from 1990 to 2021, and to report on age-specific progress between 2015 and 2020.

METHODS

We used the Global Burden of Diseases, Injuries, and Risk Factors Study 2021 (GBD 2021) analytical framework to compute age-specific tuberculosis mortality and incidence estimates for 204 countries and territories (1990-2021 inclusive). We quantified tuberculosis mortality among individuals without HIV co-infection using 22 603 site-years of vital registration data, 1718 site-years of verbal autopsy data, 825 site-years of sample-based vital registration data, 680 site-years of mortality surveillance data, and 9 site-years of minimally invasive tissue sample (MITS) diagnoses data as inputs into the Cause of Death Ensemble modelling platform. Age-specific HIV and tuberculosis deaths were established with a population attributable fraction approach. We analysed all available population-based data sources, including prevalence surveys, annual case notifications, tuberculin surveys, and tuberculosis mortality, in DisMod-MR 2.1 to produce internally consistent age-specific estimates of tuberculosis incidence, prevalence, and mortality. We also estimated age-specific tuberculosis mortality without HIV co-infection that is attributable to the independent and combined effects of three risk factors (smoking, alcohol use, and diabetes). As a secondary analysis, we examined the potential impact of the COVID-19 pandemic on tuberculosis mortality without HIV co-infection by comparing expected tuberculosis deaths, modelled with trends in tuberculosis deaths from 2015 to 2019 in vital registration data, with observed tuberculosis deaths in 2020 and 2021 for countries with available cause-specific mortality data.

FINDINGS

We estimated 9·40 million (95% uncertainty interval [UI] 8·36 to 10·5) tuberculosis incident cases and 1·35 million (1·23 to 1·52) deaths due to tuberculosis in 2021. At the global level, the all-age tuberculosis incidence rate declined by 6·26% (5·27 to 7·25) between 2015 and 2020 (the WHO End TB strategy evaluation period). 15 of 204 countries achieved a 20% decrease in all-age tuberculosis incidence between 2015 and 2020, eight of which were in western sub-Saharan Africa. When stratified by age, global tuberculosis incidence rates decreased by 16·5% (14·8 to 18·4) in children younger than 5 years, 16·2% (14·2 to 17·9) in those aged 5-14 years, 6·29% (5·05 to 7·70) in those aged 15-49 years, 5·72% (4·02 to 7·39) in those aged 50-69 years, and 8·48% (6·74 to 10·4) in those aged 70 years and older, from 2015 to 2020. Global tuberculosis deaths decreased by 11·9% (5·77 to 17·0) from 2015 to 2020. 17 countries attained a 35% reduction in deaths due to tuberculosis between 2015 and 2020, most of which were in eastern Europe (six countries) and central Europe (four countries). There was variable progress by age: a 35·3% (26·7 to 41·7) decrease in tuberculosis deaths in children younger than 5 years, a 29·5% (25·5 to 34·1) decrease in those aged 5-14 years, a 15·2% (10·0 to 20·2) decrease in those aged 15-49 years, a 7·97% (0·472 to 14·1) decrease in those aged 50-69 years, and a 3·29% (-5·56 to 9·07) decrease in those aged 70 years and older. Removing the combined effects of the three attributable risk factors would have reduced the number of all-age tuberculosis deaths from 1·39 million (1·28 to 1·54) to 1·00 million (0·703 to 1·23) in 2020, representing a 36·5% (21·5 to 54·8) reduction in tuberculosis deaths compared to those observed in 2015. 41 countries were included in our analysis of the impact of the COVID-19 pandemic on tuberculosis deaths without HIV co-infection in 2020, and 20 countries were included in the analysis for 2021. In 2020, 50 900 (95% CI 49 700 to 52 400) deaths were expected across all ages, compared to an observed 45 500 deaths, corresponding to 5340 (4070 to 6920) fewer deaths; in 2021, 39 600 (38 300 to 41 100) deaths were expected across all ages compared to an observed 39 000 deaths, corresponding to 657 (-713 to 2180) fewer deaths.

INTERPRETATION

Despite accelerated progress in reducing the global burden of tuberculosis in the past decade, the world did not attain the first interim milestones of the WHO End TB Strategy in 2020. The pace of decline has been unequal with respect to age, with older adults (ie, those aged >50 years) having the slowest progress. As countries refine their national tuberculosis programmes and recalibrate for achieving the 2035 targets, they could consider learning from the strategies of countries that achieved the 2020 milestones, as well as consider targeted interventions to improve outcomes in older age groups.

FUNDING

Bill & Melinda Gates Foundation.

High all-cause mortality and increasing proportion of older adults with tuberculosis in Texas, 2008-2020

Pulmonary tuberculosis (PTB) elimination efforts must consider the global growth of the ageing population. Here we used TB surveillance data from Texas, United States (2008-2020; total n = 10656) to identify unique characteristics and outcomes in older adults (OA, ≥65 years) with PTB, compared to young adults (YA, 18-39 years) or middle-aged adults (40-64 years). We found that the proportion of OA with PTB increased from 15% in 2008 to 24% in 2020 (trend p < 0.05). Diabetes was highly prevalent in OA (32%) but not associated with adverse outcomes. Death was 13-fold higher in OA compared to YA and was 7% at the time of diagnosis which suggests diagnostic delays. However, once TB was suspected, we found no differences in culture, smear, or nucleic acid detection of mycobacteria (although less lung cavitations) in OA. During treatment, OA had less drug-resistant TB, few adverse reactions and adhered with TB treatment. We recommend training healthcare workers to 'think TB' in OA, for prompt treatment initiation to diminish deaths. Furthermore, OA should be added as a priority group to the latent TB treatment guidelines by the World Health Organization, to prevent TB disease in this highly vulnerable group.

Effectiveness of preventive treatment among different age groups and Mycobacterium tuberculosis infection status: a systematic review and individual-participant data meta-analysis of contact tracing studies

BACKGROUND

Tuberculosis is a preventable disease. However, there is debate regarding which individuals would benefit most from tuberculosis preventive treatment and whether these benefits vary in settings with a high burden and low burden of tuberculosis. We aimed to compare the effectiveness of tuberculosis preventive treatment in exposed individuals of differing ages and Mycobacterium tuberculosis infection status while considering tuberculosis burden of the settings.

METHODS

In this systematic review and individual-participant meta-analysis, we investigated the development of incident tuberculosis in people closely exposed to individuals with tuberculosis. We searched for studies published between Jan 1, 1998, and April 6, 2018, in MEDLINE, Web of Science, BIOSIS, and Embase. We restricted our search to cohort studies; case-control studies and outbreak reports were excluded. Two reviewers evaluated titles, abstracts, and full text articles for eligibility. At each stage, two reviewers discussed discrepancies and re-evaluated articles until a consensus was reached. Individual-participant data and a pre-specified list of variables, including characteristics of the exposed contact, the index patient, and environmental characteristics, were requested from authors of all eligible studies; contacts exposed to a drug-resistant tuberculosis index patient were excluded. The primary study outcome was incident tuberculosis. We estimated adjusted hazard ratios (aHRs) for incident tuberculosis with mixed-effects Cox regression models with a study-level random effect. We estimated the number-needed-to-treat (NNT) to prevent one person developing tuberculosis. Propensity score matching procedures were used in all analyses. This study is registered with PROSPERO (CRD42018087022).

FINDINGS

After screening 25 358 records for eligibility, 439 644 participants from 32 cohort studies were included in the individual-participant data meta-analysis. Participants were followed for 1 396 413 person-years (median of 2·7 years [IQR 1·3-4.4]), during which 2496 people were diagnosed with incident tuberculosis. Overall, effectiveness of preventive treatment was 49% (aHR 0·51 [95% CI 0·44-0·60]). Participants with a positive tuberculin-skin-test (TST) or IFNγ release assay (IGRA) result at baseline benefitted from greater protection, regardless of age (0·09 [0·05-0·17] in children younger than 5 years, 0·20 [0·15-0·28] in individuals aged 5-17 years, and 0·17 [0·13-0·22] in adults aged 18 years and older). The effectiveness of preventive treatment was greater in high-burden (0·31 [0·23-0·40]) versus low-burden (0·58 [0·47-0·72]) settings. The NNT ranged from 9 to 34 depending on age among participants with a positive TST or IGRA in both high-burden and low-burden settings; among all contacts (regardless of TST or IGRA test result), the NNT ranged from 29 to 43 in high-burden settings and 213 to 455 in low-burden settings.

INTERPRETATION

Our findings suggest that a risk-targeted strategy prioritising contacts with evidence of M tuberculosis infection might be indicated in low-burden settings, and a broad approach including all contacts should be considered in high-burden settings. Preventive treatment was similarly effective among contacts of all ages.

FUNDING

None.

Interpretable machine learning in predicting drug-induced liver injury among tuberculosis patients: model development and validation study

BACKGROUND

The objective of this research was to create and validate an interpretable prediction model for drug-induced liver injury (DILI) during tuberculosis (TB) treatment.

METHODS

A dataset of TB patients from Ningbo City was used to develop models employing the eXtreme Gradient Boosting (XGBoost), random forest (RF), and the least absolute shrinkage and selection operator (LASSO) logistic algorithms. The model's performance was evaluated through various metrics, including the area under the receiver operating characteristic curve (AUROC) and the area under the precision recall curve (AUPR) alongside the decision curve. The Shapley Additive exPlanations (SHAP) method was used to interpret the variable contributions of the superior model.

RESULTS

A total of 7,071 TB patients were identified from the regional healthcare dataset. The study cohort consisted of individuals with a median age of 47 years, 68.0% of whom were male, and 16.3% developed DILI. We utilized part of the high dimensional propensity score (HDPS) method to identify relevant variables and obtained a total of 424 variables. From these, 37 variables were selected for inclusion in a logistic model using LASSO. The dataset was then split into training and validation sets according to a 7:3 ratio. In the validation dataset, the XGBoost model displayed improved overall performance, with an AUROC of 0.89, an AUPR of 0.75, an F1 score of 0.57, and a Brier score of 0.07. Both SHAP analysis and XGBoost model highlighted the contribution of baseline liver-related ailments such as DILI, drug-induced hepatitis (DIH), and fatty liver disease (FLD). Age, alanine transaminase (ALT), and total bilirubin (Tbil) were also linked to DILI status.

CONCLUSION

XGBoost demonstrates improved predictive performance compared to RF and LASSO logistic in this study. Moreover, the introduction of the SHAP method enhances the clinical understanding and potential application of the model. For further research, external validation and more detailed feature integration are necessary.

Drug-Induced Liver Injury in the Elderly: Consensus Statements and Recommendations from the IQ-DILI Initiative

The elderly demographic is the fastest-growing segment of the world's population and is projected to exceed 1.5 billion people by 2050. With multimorbidity, polypharmacy, susceptibility to drug-drug interactions, and frailty as distinct risk factors, elderly patients are especially vulnerable to developing potentially life-threatening safety events such as serious forms of drug-induced liver injury (DILI). It has been a longstanding shortcoming that elderly individuals are often a vulnerable population underrepresented in clinical trials. As such, an improved understanding of DILI in the elderly is a high-priority, unmet need. This challenge is underscored by recent documents put forward by the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) that encourage data collection in the elderly and recommend improved practices that will facilitate a more inclusive approach. To establish what is already known about DILI in the elderly and pinpoint key gaps of knowledge in this arena, a working definition of "elderly" is required that accounts for both chronologic and biologic ages and varying states of frailty. In addition, it is critical to characterize the biological role of aging on liver function, as well as the different epidemiological factors such as polypharmacy and inappropriate prescribing that are common practices. While data may not show that elderly people are more susceptible to DILI, DILI due to specific drugs might be more common in this population. Improved characterization of DILI in the elderly may enhance diagnostic and prognostic capabilities and improve the way in which liver safety is monitored during clinical trials. This summary of the published literature provides a framework to understand and evaluate the risk of DILI in the elderly. Consensus statements and recommendations can help to optimize medical care and catalyze collaborations between academic clinicians, drug manufacturers, and regulatory scientists to enable the generation of high-quality research data relevant to the elderly population.

Utility of Liver Biopsy in the Diagnosis and Management of Possible Drug-Induced Liver Injury in Patients Receiving Antituberculosis Therapy: A Retrospective Study

BACKGROUND

Drug-induced liver injury (DILI) secondary to ATT treatment (TB-DILI) is reported in 2-28% of patients. We present here a series of clinical cases of suspected DILI arising during antituberculosis treatment, studied with the aid of liver biopsy.

METHODS

this was a retrospective descriptive study including 10 tuberculosis patients who underwent liver biopsy for suspected TB-DILI at the "Lazzaro Spallanzani" Institute from 2017 to 2022.

RESULTS

Ten patients who underwent LB were extracted from the database and included in the retrospective study cohort. According to the clinical classification, eight patients had hepatocellular liver injury, one patient had cholestatic injury, and another had mixed-type injury. Histopathological diagnosis revealed liver damage due to DILI in 5/10 (50%) cases. In one case, liver biopsy showed necrotizing granulomatous hepatitis.

CONCLUSIONS

Severe and persistent elevation of hepatic transaminases, hepatic cholestasis despite discontinuation of therapy, and other suspected hepatic conditions are indications for liver biopsy, which remains a valuable tool in the evaluation of selected tuberculosis patients with suspected DILI for many reasons. However, the decision to perform a liver biopsy should be based on clinical judgment, considering the benefits and risks of the procedure.

Safety and Tolerability of Antimicrobial Agents in the Older Patient

Older patients are at high risk of infections, which often present atypically and are associated with high morbidity and mortality. Antimicrobial treatment in older individuals with infectious diseases represents a clinical challenge, causing an increasing burden on worldwide healthcare systems; immunosenescence and the coexistence of multiple comorbidities determine complex polypharmacy regimens with an increase in drug-drug interactions and spread of multidrug-resistance infections. Aging-induced pharmacokinetic and pharmacodynamic changes can additionally increase the risk of inappropriate drug dosing, with underexposure that is associated with antimicrobial resistance and overexposure that may lead to adverse effects and poor adherence because of low tolerability. These issues need to be considered when starting antimicrobial prescriptions. National and international efforts have been made towards the implementation of antimicrobial stewardship (AMS) interventions to help clinicians improve the appropriateness and safety of antimicrobial prescriptions in both acute and long-term care settings. AMS programs were shown to decrease consumption of antimicrobials and to improve safety in hospitalized patients and older nursing home residents. With the abundance of antimicrobial prescriptions and the recent emergence of multidrug resistant pathogens, an in-depth review of antimicrobial prescriptions in geriatric clinical practice is needed. This review will discuss the special considerations for older individuals needing antimicrobials, including risk factors that shape risk profiles in geriatric populations as well as an evidence-based description of antimicrobial-induced adverse events in this patient population. It will highlight agents of concern for this age group and discuss interventions to mitigate the effects of inappropriate antimicrobial prescribing.

Hepatotoxicity induced by isoniazid in patients with latent tuberculosis infection: a meta-analysis

Aim

The aim of the present study was to conduct a meta-analysis of the frequency of isoniazid-induced liver injury (INH-ILI) in patients receiving isoniazid (INH) preventative therapy (IPT).

Background

The frequency of hepatotoxicity (drug-induced liver injury: DILI) of antituberculosis drugs has been studied, especially when INH, rifampin, and pyrazinamide are co-administered. However, little is known about the frequency of DILI in patients with latent tuberculosis infection (LTBI), where IPT is indicated.

Methods

We searched PubMed, Google Scholar, and the Cochrane Database of Systematic Reviews for studies reporting the frequency of INH-ILI in patients with IPT using one or more diagnostic indicators included in the criteria of the DILI Expert Working Group.

Results

Thirty-five studies comprising a total of 22,193 participants were included. The overall average frequency of INH-ILI was 2.6% (95% CI, 1.7-3.7%). The mortality associated with INH-DILI was 0.02% (4/22193). Subgroup analysis revealed no significant differences in the frequency of INH-ILI in patients older or younger than 50 years, children, patients with HIV, candidates for liver, kidney, or lung transplant, or according to the type of study design.

Conclusion

The frequency of INH-ILI in patients receiving IPT is low. Studies on INH-ILI are needed where the current DILI criteria are used.

An Insight on the Prospect of Quinazoline and Quinazolinone Derivatives as Anti-tubercular Agents

Multiple potential drugs have been developed based on the heterocyclic molecules for the treatment of different symptoms. Among the existing heterocyclic molecules, quinazoline and quinazolinone derivatives have been found to exhibit extensive pharmacological and biological characteristics. One significant property of these molecules is their potency as anti-tubercular agents. Thus, both quinazoline and quinazolinone derivatives are modified using different functional groups as substituents for investigating their anti-tubercular activities. We present a summary of the reported anti-tubercular drugs, designed using quinazoline and quinazolinone derivatives, in this review.

A narrative review of tuberculosis in the United States among persons aged 65 years and older

Tuberculosis (TB) is a preventable infectious disease that confers significant morbidity, mortality, and psychosocial challenges. As TB incidence in the United States (U.S.) decreased from 9.7/100,000 to 2.2/100,000 from 1993 to 2020, the proportion of cases occurring among adults aged 65 and older increased. We conducted a review of published literature in the U.S. and other similar low-TB-burden settings to characterize the epidemiology and unique diagnostic challenges of TB in older adults. This narrative review also provides an overview of treatment characteristics, outcomes, and research gaps in this patient population. Older adults had a 30% higher likelihood of delayed TB diagnosis, with contributing factors such as acid-fast bacilli sputum smear-negative disease (56%) and non-classical clinical presentation. At least 90% of TB cases among older adults resulted from reactivation of latent TB infection (LTBI), but guidance around when to screen and treat LTBI in these patients is lacking. In addition, routine TB testing methods such as interferon-gamma release assays were two times more likely to have false-negative results among older adults. Advanced age was also often accompanied by complex comorbidities and impaired drug metabolism, increasing the risk of treatment failure (23%) and death (19%). A greater understanding of the unique factors of TB among older adults will inform clinical and public health efforts to improve outcomes in this complex patient population and TB control in the U.S.

Tuberculous meningitis in the elderly

OBJECTIVE

Although the elderly population remains at high risk for tuberculosis, studies addressing tuberculous meningitis (TBM) in this age group are scarce. The present study aimed to evaluate the spectrum and outcome of geriatric TBM and document differences between older and young patients.

METHODS

A prospective cohort study was conducted in the adult TBM patients admitted at PGIMER, Chandigarh (India). Consecutive older patients aged 60 years and above were enrolled from January 2019 to December 2020, and young adults aged 18-59 years were enrolled from July 2019 to December 2019.

RESULTS

Fifty-five older patients with a mean age of 66.6 years and 73 young patients with a mean age of 35.1 years were enrolled. At admission, older patients were more likely to have altered mental status (96.4% vs. 78.1%, P = 0.003) and advanced disease with British medical research council staging 2 or 3 (98.2% vs. 89.0%, P = 0.043); however, headache (38.2% vs. 67.1%, P = 0.001), vomiting (18.2% vs. 35.6%, P = 0.030) and fever (80.0% vs. 91.8%, P = 0.052) were less common. Cerebrospinal fluid (CSF) abnormalities were less marked in older patients, with a significant difference in median total cells (70 vs. 110/µl, P = 0.013). Hydrocephalous and infarct were common neuroimaging abnormalities in both groups; however, tuberculomas were significantly less in the elderly (15.1% vs. 35.2%, P = 0.012). Older patients had a significantly low survival rate (56.4% vs. 76.7%, P = 0.021).

CONCLUSION

Significant differences in clinical, CSF and radiological characteristics exist between elderly and young TBM patients, with survival remains dismal in the elderly.

Clinical standards for the dosing and management of TB drugs

BACKGROUND: Optimal drug dosing is important to ensure adequate response to treatment, prevent development of drug resistance and reduce drug toxicity. The aim of these clinical standards is to provide guidance on 'best practice´ for dosing and management of TB drugs.METHODS: A panel of 57 global experts in the fields of microbiology, pharmacology and TB care were identified; 51 participated in a Delphi process. A 5-point Likert scale was used to score draft standards. The final document represents the broad consensus and was approved by all participants.RESULTS: Six clinical standards were defined: Standard 1, defining the most appropriate initial dose for TB treatment; Standard 2, identifying patients who may be at risk of sub-optimal drug exposure; Standard 3, identifying patients at risk of developing drug-related toxicity and how best to manage this risk; Standard 4, identifying patients who can benefit from therapeutic drug monitoring (TDM); Standard 5, highlighting education and counselling that should be provided to people initiating TB treatment; and Standard 6, providing essential education for healthcare professionals. In addition, consensus research priorities were identified.CONCLUSION: This is the first consensus-based Clinical Standards for the dosing and management of TB drugs to guide clinicians and programme managers in planning and implementation of locally appropriate measures for optimal person-centred treatment to improve patient care.

Rapamycin modulates pulmonary pathology in a murine model of Mycobacterium tuberculosis infection

Tuberculosis (TB) treatment regimens are lengthy, causing non-adherence to treatment. Inadequate treatment can lead to relapse and the development of drug resistance TB. Furthermore, patients often exhibit residual lung damage even after cure, increasing the risk for relapse and development of other chronic respiratory illnesses. Host-directed therapeutics are emerging as an attractive means to augment the success of TB treatment. In this study, we used C3HeB/FeJ mice as an experimental model to investigate the potential role of rapamycin, a mammalian target of rapamycin inhibitor, as an adjunctive therapy candidate during the treatment of Mycobacterium tuberculosis infection with moxifloxacin. We report that administration of rapamycin with or without moxifloxacin reduced infection-induced lung inflammation, and the number and size of caseating necrotic granulomas. Results from this study strengthen the potential use of rapamycin and its analogs as adjunct TB therapy, and importantly underscore the utility of the C3HeB/FeJ mouse model as a preclinical tool for evaluating host-directed therapy candidates for the treatment of TB.

Summary: Rapamycin, an mTOR inhibitor, with or without moxifloxacin, reduces lung inflammation and the number and size of caseating necrotic granulomas in Mycobacterium tuberculosis-infected C3HeB/FeJ mice.

Cost effectiveness of three months of rifapentine and isoniazid for latent tuberculosis in Syrian refugees

Background

Latent Tuberculosis infection (LTBI) has a large global burden especially among refugees. We aimed to test the cost effectiveness of weekly rifapentine plus isoniazid for 3 months (3HP) versus nine months of daily isoniazid (INH-9) to treat LTBI in Syrian refugees residing in Turkey.

Methods

We used a Markov state transition model to estimate the incremental cost-effectiveness of 3HP relative to INH-9 using a simulated cohort of Syrian refugees. Both cost and effectiveness were assessed assuming that LTBI screening would be performed, with treatment of those who screen positive. Costs were measured in 2017 US dollars, and effectiveness was estimated as quality adjusted life years (QALYs) gained. An annual discount rate of 3% was applied to future costs and QALYs over the analytical time horizon of 20 years.

Results

Per 100 individuals screened at age 30 in the base case scenario, treating LTBI with 3HP rather than INH-9 resulted in a gain of 0.08 QALYs (95% uncertainty interval: -0.007, 0.221) and savings of $1421 ($483, $3478). Assuming a value of $100000 per QALY, the incremental net monetary benefit of 3HP was $9772 ($639, $24517). Findings were robust to sensitivity analyses except when treating older individuals.

Conclusions

3HP is likely to save costs and improve health compared to INH-9 when used for LTBI treatment among Syrian refugees in Turkey.

Predicting Antituberculosis Drug-Induced Liver Injury Using an Interpretable Machine Learning Method: Model Development and Validation Study

Background

Tuberculosis (TB) is a pandemic, being one of the top 10 causes of death and the main cause of death from a single source of infection. Drug-induced liver injury (DILI) is the most common and serious side effect during the treatment of TB.

Objective

We aim to predict the status of liver injury in patients with TB at the clinical treatment stage.

Methods

We designed an interpretable prediction model based on the XGBoost algorithm and identified the most robust and meaningful predictors of the risk of TB-DILI on the basis of clinical data extracted from the Hospital Information System of Shenzhen Nanshan Center for Chronic Disease Control from 2014 to 2019.

Results

In total, 757 patients were included, and 287 (38%) had developed TB-DILI. Based on values of relative importance and area under the receiver operating characteristic curve, machine learning tools selected patients’ most recent alanine transaminase levels, average rate of change of patients’ last 2 measures of alanine transaminase levels, cumulative dose of pyrazinamide, and cumulative dose of ethambutol as the best predictors for assessing the risk of TB-DILI. In the validation data set, the model had a precision of 90%, recall of 74%, classification accuracy of 76%, and balanced error rate of 77% in predicting cases of TB-DILI. The area under the receiver operating characteristic curve score upon 10-fold cross-validation was 0.912 (95% CI 0.890-0.935). In addition, the model provided warnings of high risk for patients in advance of DILI onset for a median of 15 (IQR 7.3-27.5) days.

Conclusions

Our model shows high accuracy and interpretability in predicting cases of TB-DILI, which can provide useful information to clinicians to adjust the medication regimen and avoid more serious liver injury in patients.

A partially randomised trial of pretomanid, moxifloxacin and pyrazinamide for pulmonary TB

BACKGROUND: Treatment for TB is lengthy and toxic, and new regimens are needed.METHODS: Participants with pulmonary drug-susceptible TB (DS-TB) were randomised to receive: 200 mg pretomanid (Pa, PMD) daily, 400 mg moxifloxacin (M) and 1500 mg pyrazinamide (Z) for 6 months (6Pa200MZ) or 4 months (4Pa200MZ); 100 mg pretomanid daily for 4 months in the same combination (4Pa100MZ); or standard DS-TB treatment for 6 months. The primary outcome was treatment failure or relapse at 12 months post-randomisation. The non-inferiority margin for between-group differences was 12.0%. Recruitment was paused following three deaths and not resumed.RESULTS: Respectively 4/47 (8.5%), 11/57 (19.3%), 14/52 (26.9%) and 1/53 (1.9%) DS-TB outcomes were unfavourable in patients on 6Pa200MZ, 4Pa200MZ, 4Pa100MZ and controls. There was a 6.6% (95% CI -2.2% to 15.4%) difference per protocol and 9.9% (95%CI -4.1% to 23.9%) modified intention-to-treat difference in unfavourable responses between the control and 6Pa200MZ arms. Grade 3+ adverse events affected 68/203 (33.5%) receiving experimental regimens, and 19/68 (27.9%) on control. Ten of 203 (4.9%) participants on experimental arms and 2/68 (2.9%) controls died.CONCLUSION: PaMZ regimens did not achieve non-inferiority in this under-powered trial. An ongoing evaluation of PMD remains a priority.

[Unusual presentation of late reactivated tuberculosis in immunosenescence after nine decades latency]

INTRODUCTION

 Tuberculosis is an often underestimated infectious disease which can lead to manifest infections even after years of latency. Pulmonary manifestations are by far the most frequent, although any other organ can be equally affected.

HISTORY

 A 95-year old patient presented with a localized painful swelling of the right foot for further investigation. Despite her advanced age there were no pre-existing medical conditions, except for a club foot existing since early childhood.

FINDINGS AND DIAGNOSIS

 On physical examination we found a hyperemic fluctuant swelling of 5 cm diameter at the arch of the right foot. The X-ray showed a complete destruction of the regular osseous structures from the upper ankle joint to the proximal metatarsal bones.

THERAPY AND COURSE

 Intraoperatively the suspicion of an abscess was confirmed and material was obtained for microbiological investigation. Liquid cultures grew Mycobacterium tuberculosis. In an MRI-scan, involvement of the tarsal and metatarsal bones could not be excluded, thus the duration of the standard antituberculose treatment was set to 9 months.

CONCLUSIONS

 Tuberculosis, primary or reactivated, should always be considered as a potential cause of unclear infections; especially in patients with anticipated immunosenescence.

Tuberculosis in Older Adults: Seattle and King County, Washington

BACKGROUND

In the United States, tuberculosis (TB) incidence rates are highest among adults aged ≥65 years. We performed this study to evaluate outcomes of older patients undergoing treatment for TB disease, including the frequency of adverse events related to TB treatment.

METHODS

This study evaluated adult patients who were diagnosed with pulmonary TB from 2009 to 2014 in King County, Washington. Patient characteristics, manifestation of TB, and treatment outcomes in different age groups were compared. Frequency and type of adverse events that resulted in treatment interruption were evaluated and patients aged ≥65 years were compared with selected younger patients.

RESULTS

There were 403 patients who met the study criteria, 111 of whom were aged ≥65 years. Older patients were significantly less likely to have cavitation on chest radiographs. Patients aged ≥65 years were less likely to complete TB treatment (76.6% vs 94.9%, P < .0001) and were more likely to die during treatment (18.9% vs 2.1%, P < .0001). The difference in these outcomes was heightened for those aged ≥75 years compared with those aged <75 years. Those aged ≥75 years were also more likely to have an adverse event attributable to TB medication and were more likely to have an adverse event later in therapy. Regardless of age, pyrazinamide was responsible for the majority of adverse reactions.

CONCLUSIONS

Adults aged ≥65 years with pulmonary TB had less-advanced disease but a higher risk of complications during treatment such as death or adverse events. This effect was most pronounced among those aged ≥75 years.

Predicting drug-induced liver injury from anti-tuberculous medications by early monitoring of liver tests

OBJECTIVE

Tuberculosis Drug Induced Liver Injury (TB-DILI) is a common and potentially severe complication associated with anti-tuberculous treatment (ATT). Optimal liver test monitoring for standard TB medication has not been established. We describe the predictive value of pre-treatment liver tests (LTs) and at 2-weeks after initiation of ATT for the detection of TB-DILI.

METHODS

Patients initiating ATT were monitored with routine LTs pre-treatment and after 2-weeks. Logistic regression models were constructed to retrospectively identify pre-treatment variables associated with 'late' TB-DILI (>2 weeks after treatment initiation) and whether pre-treatment and 2-week alanine aminotransferase (ALT) levels could predict late TB-DILI.

RESULTS

1247 patients with active tuberculosis managed at 5 sites across north west London between January 2015 and December 2018 were monitored with routine LTs. 103 cases (8.3%) of ATT-associated DILI were diagnosed. 60 cases (58.3%) of TB-DILI occurred later than 2-weeks. The risk of late TB-DILI was 2.2-fold greater for every 30 U/L increment in ALT pre-treatment (OR 2.16, 95% CI 1.38-3.29 p<0.001) and 2.1-fold greater for every 30 U/L increment in ALT gradient at 2-weeks (OR 2.06, 95% CI 1.52-2.76 p<0.001).

CONCLUSION

Routine 2-week LTs capture early TB-DILI and may be valuable in predicting late TB-DILI in patients on ATT.

Tuberculosis Contact Investigations Conducted in New York City Adult Day Care and Senior Centers, 2011-2018

OBJECTIVES

Multiple tuberculosis (TB) exposures have been reported in New York City (NYC) adult day care and senior centers. Strategies to identify TB transmission at such locations are needed.

METHOD

Review of the NYC TB Registry identified 12 contact investigations (CIs) at adult day care or senior centers (2011-2018).

RESULTS

Median age of the 12 index patients was 81 years. Of 148 contacts identified who had no history of TB infection or disease, 141 (95%) were tested for TB, primarily with interferon gamma release assays; 46 (33%) tested positive. Transmission was probable (n = 3) or possible (n = 1) at 4 (33%) centers; at all of these, the index patient had an acid-fast bacilli-positive sputum smear. Transmission was not found from index patients with negative sputum smears.

DISCUSSION

We found evidence of transmission of smear-positive respiratory TB disease to contacts in adult day care or senior centers, underscoring the importance of CI.

2-Aminoaryl-3,5-diaryl pyrazines: Synthesis, biological evaluation against Mycobacterium tuberculosis and docking studies

Rationally designed Mycobacterium tuberculosis (Mtb) inhibitors were synthesized under Buchwald conditions using Pd₂ (dba)₃ /xantphos and the compounds were investigated for their biological activity against the Mtb standard strain H37Rv and two other clinically isolated multidrug-resistant strains with different drug resistance patterns. Compounds 5e, 6e, 7e, and 8e exhibited excellent antituberculosis activity against H37Rv with a minimum inhibitory concentration (MIC) value of 15 μg/ml. Compounds 5a, 6c, 7b, 8a, 8b, and 8d also displayed their potency with a MIC value in the range of 15-25 μg/ml. In addition to the Mtb studies, compounds 4e, 5e, 7e, and 8e were tested for cytotoxicity on HEK-293 cells and compounds 7e and 8e were identified to have low toxicities of up to 200 and 300 μM, respectively. The synthesized compounds docked with the 2FUM protein of Mtb and the docking studies revealed that compounds 5e, 6e, 7e, and 8e can bind strongly in the active site of the enzyme and showed binding energies of -9.62, -10.7, -11.48, and -12.06 kcal/mol, respectively. Compound 7e forms four hydrogen bonds, whereas compound 8e forms five hydrogen bonds with amino acids, respectively. Based on these results, compounds 7e and 8e might be considered potential lead compounds with good anti-Mtb potency.

Abnormal Levels of Liver Enzymes and Hepatotoxicity in HIV-Positive, TB, and HIV/TB-Coinfected Patients on Treatment in Fako Division, Southwest Region of Cameroon

Hepatotoxicity is historically the 3^rd most common reason for drug withdrawal and toxicity-related discontinuation of treatment. This study was aimed at determining the incidence and the onset of hepatotoxicity and at evaluating the relationship of some risk factors for hepatotoxicity among Human Immunodeficiency Virus- (HIV-) positive, tuberculosis (TB), and HIV/TB patients on treatment. This was a prospective follow-up study involving 125 participants from the HIV/AIDS and TB treatment centres in three hospitals in Fako Division of Cameroon. These TB and HIV patients were initiated on RHEZ (R = Rifampicin, H = Isoniazid, E = Ethambutol, and P = Pyrazinamide) and TELE (efavirenz/tenofovir/lamivudine), respectively, and followed up for 12 weeks between September 2018 and November 2019. The levels of liver enzymes (transaminases, gamma-glutamyltransferase, alkaline phosphatase, and unconjugated/total bilirubin) were measured spectrophotometrically using serum. The Chi-squared (χ²) test was used to assess the association between risk factors and hepatotoxicity, while the Kaplan-Meier survival analysis with the log-rank test was used to determine the occurrence of hepatotoxicity in the different groups. We followed the general study population for a total person time of 6580 person-days, with an incidence rate and cumulative incidence of 8 cases per 1000 person-days (53/6580 person-days) and 42.4% (53/125), respectively (95% confidence interval), recorded after 12 weeks of follow-up of all the participants. The onset of hepatotoxicity in the total study population was statistically significant (χ² = 9.5334; p = 0.022979; CI = 95%), with the majority observed at week eight of follow-up. Also, the incidence rate and cumulative incidence of hepatotoxicity with respect to HIV/AIDS, TB, and HIV/TB patients, respectively, at 95% confidence interval were: 8 cases per 1000 person-days (32/3843 person-days) and 32/76 (42.1%), 6 cases per 1000 person-days (12/1932 person-days) and 12/32 (37.5%), and 11 cases per 1000 person-days (9/805 person-days) and 9/17 (52.9%). This study shows that the incidence rate and cumulative incidence of hepatotoxicity in HIV/AIDS, TB, and HIV/TB patients on treatment were high in Fako Division, Cameroon. Also, it is very important to check these patients' liver function especially within the first 12 weeks of treatment.

The clinical impact of drug-induced hepatotoxicity on anti-tuberculosis therapy: a case control study

BACKGROUND

There are limited data available on whether drug-induced hepatotoxicity (DIH) affects the clinical outcomes of tuberculosis (TB) treatment. We explored the effects of DIH on the clinical course and outcomes of pulmonary TB.

METHODS

In this retrospective cohort study, we included patients with culture-proven pulmonary TB treated in a tertiary hospital from 2013 to 2016. DIH was defined as proposed by the official American Thoracic Society statement. We compared the clinical outcomes of DIH and non-DIH patients.

RESULTS

Between January 1, 2013 and December 31, 2016, a total of 168 TB patients were included, and 20 (11.9%) were diagnosed with DIH. These patients were significantly older, had a higher Charlson Comorbidity Index score, exhibited more chronic liver disease, included more chronic alcoholics, and had a lower body mass index than non-DIH patients. We found no significant differences between DIH and non-DIH patients in the 2-month sputum culture conversion rate, the time to sputum culture conversion, treatment outcomes, or total treatment duration. However, the ratio of treatment interruption time to total treatment duration and the proportion of hepatotonic users were significantly higher among DIH patients.

CONCLUSION

DIH development during TB treatment does not significantly affect the clinical outcomes of pulmonary TB. However, treatment interruption caused by DIH may increase the risks of future relapse and acquired resistance. Further study is needed.

Completion rate of latent tuberculosis infection treatment in patients aged 65 years and older

INTRODUCTION

There are insufficient data on the treatment of latent tuberculosis infection (LTBI) in elderly patients. We investigated the completion rate of treatment in elderly LTBI patients.

METHODS

A retrospective multicentre study was conducted at five university hospitals in South Korea. We reviewed the electronic medical records of patients aged 65 years and older who were diagnosed with LTBI via positive interferon-gamma release assay results between January 2016 and December 2018. Treatment completion was defined as ingestion of more than 80% of all prescribed medications without loss to follow-up.

RESULTS

During the study period, 127 LTBI patients aged 65 years and older visited outpatient department. Among them, 77 patients aged 65-78 years (median age, 69 years [interquartile range, 66-71 years]) who received LTBI treatment were analysed. Common reasons for IGRA testing in elderly patients were health-care worker (n = 33, 42.9%) and household contact with infectious TB patients (n = 18, 23.4%). The overall completion rate of LTBI treatment was 83.1% (n = 64), and the completion rate of 3-month isoniazid plus rifampin regimen was 88.4%. Adverse effects were reported in 23 patients (29.9%), and an increase in aminotransferase level was the most common adverse effect (n = 11, 14.3%). Three patients (3.9%) with the adverse effect discontinued treatment and 10 (13.0%) patients were lost to follow-up.

CONCLUSIONS

LTBI treatment in patients aged 65-78 years was relatively well tolerated. In LTBI treatment in elderly patients, the majority of discontinuation of treatment was due to loss to follow-up rather than adverse effects of anti-TB medications.

A closer look at the spectrum of drug-induced liver injury in sub-Saharan Africa

Introduction: Drug-induced liver injury (DILI) has become the most frequent cause of acute liver failure in high-income countries. However, little is known about the determinants of DILI in sub-Saharan Africa (SSA), where the prescription of antimicrobials and the use of potentially hepatotoxic traditional medicine are common. Areas covered: Based on an extensive literature search, we summarize current data available on the epidemiology and risk factors of DILI in SSA. We discuss the most likely causes of DILI in the region, including antimicrobial therapies and traditional medicine. We also highlight research gaps as well as barriers to diagnosis and management of the condition, and explore ways to address these important challenges. Expert opinion: DILI is underestimated in SSA and several factors challenge its early diagnosis, including lack of information on the causes of DILI in the region, sub-optimal knowledge about the condition among clinicians, and structural difficulties faced by health care systems. In order to better prevent the occurrence of DILI and its complications, it is crucial to enhance awareness among health care providers and patients, adapt drug prescription habits and regulations, and improve current knowledge on the main risk factors for DILI, including host genetic and environmental determinants.

The role of regular liver function monitoring in antituberculosis drug-induced liver injury

BACKGROUND

Antituberculosis (TB) drug-induced liver injury (ATLI) is a common adverse effect of anti-TB drugs. Whether regular monitoring of liver function can ameliorate ATLI has been widely debated. The current study aimed to investigate the liver test monitoring status of patients receiving anti-TB treatment in Taiwan, as well as the impact of scheduled liver function monitoring on the risk of ATLI.

METHODS

Patients who received anti-TB treatment at our hospital between 2009 and 2017 were enrolled for retrospective analysis.

RESULTS

A total of 1062 patients were included, and of them 469 (44.2%) received regular liver function monitoring (good monitoring group). ATLI was recognized in 100 (9.4%) patients. The good monitoring group detected more ATLI cases early compared with the poor monitoring group (14.7% vs 5.2%, and 21.4 vs 61.6 days, p < 0.01), with a lower peak serum alanine aminotransferase (276.1 vs 507.1 IU/L, p = 0.05).

CONCLUSION

In the current study, less than half of all patients who received anti-TB drugs had their liver function monitored regularly. Scheduled monitoring of liver function could facilitate the early identification of more ATLI cases, thus leading to less liver injury. The implementation of periodic liver function monitoring tests in patients receiving anti-TB treatment should be re-emphasized and encouraged.

Characteristics and risk factors for antituberculosis drug-induced liver injury in a cohort of patients with cirrhosis in a tertiary referral university teaching hospital in Thailand

Background

Cirrhotic patients are susceptible to drug toxicity, which presents frequently with antituberculosis drug (ATD) treatment. Previous studies of ATD-induced liver injury (ATDILI) in cirrhotics have been limited to patients with early-stage cirrhosis.

Objectives

To describe characteristics and determine risk factors for ATDILI in cirrhotic patients.

Methods

We included 64 cirrhotic patients treated with ATDs between 2006 and 2016 in a tertiary referral university teaching hospital in Bangkok, Thailand. Cirrhosis was diagnosed by radiological features, including small-sized nodular liver and/or caudate lobe hypertrophy or evidence of portal hypertension (collateral vessels, varices, and/or splenomegaly). Clinical information was retrospectively abstracted. Characteristics of patients with ATDILI vs. those without ATDILI were compared.

Results

Six (9.4%) patients developed ATDILI with the median duration from ATD initiation of 14 days (range: 6–66). All the 6 patients who developed ATDILI received 3 hepatotoxic ATDs (isoniazid, rifampin, and pyrazinamide) and had Child–Turcotte–Pugh class B cirrhosis. The patients with ATDILI were found to have a higher percentage of human immunodeficiency virus (HIV) infection than patients without ATDILI (50% vs. 8.6%; P = 0.02).

Conclusions

Cirrhotic patients, particularly those with underlying HIV infection, are at risk of developing ATDILI. Pyrazinamide should be used cautiously in cirrhotic patients due to the significantly increased risk of ATIDLI. This study supports the current recommendation for the use of ATD in patients with cirrhosis; however, the ATD regimen should be carefully selected, particularly for cirrhotic patients with HIV infection.

Monitoring tuberculosis contact tracing outcomes in Western Sydney, Australia

Treatment of latent tuberculosis infection (LTBI) is an important component of strategies to achieve global tuberculosis (TB) elimination, but implementation is rarely monitored. This is a retrospective review of TB contact tracing outcomes at one of the busiest TB clinics in Australia, measured against the Centre for Disease Control and Prevention performance indicators. In total, 45 of 53 (85%) pulmonary TB cases had 171 close contacts, of whom 139 (81%) were evaluated with a tuberculin skin test (TST); 58 of 139 (42%) were positive at baseline. Among 57 close contacts of 16 sputum smear-positive TB cases, the elicitation, evaluation, initiation of LTBI treatment and completion rates were 93%, 86%, 14% and 100%, and among 114 close contacts of 37 sputum smear-negative pulmonary TB cases 81%, 83%, 16% and 89%, respectively. Of 79 contacts with an initial negative TST, 19 of 47 (40%) demonstrated TST conversion when retested; 5 of 19 (26%) were offered LTBI treatment. Four secondary TB cases were identified. One incident TB case developed a pleural effusion 5 months after TST conversion, despite LTBI treatment. Apart from young children, LTBI treatment was inconsistently initiated in household TB contacts. Safe and pragmatic treatment options, as well as functional monitoring frameworks, are essential to improve LTBI treatment implementation.

Clinical and experimental research in antituberculosis drug-induced hepatotoxicity: a review

Drug-induced liver injury is the common adverse effect seen in patients receiving antituberculosis drugs (ATDs). There are several risk factors associated with the development of hepatotoxicity in such patients. Though there have been appreciable efforts taken by carrying out studies investigating the efficacy of several natural and synthetic compounds in minimising this effect, the only choice available for clinicians is withdrawal of drugs. This review would give a precise idea of ATD-induced hepatotoxicity, its underlying mechanisms and alternative therapies for the same.

Drug-induced liver injury from antituberculous treatment: a retrospective study from a large TB centre in the UK

Background

We describe drug-induced liver injury (DILI) secondary to antituberculous treatment (ATT) in a large tuberculosis (TB) centre in London; we identify the proportion who had risk factors for DILI and the timing and outcome of DILI.

Methods

We identified consecutive patients who developed DILI whilst on treatment for active TB; patients with active TB without DILI were selected as controls. Comprehensive demographic and clinical data, management and outcome were recorded.

Results

There were 105 (6.9%) cases of ATT-associated DILI amongst 1529 patients diagnosed with active TB between April 2010 and May 2014. Risk factors for DILI were: low patient weight, HIV-1 co-infection, higher baseline ALP, and alcohol intake. Only 25.7% of patients had British or American Thoracic Society defined criteria for liver test (LT) monitoring. Half (53%) of the cases occurred within 2 weeks of starting ATT and 87.6% occurred within 8 weeks. Five (4.8%) of seven deaths were attributable to DILI.

Conclusions

Only a quarter of patients who developed DILI had British or American Thoracic Society defined criteria for pre-emptive LT monitoring, suggesting that all patients on ATT should be considered for universal liver monitoring particularly during the first 8 weeks of treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2330-z) contains supplementary material, which is available to authorized users.

Home-Based and Facility-Based Directly Observed Therapy of Tuberculosis Treatment under Programmatic Conditions in Urban Tanzania

Introduction

Decentralization of Directly Observed Treatment (DOT) for tuberculosis (TB) to the community (home-based DOT) has improved the coverage of TB treatment and reduced the burden to the health care facilities (facility-based DOT). We aimed to compare TB treatment outcomes in home-based and facility-based DOT under programmatic conditions in an urban setting with a high TB burden.

Methodology

A retrospective analysis of a cohort of adult TB patients (≥15 years) routinely notified between 2010 and 2013 in two representative TB sub-districts in the Temeke district, Dar es Salaam, Tanzania. We assessed differences in treatment outcomes by calculating Risk Ratios (RRs). We used logistic regression to assess the association between DOT and treatment outcomes.

Results

Data of 4,835 adult TB patients were analyzed, with a median age of 35 years, 2,943 (60.9%) were men and TB/HIV co-infection prevalence of 39.9%. A total of 3,593 (74.3%) patients were treated under home-based DOT. Patients on home-based DOT were more likely to die compared to patients on facility-based DOT (RR 2.04, 95% Confidence Interval [95% CI]: 1.52–2.73), and more likely to complete TB treatment (RR 1.14, 95% CI: 1.06–1.23), but less likely to have a successful treatment outcome (RR 0.94, 95% CI: 0.92–0.97). Home-based DOT was preferred by women (adjusted Odds Ratio [aOR] 1.55, 95% CI: 1.34–1.80, p<0.001), older people (aOR 1.01 for each year increase, 95% CI: 1.00–1.02, p = 0.001) and patients with extra-pulmonary TB (aOR 1.45, 95% CI: 1.16–1.81, p = 0.001), but less frequently by patients on a retreatment regimen (aOR 0.12, 95% CI: 0.08–0.19, p<0.001).

Conclusions/significance

TB patients under home-based DOT had more frequently risk factors of death such as older age, HIV infection and sputum smear-negative TB, and had higher mortality compared to patients under facility-based DOT. Further operational research is needed to monitor the implementation of DOT under programmatic conditions.

Diagnosis and treatment of coinfection of pulmonary tuberculosis and chronic hepatitis B

Hepatitis B virus (HBV) and tuberculosis bacillus (TB) are leading causes of infectious diseases in China, leading to a range of life-threaten diseases including chronic hepatitis B (CHB), cirrhosis, hepatocellular carcinoma (HCC) and pulmonary tuberculosis (PTB). Due to the high prevalence of infection and increased number of cases, coinfection of HCC and PTB is becoming a new hot area. Differences between coinfection and single infection include the disease process, injuries, medication selection, curative effects, drug-resistance and side effects. In particular, the adverse effects of clinical prognosis, etiological treatment, anti-tuberculosis drug induced liver injury (ATLI) and multidrug-resistant pulmonary tuberculosis (MDR-TB) have became a new challenge for therapy. This review aims to summarize the incidence of infections, clinical observations, adversely effects and existing problems of treatment, the development of antituberculous and anti-HBV therapy and hepatitis protection. Additionally, a suggestion for improving therapeutic efficacy has been proposed as well.

B cell responses in older adults with latent tuberculosis: Considerations for vaccine development

Reactivation of latent tuberculosis (LTBI) is more common among the aging population and may contribute to increased transmission in long-term health care facilities. Difficulties in detecting LTBI due to potential blunting of the tuberculin skin test (TST), and the lowered ability of the elderly to tolerate the course of antibiotics, underscore the need for an effective vaccine. Immuno-senescence reduces the capacity of vaccines to induce sufficient levels of protective immunity against many pathogens, further increasing the susceptibility of the elderly to infectious diseases. We sought to evaluate the response of B cells to Mycobacterium tuberculosis (Mtb) in residents of long-term care facilities to determine the feasibility of using a vaccine to control infection and transmission from reactivated LTBI. Our results demonstrate that although B cell responses were higher in subjects with LTBI, Mtb antigens could stimulate B cell activation and differentiation in vitro in TST negative subjects. B cells from elderly subjects expressed high basal levels of Toll-like receptor (TLR)2 and TLR4 and responded strongly to Mtb ligands with some activation pathways dependent on TLR2. B cells derived from blood, tonsil and spleen from younger subjects responded similarly and to the same magnitude. These results suggest that B cell responses are robust in the elderly and modifications to a TB vaccine, such as TLR2 ligand-based adjuvants, may help increase immune responses to a protective level.

Does tuberculosis threaten our ageing populations?

Background

The global population is ageing quickly and our understanding of age-related changes in the immune system suggest that the elderly will have less immunological protection from active tuberculosis (TB).

Discussion

Ongoing global surveillance of TB notifications shows increasing age of patients with active TB. This effect of age is compounded by changes to clinical manifestations of disease, confounding of diagnostic tests and increased rates of adverse reactions to antimicrobial treatment of TB. Future epidemiological surveillance, development of diagnostic tests and trials of treatment shortening should all include a focus on ageing people.

Summary

More detailed surveillance of TB notifications in elderly people should be undertaken and carefully evaluated. Risk stratification will help target care for those in greatest need, particularly those with comorbidities or on immunosuppressive therapies. Novel diagnostics and treatment regimes should be designed specifically to be used in this cohort.

The clinical outcomes of oldest old patients with tuberculosis treated by regimens containing rifampicin, isoniazid, and pyrazinamide

Objectives

To investigate the clinical characteristics, adverse drug reactions, and outcomes of the oldest old patients (aged ≥80 years) with tuberculosis (TB) treated with rifampicin, isoniazid, and pyrazinamide (RIP)-containing regimens.

Design

A retrospective chart review study.

Setting

A 1,200-bed tertiary teaching hospital in southwest Taiwan.

Participants

We conducted a retrospective observational study between January 1, 2005 and December 31, 2011. Seven hundred adult patients (aged ≥18 years) with TB treated with RIP-containing anti-TB regimens were reviewed, including 161 oldest old patients.

Outcome measures

Clinical outcomes included clinical responsiveness and microbiological eradication. Adverse outcomes included drug-induced hepatitis, and other symptoms included gastrointestinal upset (eg, abdominal pain, vomiting, diarrhea, or dyspepsia), skin rash, joint pain, and hyperuricemia.

Results

Compared with the non-oldest old adult patients, the oldest old patients more frequently had hepatitis (P=0.014), gastrointestinal upset (P=0.029), and unfavorable outcomes (P<0.001). In a multivariate analysis, hepatitis during treatment (adjusted odds ratio: 3.482, 95% confidence interval: 1.537–7.885; P<0.003) and oldest old age (adjusted odds ratio: 5.161, 95% confidence interval: 2.294–11.613; P<0.010) were independent risk factors for unfavorable outcomes. In the oldest old patients with hepatitis, rifampicin use was more common in the favorable outcome group than in the unfavorable outcome group (100% vs 37.5%; P=0.001).

Conclusion

The oldest old age and hepatitis during RIP treatment were associated with unfavorable outcomes. For the oldest old patients with TB having hepatitis during treatment, rifampicin rechallenge and use might benefit the treatment outcome.

Novel targeting of PEGylated liposomes for codelivery of TGF-β1 siRNA and four antitubercular drugs to human macrophages for the treatment of mycobacterial infection: a quantitative proteomic study

Tuberculosis (TB) is still a major public health issue in developing countries, and its chemotherapy is compromised by poor drug compliance and severe side effects. This study aimed to synthesize and characterize new multimodal PEGylated liposomes encapsulated with clinically commonly used anti-TB drugs with linkage to small interfering RNA (siRNA) against transforming growth factor-β1 (TGF-β1). The novel NP-siRNA liposomes could target THP-1-derived human macrophages that were the host cells of mycobacterium infection. The biological effects of the NP-siRNA liposomes were evaluated on cell cycle distribution, apoptosis, autophagy, and the gene silencing efficiency of TGF-β1 siRNA in human macrophages. We also explored the proteomic responses to the newly synthesized NP-siRNA liposomes using the stable isotope labeling with amino acids in cell culture approach. The results showed that the multifunctional PEGylated liposomes were successfully synthesized and chemically characterized with a mean size of 265.1 nm. The novel NP-siRNA liposomes functionalized with the anti-TB drugs and TGF-β1 siRNA were endocytosed efficiently by human macrophages as visualized by transmission electron microscopy and scanning electron microscopy. Furthermore, the liposomes showed a low cytotoxicity toward human macrophages. There was no significant effect on cell cycle distribution and apoptosis in THP-1-derived macrophages after drug exposure at concentrations ranging from 2.5 to 62.5 μg/mL. Notably, there was a 6.4-fold increase in the autophagy of human macrophages when treated with the NP-siRNA liposomes at 62.5 μg/mL. In addition, the TGF-β1 and nuclear factor-κB expression levels were downregulated by the NP-siRNA liposomes in THP-1-derived macrophages. The Ingenuity Pathway Analysis data showed that there were over 40 signaling pathways involved in the proteomic responses to NP-siRNA liposome exposure in human macrophages, with 160 proteins mapped. The top five canonical signaling pathways were eukaryotic initiation factor 2 signaling, actin cytoskeleton signaling, remodeling of epithelial adherens junctions, epithelial adherens junction signaling, and Rho GDP-dissociation inhibitor signaling pathways. Collectively, the novel synthetic targeting liposomes represent a promising delivery system for anti-TB drugs to human macrophages with good selectivity and minimal cytotoxicity.