Ensuring rational introduction and responsible use of new TB tools: outcome of an ERS multisector consultation

Relapse after treatment with standardized all-oral short regimens for rifampicin-resistant tuberculosis (RR-TB): A systematic review and meta-analysis

Background

Treatment for rifampicin-resistant tuberculosis (RR-TB) has been shortened to 12 months or less, with duration depending on the regimen used and treatment response. Treatment shortening has the potential to increase the risk of relapse, with a new episode of RR-TB after cure or completion. The proportion of relapses after standardized all-oral short (12 months or less) RR-TB regimens has not yet been systematically reviewed, which is the main objective of this review.

Methods

This is a systematic review and meta-analysis. PubMed, Web of Science and Google scholar databases were systematically investigated to identify studies published between January 2018 and November 2023. Characteristics of studies, demographic data, baseline clinical condition, resistance profile, and definitions used for relapse, failure, and end-of-treatment outcomes are summarized in tables and graphs. Pooled proportions are estimated for relapse.

Results

A total of ten studies were included in this review and meta-analysis, representing 1792 participants. Seven studies were clinical trials and two were cohorts. Five studies investigated all-oral six-month regimens composed of bedaquiline, pretomanid, and linezolid (BPaL). The remaining studies assessed other standardized all-oral short regimens, with treatment duration between 6 and 12 months. Post-treatment follow-up (PTFU) duration ranged from 6 to 30 months. The pooled proportion estimate of relapse was 2·0% (95 % CI, 1·0-3·0%) for all and BPaL-based regimens. Treatment extension due to poor treatment response was poorly documented.

Conclusion

This review showed that the proportion of relapse in RR-TB patients treated with standardized short all-oral regimens was low. The low relapse proportion is similar to what was achieved for drug-susceptible Tuberculosis patients treated with first-line rifampicin-containing regimens. However, most data came from trial settings, and in some studies the post-treatment follow-up was short. Studies of large programmatic cohorts with longer post-treatment follow-up periods are needed to confirm the low relapse rate shown in the clinical trials.

Polymorphisms in drug metabolism genes as a risk factor for first-line anti-tuberculosis drug-induced liver injury

BACKGROUND

Anti-tuberculosis drug-induced liver injury (AT-DILI) is one of the most common side effects in TB patients during treatment. The prime cause of liver injury during TB treatment is reported to be isoniazid and its metabolites. Different factors influenced the development of AT-DILI, and genetic factors are one of the major factors.

METHODS AND RESULTS

Polymorphisms in drug metabolism genes like NAT2, CYP2E1, PXR, and GST have been reported to be associated with AT-DILI, and they are one of the major areas of focus at present. Attempts are met in this review to analyse the different markers in these drug metabolism genes for their association with AT-DILI.

CONCLUSION

A better understanding of the polymorphisms in these genes and their functional effects will give better insights into the development of AT-DILI, and it could facilitate in designing and developing more effective personalized treatment for TB.

Toxic Effect of Combined Exposure of Microplastics and Copper on Goldfish (Carassius auratus): Insight from Oxidative Stress, Inflammation, Apoptosis and Autophagy in Hepatopancreas and Intestine

The enhancement of the toxic effect of microplastics (MPs) on heavy metals and its mechanism needs more in-depth and systematic research. In this study, the copper (Cu) accumulation, histological injury, and expression of genes involved in oxidative stress, inflammation, apoptosis, and autophagy of goldfish after single or combined exposure of MPs (1 mg/L) and Cu²⁺ (0.1 mg/L) for 7 days were determined. The results demonstrated that MPs enhanced the Cu accumulation in hepatopancreas and intestine of goldfish and induced more severe oxidative stress in the hepatopancreas and intestine of goldfish. Additionally, combined exposure of MPs and Cu induced inflammation, excessive apoptosis and insufficient autophagy in the hepatopancreas. Contrary, the inflammation and apoptosis were depressed in the intestine after combined exposure of MPs and Cu, which still requires further exploration. Hence, these findings provide further evidence for the threat of MPs and its adsorbed heavy metals.

The Relation Between the Emergence of Fluoroquinolone Resistance and Fluoroquinolone Exposure in New Cases of Active Pulmonary Tuberculosis

OBJECTIVE

This study aimed to determine the ratio of fluoroquinolone (FQ) exposure before the diagnosis of patients with a new case of active pulmonary tuberculosis (TB) and to investigate the correlation of this treatment with the emergence of FQ-resistant strains.

MATERIAL AND METHODS

In this retrospective comparative case series study, a total of 132 patients, who had been diagnosed with adult, culture-positive, active pulmonary TB were reviewed. The FQ group had 30 patients who had had ≥1 time and ≥7 days of FQ exposure within 1 year before the diagnoses. The control group included an equal number of patients with TB with similar demographic characteristics (non-FQ group). Ofloxacin (OFX) and moxifloxacin (MFX) resistance were examined at 2 different concentrations (2 and 4 mg/L for OFX; 0.25 and 0.5 mg/L for MFX).

RESULTS

Of the 132 patients, 30 (22%) had 7 days or longer of FQ monotherapy within 1 year of initiation of anti-TB treatment. FQ resistance was detected in 2 (3.3%) patients. In the FQ group, MFX resistance at 0.25 mg/L concentration was observed in 1 patient, whereas another patient had OFX and MFX resistance at 4 mg/L and 0.5 mg/L concentrations, respectively. In the non-FQ group, no FQ resistance was detected in any of the patients. No statistically significant difference in terms of development of FQ resistance was found between the ratios of FQ and non-FQ groups (p=0.492). Although there was no statistically significant difference, 2 patients, in whom resistance was detected, had FQ exposure before their diagnosis.

CONCLUSION

The FQ exposure ratio before the diagnosis is high (22%) in this cohort that includes patients with new active pulmonary TB, and the presence of patients with FQ resistance (even if only a few) should be a noteworthy and cautionary result in terms of FQ exposure and resistance development.

Advances in clinical trial design for development of new TB treatments: A call for innovation

Christian Lienhardt and Payam Nahid launch the Collection on Advances in Clinical Trial Design for Development of New Tuberculosis Treatments.

Tuberculosis elimination: where are we now?

Tuberculosis (TB) still represents a major public health issue in spite of the significant impact of the efforts made by the World Health Organization (WHO) and partners to improve its control. In 2014 WHO launched a new global strategy (End TB) with a vision of a world free of TB, and a 2035 goal of TB elimination (defined as less than one incident case per million). The aim of this article is to summarise the theoretical bases of the End TB Strategy and to analyse progresses and persistent obstacles on the way to TB elimination.The evolution of the WHO recommended strategies of TB control (Directly Observed Therapy, Short Course (DOTS), Stop TB and End TB) are described and the concept of TB elimination is discussed. Furthermore, the eight core activities recently proposed by WHO as the milestones to achieve TB elimination are discussed in detail. Finally, the recently published experiences of Cyprus and Oman on their way towards TB elimination are described, together with the regional experience of Latin America.New prevention, diagnostic and treatment tools are also necessary to increase the speed of the present TB incidence decline.

Current use and acceptability of novel diagnostic tests for active tuberculosis: a worldwide survey

OBJECTIVE

To determine the current use and potential acceptance (by tuberculosis experts worldwide) of novel rapid tests for the diagnosis of tuberculosis that are in line with World Health Organization target product profiles.

METHODS

A multilingual survey was disseminated online between July and November of 2016.

RESULTS

A total of 723 individuals from 114 countries responded to the survey. Smear microscopy was the most commonly used rapid tuberculosis test (available to 90.9% of the respondents), followed by molecular assays (available to 70.7%). Only a small proportion of the respondents in middle- and low-income countries had access to interferon-gamma-release assays. Serological and lateral flow immunoassays were used by more than a quarter (25.4%) of the respondents. Among the respondents who had access to molecular tests, 46.7% were using the Xpert assay overall, that proportion being higher in lower middle-income countries (55.6%) and low-income countries (76.6%). The data also suggest that there was some alignment of pricing for molecular assays. Respondents stated they would accept novel rapid tuberculosis tests if available, including molecular assays (acceptable to 86.0%) or biomarker-based serological assays (acceptable to 81.7%). Simple biomarker-based assays were more commonly deemed acceptable in middle- and low-income countries.

CONCLUSIONS

Second-generation molecular assays have become more widely available in high- and low-resource settings. However, the development of novel rapid tuberculosis tests continues to be considered important by tuberculosis experts. Our data also underscore the need for additional training and education of end users.

Performance of a lateral flow immunochromatography test for the rapid diagnosis of active tuberculosis in a large multicentre study in areas with different clinical settings and tuberculosis exposure levels

BACKGROUND

Tuberculosis (TB) continues to cause an outsized burden of morbidity and mortality worldwide, still missing efficient and largely accessible diagnostic tools determining an appropriate control of the disease. Serological tests have the potentially to impact TB diagnosis, in particular in extreme clinical settings.

METHODS

The diagnostic performances of the TB-XT HEMA EXPRESS (HEMA-EXPRESS) immunochromatographic rapid test for active TB diagnosis, based on use of multiple Mycobacterium tuberculosis (MTB) specific antigens, have been evaluated in a large study multicentre TB case-finding study, in populations with different exposure level to TB. A total of 1,386 subjects were enrolled in the six participating centres in Peru: 290 active-TB and 1,096 unaffected subjects.

RESULTS

The TB prevalence (overall 20.5%) varied between 4.0% and 41.1% in the different study groups. Overall, the HEMA-EXPRESS test had 30.6% sensitivity (range 3.9-77.9%) and 84.6% specificity (range 51.6-97.3%). A significant inverse correlation between test accuracy (overall 73.5%, range 40.4-96.4%) and TB prevalence in the various study populations was observed (Pearson's r=-0.7985; P=0.05).

CONCLUSIONS

HEMA-EXPRESS, is rapid and relatively inexpensive test suitable for routine use in TB diagnosis. In low TB prevalence conditions, test performance appears in line with WHO Target Product Profile for TB diagnostics. Performances appear suboptimal in high TB prevalence settings. Appropriate set-up in operative clinical settings has to be considered for novel serological tests for TB diagnosis, particularly for formats suitable for point-of-care use.

WHO strategies for the programmatic management of drug-resistant tuberculosis

INTRODUCTION

Adequate management of drug-resistant tuberculosis (TB), including multidrug- (MDR) and extensively drug-resistant (XDR-) TB are within the priorities of the newly launched World Health Organization's End TB and Elimination Strategies.

AREAS COVERED

This manuscript presents the evidence on the MDR- /XDR-TB epidemiology and discusses how the five recommended priority actions can be applied at the programmatic level to tackle the epidemic: 1) prevent development of MDR-TB thorough high quality treatment of drug- susceptible TB; 2) expand rapid testing and detection of drug-resistant TB; 3) provide immediate access to effective treatment and proper care; 4) prevent transmission through infection control; 5) increase political commitment and financing. A non-systematic review using Pubmed was carried out in addition to additional relevant information taken from the abstracts of international scientific conferences. Expert commentary: Current and future control of MDR-TB significantly relies on the correct use of new diagnostics and new drugs from one side, and on the consistent application of the five core interventions at the programmatic level. In addition, it is mandatory to tackle the social determinants and socio-economic barriers favouring the MDR-TB, otherwise it will not be possible to reach the planned goals as well as TB Elimination.

First case of extensively drug-resistant tuberculosis treated with both delamanid and bedaquiline

The European Respiratory Journal has recently discussed delamanid and bedaquiline and their use in difficult-to-treat cases affected by multidrug-resistant tuberculosis (MDR-TB) or extensively drug-resistant (XDR-TB) [1–4]. The use of delamanid or bedaquiline is particularly important when four active drugs cannot be identified and included in a regimen, as per World Health Organization (WHO) guidelines [1–6]. Recently a debate has been initiated around the report of a severe, almost untreatable, XDR-TB case who could not access both new drugs simultaneously [7–10] due to concerns about possible additive toxicity (cardiotoxicity), as well as the lack of evidence and specific guidance on their combined use [10–13].

Report of the first case, concerns and challenges of treatment of severe XDR-TB with both delamanid and bedaquilinehttp://ow.ly/WzeB3004Cmo

Host-Directed Therapies for Tackling Multi-Drug Resistant Tuberculosis: Learning From the Pasteur-Bechamp Debates

Tuberculosis remains a global emergency causing an estimated 1.5 million deaths annually. For several decades the major focus of tuberculosis treatment has been on antibiotic development targeting Mycobacterium tuberculosis. The lengthy tuberculosis treatment duration and poor treatment outcomes associated with multi-drug resistant tuberculosis (MDR-TB) are of major concern. The sparse new tuberculosis drug pipeline and widespread emergence of MDR-TB signal an urgent need for more innovative interventions to improve treatment outcomes. Building on the historical Pasteur-Bechamp debates on the role of the "microbe" vs the "host internal milieu" in disease causation, we make the case for parallel investments into host-directed therapies (HDTs). A range of potential HDTs are now available which require evaluation in randomized controlled clinical trials as adjunct therapies for shortening the duration of tuberculosis therapy and improving treatment outcomes for drug-susceptible tuberculosis and MDR-TB. Funder initiatives that may enable further research into HDTs are described.

Towards tuberculosis elimination: an action framework for low-incidence countries

This paper describes an action framework for countries with low tuberculosis (TB) incidence (<100 TB cases per million population) that are striving for TB elimination. The framework sets out priority interventions required for these countries to progress first towards "pre-elimination" (<10 cases per million) and eventually the elimination of TB as a public health problem (less than one case per million). TB epidemiology in most low-incidence countries is characterised by a low rate of transmission in the general population, occasional outbreaks, a majority of TB cases generated from progression of latent TB infection (LTBI) rather than local transmission, concentration to certain vulnerable and hard-to-reach risk groups, and challenges posed by cross-border migration. Common health system challenges are that political commitment, funding, clinical expertise and general awareness of TB diminishes as TB incidence falls. The framework presents a tailored response to these challenges, grouped into eight priority action areas: 1) ensure political commitment, funding and stewardship for planning and essential services; 2) address the most vulnerable and hard-to-reach groups; 3) address special needs of migrants and cross-border issues; 4) undertake screening for active TB and LTBI in TB contacts and selected high-risk groups, and provide appropriate treatment; 5) optimise the prevention and care of drug-resistant TB; 6) ensure continued surveillance, programme monitoring and evaluation and case-based data management; 7) invest in research and new tools; and 8) support global TB prevention, care and control. The overall approach needs to be multisectorial, focusing on equitable access to high-quality diagnosis and care, and on addressing the social determinants of TB. Because of increasing globalisation and population mobility, the response needs to have both national and global dimensions.

Bedaquiline for the treatment of drug-resistant tuberculosis

Bedaquiline is a much-needed novel drug which is highly effective against drug-resistant tuberculosis. While its clinical development has been laudably fast-tracked and the drug is now available for inclusion into treatment regimens when no suitable alternatives exist, clinical experience with bedaquiline is still limited. Phase III trial data and Phase IV studies are needed particularly to study different patient populations and to optimize treatment regimens. Drug resistance to bedaquiline needs to be monitored carefully, and full access to bedaquiline treatment where it is appropriate and needed must be promoted.