Towards tailored regimens in the treatment of drug-resistant tuberculosis: a retrospective study in two Italian reference Centres

Infections in lung transplanted patients: A review

Lung transplantation can improve the survival of patients with severe chronic pulmonary disorders. However, the short- and long-term risk of infections can increase morbidity and mortality rates. A non-systematic review was performed to provide the most updated information on pathogen, host, and environment-related factors associated with the occurrence of bacterial, fungal, and viral infections as well as the most appropriate therapeutic options. Bacterial infections account for about 50% of all infectious diseases in lung transplanted patients, while viruses represent the second cause of infection accounting for one third of all infections. Almost 10% of patients develop invasive fungal infections during the first year after lung transplant. Pre-transplantation comorbidities, disruption of physical barriers during the surgery, and exposure to nosocomial pathogens during the hospital stay are directly associated with the occurrence of life-threatening infections. Empiric antimicrobial treatment after the assessment of individual risk factors, local epidemiology of drug-resistant pathogens and possible drug-drug interactions can improve the clinical outcomes.

Impacts of clofazimine on the treatment outcomes of drug-resistant tuberculosis

BACKGROUND

The purpose of this research was to evaluate the effect of clofazimine on drug-resistant tuberculosis treatment outcomes.

METHODS

A systematic search was conducted in the PubMed, Web of Science and EMBASE databases to identify eligible studies published up to July 10, 2021. The search terms were as follows: "clofazimine," "tuberculosis," "multidrug resistant tuberculosis" or "extensively drug resistant tuberculosis" and their synonyms or similar words. Two researchers independently screened the titles, abstracts, and full texts for inclusion. Meta-analysis was performed with Stata version 16.0 (Stata Corp., College Station, Texas, USA). Risk ratios (RRs) with 95% CIs were calculated to evaluate the treatment outcome.

RESULTS

Eight studies including 3219 participants were included in the meta-analysis. The meta-analysis found that the rates of treatment completion was higher in patients receiving clofazimine-containing regimens than in those not receiving clofazimine-containing regimens (RR: 1.185 (1.060-1.325), P = 0.003). Significant reduction in treatment failure (RR: 0.598 (0.473-0.756), P < 0.001) was found in the clofazimine treatment group. The subgroup analyses of randomized controlled trials (RCTs) found a higher rates of favorable outcomes, treatment completion and cure in the clofazimine group than in the control group (RR: 1.203 (1.029-1.407), P = 0.020; RR: 3.167 (2.043-4.908), P < 0.001; and RR: 1.251 (1.031-1.518), P = 0.023, respectively). Patients receiving clofazimine had a lower risk of treatment failure than those not receiving clofazimine (RR: 0.529 (0.454-0.616), P < 0.001). However, clofazimine treatment did not have a statistically significant effect on all-cause mortality in RCTs.

CONCLUSIONS

This study demonstrated that compared with patients who do not receive clofazimine, this drug has the potential to achieve a higher favorable outcome, treatment completion and cure rates, and a lower treatment failure risk among drug-resistant tuberculosis cases.

Linezolid resistance in multidrug-resistant mycobacterium tuberculosis: A systematic review and meta-analysis

Introduction: Linezolid (LNZ) is an effective antibiotic to treat patients with multidrug-resistant tuberculosis (MDR-TB) treatment failure. M. tuberculosis strains resistant to isoniazid and rifampin are defined as MDR-TB. In recent years, resistance to LNZ among MDR-TB cases has been reported in several different countries. In this study, we performed a systematic review and meta-analysis to investigate the prevalence of LNZ resistance among MDR-TB isolates.

Methods: The databases of Embase, PubMed/Medline, and Web of Science were searched systematically from January 2000 to April 2021. Statistical analyses were performed by using Comprehensive Meta-Analysis software. Heterogeneity was reported by using the t-squared statistic and Q-statistic. Begg’s rank correlation in combination with the funnel plot were used to evaluate any possible publication bias.

Results: In total, 25 studies were selected for meta-analysis from 14 different countries; the majority was from China (n = 5) and Turkey (n = 4). Moreover, 7,366 patients were infected with MDR M. tuberculosis. Among the study population, 98 patients were co-infected with HIV, and 18 patients with hepatitis C virus (HCV). Furthermore, 28 cases had diabetes, and139 cases were alcohol abuser. Overall, 4,956 MDR M. tuberculosis strains were isolated from TB patients. The pooled frequency of LNZ resistance among the clinical isolates of MDR M. tuberculosis was 4.2% (95%). Begg’s (p = 0.72) test showed no evidence of publication bias.

Conclusion: LNZ resistance among MDR M. tuberculosis isolates is increasing. On the other hand, long-term treatment of MDR-TB cases with LNZ alone is associated with several adverse effects. Thus, it is recommended that newer anti-TB drugs, including bedaquiline and delamanid, in combination with linezolid could increase its effectiveness and decrease toxicities. However, more studies should be done in this field.

Tuberculosis and pharmacological interactions: A narrative review

Even if major improvements in therapeutic regimens and treatment outcomes have been progressively achieved, tuberculosis (TB) remains the leading cause of death from a single infectious microorganism. To improve TB treatment success as well as patients' quality of life, drug-drug-interactions (DDIs) need to be wisely managed. Comprehensive knowledge of anti-TB drugs, pharmacokinetics and pharmacodynamic (PK/PD) parameters, potential patients’ changes in absorption and distribution, possible side effects and interactions, is mandatory to built effective anti-TB regimens. Optimization of treatments and adherence to international guidelines can help bend the curve of TB-related mortality and, ultimately, decrease the likelihood of treatment failure and drop-out during anti-TB treatment. Aim of this paper is to describe the most relevant DDIs between anti-TB and other drugs used in daily clinical practice, providing an updated and “easy-to-use” guide to minimize adverse effects, drop-outs and, in the long run, increase treatment success.

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Tuberculosis (TB) remains the leading cause of death from a single infectious microorganism.

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Comprehensive knowledge of anti-TB drugs and PK/PD parameters is mandatory to built effective anti-TB regimens.

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Drug-drug-interactions (DDIs) need to be avoided and/or wisely managed to ensure treatment success.

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Optimization of anti-TB treatment to avoid DDIs can help to bend the curve of TB related mortality.

Population pharmacokinetics and target attainment analysis of linezolid in multidrug-resistant tuberculosis patients

AIM

This study investigates the pharmacokinetic/pharmacodynamic (PK/PD) target attainment of linezolid in patients infected with multidrug-resistant (MDR) tuberculosis (TB).

METHODS

A pharmacometric model was developed including 244 timed linezolid concentration samples from 39 patients employing NONMEM 7.4. The probability of target attainment (PTA, PK/PD target: unbound (f) area-under-the-concentration-time-curve (AUC)/minimal inhibitory concentration (MIC) of 119) as well as a region-specific cumulative fraction of response (CFR) were estimated for different dosing regimens.

RESULTS

A one-compartment model with linear elimination with a clearance (CL) of 7.69 L/h (interindividual variability 34.1%), a volume of distribution (Vd) of 45.2 L and an absorption constant (KA) of 0.679 h^-1 (interoccasion variability 143.7%) allometric scaled by weight best described the PK of linezolid. The PTA at an MIC of 0.5 mg/L was 55% or 97% if patients receiving 300 or 600 mg twice daily, respectively. CFRs varied greatly among populations and geographic regions. A desirable global CFR of ≥90% was achieved if linezolid was administered at a dose of 600 mg twice daily but not at a dose of 300 mg twice daily.

CONCLUSION

This study showed that a dose of 300 mg twice daily of linezolid might not be sufficient to treat MDR-TB patients from a PK/PD perspective. Thus, it might be recommendable to start with a higher dose of 600 mg twice daily to ensure PK/PD target attainment. Hereby, therapeutic drug monitoring and MIC determination should be performed to control PK/PD target attainment as linezolid shows high variability in its PK in the TB population.

Drug Resistance Pattern of M. tuberculosis Complex in Oromia Region of Ethiopia

Purpose

Multidrug resistant tuberculosis is an emerging problem in many parts of the world. The aim of this study was to determine the drug resistance pattern of Mycobacterium tuberculosis complex in Oromia Region of Ethiopia.

Patients and Methods

A cross-sectional study was conducted from Jan 2017 to June 2018 on 450 pulmonary tuberculosis patients who visited health facilities in nine administrative zones of Oromia Region. Socio-demographic characteristics and relevant clinical information were obtained using a structured questionnaire. Line Probe Assay for first and second line drugs was used to assess the pattern of drug resistance. SPSS version 20 was used for statistical analysis.

Results

Median age was 26 years and 240 (53.3%) patients were males. About 24% of them were previously treated for tuberculosis. Thirty-four (7.6%) were HIV co-infected. Line Probe Assay interpretable results were obtained for 387 isolates. Thirty (7.8%) were resistant to rifampicin and isoniazid and thus were multidrug resistant isolates. Among the multidrug resistant samples, three were found to be extensively drug resistant and one was pre-extensively drug resistant. Previous treatment history (AOR 9.94 (95% CI 3.73–26.51), P < 0.001) and nutritional status below normal (AOR 3.15 (95% CI 1.13–8.81), P < 0.029) were found to be associated with multidrug resistance. The chi-square tests have shown that there was a significant difference between the BCG vaccinated and the non-vaccinated in developing multidrug resistant tuberculosis at P = 0.027.

Conclusion

The proportion of multidrug resistance is above the WHO estimate for the country, Ethiopia, and the fact that some zones were at risk of transmission of extensively drug resistant tuberculosis warrant great attention of the control program holders even though it has to be verified through the conventional method.

Evaluation of drug-resistant tuberculosis treatment outcome in Portugal, 2000-2016

Treatment of drug-resistant tuberculosis (TB), which is usually less successful than that of drug-susceptible TB, represents a challenge for TB control and elimination. We aimed to evaluate treatment outcomes and to identify the factors associated with death among patients with MDR and XDR-TB in Portugal. We assessed MDR-TB cases reported for the period 2000-2016, using the national TB Surveillance System. Treatment outcomes were defined according to WHO recommendations. We identified the factors associated with death using logistic regression. We evaluated treatment outcomes of 294 MDR- and 142 XDR-TB patients. The treatment success rate was 73.8% among MDR- and 62.7% among XDR-TB patients (p = 0.023). The case-fatality rate was 18.4% among MDR- and 23.9% among XDR-TB patients. HIV infection (OR 4.55; 95% CI 2.31-8.99; p < 0.001) and resistance to one or more second-line injectable drugs (OR 2.73; 95% CI 1.26-5.92; p = 0.011) were independently associated with death among MDR-TB patients. HIV infection, injectable drug use, past imprisonment, comorbidities, and alcohol abuse are conditions that were associated with death early on and during treatment. Early diagnosis of MDR-TB and further monitoring of these patients are necessary to improve treatment outcome.

Anti-Tuberculosis Drug Induced Hepatotoxicity and Associated Factors among Tuberculosis Patients at Selected Hospitals, Ethiopia

Background

Tuberculosis caused by susceptible mycobacterium tuberculosis strains is effectively treated by the first-line anti-tuberculosis drugs. However, most antibacterial drugs are known to induce hepatotoxicity which may limit their adherence and hence lead to the development of mycobacterial drug resistance.

Objective

The aim of this study was to assess the incidence of anti-tuberculosis drug induced hepatotoxicity and associated factors among tuberculosis patients of Debre Markos, Mota, and Bichena Hospitals.

Methods

The prospective cross sectional-study was conducted in three hospitals of East Gojjam zone by taking blood samples of new tuberculosis patients every 2 weeks for 2 months to measure the elevation of liver proteins indicating liver toxicity from the onset of starting therapy. A semi-structured questionnaire was also used to collect the socio-demographic data and factors of anti-tubeculosis drug induced liver toxicity. To identify factors associated with drug induced hepatotoxicity, binary logistic regression followed by multivariate analysis was applied at a statistically significant level of P<0.05.

Results

The incidence of hepatotoxicity among tuberculosis patients is 7.9%. Diagnosis of extrapulmonary tuberculosis, having comorbid disease, and old age are significantly associated (P<0.05) with first-line antituberculosis drugs induced hepatotoxicity.

Conclusion

The incidence of hepatotoxicity is relatively high among tuberculosis patients taking first-line anti-tuberculosis drugs. Therefore, the liver function of patients with old age, comorbid diseases, and extrapulmonary tuberculosis should be regularly monitored to reduce the severity of drug-induced hepatotoxicity.

Predictors of mortality among multidrug-resistant tuberculosis patients in central Ethiopia: a retrospective follow-up study

The burden of multidrug-resistant tuberculosis (MDR-TB) related to mortality in resource-poor countries remains high. This study aimed to estimate the incidence and predictors of death among MDR-TB patients in central Ethiopia. A retrospective follow-up study was conducted at three hospitals in the Amhara region on 451 patients receiving treatment for MDR-TB from September 2010 to January 2017. Data were collected from patient registration books, charts and computer databases. Data were fitted to a parametric frailty model and survival was expressed as an adjusted hazard ratio (AHR) with a 95% confidence interval (CI). The median follow-up time of participants was 20 months (interquartile range: 12, 22) and 46 (10.20%) of patients died during this period. The incidence rate of mortality was 7.42 (95% CI 5.56-9.91)/100 person-years. Older age (AHR = 1.04, 95% CI 1.01-1.08), inability to self-care (AHR = 13.71, 95% CI 5.46-34.40), co-morbidity (AHR = 5.74, 95% CI 2.19-15.08), low body mass index (AHR = 4.13, 95% CI 1.02-16.64), acute lung complications (AHR = 4.22, 95% CI 1.66-10.70) and lung consolidation at baseline (AHR = 5.27, 95% CI 1.06-26.18) were independent predictors of mortality. Most of the identified predictor factors of death in this study were considered to be avoidable if the TB programme had provided nutritional support for malnourished patients and ensured a close follow-up of the elderly, and patients with co-morbidities.

Advantages and Challenges of Tailored Regimens for Drug-Resistant Tuberculosis: A StopTB Italia Look into the Future

The emerge of drug-resistant tuberculosis (TB) strain in recent decades is hampering the efforts of the international community to eliminate the disease worldwide. The World Health Organization (WHO) has drafted many strategies to achieve this ambitious goal. In the very beginning, the aim was to standardize inadequate regimens used in many countries and, thereafter, evolved to tackle the social determinants which hinder TB elimination. However, following the path of narrowing the clinical vision to deal with TB, there is an increased need to personalize the treatment considering both patients and pathogen unique characteristics. In our narrative review, we report the advantages and the backwards in developing a method to implement the concept of precision medicine to the treatment of TB. In this dissertation, we highlight the importance to address different aspects of the diseases encompassing the host and pathogen features, as well as the needs to further implement an adequate follow-up based on the available resources. Nevertheless, many things may hamper the vision of precision medicine in TB, such as the complexity and the costs to develop novel compounds and the costs related to global-scale implementation of patient-centered follow-up. To achieve the ambitious goal of TB elimination, a radical change in TB treatment is needed in order to give a more comprehensive approach based both on patients’ peculiarities and driven by drug susceptibility tests and whole-genome sequencing.

Outcomes and adverse events of pre- and extensively drug-resistant tuberculosis patients in Kinshasa, Democratique Republic of the Congo: A retrospective cohort study

Background

Extensively drug-resistant tuberculosis (XDR TB) is a very serious form of tuberculosis that is burdened with a heavy mortality toll, especially before the advent of new TB drugs. The Democratic Republic of the Congo (DRC) is among the countries most affected by this new epidemic.

Methods

A retrospective analysis was performed of the records of all patients with pre- and extensively drug-resistant tuberculosis hospitalized from January 1, 2015 to December 31, 2017 and monitored for at least 6 months to one year after the end of their treatment in Kinshasa; an individualized therapeutic regimen with bedaquiline for 20 months was built for each patient. The adverse effects were systematically monitored.

Results

Of the 40 laboratory-confirmed patients, 32 (80%) patients started treatment, including 29 preXRB and 3 XDR TB patients. In the eligible group, 3 patients (9.4%) had HIV-TB coinfections. The therapeutic success rate was 53.2%, and the mortality rate was 46.8% (15/32); there were no relapses, failures or losses to follow-up. All coinfected HIV–TB patients died during treatment. The cumulative patient survival rate was 62.5% at 3 months, 53.1% at 6 months and 53.1% at 20 months. The most common adverse events were vomiting, Skin rash, anemia and peripheral neuropathy.

Conclusion

The new anti-tuberculosis drugs are a real hope for the management of Drug Resistant tuberculosis patient and other new therapeutic combinations may improve favorable outcomes.

From the past, a long way to future challenges for a greater control of tuberculosis

Tuberculosis (TB) and humans have coexisted for more than 40,000 years; however TB remains a global threat to human kind. The international community has developed new tools for early detection, but TB strains evolved acquiring resistance to first-line therapeutic drugs with increasing treatment challenges. Furthermore, TB has formed also an alliance with human immunodeficiency virus; in this way the poorest populations are most affected. The current vaccine planning activity includes 14 new vaccines against TB (11 of those in the phaseII/III) developed with different techniques. Now, more than ever, new anti-TB drugs and new anti-TB regimens are urgently required as well as universal health care and social protection in order to tackle down both hard to treat TB and the social determinants of TB. Coordinated actions and sharing of information are needed to aspire everywhere to the best clinical practices and improve quality of life of patients and their families.

Clofazimine: an old drug for never-ending diseases

Clofazimine (CFZ), an old hydrophobic riminophenazine, has a wide range of antimycobacterial activity ranging from leprosy to nontuberculous mycobacterial diseases. CFZ has several advantages such as a favorable pharmacokinetic profile, dose-dependent side effects as well as low price. In this narrative review, we have assessed the clinical development of CFZ, starting from the potential in vitro mechanism of actions, to the spectrum of side effects and potential drug-drug interactions, highlighting its current place in therapy and future possible use in leprosy, nontuberculous mycobacterial diseases and drug-resistant tuberculosis.

HIV and tuberculosis: The paradox of dual illnesses and the challenges of their fighting in the history

Tuberculosis is an ancient infectious disease caused by the bacillus Mycobacterium tuberculosis that is still nowadays afflicting humans all over the world. It causes ill-health for 10 million people each year. Tuberculosis (TB) has been the leading cause of death from a single infectious agent, ranking above HIV/AIDS. In recent years, infection with HIV represents a major risk factor predisposing for infection and TB is the most common cause of AIDS-related death. Despite the treatment of HIV-associated TB has essentially retraced that recommended in HIV-negative cases, it has disclosed some additional challenges over the years. The association of delayed and missed diagnoses, logistic accidents and some well-known complications of HIV and TB treatment co-administration has contributed to 300,000 people living with HIV died from a preventable and curable disease like TB in 2017. The evaluation of new diagnostic and therapeutic approaches with the struggle to erase stigma are essential to successfully manage HIV-TB coinfection.

Repurposed drug candidates for antituberculosis therapy

Antibiotics have been a key part of clinical treatments for more than 70 years. Long-term use of antimicrobial treatments has led to the development of severe bacterial resistance, which has become increasingly serious due to antibiotic abuse, resulting in the treatment of bacterial infections becoming challenging. The repurposing of approved drugs presents a promising strategy to address current bottlenecks in the development of novel antibacterial agents. Drug repurposing is a cost-effective emerging strategy, which aims to treat resistant infectious diseases by identifying known drugs with predicted efficacy for diseases other than the target disease. This strategy has potential in the treatment of tuberculosis (TB), particularly drug-resistant TB. In recent years, a panel of drugs approved for clinical use or clinical trials, such as linezolid, vancomycin and celecoxib, have been found to have anti-TB activities. However, the utility of drug repurposing is limited by the number of candidate compounds and their low activities. The low activities of repurposed drugs have slowed the development of a drug-repurposing strategy for anti-TB drugs. The present review discusses progress in the discovery of new anti-TB agents through drug repurposing since 2014. We also discuss the challenges faced and analyze the innovative ways that are being used to overcome these difficulties. This review may provide a useful guide for researchers in the field of drug repurposing.

Adherence to Anti-Tuberculosis Treatment Among Pediatric Patients at Nekemte Specialized Hospital, Western Ethiopia

BACKGROUND

Non-adherence to tuberculosis treatment is the most challenging and hindering factor for successful tuberculosis therapy. The long duration of tuberculosis treatment and the undesirable effects of anti-tuberculosis drugs result in non-adherence to treatment among pediatric patients. Hence, this study was aimed to evaluate pediatrics adherence status among tuberculosis pediatric patients on anti-tuberculosis treatment at Nekemte Specialized Hospital.

METHODS

A health facility-based cross-sectional study design was used to recruit pediatric TB patients who were receiving their treatment between February 15 and March 15, 2019. Adherence to tuberculosis therapy was evaluated using data obtained from face-to-face interviews of their respective caregivers. The collected data were entered into EPI-manager 4.0.2 software and analyzed using SPSS version 24. Logistic regression was used to analyze the variables and variables with p-value <0.05 had a statistically significant association with the adherence to anti TB treatment.

RESULTS

Among 202 participants involved in the study, 120 (59.4%) of them were males and 119 (58.9%) were in the age category of 11-15 years. A total of 166 (82.2%) of the patients had extra-pulmonary tuberculosis and 174 (86.1%) of them were in the intensive phase. Of the pediatric tuberculosis patients, 48 (73.3%) of them have adhered to the treatment regimen. Female gender [AOR: 3.3, 95% CI: 1.52-7.2], younger age (0-5 years) [AOR: 5.96 95% CI: 1.81-19.6], living in urban area [AOR: 3.73, 95% CI: 1.67-8.36], and patients who did not experience side effect [AOR: 2.87, 95% CI: 1.41-5.81] were predictors of good adherence to tuberculosis treatment up on multivariable logistic regression analysis.

CONCLUSION

The level of adherence observed in our study area was low. Age, sex, residence, and side effect experience showed an association with tuberculosis treatment adherence. Therefore, health care providers should educate all patients with tuberculosis before the initiation of anti-tuberculosis treatment.

Assessment of multidrug-resistant tuberculosis (MDR-TB) treatment outcomes in Sudan; findings and implications

Background: Multidrug-resistant tuberculosis (MDR-TB) has a socioeconomic impact and threatens global public health. We assessed treatment outcomes of MDR-TB and predictors of poor treatment outcomes in Sudan given current high prevalence rates.Methods: Combined retrospective and prospective cohort study at Abu-Anga hospital (TB specialized hospital in Sudan). All patients with MDR-TB between 2013 and 2017 were targeted.Results: A total of 156 patients were recruited as having good records, 117 (75%) were male, and 152 (97.4%) had pulmonary TB. Patients were followed for a median of 18 months and a total of 2108 person-months. The overall success rate was 63.5% and the mortality rate was 14.1%. Rural residency (P < 0.05) and relapsing on previous treatments (P < 0.05) were determinants of time to poor MDR-TB treatment outcomes.Conclusion: Overall, more attention needs to be given to special MDR-TB groups that are highly susceptible to poor outcomes, i.e. rural patients. As a result, it is highly recommended to maintain total coverage of medicines for all MDR-TB patients for the entire period of treatment in Sudan. It is also recommended to instigate more treatment centers in rural areas in Sudan together with programs to enhance adherence to treatments including patient counseling to improve future outcomes.