Barriers and gaps in tuberculosis care and treatment in Iran: A multi-center qualitative study

Introduction

Patients with Tuberculosis (TB) still have barriers in accessing high quality care and treatment services. In this qualitative study, we investigated barriers in accessing TB health services including confirmatory diagnosis, treatment adherence and recurrence of pulmonary TB using patients, physicians, and policy makers point of view.

Materials and methods

In this qualitative research from November to March 2021, 3 policy makers from the Ministry of Health, 12 provincial TB experts and physicians from the TB control program and 33 patients diagnosed with TB from 4 provinces were enrolled for a semi-structured in-depth interview. All interviews were audio recorded and then transcribed. Framework analysis was done by MAXQDA 2018 software to identify key themes.

Results

Several barriers reported for TB care and treatment: Poor knowledge of patents about TB symptoms, failure to screen for TB among at-risk patients by physicians, similar symptoms between TB and other lung diseases, low sensitivity of TB diagnostic tests, incomplete case finding and contact-tracing, stigma related to TB, and patients poor adherence due to long TB treatment. In addition, COVID-19 pandemic disrupted TB services and decreased detection, care and treatment services for TB patients.

Conclusion

Our findings highlight the need for interventions to increase public and healthcare providers awareness about TB symptoms, using more sensitive diagnostic tests, and interventions to reduce stigma, and improve case finding and contact tracing effort. Improving patients' adherence required better monitoring and shorter effective treatment regimes.

Imaging modalities for pulmonary tuberculosis in children: A systematic review

Purpose

The optimal choice of protocol for diagnostic imaging in children with tuberculosis (TB) is a contemporary challenge due to the war in Ukraine, which potentially can create a steep rise in TB cases in Western Europe. We aimed to gather all primary research comparing imaging modalities and their diagnostic accuracies for pulmonary findings in children with suspected or confirmed pulmonary tuberculosis (PTB).

Method

We searched the databases PubMed and Embase using pre-specified search terms, for English- and non-English published and un-published reports from the period 1972 to 2022. We retrieved reports via citation search in excluded literature reviews and systematic reviews. Studies were eligible if most of the study population was between 0 and 18 years of age with confirmed or suspected PTB, and study participants had described diagnostic images from two or more different imaging modalities.

Results

A total of 15 studies investigated conventional chest X-Ray (CXR) and computed tomography (CT) in diagnosing PTB in children. Nine studies investigated the number of participants in where CT or CXR confirmed the diagnosis of TB, and all of them, including a total of 1244 patients, reported that findings compatible with TB were more frequently detected on CT than CXR. Only two studies did not include radiological findings as part of their diagnostic criteria for PTB, and combined they showed that CT diagnosed 54/54 (100 %) children with confirmed PTB, while CXR diagnosed 42/54 (78 %). Two studies compared magnetic resonance imaging (MRI) with CXR and showed that MRI diagnosed more children with PTB than CXR. One study reported a higher positive predictive value (PPV), sensitivity and specificity for PTB findings for MRI than CXR. One study compared CXR with high-kilovolt (high-kV) CXR, finding compatible sensitivity and specificity regarding confirmation of PTB. Two studies compared ultrasound (US) with CXR and found that US had a higher diagnostic yield and more often correctly identified consolidations, mediastinal LAP, and pleural effusion.

Conclusion

CT showed a higher diagnostic accuracy for PTB findings than CXR, MRI and US, and should be the imaging modality of first choice when available. MRI had a higher sensitivity and specificity than CXR for LAP, pleural effusion, and cavitation. US was complimentary in initial diagnostic work-up and follow up. A diagnostic strategy for PTB in children according to local availability and expertise is proposed, as no evidence from this systematic review shows otherwise, in acknowledgement of the expertise in high TB-burdened countries. CT can be performed when in doubt, due to the higher diagnostic yield.

An explanation of the 15-year trend and investigation of the tuberculosis cascade in Kurdistan province

Objective

This study's objectives were to describe the 15-year trend from 2005 to 2019 and examine the tuberculosis cascade in the Kurdistan province from 21 march 2018–20 march 2019.

Methods

This retrospective study was in 2744 patients with tuberculosis from 2005 to 2019 who were registered in Kurdistan disease registration centers. For the initial evaluation of demographic data, we utilized SPSS software version 20 and excel. Additionally, to design a care cascade, we utilized draw.io software for registered patients between March 21, 2018, and March 20, 2019. As a result, 2489 new cases of tuberculosis remained in our study.

Results

The results showed that the mean of age of people with tuberculosis was 58 years and sex distribution were 1441 (57.9) female and 1048 (42.1) male. Additionally, a cascade model showed that in Kurdistan Province, an estimated 112 new cases of smear-positive pulmonary tuberculosis in 2018, of which 90% (101 people) were sent to medical facilities and underwent diagnostic testing, with 80% of these patients (81 people). Infection was identified in 81 individuals, all of whom had their diagnoses recorded in the medical database. 82% (67 patients) of the patients who were enrolled in the treatment system received access to treatment, and 65 patients, or 97 percent, experienced no recurrence for at least a year after treatment. Correct diagnosis and therapy represented the biggest gap.

Conclusion

Cascade can enhance surveillance program and focus activities to better cases, diagnose, connect to care, and help TB patients survive without recurrence.

Effect of adjusted cut-offs of interferon-γ release assays on diagnosis of tuberculosis in patients with fever of unknown origin

Background

Tuberculosis (TB) is a leading cause of fever of unknown origin (FUO). In recent years, interferon-γ release assays (IGRAs) have been widely utilized and the cut-off values given by the manufacturers are set in countries where rates of TB are not as high.

Methods

A prospective cohort study was conducted in a Chinese general hospital to evaluate the diagnostic performance of T-SPOT.TB (T-SPOT) and QuantiFERON-TB Gold (QFT) in detecting active TB (ATB) in a high TB endemic area. Test results were compared with the culture and clinically confirmed diagnosis. Further, we explored an alternative method of interpreting IGRAs by increasing the cut-off values.

Results

The sensitivity and specificity of T-SPOT in detecting ATB were 85.3% (95% CI 81.6–94.0%) and 71.8% (95% CI 67.3–76.0%), respectively. The sensitivity and specificity of QFT were 72.3% (95% CI 62.8–80.1%) and 77.0% (95% CI 72.7–80.8%), respectively. Receiver operating characteristic analysis was used for evaluation of different cut-off values. When the cut-off values were adjusted as 125 spot-forming cells (SFCs)/ 2.5*10⁵ cells for T-SPOT and 4.0 IU/ml for QFT, the specificity could be improved to > 90.0% (90.3% and 94.1%, respectively), and the sensitivity were 43.1% and 41.6%, respectively. The new adjusted cut-off values were validated in another independent validation cohort.

Conclusion

The adjusted cut-off values of the two assays considerably improved the diagnostic value when applied to FUO patients in clinical settings.

Disseminated Tuberculosis With Myocarditis and Intracardiac Thrombus in a Previously Young Healthy Woman

A 33-year-old woman with newly diagnosed disseminated tuberculosis presented with acute heart failure and incidental findings of intracardiac thrombus, demonstrating possible tuberculous myocarditis. (Level of Difficulty: Intermediate.)

Recent developments in the medicinal chemistry of single boron atom-containing compounds

Various boron-containing drugs have been approved for clinical use over the past two decades, and more are currently in clinical trials. The increasing interest in boron-containing compounds is due to their unique binding properties to biological targets; for example, boron substitution can be used to modulate biological activity, pharmacokinetic properties, and drug resistance. In this perspective, we aim to comprehensively review the current status of boron compounds in drug discovery, focusing especially on progress from 2015 to December 2020. We classify these compounds into groups showing anticancer, antibacterial, antiviral, antiparasitic and other activities, and discuss the biological targets associated with each activity, as well as potential future developments.

Correlation of inflammatory cytokines on corrected QT interval in rifampicin-resistant tuberculosis patients

Background

The cases of Rifampicin-Resistant Tuberculosis (RR-TB) in our country have increased every year and RR-TB deaths are thought to be caused by prolongation of the QTc interval due to side effects of anti-tuberculosis drugs. Thus, cytokines are needed to be used as early markers of prolongation of the QTc interval in RR-TB patients.

Objective

This study aims to analyze the correlation of inflammatory cytokines on QTc interval in RR-TB patients who received shorter regimens.

Methods

This study uses a case-control study with a time series conducted in the period September 2019 to February 2020 in one of the referral hospitals for Tuberculosis in Indonesia. Cytokines levels from blood samples were measured using the ELISA method, while QTc intervals were automatically recorded using an electrocardiography machine. The statistical analysis used was the Chi-square test, Man Whitney test, Independence t-test, and Spearman-rank test with p < 0.05.

Results

There was no significant correlation between inflammatory cytokines and QTc prolongation in intensive phase which TNF-α value (6.8 pg/ml; r = 0.207; p = 0.281), IL-1β (20.13 pg/ml; r = 0.128; p = 0.509), and IL-6 (43.17 pg/ml; r = -0.028; p = 0.886). Meanwhile, in the continuation phase, the values for TNF-α (4.79 pg/ml; r = 0.046; p = 0.865), IL-1β (7.42 pg/ml; r = -0.223; p = 0.406), and IL- 6 (40.61 pg/ml; r = -0.147; p = 0.586).

Conclusion

inflammatory cytokines (TNF-α, IL-1β, and IL-6) cannot be used to identify QTc interval prolongation in RR-TB patients who received shorter regimens.

Microneedle-based devices for point-of-care infectious disease diagnostics

Recent infectious disease outbreaks, such as COVID-19 and Ebola, have highlighted the need for rapid and accurate diagnosis to initiate treatment and curb transmission. Successful diagnostic strategies critically depend on the efficiency of biological sampling and timely analysis. However, current diagnostic techniques are invasive/intrusive and present a severe bottleneck by requiring specialist equipment and trained personnel. Moreover, centralised test facilities are poorly accessible and the requirement to travel may increase disease transmission. Self-administrable, point-of-care (PoC) microneedle diagnostic devices could provide a viable solution to these problems. These miniature needle arrays can detect biomarkers in/from the skin in a minimally invasive manner to provide (near-) real-time diagnosis. Few microneedle devices have been developed specifically for infectious disease diagnosis, though similar technologies are well established in other fields and generally adaptable for infectious disease diagnosis. These include microneedles for biofluid extraction, microneedle sensors and analyte-capturing microneedles, or combinations thereof. Analyte sampling/detection from both blood and dermal interstitial fluid is possible. These technologies are in their early stages of development for infectious disease diagnostics, and there is a vast scope for further development. In this review, we discuss the utility and future outlook of these microneedle technologies in infectious disease diagnosis.

A fragment-based approach to assess the ligandability of ArgB, ArgC, ArgD and ArgF in the L-arginine biosynthetic pathway of Mycobacterium tuberculosis

The L-arginine biosynthesis pathway consists of eight enzymes that catalyse the conversion of L-glutamate to L-arginine. Arginine auxotrophs (argB/argF deletion mutants) of Mycobacterium tuberculosis are rapidly sterilised in mice, while inhibition of ArgJ with Pranlukast was found to clear chronic M. tuberculosis infection in a mouse model. Enzymes in the arginine biosynthetic pathway have therefore emerged as promising targets for anti-tuberculosis drug discovery. In this work, the ligandability of four enzymes of the pathway ArgB, ArgC, ArgD and ArgF is assessed using a fragment-based approach. We identify several hits against these enzymes validated with biochemical and biophysical assays, as well as X-ray crystallographic data, which in the case of ArgB were further confirmed to have on-target activity against M. tuberculosis. These results demonstrate the potential for more enzymes in this pathway to be targeted with dedicated drug discovery programmes.

Approach to the diagnosis and treatment of non-tuberculous mycobacterial disease

Non-tuberculous mycobacteria (NTM) is a collective name given to a group of more than 190 species of Mycobacterium. The clinical presentation for most NTM infections is non-specific, often resulting in delayed diagnosis. Further complicating matters is that NTM organisms can be difficult to isolate. Medications used to treat NTM infection can be difficult for patients to tolerate, and prolonged courses of anti-mycobacterial therapy are often required for adequate suppression or eradication. Herein, we review different NTM syndromes, appropriate diagnostic tests, and treatment regimens.

Phagocytosis and the antigen-processing abilities of macrophages derived from monocytes in spinal tuberculosis patients

This study examined the hypothesis that there is an impairment of macrophageal function in spinal TB. We examined macrophageal functions in spinal TB patients. Monocytes were isolated from peripheral blood mononuclear cells (PBMCs) of five spinal TB patients and five healthy persons as control. The isolated monocytes were cultured with stimulation of macrophage colony-stimulating factor (M-CSF) for seven days for maturation. The phagocytic ability of the macrophages derived from monocytes was measured. Also, nitric oxide (NO), myeloperoxidase (MPO), beta-glucuronide, and acid phosphatase activity was investigated. We found that the monocytes collected from patient PBMCs were significantly fewer than those of the control group (2992.10³ vs. 6474.10³ (cells/mL)). There were also fewer macrophages that had adhered to sheep red blood cells (SRBC) (598.10³ vs. 264.10³ (cells/mL)). However, NO production (2346 vs. 325.17 (µmol/gram of protein)), and the MPO (570.7 vs. 17.4 (unit/mg), beta-glucuronide (0.149 vs. 0.123 (μmol/hour/100 mg of protein)), and acid phosphatase activities (1776.9 vs. 287.9 (μmol/hour/100 mg of protein)) of the macrophages in the spinal TB group were markedly higher than in the healthy group. Despite the low adhesion to foreign bodies, the intracellular processing of TB macrophages, including oxidative activity and lysosome function, was significantly high. These results suggested the impairment of macrophageal function in spinal TB. Possibly, there is a dominance of innate non-specific immunity in spinal TB infection.

Non-contrast versus contrast-enhanced MR in the diagnosis of spondylitis: A quantitative concordance-analysis

Introduction

: Magnetic Resonance (MR) imaging using gadolinium contrast media is an essential imaging modality in diagnosing spondylitis. However, gadolinium contrast is not widely available in Indonesia and relatively expensive. Many MR studies in Indonesia are performed without contrast administration. It is unclear how confident non-contrast MR can diagnose tuberculous spondylitis in comparison to standard contrast MR.

Purposes

: This study aims to evaluate the concordance between the contrast MR and non-contrast spine MR in diagnosing tuberculous spondylitis. We also evaluate the interobserver agreement between the general radiologist and musculoskeletal radiologist in interpreting non-contrast MR of spondylitis.

Materials and Methods

: A cross-sectional study using secondary data was performed to evaluate the concordance between the MR results regarding the usage of contrast media in diagnosing spondylitis. The inclusion criteria were patients over 17 years old who underwent complete sequences of contrast-enhanced MR examination of the spine, referred to radiology with the clinical diagnosis of suspected tuberculous spondylitis, spondylodiscitis, or both. All of the non-contrast and contrast-enhanced MR results were read and interpreted by two independent observers, a musculoskeletal radiologist and a general radiologist, blindly. The interobserver agreement analysis of the MR examination was conducted using Kappa and McNemar test.

Results

: There was no significant difference between the contrast and non-contrast MR in diagnosing spondylitis (P= 0.368) and no significant difference in the interpretation of MR between the first and the second observer (P =  0.343). The concordance between the contrast and non-contrast spine MR in diagnosing spondylitis (R: 0.88, P < 0.001) and the interpretation of MR between both observers (R: 0.65, P < 0.001) were showed in this study.

Conclusion

: There is a high concordance between the contrast and non-contrast MR in diagnosing tuberculous spondylitis. Although contrast MR is preferred as the standard imaging method of spondylitis, in case gadolinium contrast is unavailable, non-contrast MR can still provide valuable information in diagnosing spondylitis.

Disseminated histoplasmosis in a kidney liver transplant patient from a non-endemic area: A diagnostic challenge

Disseminated histoplasmosis is a rare opportunistic infection in non-endemic areas, where the disease is often diagnosed late. The spectrum of clinical manifestations is broad and life-threatening complications occur.

We present a detailed case of a kidney liver transplant patient with disseminated histoplasmosis in a non-endemic area. Our case highlights the wide range of pathogens to consider in the immunocompromised patient, the delayed diagnosis of Histoplasmosis Capsulatum in non-endemic areas and the possibility of severe gastrointestinal disease. We also briefly review diagnostic tests and treatment options.

Miliary pattern, a classic pulmonary finding of tuberculosis disease

Introduction

The increase in age of the population and in the use of immunosuppressive treatment makes tuberculosis (TB) with hematogenous or lymphatic dissemination a current problem.

Methods

We collected all the patients diagnosed with tuberculosis with miliary pulmonary pattern at the Santiago de Compostela University Teaching Hospital (NW Spain) from 1 January 2006 to 31 December 2015.

Results

A total of 27 patients were included, 70.4% women, with a median age of 69.0 years old. A cause of immunosuppression was observed only in 51.9% of patients. The majority of the cases (65.0%) presented pulmonary affectation. The most frequently isolated species was Mycobacterium tuberculosis (88.9%). Multiresistance to first-line antituberculosis drugs was observed only in 3.7%. 92.6% of the patients received treatment with Isoniazid, Rifampicin and Pyrazinamine, associated in 48.1% of them with Ethambutol. Two patients died during admission and there were no recurrences in the 2-years follow-up.

Conclusions

Miliary tuberculosis remains a current pathology. Most patients do not have a known cause of immunosuppression. The response to the typical treatment is usually good.

Indian National Association for the Study of the Liver Consensus Statement on Acute Liver Failure (Part 1): Epidemiology, Pathogenesis, Presentation and Prognosis

Acute liver failure (ALF) is an infrequent, unpredictable, potentially fatal complication of acute liver injury (ALI) consequent to varied etiologies. Etiologies of ALF as reported in the literature have regional differences, which affects the clinical presentation and natural course. In this part of the consensus article designed to reflect the clinical practices in India, disease burden, epidemiology, clinical presentation, monitoring, and prognostication have been discussed. In India, viral hepatitis is the most frequent cause of ALF, with drug-induced hepatitis due to antituberculosis drugs being the second most frequent cause. The clinical presentation of ALF is characterized by jaundice, coagulopathy, and encephalopathy. It is important to differentiate ALF from other causes of liver failure, including acute on chronic liver failure, subacute liver failure, as well as certain tropical infections which can mimic this presentation. The disease often has a fulminant clinical course with high short-term mortality. Death is usually attributable to cerebral complications, infections, and resultant multiorgan failure. Timely liver transplantation (LT) can change the outcome, and hence, it is vital to provide intensive care to patients until LT can be arranged. It is equally important to assess prognosis to select patients who are suitable for LT. Several prognostic scores have been proposed, and their comparisons show that indigenously developed dynamic scores have an edge over scores described from the Western world. Management of ALF will be described in part 2 of this document.

Burden of tuberculosis and challenges related to screening and diagnosis in Ethiopia

INTRODUCTION

One-third of tuberculosis (TB) cases in Ethiopia are missing from care for reasons that are not well studied. The aim of this study was to assess TB burden and identify challenges related to TB screening and diagnosis in Ethiopia.

METHODS

A facility-based cross-sectional study was conducted in seven health facilities selected from two regions and 2 city administrations of Ethiopia using stratified random sampling procedures. The data of 1,059,065 patients were included from outpatient department, HIV clinic, diabetic, and maternal-child health clinics. Data were collected from October to December 2018 using a retrospective review of three years' facility data (2015 to 2017) supplemented by a semi-structured interview with purposively selected health care workers and heads of the health facilities.

RESULTS

A total of 1,059,065 patients visited the health facilities in three years, of these, 978,480 (92.4%) were outpatients. Of the total, 20,284 (2%) were presumptive TB cases (with 14 days or more cough), 12.2% (2483/20,284) of which had TB. For the type of TB, 604 (24.3%) were smear-positive pulmonary TB (PTB), 789 (31.8%) were smear-negative PTB, 719 (29%) were extra-pulmonary TB, and data were missing for the rest. TB screening was integrated into HIV clinic, outpatient department, diabetic clinic but not with the maternal and child clinics. High patient load, weak TB laboratory specimen referral system, and shortage of TB diagnostic tools including Xpert MTB/RIF assay and chest X-ray, were the major challenges in the screening and diagnosis of TB.

CONCLUSION

The burden of TB was high in the study setting, and frequent interruption of laboratory reagents and supplies hampered TB screening and diagnostic services. Realizing the END-TB strategy in such resource-limited settings requires sustainable TB diagnostic capacity and improved case detection mechanisms, with national TB programs strongly integrated into the general health care system.

Variations in the C-unit of bedaquiline provides analogues with improved biology and pharmacology

Analogues of the anti-tuberculosis drug bedaquiline, bearing a 3,5-dimethoxy-4-pyridyl C-unit, retain high anti-bacterial potency yet exert less inhibition of the hERG potassium channel, in vitro, than the parent compound. Two of these analogues (TBAJ-587 and TBAJ-876) are now in preclinical development. The present study further explores structure-activity relationships across a range of related 3,5-disubstituted-4-pyridyl C-unit bedaquiline analogues of greatly varying lipophilicity (clogP from 8.16 to 1.89). This broader class shows similar properties to the 3,5-dimethoxy-4-pyridyl series, being substantially more potent in vitro and equally active in an in vivo (mouse) model than bedaquiline, while retaining a lower cardiovascular risk profile through greatly attenuated hERG inhibition.

Utility of urine as a clinical specimen for the diagnosis of pulmonary tuberculosis in people living with HIV in Addis Ababa, Ethiopia

Background

Tuberculosis is a common cause of mortality and morbidity among people living with HIV/AIDS. Despite the increased prognosis of tuberculosis among HIV infected patients, diagnosis of pulmonary tuberculosis (PTB) smear microscopy has a low sensitivity due to low bacterial load in a sputum specimen of HIV patients. Having alternative specimens for increasing detection of Mycobacterium tuberculosis (Mtb) is very important.

Objective

The aim of this study was to evaluate the efficacy of urine as clinical specimen for the diagnosis of pulmonary tuberculosis in people living with HIV.

Method

A total of 117 HIV-seropositive individuals from three public health facilities in Addis Ababa, Ethiopia were enrolled consecutively from December 2013 to July 2014. A total of 117 paired morning sputum and urine samples were simultaneously collected from anti-retroviral therapy (ART) naïve PTB suspected individuals living with HIV. Both sputum and urine samples were processed for culture using Lowenstein-Jensen medium, and the left was subjected to PCR using RD9 primers. Chi-square test and kappa value were used to compare different methods used.

Result

Out of 117 suspected PTB HIV-infected people, sputum culture alone detected more mycobacterial isolates 33 (28.2%) than the urine specimen alone 17 (14.5%). Of the 33 patients positive for sputum culture, 13 patients were observed as a urine culture positive. Of the 84 individuals negative for mycobacterial by sputum culture, four (4.8%) were urine culture positive and thus, the sensitivity, and the agreement between urine culture as compare to sputum culture were 39.4% and 0.49, respectively. On the other hand, the sensitivity of RD9-based PCR directly on urine was 72.7% by considering sputum culture as a reference standard. Moreover, RD9-based PCR directly on sputum detected 9 (7.7%) individuals who were sputum culture negative for M. Tuberculosis. The detection rate of M. tuberculosis from urine in patients those who couldn't produce sputum were 9(34.6%).

Conclusion

PCR and culture examination of urine samples also can improve the detection rate of M. tuberculosis in PTB suspected HIV positive individuals.

Role of nanostructures in improvising oral medicine

The most preferable mode of drugs administration is via the oral route but physiological barriers such as pH, enzymatic degradation etc. limit the absolute use of this route. Herein lies the importance of nanotechnology having a wide range of applications in the field of nano-medicine, particularly in drug delivery systems. The exclusive properties particularly small size and high surface area (which can be modified as required), exhibited by these nanoparticlesrender these structures more suitable for the purpose of drug delivery. Various nanostructures, like liposomes, dendrimers, mesoporous silica nanoparticles, etc. have been designed for the said purpose. These nanostructures have several advantages over traditional administration of medicine. Apart from overcoming the pharmacokinetic and pharmacodynamics limitations of many potential therapeutic molecules, they may also be useful for advanced drug delivery purposes like targeted drug delivery, controlled release, enhanced permeability and retention (EPR) effect. In this review, we attempt to describe an up-to-date knowledge on various strategically devised nanostructures to overcome the problems related to oral drug administration.

3,5-Dialkoxypyridine analogues of bedaquiline are potent antituberculosis agents with minimal inhibition of the hERG channel

Bedaquiline is a new drug of the diarylquinoline class that has proven to be clinically effective against drug-resistant tuberculosis, but has a cardiac liability (prolongation of the QT interval) due to its potent inhibition of the cardiac potassium channel protein hERG. Bedaquiline is highly lipophilic and has an extremely long terminal half-life, so has the potential for more-than-desired accumulation in tissues during the relatively long treatment durations required to cure TB. The present work is part of a program that seeks to identify a diarylquinoline that is as potent as bedaquiline against Mycobacterium tuberculosis, with lower lipophilicity, higher clearance, and lower risk for QT prolongation. Previous work led to the identification of compounds with greatly-reduced lipophilicity compounds that retain good anti-tubercular activity in vitro and in mouse models of TB, but has not addressed the hERG blockade. We now present compounds where the C-unit naphthalene is replaced by a 3,5-dialkoxy-4-pyridyl, demonstrate more potent in vitro and in vivo anti-tubercular activity, with greatly attenuated hERG blockade. Two examples of this series are in preclinical development.

Cloning and expression of MPT83 gene from Mycobacterium tuberculosis in E. coli BL21 as vaccine candidate of tuberculosis: A preliminary study

The appearance of Mycobacterium tuberculosis strains leading to drug resistance has caused new problems in TB treatment in various parts of the world and forces WHO to declare TB as a global emergency. With the increase of TB drug resistance, it is convinced that a more effective vaccine development will stop the epidemic of TB. Some M. tuberculosis antigens, one of which is MPT83, have been examined as TB vaccine candidate. MPT83 antigen, which is very immunogenic in lipoprotein micro bacteria, is identified as surface cell interrelated to antigen with cytometry circulation. Having TB resistance from BCG vaccine, MPT83 is considered TB vaccine candidate that can protect people against TB at adult age. The purpose of this research is to conduct amplification of MPT83 antigen cloning, and expression of its antigen on E. coli bacteria. From the result of the research, it is expected that raw material to produce TB vaccine as well as a high-quality antigen can be obtained. The band of DNA in PCR product is 660 bp, while the one in pGEMT-Easy-Mpt83 recombinant plasmid is 3678 bp. This is expressed in E. coli BL21 strain and produces 48 kDa protein as well as GST-MPT83 fusion protein.

Molecular dynamics simulation and binding free energy studies of novel leads belonging to the benzofuran class inhibitors of Mycobacterium tuberculosis Polyketide Synthase 13

In this work, the binding mechanism of new Polyketide Synthase 13 (Pks13) inhibitors has been studied through molecular dynamics simulation and free energy calculations. The drug Tam1 and its analogs, belonging to the benzofuran class, were submitted to 100 ns simulations, and according to the results obtained for root mean square deviation, all the simulations converged from approximately 30 ns. For the analysis of backbone flotation, the root mean square fluctuations were plotted for the Cα atoms; analysis revealed that the greatest fluctuation occurred in the residues that are part of the protein lid domain. The binding free energy value (ΔG_bind) obtained for the Tam16 lead molecule was of -51.43 kcal/mol. When comparing this result with the ΔG_bind values for the remaining analogs, the drug Tam16 was found to be the highest ranked: this result is in agreement with the experimental results obtained by Aggarwal and collaborators, where it was verified that the IC₅₀ for Tam16 is the smallest necessary to inhibit the Pks13 (IC₅₀ = 0.19 μM). The energy decomposition analysis suggested that the residues which most interact with inhibitors are: Ser1636, Tyr1637, Asn1640, Ala1667, Phe1670, and Tyr1674, from which the greatest energy contribution to Phe1670 was particularly notable. For the lead molecule Tam16, a hydrogen bond with the hydroxyl of the phenol not observed in the other analogs induced a more stable molecular structure. Aggarwal and colleagues reported this hydrogen bonding as being responsible for the stability of the molecule, optimizing its physic-chemical, toxicological, and pharmacokinetic properties.

Anal tuberculosis: A non-Healing anal lesion

Anal tuberculosis is an extremely rare extrapulmonary presentation of tuberculosis (TB). Less than 1% of the individuals who contract TB manifests as gastrointestinal TB, and anoperineal TB is much less frequently encountered, 1% of the TB cases of the digestive tract. A rare case of anal tuberculosis is reported in a 37-year-old male patient with a recent anal fistula surgery and relapsing anal lesions. AFB were detected by biopsy and culture. In total, the treatment course lasted 6 months and the patient showed signs of recovery in the early stages of the treatment (after 2 weeks), and complete remission was achieved. In conclusion, it is recommended that in case of encountering Non-healing and recurrent anal lesions, especially in regions endemic for TB, should be evaluated for tuberculosis.

A patient with central nervous system tuberculomas and a history of disseminated multi-drug-resistant tuberculosis

Tuberculosis (TB) is one of the leading causes of death worldwide, particularly in low- and middle-income countries. The global rates and numbers of drug resistant TB are rising. With increasing globalization, the spread of drug-resistant strains of TB has become a mounting global public health concern. We present a case of a young man previously treated for multi-drug resistant (MDR) TB in India who presented with neurological symptoms and central nervous system TB in the United States. His case highlights unique diagnostic and treatment challenges that are likely to become more commonplace with the increase of patients infected with drug-resistant TB and complicated extrapulmonary disease.

Overcoming the Declining Trends in Innovation and Investment in Cardiovascular Therapeutics: Beyond EROOM's Law

Eroom's law (Moore's law spelled backwards), describes adverse trends towards declining innovation and rising costs of drug development over the last several decades. Therapeutics for cardiovascular diseases (CVD) appear to have been particularly sensitive to these trends. Thirty-three percent fewer CVD therapeutics were approved between 2000 and 2009 compared to the previous decade, and the number of CVD drugs starting all clinical trial stages declined in both absolute and relative numbers between 1990 and 2012. In the last 5 years, drugs to treat CVD disease comprised just 6% of all new drug launches. This review discusses the decline in CVD therapeutics, the reasons behind it, and ways in which this trend is being or might be addressed.

Biochemical characterization and novel inhibitor identification of Mycobacterium tuberculosis Endonuclease VIII 2 (Rv3297)

Nei2 (Rv3297) is a DNA Base Excision Repair (BER) glycosylase that is essential for survival of Mycobacterium tuberculosis in primates. We show that MtbNei2 is a bifunctional glycosylase that specifically acts on oxidized pyrimidine-containing single-stranded, double-stranded, 5’/3’ fork and bubble DNA substrates. MtbNei2 possesses Uracil DNA glycosylase activity unlike E. coli Nei. Mutational studies demonstrate that Pro2 and Glu3 located in the active site are essential for glycosylase activity of MtbNei2. Mutational analysis demonstrated that an unstructured C-terminal zinc finger domain that was important for activity in E. coli Nei and Fpg, was not required for the glycosylase activity of MtbNei2. Lastly, we screened the NCI natural product compound database and identified three natural product inhibitors with IC50 values ranging between 41.8 μM-92.7 μM against MtbNei2 in in vitro inhibition assays. Surface Plasmon Resonance (SPR) experiments showed that the binding affinity of the best inhibitor, NSC31867, was 74 nM. The present results set the stage for exploiting this important target in developing new therapeutic strategies that target Mycobacterial BER.

•

Biochemical characterization of MtbNei2 (Rv3297).

•

Pro2 and Glu3 residues are essential for MtbNei2 activity.

•

Zinc finger domain is dispensable for activity.

•

3 natural product inhibitors identified against MtbNei2.

Paradoxical response with increased tumor necrosis factor-α levels to anti-tuberculosis treatment in a patient with disseminated tuberculosis

It has been reported that tuberculosis (TB) worsens after cessation of tumor necrosis factor-α inhibitors and starting anti-TB treatment. Little is known about the immunological pathogenesis of this paradoxical response (PR). We report the first case of a TB patient in whom PR occurred concurrently with elevation of circulating tumor necrosis factor-α (TNFα) levels. A 75-year-old woman, who had been treated with adalimumab for SAPHO syndrome, developed disseminated TB. Soon after administration of anti-TB treatment (isoniazid, rifampicin, pyrazinamide, and ethambutol), and after discontinuation of adalimumab, a PR occurred. Serial testing of serum cytokine levels revealed a marked increase in TNFα, and a decline in interferon-γ levels. Despite intensive treatment with antibiotics, prednisolone, noradrenaline, and mechanical ventilation, acute respiratory distress syndrome developed and she died. Thus, overproduction of TNFα after cessation of TNFα inhibitors may partially account for the pathogenesis of a PR. This supports preventative or therapeutic reinitiation of TNFα inhibitors when PR occurs. Serial monitoring of circulating inflammatory cytokine levels could lead to earlier identification of a PR.

Funding Research Through the Online Partnership to Accelerate Research (OnPAR)

OnPAR-the Online Partnership to Accelerate Research-seeks to provide a second opportunity for funding of high-quality, unfunded applications originally submitted to the National Institutes of Health and other national and international funding agencies. OnPAR will match applicable, unfunded applications with the research priorities of nongovernment organizations such as private biomedical foundations, pharmaceutical companies, venture capital funds, and other private funds. Funding organization members will review and make final funding decisions through a simple, 2-step process whereby applicants can submit public abstracts directly to OnPAR. If a member requests additional information, then, by invitation only, an applicant can submit their original unfunded application and their peer review summary statement. Advancing research discovery and drug development to improve clinical outcomes for patients afflicted with or at risk for disease is the primary goal of OnPAR. OnPAR invites the scientific community to fully participate in this new funding paradigm by submitting their National Institutes of Health public abstracts so that funding members can review and potentially support these high-quality, unfunded applications.

Isoniazid metabolism and hepatotoxicity

Isoniazid (INH) is highly effective for the management of tuberculosis. However, it can cause liver injury and even liver failure. INH metabolism has been thought to be associated with INH-induced liver injury. This review summarized the metabolic pathways of INH and discussed their associations with INH-induced liver injury.

Effects of the fusion design and immunization route on the immunogenicity of Ag85A-Mtb32 in adenoviral vectored tuberculosis vaccine

Vaccines containing multiple antigens may induce broader immune responses and provide better protection against Mycobacterium tuberculosis (Mtb) infection as compared to a single antigen. However, strategies for incorporating multiple antigens into a single vector and the immunization routes may affect their immunogenicity. In this study, we utilized recombinant adenovirus type 5 (rAd5) as a model vaccine vector, and Ag85A (Rv3804c) and Mtb32 (Rv0125) as model antigens, to comparatively evaluate the influence of codon usage optimization, signal sequence, fusion linkers, and immunization routes on the immunogenicity of tuberculosis (TB) vaccine containing multiple antigens in C57BL/6 mice. We showed that codon-optimized Ag85A and Mtb32 fused with a GSG linker induced the strongest systemic and pulmonary cell-mediated immune (CMI) responses. Strong CMI responses were characterized by the generation of a robust IFN-γ ELISPOT response as well as antigen-specific CD4(+) T and CD8(+) T cells, which secreted mono-, dual-, or multiple cytokines. We also found that subcutaneous (SC) and intranasal (IN)/oral immunization with this candidate vaccine exhibited the strongest boosting effects for Mycobacterium bovis bacille Calmette-Guérin (BCG)-primed systemic and pulmonary CMI responses, respectively. Our results supported that codon optimized Ag85A and Mtb32 fused with a proper linker and immunized through SC and IN/oral routes can generate the strongest systemic and pulmonary CMI responses in BCG-primed mice, which may be particularly important for the design of TB vaccines containing multiple antigens.

A 22-year-old man with pleural tuberculosis associated hydropneumothorax: Case report and literature review

A 22-year-old Asian male presented with fever, non-productive cough, right-sided pleuritic chest pain and was found to have a large right hydropneumothorax. A chest tube was placed. Pleural fluid analysis revealed a lymphocytic predominant exudate and he was subsequently started on four-drug daily anti-tuberculosis therapy (isoniazid, ethambutol, rifampin, pyrazinamide). Pleural biopsy revealed acid-fast bacilli. Given his persistent pleural effusion, he was given four doses of intrapleural tissue plasminogen activator (tPA) and dornase alpha (DNase) via his chest tube over a period of 6 days resulting in clinical and radiologic improvement. Pleural biopsy and pleural fluid culture specimens later revealed Mycobacterium tuberculosis. Intrapleural tPA-DNase therapy has demonstrated improved resolution of infections and shortened hospitalizations for parapneumonic infectious effusions. However, there is little literature on the use of intrapleural fibrinolytics specifically for pleural tuberculosis associated effusions. Furthermore, the American Thoracic Society does not comment on therapeutic thoracentesis or intrapleural fibrinolytic therapy in their recommendations for treatment of pleural tuberculosis. In our case of pleural TB-associated hydropneumothorax, the use of intrapleural tPA-DNase therapy facilitated pleural fluid drainage and resulted in near-complete resolution of the effusion.

In vitro T-cell profile induced by BCG Moreau in healthy Brazilian volunteers

Tuberculosis (TB) remains the world's leading cause of morbidity and mortality. Although Mycobacterium bovis bacillus Calmette-Guérin (BCG) is the only vaccine currently in use, its efficacy is highly variable. It has been suggested that early antigenic presentation is a pivotal event leading to a better immune response in TB vaccine models. To investigate this further, we compared in vitro cell-mediated immune responses in the context of early sensitization with TB (i.e. healthy adults vaccinated with BCG when they were young, HD; n = 25) to those in its absence (i.e., newborns with naïve immunity to TB, UV; n = 10) by challenging mononuclear cells with BCG Moreau. After 48 hours, CD4+ and CD8+ T cells were harvested from both groups and stained for PD-1/CD25/ FOXP3. In addition, supernatants were assayed for a broad range of cytokines using an array system. The HD group showed robust reactivity to Protein Purified Derivative and BCG while the naïve, UV group did not. Similarly, in terms of PD-1 expression and Treg cells (CD4+/CD25high(+)/FOXP3+), only the HD group showed higher levels in CD4 lymphocytes. Otherwise, only the UV group showed expression of CD25dim+ as an activation marker dependent on BCG infection. In terms of cytokines, the HD group showed higher levels of Th1 (IL-2/TNF-α/IFN-γ) and regulatory (IL-10) profiles, with monocytes, but not Tr1 cells, acting as the main source of IL-10. Taken together, our results highlight critical roles of early sensitization with TB in mounting cell-mediated immune responses.

IFNG-mediated immune responses enhance autophagy against Mycobacterium tuberculosis antigens in patients with active tuberculosis

Protective immunity against Mycobacterium tuberculosis (Mtb) requires IFNG. Besides, IFNG-mediated induction of autophagy suppresses survival of virulent Mtb in macrophage cell lines. We investigated the contribution of autophagy to the defense against Mtb antigen (Mtb-Ag) in cells from tuberculosis patients and healthy donors (HD). Patients were classified as high responders (HR) if their T cells produced significant IFNG against Mtb-Ag; and low responders (LR) when patients showed weak or no T cell responses to Mtb-Ag. The highest autophagy levels were detected in HD cells whereas the lowest quantities were observed in LR patients. Interestingly, upon Mtb-Ag stimulation, we detected a positive correlation between IFNG and MAP1LC3B-II/LC3-II levels. Actually, blockage of Mtb-Ag-induced IFNG markedly reduced autophagy in HR patients whereas addition of limited amounts of IFNG significantly increased autophagy in LR patients. Therefore, autophagy collaborates with human immune responses against Mtb in close association with specific IFNG secreted against the pathogen.

Liver Transplantation in India: At the Crossroads

As the liver transplant journey in India reaches substantial numbers and suggests quality technical expertise, it is time to dispassionately look at the big picture, identify problems, and consider corrective measures for the future. Several features characterize the current scenario. Although the proportion of deceased donor liver transplants is increasing, besides major regional imbalances, the activity is heavily loaded in favor of the private sector and live donor transplants. The high costs of the procedure, the poor participation of public hospitals, the lack of a national registry, and outcomes reporting are issues of concern. Organ sharing protocols currently based on chronology or institutional rotation need to move to a more justiciable severity-based system. Several measures can expand the deceased donor pool. The safety of the living donor continues to need close scrutiny and focus. Multiple medical challenges unique to the Indian situation are also being thrown up. Although many of the deficits demand state intervention and policy changes the transplant community needs to take notice and highlight them. The future of liver transplantation in India should move toward a more accountable, equitable, and accessible form. We owe this to our citizens who have shown tremendous faith in us by volunteering to be living donors as well as consenting for deceased donation.

Reactivation Mycobacterium Tuberculosis Presenting as Empyema Necessitans 55 Years Following Thoracoplasty

We describe the case of a 79-year-old man who presented with an enlarging mass on his chest wall. He had a history of thoracoplasty performed 55 years ago for treatment of pulmonary tuberculosis. The mass was subsequently proven to be the result of empyema neccesitans caused by reactivation tuberculosis. Empyema neccesitans is a well described entity in which an empyema spontaneously decompresses by dissecting into the chest wall and extrathoracic soft tissues. This can occur following necrotizing pneumonia, including pyogenic or tuberculus, or pulmonary abscess. Complications from collapse therapy for tuberculosis can be encountered decades following the surgery, however, empyema necessitans due to reactivation tuberculosis is rare. This case affords the opportunity to review the goals, techniques, and radiologic appearance of thoracoplasty.

Portal vein thrombosis

Portal vein thrombosis is an important cause of portal hypertension. PVT occurs in association with cirrhosis or as a result of malignant invasion by hepatocellular carcinoma or even in the absence of associated liver disease. With the current research into its genesis, majority now have an underlying prothrombotic state detectable. Endothelial activation and stagnant portal blood flow also contribute to formation of the thrombus. Acute non-cirrhotic PVT, chronic PVT (EHPVO), and portal vein thrombosis in cirrhosis are the three main variants of portal vein thrombosis with varying etiological factors and variability in presentation and management. Procoagulant state should be actively investigated. Anticoagulation is the mainstay of therapy for acute non-cirrhotic PVT, with supporting evidence for its use in cirrhotic population as well. Chronic PVT (EHPVO) on the other hand requires the management of portal hypertension as such and with role for anticoagulation in the setting of underlying prothrombotic state, however data is awaited in those with no underlying prothrombotic states. TIPS and liver transplant may be feasible even in the setting of PVT however proper selection of candidates and type of surgery is warranted. Thrombolysis and thrombectomy have some role. TARE is a new modality for management of HCC with portal vein invasion.

Transcriptional regulation of bacterial virulence gene expression by molecular oxygen and nitric oxide

Molecular oxygen (O₂) and nitric oxide (NO) are diatomic gases that play major roles in infection. The host innate immune system generates reactive oxygen species and NO as bacteriocidal agents and both require O₂ for their production. Furthermore, the ability to adapt to changes in O₂ availability is crucial for many bacterial pathogens, as many niches within a host are hypoxic. Pathogenic bacteria have evolved transcriptional regulatory systems that perceive these gases and respond by reprogramming gene expression. Direct sensors possess iron-containing co-factors (iron–sulfur clusters, mononuclear iron, heme) or reactive cysteine thiols that react with O₂ and/or NO. Indirect sensors perceive the physiological effects of O₂ starvation. Thus, O₂ and NO act as environmental cues that trigger the coordinated expression of virulence genes and metabolic adaptations necessary for survival within a host. Here, the mechanisms of signal perception by key O₂- and NO-responsive bacterial transcription factors and the effects on virulence gene expression are reviewed, followed by consideration of these aspects of gene regulation in two major pathogens, Staphylococcus aureus and Mycobacterium tuberculosis.

Hepatotoxicity Related to Anti-tuberculosis Drugs: Mechanisms and Management

Development of idiosyncratic hepatotoxicity is an intricate process involving both concurrent as well as sequential events determining the direction of the pathways, degree of liver injury and its outcome. Decades of clinical observation have identified a number of drug and host related factors that are associated with an increased risk of antituberculous drug-induced hepatotoxicity, although majority of the studies are retrospective with varied case definitions and sample sizes. Investigations on genetic susceptibility to hepatotoxicity have so far focused on formation and accumulation reactive metabolite as well as factors that contribute to cellular antioxidant defense mechanisms and the environment which can modulate the threshold for hepatocyte death secondary to oxidative stress. Recent advances in pharmacogenetics have promised the development of refined algorithms including drug, host and environmental risk factors that allow better tailoring of medications based on accurate estimates of risk-benefit ratio. Future investigations exploring the pathogenesis of hepatotoxicity should be performed using human tissue and samples whenever possible, so that the novel findings can be translated readily into clinical applications.

Perioperative bacterial infections in deceased donor and living donor liver transplant recipients

BACKGROUND

Deceased donor (DDLT) and living donor (LDLT) liver transplant (LT) is in vogue in several centers in India. Most centers are resorting to LDLT as a preferred surgery due to shortage of deceased donor liver. The risk of infection and its effect on survival in both groups of recipients from the Indian subcontinent are not known. The study was conducted to compare the bacterial infection rates among LDLT and DDLT recipients and their impact on survival at a tertiary referral center.

METHODS

Retrospective data on 67 LT recipients were reviewed. Data on pre-, per-, and postoperative bacterial infection rates and the common isolates were obtained.

RESULTS

Thirty-five patients had LDLT and 32 had DDLT. The prevalence of pre-operative bacterial infection and the isolates was similar in both groups. The perioperative bacterial infection rates were significantly higher in DDLT recipients (P < 0.01) (relative risk: 1.44 95% confidence interval 1.04-1.9). In both LDLT and DDLT, the common source was urinary tract followed by bloodstream infection. The common bacterial isolates in either transplant were Klebsiella followed by Escherichia coli, Pseudomonas spp. and nonfermenting gram-negative bacteria. Six patients (four LDLT; two DDLT) were treated for tuberculosis. Among the risk factors, cold ischemic time, and duration of stay in the intensive care unit was significantly higher for DDLT (p < 0.01). The death rates were not significantly different in the two groups. However, the odds for death were significantly high at 26.8 (p < 0.05) for postoperative bacterial infection and 1.8 (p < 0.001) for past alcohol.

CONCLUSION

Liver transplant recipients are at high-risk for bacterial infection irrespective of type of transplant, more so in DDLT.