An official ATS statement: hepatotoxicity of antituberculosis therapy

Long-term Efficacy and Safety of Rifampin in the Treatment of a Patient Carrying a CYP24A1 Loss-of-Function Variant

BACKGROUND

Pharmacological therapy may be useful in the treatment of moderate to severe hypercalcemia in patients with infantile hypercalcemia-1 (HCINF1) due to pathogenic variants in the cytochrome P450 24 subfamily A member 1 (CYP24A1). Rifampin is an antituberculosis drug that is a potent inducer of cytochrome P450 3 subfamily A member 4, which is involved in an alternative catabolic pathway of vitamin D. The efficacy of rifampin in improving hypercalcemia was previously reported, but many questions remain on the long-term efficacy and safety. The aim of the study is to test the long-term efficacy and safety of rifampin in a patient with HCINF1.

METHODS

We report clinical, biochemical, and imaging features of a 23-year-old man affected by HCINF1 with moderate hypercalcemia (12.9 mg/dL), symptomatic nephrolithiasis, nephrocalcinosis, and impaired kidney function [estimated glomerular filtration rate (eGFR) 60 mL/min/1.73 m2] treated with rifampin for an overall period of 24 months. Kidney, liver, and adrenal function were evaluated at every follow-up visit.

RESULTS

In 2 months, rifampin induced a normalization of serum calcium (9.6 mg/dL) associated with an improvement of kidney function (eGFR 92 mL/min/1.73 m2) stable during the treatment. After 15 months, rifampin was temporally withdrawn because of asthenia, unrelated to impairment of adrenal function. After 3 months, the timing of drug administration was shifted from the morning to the evening, obtaining the remission of asthenia. At the end of follow-up, the nephrolithiasis disappeared and the nephrocalcinosis was stable.

CONCLUSIONS

Rifampin could represent an effective choice to induce a stable reduction of calcium levels in patients with HCINF1, with a good safety profile.

Hsa_circ_0093884 bound to RNA-binding protein RPS3 ameliorates hepatocyte inflammation in anti-tuberculosis drug-induced liver injury by competitively activating SIRT1

Anti-tuberculosis drug-induced liver injury (ADLI) is one of the main factors hindering the efficacy of routine chemotherapy against tuberculosis. Understanding the mechanism of ADLI will aid in the effective treatment of patients with tuberculosis. Recently, we found that the expression of hsa_circ_0093884, a circular RNA derived from the NAD-dependent deacetylase, sirtuin-1 (SIRT1), was down-regulated in ADLI. Hsa_circ_0093884 was negatively correlated with the NLR family pyrin domain containing 3 (NLRP3) inflammasome and its overexpression increased the expression levels of NLRP3, interleukin-1β, and caspase-1. Mechanistically, RNA immunoprecipitation and immunofluorescence assays revealed that the ribosomal protein S3 (RPS3) could bind to hsa_circ_0093884 and SIRT1. Additionally, the expression of hsa_circ_0093884 was positively correlated with that of SIRT1, and the upregulation of hsa_circ_0093884 expression was crucial for the upregulation of SIRT1 expression. We confirmed that the mRNA and protein expression levels of SIRT1 were influenced by hsa_circ_0093884 and RPS3. Furthermore, hsa_circ_0093884 recruited RPS3 to increase SIRT1 mRNA and protein levels. Importantly, we found a marked decrease in the upregulating effect of hsa_circ_0093884 on SIRT1 owing to RPS3 depletion. To the best of our knowledge, this study is the first to reveal that hsa_circ_0093884 regulates SIRT1 expression and inhibits the inflammatory response by binding to RPS3 in ADLI, which may be used to develop novel strategies for ADLI treatment.

Review article: latent tuberculosis in patients with inflammatory bowel diseases receiving immunosuppression-risks, screening, diagnosis and management

BACKGROUND

One quarter of the world's population has latent tuberculosis infection (LTBI). Systemic immunosuppression is a risk factor for LTBI reactivation and the development of active tuberculosis. Such reactivation carries a risk of significant morbidity and mortality. Despite the increasing global incidence of inflammatory bowel disease (IBD) and the use of immune-based therapies, current guidelines on the testing and treatment of LTBI in patients with IBD are haphazard with a paucity of evidence.

AIM

To review the screening, diagnostic practices and medical management of LTBI in patients with IBD.

METHODS

Published literature was reviewed, and recommendations for testing and treatment were synthesised by experts in both infectious diseases and IBD.

RESULTS

Screening for LTBI should be performed proactively and includes assessment of risk factors, an interferon-gamma releasing assay or tuberculin skin test and chest X-ray. LTBI treatment in patients with IBD is scenario-dependent, related to geographical endemicity, travel and other factors. Ideally, LTBI therapy should be used prior to immune suppression but can be applied concurrently where urgent IBD medical treatment is required. Management is best directed by a multidisciplinary team involving gastroenterologists, infectious diseases specialists and pharmacists. Ongoing surveillance is recommended during therapy. Newer LTBI therapies show promise, but medication interactions need to be considered. There are major gaps in evidence, particularly with specific newer therapeutic approaches to IBD.

CONCLUSIONS

Proactive screening for LTBI is essential in patients with IBD undergoing immune-suppressing therapy and several therapeutic strategies are available. Reporting of real-world experience is essential to refining current management recommendations.

Rechallenge after anti-tuberculosis drug-induced liver injury in a high HIV prevalence cohort

Background: There are limited data on the outcomes of rechallenge with anti-tuberculosis therapy (ATT) following anti-tuberculosis drug-induced liver injury (AT-DILI) in a high HIV prevalence setting.Objectives: To describe the outcomes of rechallenge with first-line ATT.Method: Hospitalised participants with AT-DILI who were enrolled into a randomised controlled trial of N-acetylcysteine in Cape Town, South Africa, were followed up until completion of ATT rechallenge. We described rechallenge outcomes, and identified associations with recurrence of liver injury on rechallenge (positive rechallenge).Results: Seventy-nine participants were rechallenged of whom 41 (52%) were female. Mean age was 37 years (standard deviation [s.d.] ±10). Sixty-eight (86%) were HIV-positive, of whom 34 (50%) were on antiretroviral therapy (ART) at time of AT-DILI presentation. Five participants had serious adverse reactions to an aminoglycoside included in the alternate ATT regimen given after first-line ATT interruption: acute kidney injury in three and hearing loss in two. The median time from first-line ATT interruption to start of first-line ATT rechallenge was 13 days (interquartile range [IQR]: 8–18 days). Antiretroviral therapy was interrupted for a median of 32 days (IQR: 17–58) among HIV-positive participants on ART before AT-DILI. Fourteen participants had positive rechallenge (18%). Positive rechallenge was associated with pyrazinamide rechallenge (P = 0.005), female sex (P = 0.039) and first episode of tuberculosis (TB) (P = 0.032).Conclusion: Rechallenge was successful in most of our cohort. Pyrazinamide rechallenge should be carefully considered.

Design and synthesis of benzimidazole derivatives as antimycobacterial agents

A series of 2,5-disubstituted benzimidazole derivatives was synthesized with the aim to identify compounds with potent anti-TB activity. All the compounds were screened in vitro against cultured Mycobacterium tuberculosis H₃₇ Rv strain and found to be exhibiting MIC₉₉ values in the range of 0.195-100 µM. Out of 43 synthesized compounds, two compounds 11h and 13e showed better anti-TB activity than the reference drug isoniazid.

Antituberculous Drug-Induced Hepatitis in a Patient With Congenital Adrenal Hyperplasia: A Clinical Challenge

Pulmonary tuberculosis (TB) is highly prevalent in Pakistan, and immunosuppressed individuals (including those on long-term corticosteroid therapy) are at an especially high risk of infection. Owing to the limited number of effective antituberculous drugs, treating resistant cases or patients who develop unfavorable side effects from the first-line agents becomes a daunting task. We discuss a patient with congenital adrenal hyperplasia (CAH) suffering from pulmonary TB who developed drug-induced hepatitis after being started on recommended first-line anti-TB drugs.

Recent Developments in Drug Delivery for Treatment of Tuberculosis by Targeting Macrophages

Tuberculosis (TB) is among the greatest public health and safety concerns in the 21st century, Mycobacterium tuberculosis, which causes TB, infects alveolar macrophages and uses these cells as one of its primary sites of replication. The current TB treatment regimen, which consist of chemotherapy involving a combination of 3-4 antimicrobials for a duration of 6-12 months, is marked with significant side effects, toxicity, and poor compliance. Targeted drug delivery offers a strategy that could overcome many of the problems of current TB treatment by specifically targeting infected macrophages. Recent advances in nanotechnology and material science have opened an avenue to explore drug carriers that actively and passively target macrophages. This approach can increase the drug penetration into macrophages by using ligands on the nanocarrier that interact with specific receptors for macrophages. This review encompasses the recent development of drug carriers specifically targeting macrophages actively and passively. Future directions and challenges associated with development of effective TB treatment is also discussed.

NAT2 polymorphism and clinical factors that increased antituberculosis drug-induced hepatotoxicity

Aim: Hepatotoxicity is a known adverse effect of antituberculosis drugs. The NAT2 gene polymorphism has been associated with an increased risk of antituberculosis drug-induced hepatotoxicity (ATDIH). Materials and methods: This study investigates the association of NAT2 polymorphism and clinical risk factors that may contribute to the development of ATDIH. The authors sequenced the NAT2 region of 33 tuberculosis patients who developed ATDIH and 100 tuberculosis patients who did not develop ATDIH during tuberculosis treatment. NAT2 haplotypes were inferred and NAT2 acetylator status was predicted from the combination of the inferred haplotypes. Multiple logistic regression was performed to identify possible factors that are associated with ATDIH. Results: The TT genotype of NAT2*13A and the AA genotype of NAT2*6B were found to be substantially linked with the risk of ATDIH, with odds ratios of 3.09 (95% CI: 1.37-6.95) and 3.07 (95% CI: 1.23-7.69), respectively. NAT2 slow acetylators are 3.39-times more likely to develop ATDIH. Factors that were associated with ATDIH include underlying diabetes mellitus (adjusted odds ratio [AOR] 2.96; 95% CI: 1.05-8.37), pre-treatment serum bilirubin (AOR 1.09; 95% CI: 1.02-1.16) and NAT2 slow acetylator (AOR 3.77; 95% CI: 1.51-9.44). Conclusion: Underlying diabetes mellitus, having a higher baseline bilirubin and being a slow acetylator are identified as the risk factors associated with ATDIH among patients in Malaysia.

Clinical and Genetic Risk Factors for Drug-Induced Liver Injury Associated with Anti-Tuberculosis Treatment-A Study from Patients of Portuguese Health Centers

Drug-induced liver injury (DILI) is an unpredictable and feared side effect of antituberculosis treatment (AT). The present study aimed to identify clinical and genetic variables associated with susceptibility to AT-associated hepatotoxicity in patients with pulmonary tuberculosis treated with a standard protocol. Of 233 patients enrolled, 90% prospectively, 103 developed liver injury: 37 with mild and 66 with severe phenotype (DILI). All patients with mild hepatitis had a RUCAM score ≥4 and all patients with DILI had a RUCAM score ≥ 6. Eight clinical variables and variants in six candidate genes were assessed. A logistic multivariate regression analysis identified four risk factors for AT-DILI: age ≥ 55 years (OR:3.67; 95% CI:1.82−7.41; p < 0.001), concomitant medication with other hepatotoxic drugs (OR:2.54; 95% CI:1.23−5.26; p = 0.012), NAT2 slow acetylator status (OR:2.46; 95% CI:1.25−4.84; p = 0.009), and carriers of p.Val444Ala variant for ABCB11 gene (OR:2.06; 95%CI:1.02−4.17; p = 0.044). The statistical model explains 24.9% of the susceptibility to AT-DILI, with an 8.9 times difference between patients in the highest and in the lowest quartiles of risk scores. This study sustains the complex architecture of AT-DILI. Prospective studies should evaluate the benefit of NAT2 and ABCB11 genotyping in AT personalization, particularly in patients over 55 years.

Baicalin provides protection against fluoxetine-induced hepatotoxicity by modulation of oxidative stress and inflammation

BACKGROUND

Fluoxetine is one of the most widely prescribed anti-depressant drugs belonging to the category of selective serotonin reuptake inhibitors. Long-term fluoxetine treatment results in hepatotoxicity. Baicalin, a natural compound obtained from the Chinese herb Scutellaria baicalensis is known to have antioxidant, hepatoprotective and anti-inflammatory effects. However, the beneficial effects of baicalin against fluoxetine-induced hepatic damage have not previously been reported.

AIM

To evaluate the protective action of baicalin in fluoxetine-induced liver toxicity and inflammation.

METHODS

Male albino Wistar rats were divided into seven groups. Group 1 was the normal control. Oral fluoxetine was administered at 10 mg/kg body weight to groups 2, 3, 4 and 5. In addition, groups 3 and 4 were also co-administered oral baicalin (50 mg/kg and 100 mg/kg, respectively) while group 5 received silymarin (100 mg/kg), a standard hepatoprotective compound for comparison. Groups 6 and 7 were used as a positive control for baicalin (100 mg/kg) and silymarin (100 mg/kg), respectively. All treatments were carried out for 28 d. After sacrifice of the rats, biomarkers of oxidative stress [superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione-S-transferase (GST), advanced oxidation protein products (AOPP), malondialdehyde (MDA)], and liver injury [alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total protein, albumin, bilirubin] were studied in serum and tissue using standard protocols and diagnostic kits. Inflammatory markers [tumor necrosis factor (TNF-α), interleukin (IL)-6, IL-10 and interferon (IFN)-γ] in serum were evaluated using ELISA-based kits. The effect of baicalin on liver was also analyzed by histopathological examination of tissue sections.

RESULTS

Fluoxetine-treated rats showed elevated levels of the serum liver function markers (total bilirubin, ALT, AST, and ALP) and inflammatory markers (TNF-α, IL-6, IL-10 and IFN-γ), with a decline in total protein and albumin levels. Biochemical markers of oxidative stress such as SOD, CAT, GST, GSH, MDA and AOPP in the liver tissue homogenate were also altered indicating a surge in reactive oxygen species leading to oxidative damage. Histological examination of liver tissue also showed degeneration of hepatocytes. Concurrent administration of baicalin (50 and 100 mg/kg) restored the biomarkers of oxidative stress, inflammation and hepatic damage in serum as well as in liver tissues to near normal levels.

CONCLUSION

These findings suggested that long-term treatment with fluoxetine leads to oxidative stress via the formation of free radicals that consequently cause inflammation and liver damage. Concurrent treatment with baicalin alleviated fluoxetine-induced hepatotoxicity and liver injury by regulating oxidative stress and inflammation.

The role of the genetic variant FECH rs11660001 in the occurrence of anti-tuberculosis drug-induced liver injury

WHAT IS KNOWN AND OBJECTIVE

The pathogenic mechanism of anti-tuberculosis drug-induced liver injury (AT-DILI) is still largely unknown. Recent studies have indicated that rifampicin and isoniazid cotreatment causes the accumulation of endogenous protoporphyrin IX in the liver through the haem biosynthesis pathway. Alanine synthase 1 (ALAS1) and ferrochelatase (FECH) are the rate-limiting enzymes in the production of haem. The present study aimed to investigate the genetic contribution of the ALAS1 and FECH genes to the risk of AT-DILI in an Eastern Chinese Han population.

METHODS

A 1:4 matched case-control study was conducted, and eight SNPs in the ALAS1 and FECH genes were detected and assessed. A multivariate conditional logistic regression model was used to estimate the association between genotypes and the risk of AT-DILI by the odds ratios (ORs) with 95% confidence intervals (CIs), with liver disease history, hepatoprotectant use, smoking and drinking history as covariates.

RESULTS AND DISCUSSION

Overall, 202 AT-DILI cases and 808 controls were included in this study. The female patients carrying polymorphisms of rs11660001 in FECH had an increased risk of AT-DILI under the dominant and additive models (OR = 1.831, 95% CI: 1.014-3.307, p = 0.045; OR = 1.673, 95% CI: 1.015-2.760, p = 0.044, respectively). The peak aspartate transaminase level was significantly higher in female patients carrying the GA+AA genotype of rs11660001 than in those with the GG genotype during anti-TB treatment (p = 0.032).

WHAT IS NEW AND CONCLUSION

Based on this 1:4 individual matched case-control study, SNP rs11660001 in the FECH gene may be associated with susceptibility to AT-DILI in Chinese female anti-TB treatment patients. Further studies in larger varied populations are needed to validate our findings.

Tuberculosis challenges: Resistance, co-infection, diagnosis, and treatment

Early diagnosis of tuberculosis (TB), followed by effective treatment, is the cornerstone of global TB control efforts. An estimated 3 million cases of TB remain undetected each year. Early detection and effective management of TB can prevent severe disease and reduce mortality and transmission. Intrinsic and acquired drug resistance of Mycobacterium tuberculosis (MTB) severely restricted the anti-TB therapeutic options, and public health policies are required to preserve the new medications to treat TB. In addition, TB and HIV frequently accelerate the progression of each other, and one disease can enhance the other effect. Overall, TB-HIV co-infections show an adverse bidirectional interaction. For HIV-infected patients, the risk of developing TB disease is approximately 22 times higher than for persons with a protective immune response. Analysis of the current TB challenges is critical to meet the goals of the end TB strategy and can go a long way in eradicating the disease. It provides opportunities for global TB control and demonstrates the efforts required to accelerate eliminating TB. This review will discuss the main challenges of the TB era, including resistance, co-infection, diagnosis, and treatment.

BTS clinical statement for the diagnosis and management of ocular tuberculosis

The BTS clinical statement for the diagnosis and management of ocular tuberculosis (TB) draws on the expertise of both TB and and ophthalmic specialists to outline the current understanding of disease pathogenesis, diagnosis and management in adults. Published literature lacks high-quality evidence to inform clinical practice and there is also a paucity of data from animal models to elucidate mechanisms of disease. However, in order to improve and standardise patient care, this statement provides consensus points with the currently available data and agreed best practice.

Beneficial effects of coconut oil (Cocos nucifera) on hematobiochemicl and histopathological markers in CCL4-intoxicated rabbits

The study was designed to investigate the effect of Coconut Oil on the levels of some liver and hematological parameters in carbon tetrachloride intoxicated rabbits. Also the antioxidant capacity of Coconut Oil for various concentrations was assessed on the basis of percent scavenging of (DPPH) free radical. Experimental animals were divided into five groups, eight rabbits in each group. These were: group A (Normal control), group B (Toxic control), group C (Standard control), group D (Treated with Coconut Oil 50 mL/kg body weight after CCl4 intoxication), group E (Treated with Coconut Oil 200 mL/kg body weight after CCl4 intoxication). The effects observed were compared with a standard hepatoprotective drug silymarine (50 mL/kg body weight). The Coconut Oil (200 mL/kg body weight) significantly (P<0.05) reduced the elevated serum levels of alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) when compared to a toxic control rabbits. The results of extract treated rabbits were similar to silymarine administered rabbits group. Treatment with Coconut Oil root and silymarine caused no significant changes in RBC, Platelets, (Hb), (MCH) concentration and (HCT) values. However, significant (P<0.05) increase was observed in the total WBC count. The present study suggested that Coconut Oil can be used as an herbal alternative (need further exploration i.e to detect its bioactive compound and its efficacy) for hepatoprotective activity.

Clinical characteristics and outcomes of drug-induced liver injury in Taiwan: With emphasis on the impact of chronic hepatitis B infection

BACKGROUND

Whether hepatitis B virus (HBV) infection can affect the outcomes of drug-induced liver injury (DILI) is controversial. This study aimed to evaluate the characteristics and outcomes of DILI in Taiwan, with an emphasis on the impact of HBV infection.

METHODS

We prospectively recruited patients with DILI from multiple centers in Taiwan from 2010 to 2018.

RESULTS

A total of 1,014 patients were enrolled. The leading culprit drug category was antimicrobials (481, 47.4%), followed by nonsteroidal anti-inflammatory drugs, anticonvulsants, and statins. Among the antimicrobials, antituberculosis agents were most likely to induce liver injury (257, 25.3%), followed by antibacterial, antifungal, and antiviral agents. The liver-related mortality rate was 8.2% (83/1,014). The patients who died had higher rates of hepatocellular-type liver injury, elevated liver biochemical tests, preexisting liver cirrhosis, jaundice, chronic HBV infection, and antituberculosis drug-induced liver injury (ATDILI) than the survivors. A total of 131 patients (12.9%) with DILI were HBV carriers, of whom 23 (17.6%) died of hepatic failure. The rate of HBV-DNA > 2000 IU/mL was higher in the patients who died (47.8% vs. 26.9%, p = 0.047) than in the survivors. After adjusting for possible risk factors, active HBV infection with HBV-DNA > 2000 IU/mL was the most significant risk factor for liver-related mortality (adjusted HR, 4.40, 95% CI, 2.31%-8.38%, p < 0.001). The other independent risk factors for mortality were ATDILI and albumin-bilirubin (ALBI) score (adjusted HR, 1.25 and 4.09, respectively, p < 0.003).

CONCLUSION

Antituberculosis agents were the leading cause of DILI in Taiwanese, and they were associated with poorer outcomes than other drug categories. Active HBV infection, ATDILI and ALBI score were independent risk factors for fatal DILI. Close monitoring of liver tests and timely antiviral therapy should be implemented in HBV carriers during the administration of high-risk drugs, such as antituberculosis agents.

Glutathione-S-transferase genetic polymorphism and risk of hepatotoxicity to antitubercular drugs in a North-African population: A case-control study

INTRODUCTION

GST non-functional genotypes can lead to the accumulation of toxic intermediates, resulting in liver damage and increasing susceptibility to ATDH.

AIM

To investigate the impact of GST Mu (GSTM1), GST Theta (GSTT1) null genotypes, and GST Pi (GSTP1; adenosine (A) > guanine (G), rs1695) variant allele on the development of ATDH in Tunisian patients treated with anti-tuberculosis therapy.

METHODS

This was a case-control study including patients receiving anti-tuberculosis regimen. Cases (n = 23) were tuberculosis patients presenting ATDH during two months of anti-tuberculosis drug therapy. Controls (n = 30) were patients treated for tuberculosis, but presenting no ATDH. Genotyping was performed using a polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

No statistically significant association was observed between GSTM1 and GSTT1 homozygous null genotypes, and the risk of ATDH. A statistically significant association between GSTM1 and GSTT1 double null genotypes, and the risk of ATDH was found (p = 0.033) between cases and controls. For GSTP1, the distribution of GG homozygous mutant genotype was significantly associated with ATDH compared with the wild and the transition A to G (AA + AG) genotypes.

CONCLUSION

Double deletion of GSTM1 and GSTT1 may predispose to ATDH in a Tunisian population. Moreover, GSTP1 rs1695 (A > G) genotyping can predict susceptibility to developing ATDH.

Analysis of the Research Hotspot of Drug Treatment of Tuberculosis: A Bibliometric Based on the Top 50 Cited Literatures

Objective

The objective of the current study was to analyze the research hotspot of drug treatment for tuberculosis via top literatures.

Materials and Methods

A retrospective analysis was performed on June 7th, 2021. Literatures were searched on the Web of Science Core Collection to identify the top 50 cited literatures related to drug treatment of tuberculosis. The characteristics of the literatures were identified. The outcomes included authorship, journal, study type, year of publication, and institution. Cooccurrence network analysis and visualization were conducted using the VOS viewer (Version 1.6.16; Leiden University, Leiden, The Netherlands).

Results

The top 50 cited literatures were cited 308 to 2689 times and were published between 1982 and 2014. The most studied drugs were the first-line drugs such as isoniazid and rifampicin (n = 22), and drug-resistant tuberculosis was most frequently reported (n = 16). They were published in 18 journals, and the New England Journal of Medicine published the most literatures (n = 18), followed by the American Journal of Respiratory and Critical Care Medicine (n = 7), and the Lancet (n = 6). The authors were from 13 countries, and the authors from the USA published most of the literatures (n = 30), while authors from other countries published less than five literatures. The CDC in the USA (n = 4), the World Health Organization (WHO) (n = 3), and the American Philosophical Society (n = 3) were the leading institutions, and only two authors published at least two top-cited literatures as first authors.

Conclusions

This study provides insights into the development and most important literatures on drug therapy for tuberculosis and evidence for future research on tuberculosis treatment.

Metabolomics and microbiomes for discovering biomarkers of antituberculosis drugs-induced hepatotoxicity

Anti-tuberculosis (TB) drug-induced hepatotoxicity (ATDH) was related to metabolic and microbial dysregulation, but only limited data was available about the metabolomes and microbiomes in ATDH. We aimed at detecting the metabolic and microbial signatures of ATDH. Urine samples were obtained from ATDH (n = 33) and non-ATDH control (n = 41) and analyzed by untargeted gas chromatography time-of-flight mass spectrometry (GC-TOF-MS). Metabolites were analyzed by orthogonal projections to latent structures-discriminate analysis (OPLS-DA) and pathway analysis. Eight ATDH and eight non-ATDH control were evaluated by sequencing of 16S rRNA genes, and the Clusters of Orthologous Groups of proteins (COG) database were used for function prediction. Linear discriminant analysis (LDA) effect size (LEfSe) was applied to detect the differential microbiotas between the two groups. The differential microbiotas were further validated by correlation analysis with differential metabolites. OPLS-DA analysis suggested 11 metabolites that differed ATDH from non-ATDH control. Pathway analysis demonstrated that metabolism of arginine and proline, metabolism of d-arginine and d-ornithine, glutathione glycine metabolism, galactose metabolism, niacin and nicotinamide metabolism, and glycine, serine and threonine metabolism were related to ATDH. LEfSe suggested significant differences in microbiotas between the two groups. The o_ Bacteroidales, f_Prevotellaceae, and g_Prevotella were significantly increased in ATDH. In contrast, the f_Chitinophagaceae, c_Gammaproteobacteria, and p_Proteobacteria were significantly increased in non-ATDH group. The biological functions of the sequenced microbiota in this study were related to amino acid transport and metabolism and defense mechanisms. Finally, we detected strong association between urine metabolites and specific urine bacteria (|r| > 0.8). d-glucoheptose showed a strong relationship to Symbiobacterium. Creatine (r = -0.901; P < 0.001) and diglycerol were strongly associated with Alishewanella. Metabolomics and microbiomes indicate ATDH characterized by metabolic and microbial profiles may differ from non-ATDH control.

Pharmacokinetics and safety/tolerability of isoniazid, rifampicin and pyrazinamide in children and adolescents treated for tuberculous meningitis

OBJECTIVE

To assess the pharmacokinetics and safety/tolerability of isoniazid, rifampicin and pyrazinamide in children and adolescents with tuberculous meningitis (TBM).

DESIGN

Prospective observational pharmacokinetic study with an exploratory pharmacokinetic/pharmacodynamic analysis.

SETTING

Hasan Sadikin Hospital, Bandung, Indonesia.

PATIENTS

Individuals aged 0-18 years clinically diagnosed with TBM and receiving first-line anti-tuberculosis drug dosages according to revised WHO-recommended treatment guidelines.

INTERVENTIONS

Plasma and cerebrospinal fluid (CSF) concentrations of isoniazid, rifampicin and pyrazinamide were assessed on days 2 and 10 of treatment.

MAIN OUTCOME MEASURES

Plasma exposures during the daily dosing interval (AUC_0-24), peak plasma concentrations (C_max) and CSF concentrations.

RESULTS

Among 20 eligible patients, geometric mean AUC_0-24 of isoniazid, rifampicin and pyrazinamide was 18.5, 66.9 and 315.5 hour∙mg/L on day 2; and 14.5, 71.8 and 328.4 hour∙mg/L on day 10, respectively. Large interindividual variabilities were observed in AUC_0-24 and C_max of all drugs. All patients had suboptimal rifampicin AUC_0-24 for TBM treatment indication and very low rifampicin CSF concentrations. Four patients developed grade 2-3 drug-induced liver injury (DILI) within the first 4 weeks of treatment, in whom anti-tuberculosis drugs were temporarily stopped, and no DILI recurred after reintroduction of rifampicin and isoniazid. AUC_0-24 of isoniazid, rifampicin and pyrazinamide along with C_max of isoniazid and pyrazinamide on day 10 were higher in patients who developed DILI than those without DILI (p<0.05).

CONCLUSION

Higher rifampicin doses are strongly warranted in treatment of children and adolescents with TBM. The association between higher plasma concentrations of isoniazid, rifampicin and pyrazinamide and the development of DILI needs confirmatory studies.

Homozygotes NAT2*5B slow acetylators are highly associated with hepatotoxicity induced by anti-tuberculosis drugs

BACKGROUND

Distinct N-acetyltransferase 2 (NAT2) slow acetylators genotypes have been associated with a higher risk to develop anti-tuberculosis drug-induced hepatotoxicity (DIH). However, studies have not pointed the relevance of different acetylation phenotypes presented by homozygotes and compound heterozygotes slow acetylators on a clinical basis.

OBJECTIVES

This study aimed to investigate the association between NAT2 genotypes and the risk of developing DIH in Brazilian patients undergoing tuberculosis treatment, focusing on the discrimination of homozygotes and compound heterozygotes slow acetylators.

METHODS/FINDINGS

The frequency of NAT2 genotypes was analysed by DNA sequencing in 162 patients undergoing tuberculosis therapy. The mutation analyses revealed 15 variants, plus two new NAT2 mutations, that computational simulations predicted to cause structural perturbations in the protein. The multivariate statistical analysis revealed that carriers of NAT2*5/*5 slow acetylator genotype presented a higher risk of developing anti-tuberculosis DIH, on a clinical basis, when compared to the compound heterozygotes presenting NAT2*5 and any other slow acetylator haplotype [aOR 4.97, 95% confidence interval (CI) 1.47-16.82, p = 0.01].

CONCLUSION

These findings suggest that patients with TB diagnosis who present the NAT2*5B/*5B genotype should be properly identified and more carefully monitored until treatment outcome in order to prevent the occurrence of anti-tuberculosis DIH.

Inclusion Complexes of Rifampicin with Native and Derivatized Cyclodextrins: In Silico Modeling, Formulation, and Characterization

Inclusion complexation of rifampicin (RIF) with several types of cyclodextrins (βCD, hydroxypropyl-βCD, γCD, hydroxypropyl-γCD) in aqueous solutions at different pH values was investigated to assess the interactions between RIF and cyclodextrins (CDs). Molecular modeling was performed to determine the possible interactions between RIF and CDs at several pH values. The inclusion complexes were characterized by differential scanning calorimetry, Fourier transform infrared spectroscopy, powder X-ray diffractometry, and scanning electron microscopy. Moreover, this study evaluated the dissolution profile and antibacterial activity of the formed complexes. Phase solubility analysis suggested the formation of RIF-CD affirmed 1:1 stoichiometry at all pH values (except RIF-βCD at pH 4.0 and both βCD and γCD at pH 9.0). The inclusion complexation of RIF with CD successfully increased the percentage of RIF released in in vitro studies. The inclusion complexes of RIF exhibited more than 60% of RIF released in 2 h which was significantly higher (p < 0.05) than release of pure RIF, which was only less than 10%. Antibacterial activity of RIF-CD complexes (measured by the minimum inhibitory concentration of RIF against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus) was lower for both RIF-βCD and RIF-HPγCD at pH 7.0 to pure RIF suspension. In conclusion, this work reports that both βCD and γCD can be used to enhance the solubility of RIF and thus, improve the effectivity of RIF by decreasing the required daily dose of RIF for the treatment of bacterial infections.

Fatal Events Associated with Adverse Drug Reactions in the Korean National Pharmacovigilance Database

Adverse drug reactions (ADRs) pose a global public health threat, substantially contributing to death. Due to the relative paucity of clinical evidence regarding fatal ADRs, this study was performed to characterize the epidemiology of fatal ADRs in Korea. This was a retrospective, cross-sectional analysis of ADR cases reported to the Korea Adverse Event Reporting System from 2010 to 2019. All ADRs were coded using the World Health Organization-Adverse Reaction Terminology system and classified as either fatal or non-fatal events. Logistic regression was performed to identify factors associated with fatal events. Among 289,756 ADR records, 629 fatal events (0.2%) occurred. The most common causative agent of fatal ADRs was antibacterials (20.3%), followed by antimycobacterials (5.4%), analgesics (4.0%), and contrast media (1.9%). Among antimicrobials, vancomycin was most frequently implicated without significantly increasing the risk of fatal events. The risk for fatal ADRs was significantly increased with male sex; advanced age; polypharmacy; piperacillin/β-lactamase inhibitor; cefotetan; ceftriaxone; combination antimycobacterial therapy consisting of rifampicin, isoniazid, pyrazinamide, and ethambutol; morphine; and iopromide (reporting odds ratio > 1, p < 0.05 for all). Although fatal ADRs are uncommon (<1%) in Korea, they are primarily caused by commonly used medications including antibiotics, analgesics, and contrast media.

Tuberculosis in the Elderly

The tuberculosis (TB) epidemic is most prevalent in the elderly, and there is a progressive increase in the notification rate with age. Most cases of TB in the elderly are linked to the reactivation of lesions that have remained dormant. The awakening of these lesions is attributable to changes in the immune system related to senescence. The mortality rate from tuberculosis remains higher in elderly patients. Symptoms of active TB are nonspecific and less pronounced in the elderly. Diagnostic difficulties in the elderly are common in many diseases but it is important to use all possible techniques to make a microbiological diagnosis. Recognising frailty to prevent loss of independence is a major challenge in dealing with the therapeutic aspects of elderly patients. Several studies report contrasting data about poorer tolerance of TB drugs in this population. Adherence to antituberculosis treatment is a fundamental issue for the outcome of treatment. Decreased completeness of treatment was shown in older people as well as a higher risk of treatment failure.

miR-15a-3p Protects Against Isoniazid-Induced Liver Injury via Suppressing N-Acetyltransferase 2 Expression

Isoniazid (INH), an effective first-line drug for tuberculosis treatment, has been reported to be associated with hepatotoxicity for decades, but the underlying mechanisms are poorly understood. N-acetyltransferase 2 (NAT2) is a Phase II enzyme that specifically catalyzes the acetylation of INH, and NAT2 expression/activity play pivotal roles in INH metabolism, drug efficacy, and toxicity. In this study, we systematically investigated the regulatory roles of microRNA (miRNA) in NAT2 expression and INH-induced liver injury via a series of in silico, in vitro, and in vivo analyses. Four mature miRNAs, including hsa-miR-15a-3p, hsa-miR-628-5p, hsa-miR-1262, and hsa-miR-3132, were predicted to target the NAT2 transcript, and a negative correlation was observed between hsa-miR-15a-3p and NAT2 transcripts in liver samples. Further experiments serially revealed that hsa-miR-15a-3p was able to interact with the 3′-untranslated region (UTR) of NAT2 directly, suppressed the endogenous NAT2 expression, and then inhibited INH-induced NAT2 overexpression as well as INH-induced liver injury, both in liver cells and mouse model. In summary, our results identified hsa-miR-15a-3p as a novel epigenetic factor modulating NAT2 expression and as a protective module against INH-induced liver injury, and provided new clues to elucidate the epigenetic regulatory mechanisms concerning drug-induced liver injury (DILI).

Mechanism of drug-induced liver injury and hepatoprotective effects of natural drugs

Drug-induced liver injury (DILI) is a common adverse drug reaction (ADR) and a serious threat to health that affects disease treatments. At present, no targeted clinical drugs are available for DILI. Traditional natural medicines have been widely used as health products. Some natural medicines exert specific hepatoprotective effects, with few side effects and significant clinical efficacy. Thus, natural medicines may be a promising direction for DILI treatment. In this review, we summarize the current knowledge, common drugs and mechanisms of DILI, as well as the clinical trials of natural drugs and their bioactive components in anticipation of the future development of potential hepatoprotective drugs.

Safety and Efficacy of Rifampin or Isoniazid Among People With Mycobacterium tuberculosis Infection and Living With Human Immunodeficiency Virus or Other Health Conditions: Post Hoc Analysis of 2 Randomized Trials

BACKGROUND

The safety and efficacy of rifampin among people living with human immunodeficiency virus (PLHIV) or other health conditions is uncertain. We assessed completion, safety, and efficacy of 4 months of rifampin vs 9 months of isoniazid among PLHIV or other health conditions.

METHODS

We conducted post hoc analysis of 2 randomized trials that included 6859 adult participants with Mycobacterium tuberculosis infection. Participants were randomized 1:1 to 10 mg/kg/d rifampin or 5 mg/kg/d isoniazid. We report completion, drug-related adverse events (AE), and active tuberculosis incidence among people living with HIV; with renal failure or receiving immunosuppressants; using drugs or with hepatitis; with diabetes mellitus; consuming >1 alcoholic drink per week or current/former smokers; and with no health condition.

RESULTS

Overall, 270 (3.9%) people were living with HIV (135 receiving antiretroviral therapy), 2012 (29.3%) had another health condition, and 4577 (66.8%) had no condition. Rifampin was more often or similarly completed to isoniazid in all populations. AEs were less common with rifampin than isoniazid among PLHIV (risk difference, -2.1%; 95% confidence interval [CI], -5.9 to 1.6). This was consistent for others except people with renal failure or on immunosuppressants (2.1%; 95% CI, -7.2 to 11.3). Tuberculosis incidence was similar among people receiving rifampin or isoniazid. Among participants receiving rifampin living with HIV, incidence was comparable to those with no health condition (rate difference, 4.1 per 1000 person-years; 95% CI, -6.4 to 14.7).

CONCLUSIONS

Rifampin appears to be safe and as effective as isoniazid across many populations with health conditions, including HIV.

CLINICAL TRIALS REGISTRATION

NCT00170209; NCT00931736.

Comparison and lessons learned from neglected tropical diseases and tuberculosis

Currently, tuberculosis (TB) is the leading cause of death from a single infectious agent and accounts for over one-third of all HIV-related deaths. However, research and programmatic funding have lagged far behind investments for many other diseases. For about a century, the current Bacillus Calmette-Guérin vaccine has been the only effective vaccine and is only effective in preventing severe disease in children; the first new therapeutic drug for TB in over 40 years was brought to market a few years ago; and until 10 years ago, diagnosis of TB depended on a century-old testing technique. This paper relates TB to neglected tropical diseases (NTDs) and highlights shared characteristics. The aim is to elevate awareness of TB within the framework of NTDs and gain insights from successes in addressing NTDs and how these lessons can be applied to help global health programs change the trajectory of the TB epidemic. A literature review was conducted to compare TB to NTDs and highlight lessons learned from NTD control that can be applied to the TB epidemic. Common features of NTDs include underlying burden of disease, influence and effect on poverty and development, and neglect through political will and funding. There are overarching principles for the design and implementation of NTD control programs that could be applied to ending TB.

Instant hydrogelation encapsulates drugs onto implants intraoperatively against osteoarticular tuberculosis

Osteoarticular Tuberculosis (TB) is a challenging issue because of its chronicity and recurrence. Many drug delivery systems (DDSs) have been developed for general chemotherapy. Herein, we take advantage of instant hydrogelation to in situ encapsulate drugs onto implants intraoperatively, optimizing the drug release profile against osteoarticular TB. First-line chemodrugs, i.e. rifampicin (RFP) and isoniazid (INH) are firstly loaded on tricalcium phosphate (TCP). Then, the encapsulating hydrogel is fabricated by dipping in chitosan (CS) and β-glycerophosphate (β-GP) solution and heating at 80 °C for 40 min. The hydrogel encapsulation inhibits explosive drug release initially, but maintains long-term drug release (INH, 158 days; RFP, 53 days) in vitro. Therefore, this technique could inhibit bone destruction and inflammation from TB effectively in vivo, better than our previous ex situ prepared DDSs. The encapsulating technology, i.e. instant hydrogelation of drug-loaded implants, shows potential for regulating the type and ratio of drugs, elastic and viscous modulus of the hydrogel according to the state of illness intraoperatively for optimal drug release.

Tuberculosis treatment incompletion in patients with lung cancer: occurrence and predictors

BACKGROUND

Lung cancer patients are high-risk for active tuberculosis (TB); however, fragility and drug-drug interaction might lead to TB treatment interruption. TB treatment incompletion occurrence and predictors among lung cancer patients remain unclear.

METHODS

We recruited lung cancer patients with new-onset TB from Taiwan Cancer Registry and Taiwanese National Health Insurance 2007-2015 databases. TB treatment incompletion was the identified primary outcome, and associated risk factors were analyzed.

RESULTS

A total of 1155 lung cancer patients with new-onset TB were identified and classified as treatment incompletion (n=706, 61.13%) or completion (n=449). Gender and age distribution was similar in both groups. Under multivariable logistic regression, advanced cancer (stage III and IV) and no first-line TB drugs use were independent factors for treatment incompletion; but older age was not significant. For patients surviving >1 year since TB diagnosis, independent factors for treatment incompletion included no first-line TB drugs use (except pyrazinamide) and absence of hypertension. Cancer stage had borderline significance.

CONCLUSIONS

TB treatment incompletion occurred in 61.13% of lung cancer patients. Clinicians should carefully titrate anti-TB medications and monitor side effects in lung cancer patients, especially those with treatment incompletion risk factors, to avoid treatment interruption due to fragility and/or drug intolerance.

A Case Series of Extrapulmonary Mycobacterium in Liver Transplant Recipients

Liver transplant recipients are at increased risk of infection because of the immunosuppression required after transplantation. Infection by Mycobacterium species increases the morbidity and mortality of liver transplant recipients. The prompt recognition and diagnosis of opportunistic infection is necessary for good outcomes, particularly during periods of increased immunosuppression. The balance of immunosuppressive therapies during prolonged treatment with hepatotoxic medications has not been well studied and should be tailored for the unique clinical setting of each patient. The goal of treatment in these patients is to eradicate the disease and preserve allograft function.

A pilot study to investigate the utility of NAT2 genotype-guided isoniazid monotherapy regimens in NAT2 slow acetylators

Isoniazid is a therapeutic agent for the treatment of latent tuberculosis infection. Genetic variants in the N-acetyltransferase 2 (NAT2) are associated with the safety and pharmacokinetics of isoniazid. The study aimed to evaluate the safety and pharmacokinetics of a NAT2 genotype-guided regimen of isoniazid monotherapy. A randomized, open-label, parallel-group and multiple-dosing study was performed in healthy subjects. The subjects received isoniazid for 29 days. The NAT2 slow acetylators (NAT2*5/*5, -*5/*6, -*5/*7, -*6/*6, -*6/*7, -*7/*7) randomly received standard dose (300 mg, standard-treatment group) or reduced dose (200 mg, PGx-treatment group) of isoniazid. Also, all the NAT2 rapid acetylators (NAT2*4/*4) received isoniazid 300 mg (reference group). The safety and pharmacokinetics were evaluated during the study. The PGx-treatment group showed a more stable serum liver enzyme profile and a lower incidence of adverse drug reactions (ADRs) than the standard-treatment group. The emergence rates of ADRs were 12.5, 60 and 33.3% in the reference, standard-treatment and PGx-treatment groups, respectively. The PGx-treatment group showed higher plasma isoniazid concentrations than the reference group, although the PGx-treatment group received a reduced dose of isoniazid. Our results showed that a NAT2 genotype-guided regimen may reduce ADRs during isoniazid monotherapy without concern over insufficient drug exposure.

Relationship between xanthine oxidase gene polymorphisms and anti-tuberculosis drug-induced liver injury in a Chinese population

This study was designed to investigate the association of the xanthine oxidase (XO) polymorphisms and susceptibility to anti-tuberculosis drug-induced liver injury (ATDILI) in Chinese population. A total of 183 tuberculosis patients were enrolled. Patients with ATDILI were classified as cases and those without ATDILI were classified as controls. Genotyping for XO polymorphisms was determined by polymerase chain reaction and direct sequencing. The allele frequencies and genotype distribution was analyzed using the Chi square test to analyze the association between the gene polymorphisms and ATDILI. Binary logistic regression analysis was performed to assess the risk factors of ATDILI. A total of 21 patients were developed liver injury during anti-tuberculosis treatment in this study, with an incidence of 11.48%. In genotype analysis, no significant difference was observed in the alleles and genotypes frequencies of the six SNPs between two groups (P > 0.05). In haplotype analysis, carriers with GGGATA (rs1884725- rs2295475 -rs45523133- rs206812- rs206813- rs7575607) haplotype had a significantly higher risk of ATDILI compared with other haplotypes (OR = 2.445, 95%CI: 1.058-5.652, P < 0.05). This study suggested that the haplotype GGGATA constructed with rs206812 and rs7575607 mutant alleles might contribute to ATDILI susceptibility in a Chinese population.

Low uptake of isoniazid window prophylaxis in patients exposed to a health-care worker with pulmonary tuberculosis in a paediatric ward

AIM

A nurse on a paediatric multidisciplinary ward was diagnosed with smear-positive pulmonary tuberculosis. Children <2 years old, immunocompromised, or >40 h of contact (n = 173) were contact-traced.

METHODS

Children received clinical review, chest X-ray, tuberculin skin test (TST; <5 years old) and/or an interferon-gamma release assay (Quantiferon TB-Gold, ≥5 years old). Infants <6 months old or children <5 years old screened <2 months from exposure were recommended isoniazid window prophylaxis (WP) until a repeat TST at 6 months old or 8-10 weeks after the last exposure to the index case, respectively. Empiric treatment for latent tuberculosis infection (LTBI) was individually considered for immunocompromised patients.

RESULTS

Of 173 children (135 immunocompetent, 38 immunocompromised), two were uncontactable, seven refused screening and two immunocompromised children excluded. Eight of 126 immunocompetent children were diagnosed with LTBI (initial TST positive n = 7, TST conversion n = 1); seven started isoniazid. Thirty-two of 36 immunocompetent children were recommended WP; 15 accepted (one non-compliant after 1 month). Six of seven immunocompromised children accepted empiric LTBI treatment due to severe immunosuppression/initial indeterminate Quantiferon TB-Gold result. Of 15 immunocompromised children offered WP, only five accepted.

CONCLUSIONS

There was high acceptance of screening but low uptake of isoniazid WP in high-risk children exposed to pulmonary tuberculosis. Perception of exposure risk and chemoprophylaxis should be explored further.

Drug-induced liver injury: A management position paper from the Latin American Association for Study of the liver

Idiosyncratic drug-induced liver injury (DILI) caused by xenobiotics (drugs, herbals and dietary supplements) is an uncommon cause of liver disease presenting with a wide range of phenotypes and disease severity, acute hepatitis mimicking viral hepatitis to autoimmune hepatitis, steatosis, fibrosis or rare chronic vascular syndromes. Disease severity ranges from asymptomatic liver test abnormalities to acute liver failure. DILI has been traditionally classified in predictable or intrinsic (dose-related) or unpredictable (not dose-related) mechanisms. Few prospective studies are assessing the real prevalence and incidence of hepatotoxicity in the general population. DILI registries represent useful networks used for the study of liver toxicity, aimed at improving the understanding of causes, phenotypes, natural history, and standardized definitions of hepatotoxicity. Although most of the registries do not carry out population-based studies, they may provide important data related to the prevalence of DILI, and also may be useful to compare features from different countries. With the support of the Spanish Registry of Hepatotoxicity, our Latin American Registry (LATINDILI) was created in 2011, and more than 350 DILI patients have been recruited to date. This position paper describes the more frequent drugs and herbs-induced DILI in Latin America, mainly focusing on several features of responsible medicaments. Also, we highlighted the most critical points on the management of hepatotoxicity in general and those based on findings from our Latin American experience in particular.

TANC1 methylation as a novel biomarker for the diagnosis of patients with anti-tuberculosis drug-induced liver injury

We aimed to elucidate the differences in genomic methylation patterns between ADLI and non-ADLI patients to identify DNA methylation-based biomarkers. Genome-wide DNA methylation patterns were obtained using Infinium MethylationEPIC (EPIC) BeadChip array to analyze 14 peripheral blood samples (7 ADLI cases, 7 non-ADLI controls). Changes in the mRNA and DNA methylation in the target genes of another 120 peripheral blood samples (60 ADLI cases, 60 non-ADLI controls) were analyzed by real-time polymerase chain reaction and pyrosequencing, respectively. A total of 308 hypermethylated CpG sites and 498 hypomethylated CpG sites were identified. Significantly, hypermethylated CpG sites cg06961147 and cg24666046 in TANC1 associated with ADLI was identified by genome-wide DNA methylation profiling. The mRNA expression of TANC1 was lower in the cases compared to the controls. Pyrosequencing validated these two differentially methylated loci, which was consistent with the results from the EPIC BeadChip array. Receiver operating characteristic analysis indicated that the area under the curve of TANC1 (cg06961147, cg24666046, and their combinations) was 0.812, 0.842, and 0.857, respectively. These results indicate that patients with ADLI have different genomic methylation patterns than patients without ADLI. The hypermethylated differentially methylated site cg06961147 combined with cg24666046 in TANC1 provides evidence for the diagnosis of ADLI.

A Rapid Pharmacogenomic Assay to Detect NAT2 Polymorphisms and Guide Isoniazid Dosing for Tuberculosis Treatment

RATIONALE

Standardized dosing of anti-tubercular drugs contributes to a substantial incidence of toxicities, inadequate treatment response, and relapse, in part due to variable drug levels achieved. Single nucleotide polymorphisms (SNPs) in the N-acetyltransferase-2 (NAT2) gene explain the majority of interindividual pharmacokinetic variability of isoniazid (INH). However, an obstacle to implementing pharmacogenomic-guided dosing is the lack of a point-of-care assay.

OBJECTIVES

To develop and test a NAT2 classification algorithm, validate its performance in predicting isoniazid clearance, and develop a prototype pharmacogenomic assay.

METHODS

We trained random forest models to predict NAT2 acetylation genotype from unphased SNP data using a global collection of 8,561 phased genomes. We enrolled 48 pulmonary TB patients, performed sparse pharmacokinetic sampling, and tested the acetylator prediction algorithm accuracy against estimated INH clearance. We then developed a cartridge-based multiplex qPCR assay on the GeneXpert platform and assessed its analytical sensitivity on whole blood samples from healthy individuals.

MEASUREMENTS AND MAIN RESULTS

With a 5-SNP model trained on two-thirds of the data (n=5,738), out-of-sample acetylation genotype prediction accuracy on the remaining third (n=2,823) was 100%. Among the 48 TB patients, predicted acetylator types were: 27 (56.2%) slow, 16 (33.3%) intermediate and 5 (10.4%) rapid. INH clearance rates were lowest in predicted slow acetylators (median 14.5 L/hr), moderate in intermediate acetylators (median 40.3 L/hr) and highest in fast acetylators (median 53.0 L/hr). The cartridge-based assay accurately detected all allele patterns directly from 25 ul of whole blood.

CONCLUSIONS

An automated pharmacogenomic assay on a platform widely used globally for tuberculosis diagnosis could enable personalized dosing of isoniazid.

A turn-on probe for detecting antituberculotic drug-induced liver injury in mice via NIR-II fluorescence/optoacoustic imaging

A turn-on optoacoustic and NIR-II fluorescent probe for imaging antituberculotic drug-induced liver injury has been developed. Probe TC-H2O2 responds to hepatic H2O2, thus releasing chromophore TC-NN, which displays prominent NIR-II fluorescence and optoacoustic signals for diagnosing liver injury.

Evaluation of Risk Factors for Development of Anti-Tubercular Therapy Induced Hepatotoxicity: A Prospective Study

BACKGROUND

Incidence of Antitubercular Therapy (ATT)-induced hepatotoxicity is higher in India when compared to Western countries. As the occurrence of ATT-induced hepatotoxicity is unpredictable, serial intensive monitoring of hepatic function is now being recommended by the American Thoracic Society in individuals at high risk. This study was done to evaluate the risk factors for the development of ATT induced hepatotoxicity in India.

METHODOLOGY

In this prospective, observational study, patient characteristics of microbiologically/ radiologically/ histopathologically confirmed tuberculosis were prospectively compiled. Serial liver function tests were done once a month in all patients. Patients who developed ATT-induced hepatotoxicity were considered as the study group and those who did not develop the event as a control group. The primary outcome measure was to estimate the hazard ratios associated with risk factors for the development of ATT induced hepatotoxicity. Cox Regression Analysis was done using SPSS 20.

RESULTS

A total of 200 patients were enrolled in the study, of them, 14% developed ATT-induced hepatotoxicity and 86% did not develop the event. The baseline liver function tests in the study group and control group were within normal limits. Female gender, alcoholism, HIV co-infection and age >35 yrs were identified to have a higher risk for development of ATT-induced hepatotoxicity, while cases with pulmonary tuberculosis were found to be at lower risk of developing event.

CONCLUSION

Intensive liver function monitoring needs to be done in patients with these risk factors, female gender, alcoholism, HIV co-infection, extra-pulmonary tuberculosis and age >35 yrs.

The efficacy of isoniazid prophylaxis in renal transplant recipients in a high tuberculosis burden country

INTRODUCTION

Renal transplant recipients are at high risk of tuberculosis (TB). We started isoniazid (INH) prophylaxis of 1 year duration in all renal transplant recipients from April 2009. Our aim was to assess the incidence of TB on INH prophylaxis and its tolerability.

METHODS

This was a retrospective observational study. The files of renal transplant recipients from April 2009 to December 2011 were reviewed till June 2015. We noted the incidence of TB, INH tolerability, and development of resistance. We compared the incidence of TB with the historical controls who never received the prophylaxis.

RESULTS

A total of 910 patients were reviewed and followed up for 4.8 years. INH prophylaxis was completed by 825 (91%) patients. A total of 46 patients (5%) developed active TB as compared to 15% in the historical controls. The median time of TB diagnosis from transplantation was 2.8 years. In the first-year post transplant, out of total TB cases, 52% occurred in the historical controls whereas 13% occurred in study cohort. Around 67% had TB >2 years after transplant. Overall 1.43% had hepatotoxicity. There was a significant reduction in TB among those who completed prophylaxis to those who did not (p < 0.001). Of 14 cultures, one isolate was INH resistant (7%).

CONCLUSION

INH prophylaxis was well tolerated. The incidence of TB decreased in the first 2 years. However there was a surge in TB cases 1 year after stopping INH therapy. We should consider prolonging the duration of INH prophylaxis in high TB burden countries in renal transplant recipients.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusions

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

Management of Drug Toxicity in Mycobacterium avium Complex Pulmonary Disease: An Expert Panel Survey

Adverse events are frequent in nontuberculous mycobacteria pulmonary disease treatment, but evidence to support their management is scarce. An expert panel survey on management of adverse events shows consistent opinions on management of hepatoxicity, ocular toxicity, ototoxicity, tinnitus, and gastrointestinal upset. These opinions can provide assistance in individual patient management decisions.

Screening for latent tuberculosis before starting TNF-alpha inhibitors in a population with high BCG vaccination rates

It is assumed that in candidates for TNF-alpha inhibitor (TNFi) treatment, tuberculin skin test (TST) may be unreliable, since BCG vaccination causes false positive and drugs cause false negative results, favoring the use of Quantiferon or T-spot assays. However, these tests may not be readily available in all parts of the world. We aimed to determine the reliability of TST with respect to BCG vaccination and drugs in candidates for TNFi treatment, and how isoniazid is tolerated, assuming that the use of TST would result in increased isoniazid use. We included 1031 adult patients who were prescribed a TNFi for the first time. We analysed the association of BCG and drugs with TST and Quantiferon results, the determinants of a positive TST, and evaluated the tolerability of isoniazid. BCG vaccination and male sex were associated with positive TST (OR 3.56, 95% CI 1.98-6.41 and OR 2.54, 95% CI 1.75-3.68, respectively), while prednisolone and azathioprine were associated with negative TST (OR 0.63, 95% CI 0.43-0.91 and OR 0.40, 95% CI 0.11-0.76). Isoniazid was prescribed to 684 (66.3%) patients and had to be discontinued in 12.2% of these before 9 months, most commonly due to hepatotoxicity (44%). One patient developed tuberculosis despite isoniazid use. BCG vaccination may be associated with false positive TST, despite a long time since vaccination in candidates for TNFi treatment. Prednisolone and azathioprine use were associated with negative TST. Despite the high frequency of isoniazid use associated with using TST instead of QTF, isoniazid was generally well tolerated.

Standard versus sequential anti-tubercular treatment in patients with tuberculous meningitis: a randomized controlled trial

BACKGROUND

To compare the safety and efficacy of sequential anti-tubercular treatment (ATT) regimen with the standard regimen in tuberculous meningitis (TBM).

METHODS

This single-centre, open-label, parallel group randomized controlled trial was conducted from May 2017 to June 2019 in India. Treatment-naïve patients with TBM fulfilling the inclusion criteria were randomized to four drug ATT regimens (rifampicin, isoniazid, ethambutol and pyrazinamide) administered either simultaneously (standard arm) or one after another (sequential arm) in a 1 : 1 ratio. The primary endpoint was drug-induced hepatitis (DIH) and the secondary endpoints were in-hospital death and disability at 3 and 6 months using a modified Rankin Scale.

RESULTS

A total of 97 patients with TBM were recruited; 15 did not meet the inclusion criteria and 2 refused to participate. The median age of the patients was 26 y (range 15-75) and 37 (46.2%) were males. The patients in the sequential arm had fewer cases of DIH (20% vs 42.5%; p=0.03). The patients in the sequential arm had lower in-hospital mortality (2.5% vs 17.5%; p=0.025) and better 6-month outcomes (25.0% vs 50.0%; p=0.02) compared with the standard arm.

CONCLUSIONS

Sequential ATT was associated with a lower frequency of DIH, lower in-hospital mortality and better 6-month outcome.

TRIAL REGISTRATION

Clinical Trials Registry of India (ctri.nic.in) identifier: REF/2016/09/012214/CTRI/2017/10/010072.

Nutrition Assessment and Adverse Outcomes in Hospitalized Patients with Tuberculosis

Background: Malnutrition in patients with tuberculosis (TB) is associated with poor outcomes. This study assessed the validity of the patient-generated subjective global assessment (PG-SGA) in adult TB patients and examined the association of the PG-SGA score with adverse outcomes. Methods: This is a retrospective chart review study compared with the well-nourished and malnourished TB patients. The nutritional status was determined using the PG-SGA for adult patients (n = 128). Clinical outcomes included liver injury and mortality. Adverse outcomes included hepatitis during anti-tuberculosis therapy. Results: By comparing nutritional status using global assessment, well-nourished patients had a significantly higher body weight index (p = 0.002), a lower PG-SGA score (p < 0.001), and lower diabetic rate (p = 0.029). Malnourishment was a risk factor (p = 0.022) for liver injury and fatal outcomes (p < 0.001). A higher PG-SGA score was a risk factor for liver injury (p = 0.002) and an independent risk factor for fatal outcomes (p = 0.031). ROC analysis for outcome prediction showed that a PG-SGA score of 5.5 points yielded the most appropriate sensitivity (61.5%) and specificity (64.7%). Conclusion: Both global assessment and the total PG-SGA score were related to tuberculosis outcome and liver injury during anti-TB treatment.