Multidrug-resistant Tuberculosis Therapy Research Articles

Treatment of Multidrug-Resistant Tuberculosis in Children and Adolescents

AbstractAlthough tens of thousands of children and adolescents become sick with multidrug-resistant tuberculosis (MDR-TB) each year, fewer than 1,500 cases documenting treatment have been reported in the literature. Children treated for MDR-TB tend to have excellent clinical outcomes, but they suffer from the adverse events associated with current management strategies. This article will review the recommendations, evidence base, and future directions for MDR-TB therapy in children and adolescents.

Avances en el tratamiento de la tuberculosis multirresistente

Abstract Therapy of multi-drug resistant tuberculosis (MDR TB) is based on trials with drugs with highly variable patterns of resistance and non-standardized follow-ups that make it difficult to provide recommendations with strong levels of evidence. Also, the vast majority of MDR-TB patients fail to receive therapy and those who receive it, only achieve around 50% of good results. Fortunately new drugs have emerged (bedaquiline, delamanid, pretomanid) that are being useful for these patients with better designed trials and monitoring, in which the efficacy, toxicity and degree of relapses can be evaluated more accurately. Some drugs already known (fluorquinolones, linezolid and clofazimine) are also being introduced in new schemes of therapy.

Group 5 drugs for multidrug-resistant tuberculosis: individual patient data meta-analysis.

The role of so-called "group 5" second-line drugs as a part of antibiotic therapy for multidrug-resistant tuberculosis (MDR-TB) is widely debated. We performed an individual patient data meta-analysis to evaluate the effectiveness of several group 5 drugs including amoxicillin/clavulanic acid, thioacetazone, the macrolide antibiotics, linezolid, clofazimine and terizidone for treatment of patients with MDR-TB.Detailed individual patient data were obtained from 31 published cohort studies of MDR-TB therapy. Pooled treatment outcomes for each group 5 drug were calculated using a random effects meta-analysis. Primary analyses compared treatment success to a combined outcome of failure, relapse or death.Among 9282 included patients, 2191 received at least one group 5 drug. We found no improvement in treatment success among patients taking clofazimine, amoxicillin/clavulanic acid or macrolide antibiotics, despite applying a number of statistical approaches to control confounding. Thioacetazone was associated with increased treatment success (OR 2.6, 95% CI 1.1-6.1) when matched controls were selected from studies in which the group 5 drugs were not used at all, although this result was heavily influenced by a single study.The development of more effective antibiotics to treat drug-resistant TB remains an urgent priority.

Fluoroquinolones for the treatment and prevention of multidrug-resistant tuberculosis.

Although fluoroquinolones (FQs) play an important role in the treatment of multidrug-resistant tuberculosis (MDR-TB), there are several issues that need to be addressed to optimize their effectiveness and minimize toxicity. This includes identification of the optimal dose of FQs such as levofloxacin (LVX) and moxifloxacin, and the optimal role of FQs in combination with other anti-tuberculosis drugs, particularly those with overlapping toxicity, such as QT prolongation. While the ability of FQs to penetrate into cavities and granulomas is likely beneficial, suboptimal sensitivity of genotypic tests to detect FQ resistance could negatively affect treatment outcomes of FQ-containing regimens. Several trials are underway to evaluate the safety and effectiveness of FQs as part of combination MDR-TB therapy; there are also two planned studies of LVX to prevent tuberculosis among close contacts of MDR-TB.

FORMULATION, OPTIMIZATION, AND CHARACTERIZATION OF BIOCOMPATIBLE INHALABLE D-CYCLOSERINE-LOADED ALGINATE-CHITOSAN NANOPARTICLES FOR PULMONARY DRUG DELIVERY

<p>ABSTRACT<br />Objective: To prepare Nanoparticulate dosage form having improved drug bioavailability and reduced dosing frequency of antitubercular drugs<br />which will helps in improving patient compliance in the treatment of multi-drug resistant tuberculosis (MDR-TB).<br />Methods: Ionotropic gelation method was used to prepare D-cycloserine (D-CS)-loaded alginate-chitosan nanoparticles, and the particles are<br />characterized by their particle size and morphology using particle size analyzer and scanning electron microscopy (SEM). X-ray diffraction (XRD),<br />differential scanning calorimetry (DSC), and Fourier-transformed infrared (FTIR) studies were used to determine drug-polymer interactions and drug<br />entrapment. Entrapment efficiency, drug loading (DL), particle size, and zeta potential of nanoparticles were also studied. The 2<br /> factorial designs of<br />experiments by Design-Expert<br />®<br /> V9 were used to optimize the particle size and entrapment efficiency of nanoparticles.<br />Results: The optimized batch had shown the entrapment efficiency of 98.10±0.24% and DL of 69.32±0.44% with particle size and zeta potential<br />as 344±5 nm and −42±11.40 mV, respectively. DSC, FTIR, and XRD studies confirmed the drug entrapment within nanoparticle matrix. SEM results<br />showed spherical-shaped particles. Sustained release of drug from the nanoparticles was observed for 24 hrs period. Respirable fraction up to<br />52.37±0.7% demonstrates the formulation suitability for deep lung delivery. Lung inflammatory study showed a less inflammatory response.<br />Conclusion: Ionotropic gelation method can be used to prepare biocompatible particles with a high entrapment efficiency, DL, optimum particle size,<br />and controlled release characteristics, which can serve as a convenient delivery system for D-CS and could be a potential alternative to the existing<br />conventional therapy in MDR-TB.<br />Keywords: Nanoparticles, Alginate, Chitosan, Inhalation, Sustained release, Tuberculosis.<br />3</p>

Impact of Infection Control Measures to Control an Outbreak of Multidrug-Resistant Tuberculosis in a Human Immunodeficiency Virus Ward, Peru.

Multidrug-resistant tuberculosis (MDRTB) rates in a human immunodeficiency virus (HIV) care facility increased by the year 2000—56% of TB cases, eight times the national MDRTB rate. We reported the effect of tuberculosis infection control measures that were introduced in 2001 and that consisted of 1) building a respiratory isolation ward with mechanical ventilation, 2) triage segregation of patients, 3) relocation of waiting room to outdoors, 4) rapid sputum smear microscopy, and 5) culture/drug–susceptibility testing with the microscopic-observation drug-susceptibility assay. Records pertaining to patients attending the study site between 1997 and 2004 were reviewed. Six hundred and fifty five HIV/TB–coinfected patients (mean age 33 years, 79% male) who attended the service during the study period were included. After the intervention, MDRTB rates declined to 20% of TB cases by the year 2004 (P = 0.01). Extremely limited access to antiretroviral therapy and specific MDRTB therapy did not change during this period, and concurrently, national MDRTB prevalence increased, implying that the infection control measures caused the fall in MDRTB rates. The infection control measures were estimated to have cost US$91,031 while preventing 97 MDRTB cases, potentially saving US$1,430,026. Thus, this intervention significantly reduced MDRTB within an HIV care facility in this resource-constrained setting and should be cost-effective.

Potential of immunomodulatory agents as adjunct host-directed therapies for multidrug-resistant tuberculosis.

Treatment of multidrug-resistant tuberculosis (MDR-TB) is extremely challenging due to the virulence of the etiologic strains of Mycobacterium tuberculosis (M. tb), the aberrant host immune responses and the diminishing treatment options with TB drugs. New treatment regimens incorporating therapeutics targeting both M. tb and host factors are urgently needed to improve the clinical management outcomes of MDR-TB. Host-directed therapies (HDT) could avert destructive tuberculous lung pathology, facilitate eradication of M. tb, improve survival and prevent long-term functional disability. In this review we (1) discuss the use of HDT for cancer and other infections, drawing parallels and the precedent they set for MDR-TB treatment, (2) highlight preclinical studies of pharmacological agents commonly used in clinical practice which have HDT potential, and (3) outline developments in cellular therapy to promote clinically beneficial immunomodulation to improve treatment outcomes in patients with pulmonary MDR-TB. The use of HDTs as adjuncts to MDR-TB therapy requires urgent evaluation.

Effectiveness of a novel cellular therapy to treat multidrug-resistant tuberculosis

IntroductionWe urgently need novel treatments for multidrug-resistant tuberculosis (MDR-TB). Autologous mesenchymal stromal cell (MSC) infusion is one such possibility due to its potential to repair damaged lung tissue and boost immune responses. We aimed to assess the effectiveness of MSC to improve outcomes among MDR-TB patients. MethodsWe analyzed outcomes for 108 Belarussian MDR-TB patients receiving chemotherapy. Thirty-six patients (“cases”) also had MSCs extracted, cultured and re-infused (average time from chemotherapy start to infusion was 49 days); another 36 patients were “study controls”. We identified another control group: 36 patients from the Belarussian surveillance database (“surveillance controls”) 1:1 matched to cases. ResultsOf the cases, 81% had successful outcomes versus 42% of surveillance controls and 39% of study controls. Successful outcome odds were 6.5 (95% Confidence Interval: 1.2–36.2, p=0.032) times greater for cases than surveillance controls (age-adjusted). Radiological improvement was more likely in cases than study controls. Culture analysis prior to infusion demonstrated a poorer initial prognosis in cases, yet despite this they had better outcomes than the control groups. ConclusionMSC treatment could vastly improve outcomes for MDR-TB patients. Our findings could revolutionize therapy options and have strong implications for future directions of MDR-TB therapy research.

Glycated haemoglobin levels in patients with multidrug-resistant tuberculosis infection during 6 months of treatment

Background: There is little information on the possible impact of drugs used in the treatment of multi-drug resistant tuberculosis (MDR-TB) on glycaemic levels. This study therefore assessed changes in glycated haemoglobin levels in patients with MDR-TB.Materials and Methods: This longitudinal study involved 21 MDR-TB patients who were followed up for 6 months. Glycated haemoglobin (HbA1c) level of each patient was determined before the commencement of MDR-TB drug regimen and at 2, 4 and 6 months post treatment as part of a study which investigated them every 2 months. Differences in means were assessed using the paired Student’s t-test and statistical significance was set at P<0.05.Results: A patient had undiagnosed diabetes mellitus (DM) with an HbA1c value of 6.5% and died before the second month sample collection; another patient became critically ill; therefore, 19 patients completed the study. Before the commencement of MDR-TB therapy, two patients had pre-diabetes with HbA1c values of 6.0% and 5.8% while the HbA1c values of the remaining patients were less than 5.7%. There was a significant reduction in the mean HbA1c level at 2 months post therapy compared with the baseline. However, the HbA1c levels increased slightly after the 2nd month of therapy but no significant change was observed in the HbA1c levels at 4 and 6 months of MDR-TB therapy compared with baseline.Conclusion: Diabetes mellitus is not common among Nigerians with MDR-TB and MDR-TB drug regimen might have an acute effect on glycaemic changes in patients with MDR-TB.Keywords: Diabetes mellitus, Glycaemic change, Glycated haemoglobin, Multidrug resistant tuberculosis therapy

Aggressive Regimens Reduce Risk of Recurrence After Successful Treatment of MDR-TB.

We sought to determine whether treatment with a "long aggressive regimen" was associated with lower rates of relapse among patients successfully treated for pulmonary multidrug-resistant tuberculosis (MDR-TB) in Tomsk, Russia. We conducted a retrospective cohort study of adult patients that initiated MDR-TB treatment with individualized regimens between September 2000 and November 2004, and were successfully treated. Patients were classified as having received "aggressive regimens" if their intensive phase consisted of at least 5 likely effective drugs (including a second-line injectable and a fluoroquinolone) used for at least 6 months post culture conversion, and their continuation phase included at least 4 likely effective drugs. Patients that were treated with aggressive regimens for a minimum duration of 18 months post culture conversion were classified as having received "long aggressive regimens." We used recurrence as a proxy for relapse because genotyping was not performed. After treatment, patients were classified as having disease recurrence if cultures grew MDR-TB or they re-initiated MDR-TB therapy. Data were analyzed using Cox proportional hazard regression. Of 408 successfully treated patients, 399 (97.5%) with at least 1 follow-up visit were included. Median duration of follow-up was 42.4 months (interquartile range: 20.5-59.5), and there were 27 recurrence episodes. In a multivariable complete case analysis (n = 371 [92.9%]) adjusting for potential confounders, long aggressive regimens were associated with a lower rate of recurrence (adjusted hazard ratio: 0.22, 95% confidence interval, .05-.92). Long aggressive regimens for MDR-TB treatment are associated with lower risk of disease recurrence.

PncA mutations in mycobacterium tuberculosis is a strong predictor of poor treatment outcome in the therapy of multidrug resistant tuberculosis

pncA mutations in mycobacterium tuberculosis is a strong predictor of poor treatment outcome in the therapy of multidrug resistant tuberculosis

Adverse Events Associated With the Treatment of Multidrug-Resistant Tuberculosis

Multidrug-resistant tuberculosis (MDR-TB) is a growing public health problem. Due to long duration of therapy and concurrent use of multiple second-line drugs, adverse drug events (ADEs) are regarded as the most important clinical consideration in patients undergoing anti-MDR-TB treatment. To evaluate the frequency and type of treatment-related ADEs owing to MDR-TB therapy. The Cochrane Library, MEDLINE, and EMBASE were searched from inception through October 1, 2012, with additional manual search of International Journal of Tuberculosis and Lung Disease. Studies with available ADEs were selected if MDR-TB patients were treated with regimen including second-line drugs. Pooled estimations of incidence for each specific type of ADEs were calculated with 95% confidence intervals using random-effects model. Of the 5346 patients included, 2602 (57.3%) experienced at least 1 kind of ADE. The 3 most common side effects were gastrointestinal disorders (32.1%), ototoxicity (14.6%), and psychiatric disorders (13.2%). Subgroup analyses based on each characteristic (study population, previous tuberculosis treated, human immunodeficiency virus prevalence, and length of treatment) did not show any significant difference between groups. Additionally, among 1519 patients who developed ADEs with available data of impact on MDR-TB therapy, 70.4% required change of MDR-TB treatment. Adverse events were common among MDR-TB cases, occurring in more than half of the cases, with over two-thirds requiring change of anti-MDR-TB treatment. MDR-TB patients should be monitored closely and managed aggressively for side effects during therapy, especially for ototoxicity and psychiatric disorders.

A study on prevalence of multi drug resistance tuberculosis and factors influencing it in Davangere district, Karnataka, India

Background: India is one of the high tuberculosis (TB) burden countries in the world accounting for nearly 20% of the global incidence. Standard anti-TB drugs have been used for decades, and resistance to the medicines is growing. The emergence and spread of multi-drug resistant tuberculosis (MDR-TB) is threatening to destabilize global tuberculosis control. Methods: Case records of all the patients put on DOTS plus therapy for MDR-TB were obtained from District Tuberculosis Centre (DTC) located at Chigateri General Hospital Davangere. Details of all the suspected MDR-TB patients registered in the DTC during January 2013 to June 2015 and sent for culture and drug sensitivity testing (DST) were obtained. MDR-TB was defined as Tuberculosis caused by bacilli showing resistant to Isoniazid and Rifampicin. Cases are analysed based on MDR Suspect criteria as per RNTCP. Further details about the influencing factors were obtained by calling the patients on their contact numbers. Corroborative evidence of the details provided by the patients regarding the influencing factors was substantiated from STLS or DOTS providers. Results: The prevalence of MDR-TB cases in three years was 32/4136 cases. Among the factors age, gender, pattern of resistant and high Random Blood Sugar level were the key determining factors influencing MDR-TB. Conclusions: A main component in stopping the spread of MDR-TB is to rapidly diagnose infectious TB disease cases and treat these so the patient can be cured and the chain of transmission will be stopped.

BEDAQUILINE: A long but much fruitful wait since seventies

Tuberculosis (TB) is a major health problem in developing countries one of the leading cause of deaths due to infectious disease in the world. Drug treatment had being successful with anti-tubercular drugs available, but Multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant TB (XDR-TB) are serious forms of TB which have emerged as real concern. Bedaquiline (TMC-207 or R207910), is a new anti TB agent been approved as a part of drug regimen therapy in pulmonary MDR-TB. Bedaquiline acts on energy metabolism of the bacteria. It acts as a bactericidal drug. There are two important black box warnings for this drug, firstly prolongation of QT interval and secondly increased risk of death with bedaquiline as compared to placebo treatment. Fast track approval for bedaquiline was based on two phase 2 trials. The FDA has approved bedaquiline on Dec 2012, for the treatment of MDR-TB in adults (>18 years) as part of combination therapy under the fast track designation, priority review and orphan-product designation based on two Phase II trials. Careful use of this drug along with monitoring of the potential adverse effects and drug interactions becomes very important, as this new anti-tubercular drug has being approved after forty years, since last anti tubercular drug was approved.doi: http://dx.doi.org/10.3126/mjsbh.v13i1.13000

Outcomes of Chinese herb medicine for the treatment of multidrug-resistant tuberculosis: a systematic review and meta-analysis

Several studies have suggested that Chinese herb medicine (CHM) in combination with chemotherapy has efficacy in the treatment of multidrug-resistant tuberculosis (MDR-TB). The purpose of this meta-analysis was to assess the efficacy of CHM as a concomitant therapy for MDR-TB. Six databases were searched up to October 2014. Controlled trials comparing CHM combined with chemotherapy (treatment group) with chemotherapy alone (control group) for the treatment of MDR-TB were analyzed. Twenty studies, comprising 1823 patients across China, were included in this review. The meta-analysis showed CHM combined with chemotherapy was associated with a superiority in treatment success (odds ratio [OR], 1.33; 95% confidence interval [CI]: 1.15–1.54; P<0.001), and radiological improvement (OR, 1.32; 95% CI: 1.14–1.52; P<0.001). Patients who received CHM combined with chemotherapy were associated with a similar likely to relapse (OR, 0.88; 95% CI: 0.62–1.25, P=0.478). CHM combination with chemotherapy appeared to be associated with a low incidence of adverse effects for MDT-TB treatment. According to the pooled results and the poor quality of the included trials, it might be uncertainty that there was a superiority of CHM combined with chemotherapy for treating MDR-TB. More rigorous controlled trials are required to substantiate or refute these early findings.

Cellular therapy in Tuberculosis

Cellular therapy now offer promise of potential adjunct therapeutic options for treatment of drug-resistant tuberculosis (TB). We review here the role of Mesenchymal stromal cells, (MSCs), as well as other immune effector cells in the therapy of infectious diseases with a focus on TB. MSCs represent a population of tissue-resident non-hematopoietic adult progenitor cells which home into injured tissues increase the proliferative potential of broncho-alveolar stem cells and restore lung epithelium. MSCs have been shown to be immune-modulatory and anti-inflammatory mediated via cell-cell contacts as well as soluble factors. We discuss the functional profile of MSCs and their potential use for adjunct cellular therapy of multi-drug resistant TB, with the aim of limiting tissue damage, and to convert unproductive inflammatory responses into effective anti-pathogen directed immune responses. Adjunct cellular therapy could potentially offer salvage therapy options for patients with drug-resistant TB, increase clinically relevant anti-M.tuberculosis directed immune responses and possibly shorten the duration of anti-TB therapy.

Resistance to second-line drugs in migrants with multidrug-resistant tuberculosis in the Berlin region

The empiric therapy of multidrug-resistant (MDR) tuberculosis (TB) after rapid molecular testing is rendered difficult by an often several weeks-long period of uncertainty, because results of susceptibility testing for second-line TB drugs are pending. The analysis of regional resistance patterns could lead to a more targeted empiric treatment for migrants depending on their country of origin. The results of the susceptibility testing from 2008 to 2013 of all mycobacteria sent to the Institute of Microbiology, working with the department of Pneumology, Heckeshorn Lung Clinic, Berlin, were reanalysed and tested for regional differences. We found 39 multidrug-resistant Mycobacterium tuberculosis strains among the examined strains. More than half of these strains tested susceptible to the following second line drugs namely, linezolid (97%), clofazimine (95%), cycloserine (95%), capreomycin (90%), p-aminosalicylic acid (82%), moxifloxacin (79%) and amikacin (79%). The proportion of strains susceptible to pyrazinamide (44%), ethambutol (28%), prothionamide (15%), rifabutin (8%) and streptomycin (8%) was lower. The mycobacterial cultures of the Chechen patients (n = 14) showed significantly different susceptibilities to amikacin (57%) and prothionamide (36%) compared to the strains from migrants of other regions. In this study, the regional differences in mycobacterial susceptibility to second line drugs suggest that the initial MDR TB therapy of migrants should be tailored to their country of origin.

Weight variation over time and its relevance among multidrug-resistant tuberculosis patients

We aimed to assess the variation in patient body weight over time according to the treatment outcome among multidrug-resistant tuberculosis (MDR-TB) cases. This was a retrospective cohort study. The data of patients commencing MDR-TB therapy were analyzed. Data were collected from different public TB treatment facilities located in peri-urban areas to the south of Lima, Peru. The outcome was patient body weight (kilograms) from treatment commencement, measured monthly. A random effects model was fitted using robust standard errors to calculate 95% confidence intervals. Of a total of 1242 TB cases, 243 (19.6%) were MDR-TB. Only 201 cases were included in the analysis; 127 (63.2%) were males and the mean patient age was 33.6 (standard deviation 16.2) years. Weight changes over time among the patients who were cured differed from changes in those who died during therapy (p<0.001). Weight curve divergence was important at the end of the third, fourth, and fifth treatment months: on average, the weight difference was 2.18kg (p<0.001), 3.27kg (p=0.007), and 3.58kg (p=0.03), respectively, when cured patients were compared to those who died. Our results show that weight variation during treatment can be a useful surrogate for the treatment outcome, specifically death during therapy. MDR-TB patients with weight loss should be followed more closely, as they are at greater risk of death.

A review of tuberculosis: Focus on bedaquiline

The history and prevalence of tuberculosis and the role of bedaquiline in multidrug-resistant (MDR) tuberculosis are reviewed. Tuberculosis continues to cause significant morbidity and mortality worldwide. Increasing rates of drug-resistant tuberculosis are a significant concern and pose serious implications for current and future treatment of the disease. In December 2012, the Food and Drug Administration approved bedaquiline as part of the treatment regimen for pulmonary MDR tuberculosis. Bedaquiline's unique mechanism of action presents an alternative approach to current antimycobacterial killing. By directly inhibiting adenosine triphosphate (ATP) synthase, bedaquiline is effective against both replicating and dormant mycobacteria. Pulmonary cavitary lesions can contain heterogeneous populations. This potential mix of semireplicating and hypometabolic mycobacteria is more difficult to eliminate with conventional antitubercular drugs, thus increasing the risk of resistance. No in vitro cross-resistance between bedaquiline and currently available antitubercular agents has been observed thus far. Because bedaquiline targets a completely different enzyme, cross-resistance with other conventional agents remains unlikely. Enhanced sterilizing capacity via synergistic depletion of ATP further exhibits the promising potential of bedaquiline with pyrazinamide. A course of bedaquiline requires 24 weeks of therapy in combination with other antitubercular drugs. The approval of bedaquiline represents a major milestone in MDR tuberculosis therapy. Bedaquiline should be considered in patients who have not responded to a regimen containing four second-line drugs and pyrazinamide and patients with documented evidence of MDR tuberculosis resistant to fluoroquinolones. The exact role of bedaquiline cannot be determined until further efficacy and safety data are obtained through ongoing Phase III trials.

A Review of the Evidence for Using Bedaquiline (TMC207) to Treat Multi-Drug Resistant Tuberculosis.

Existing therapies for multi-drug resistant tuberculosis (MDR-TB) have substantial limitations, in terms of their effectiveness, side-effect profile, and complexity of administration. Bedaquiline is a novel diarylquinoline antibiotic that has recently been investigated as an adjunct to existing therapies for MDR-TB. Currently, limited clinical data are available to evaluate the drug’s safety and effectiveness. In two small randomized-controlled clinical studies, bedaquiline given for 8 or 24 weeks has been shown to improve surrogate microbiological markers of treatment response, but trials have not yet evaluated its impact on clinical failure and relapse. Safety concerns include an increased mortality in the bedaquiline arm of one study, an increased incidence of QT segment prolongation on electrocardiogram, and hepatotoxicity. Until further research data are available, the use of bedaquiline should be confined to settings where carefully selected patients can be closely monitored.