Female sex and discontinuation of isoniazid due to adverse effects during the treatment of latent tuberculosis

Influence of sex on the exposure to isoniazid in patients with pulmonary tuberculosis

Isoniazid is a key component of tuberculosis treatment. Adequate exposure is a determinant for therapeutic success; however, considerable inter- and intraindividual variations in drug plasma levels can lead to unfavorable outcomes. While some predictors of isoniazid levels are well-known, others, such as sex, yield controversial results, requiring further investigation to optimize exposure. This study investigates whether the sex of patients influences the dose administered and the concentrations of isoniazid in plasma. Levels of isoniazid were associated with the N-acetyltransferase 2 phenotypes. A total of 76 male and 58 female patients were included. Isoniazid was measured by high-performance liquid chromatography, and N-acetyltransferase 2 phenotypes were assessed using molecular techniques. The results show that the dose administered, expressed in mg/kg, was higher in females, but the plasma levels were similar between both sexes. Among patients, 46.2%, 38.8%, and 15% were slow, intermediate, and fast acetylators, respectively. As expected, isoniazid levels were associated with the acetylation phenotypes, with higher concentrations in the slow acetylators. Thus, sex-related difference in isoniazid levels is due to the body weight of patients, and the optimized dose regimen based on patient weight and acetylator phenotypes can improve the treatment outcomes.

Correlation of N-acetyltransferase 2 genotype and acetylation status with plasma isoniazid concentration and its metabolic ratio in ethiopian tuberculosis patients

Unfavorable treatment outcomes for tuberculosis (TB) treatment might result from altered plasma exposure to antitubercular drugs in TB patients. The present study investigated the distribution of the N-Acetyltransferase 2 (NAT2) genotype, isoniazid acetylation status, genotype-phenotype concordance of NAT2, and isoniazid plasma exposure among Ethiopian tuberculosis patients. Blood samples were collected from newly diagnosed TB patients receiving a fixed dose combination of first-line antitubercular drugs daily. Genotyping of NAT2 was done using TaqMan drug metabolism assay. Isoniazid and its metabolite concentration were determined using validated liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of 120 patients (63 male and 57 female) were enrolled in this study. The mean daily dose of isoniazid was 4.71 mg/kg. The frequency of slow, intermediate, and fast NAT2 acetylators genotypes were 74.2%, 22.4%, and 3.3% respectively. The overall median isoniazid maximum plasma concentration (Cmax) was 4.77 µg/mL and the AUC0-7 h was 11.21 µg.h/mL. The median Cmax in slow, intermediate, and fast acetylators were 5.65, 3.44, and 2.47 μg/mL, respectively. The median AUC0-7 h hour in slow, intermediate, and fast acetylators were 13.1, 6.086, and 3.73 mg•h/L, respectively. The majority (87.5%) of the study participants achieved isoniazid Cmax of above 3 µg/mL, which is considered a lower limit for a favorable treatment outcome. There is 85% concordance between the NAT2 genotype and acetylation phenotypes. NAT2 genotype, female sex, and dose were independent predictors of Cmax and AUC0-7 h (p < 0.001). Our finding revealed that there is a high frequency of slow NAT2 genotypes. The plasma Cmax of isoniazid was higher in the female and slow acetylators genotype group. The overall target plasma isoniazid concentrations in Ethiopian tuberculosis patients were achieved in the majority of the patients. Therefore, it is important to monitor adverse drug reactions and the use of a higher dose of isoniazid should be closely monitored.

Sex and Gender Differences in Tuberculosis Pathogenesis and Treatment Outcomes

Tuberculosis remains a daunting public health concern in many countries of the world. A consistent observation in the global epidemiology of tuberculosis is an excess of cases of active pulmonary tuberculosis among males compared with females. Data from both humans and animals also suggest that males are more susceptible than females to develop active pulmonary disease. Similarly, male sex has been associated with poor treatment outcomes. Despite this growing body of evidence, little is known about the mechanisms driving sex bias in tuberculosis disease. Two dominant hypotheses have been proposed to explain the predominance of active pulmonary tuberculosis among males. The first is based on the contribution of biological factors, such as sex hormones and genetic factors, on host immunity during tuberculosis. The second is focused on non-biological factors such as smoking, professional exposure, and health-seeking behaviors, known to be influenced by gender. In this chapter, we review the literature regarding these two prevailing hypotheses by presenting human but also experimental animal studies. In addition, we presented studies aiming at examining the impact of sex and gender on other clinical forms of tuberculosis such as latent tuberculosis infection and extrapulmonary tuberculosis, which both appear to have their own specificities in relation to sex. We also highlighted potential intersections between sex and gender in the context of tuberculosis and shared future directions that could guide in elucidating mechanisms of sex-based differences in tuberculosis pathogenesis and treatment outcomes.

Possible sex difference in latent tuberculosis infection risk among close tuberculosis contacts

OBJECTIVES

More men than women develop and die of tuberculosis (TB). Fewer data exist on sex differences in latent TB infection (LTBI). We assessed for potential sex differences in LTBI acquisition among close TB contacts.

METHODS

Regional Prospective Observational Research for TB-Brazil is an observational multi-center cohort of individuals with culture-confirmed pulmonary TB and their close contacts. Participants were enrolled from five sites in Brazil from June 2015 - June 2019. Close contacts were followed for 24 months after enrollment, with LTBI defined as a positive interferon-γ release assay (IGRA; QuantiFERON 3rd or 4th generation) at baseline or 6 months. We performed univariate, bivariate, and multivariable logistic regression and propensity-score weighted models to assess odds ratios (OR) and 95% confidence intervals (CI) for LTBI acquisition by birth sex among close contacts.

RESULTS

Of 1093, 504 (46%) female close contacts were IGRA positive compared to 295 of 745 (40%) men. The unadjusted OR for IGRA positivity among women vs men was 1.31 (95% CI: 1.08-1.58). Bivariate adjustments yielded ORs in women vs men ranging from 1.19 to 1.33 (P-value range: <0.01-0.07). Multivariable regression and weighted models yielded similar ORs in women vs men, of 1.14 (95% CI: 0.92-1.41) and 1.15 (95% CI: 0.94-1.40), respectively.

CONCLUSION

The point estimate for LTBI among close TB contacts in Brazil was higher in women, though less pronounced in multivariable models. If the sex difference in LTBI is confirmed in additional settings, studies of possible underlying differences in socio-behavioral factors or TB pathogenesis are warranted.

High burden of adverse drug reactions to Isoniazid Preventive Therapy in people living with HIV at three tertiary hospitals in Uganda: associated factors

BACKGROUND

HIV is one of the most important risk factors for TB-related morbidity and mortality. Isoniazid preventive therapy (IPT) is recommended to prevent latent TB reactivation in HIV patients. However, due to multiple therapies and comorbidities these patients are predisposed to adverse drug reactions (ADRs) which lead to increased morbidity and mortality. The aim of this study was to determine the prevalence and associated factors of suspected IPT-linked ADRs in HIV-positive patients using IPT.

METHODS

A cross-sectional study was conducted between February and March 2020 at three regional referral hospitals (RRHs) in central Uganda. We sampled 660 HIV-positive patients aged 10 years and older who received IPT between July and December 2019 inclusive. Patients were interviewed using a pre-tested structured questionnaire and their treatment records were reviewed. A modified poisson regression model with clustered robust standard errors was used to identify factors associated with suspected IPT-linked ADRs.

RESULTS

The prevalence of the suspected ADRs was 51 % (334/660; 95% CI: 18% - 83%). Patients' self-reported 7-fold more suspected ADRs than were documented by the Health Care Workers (HCWs). Musculoskeletal symptoms were the most frequently experienced reaction (14%) followed by dizziness (13%) and peripheral neuropathy (11%). Serious suspected ADRs were experienced by 12 % of the study participants; the most common were hepatotoxicity (26%), dizziness (23%) and neuropathy (17%). Female sex (aPR: 0.92, 95% CI = 0.88-0.95), study site (aPR: 1.09, 95% CI = 1.09-1.18), level of education (aPR: 0.94, 95% CI = 0.94-0.99) and history of TB (aPR: 0.93, 95% CI = 0.87-0.99), good IPT adherence (aPR: 1.16, 95% CI = 1.05-1.29) and use of protease inhibitor (PI)-based ART (aPR: 1.01, 95% CI = 1.00-1.02) were significantly associated with suspected IPT-linked ADRs.

CONCLUSION

The prevalence of suspected IPT-linked ADRs is high and hepatotoxicity is the most commonly reported serious suspected ADR. Patients self-reported more suspected ADRs than were documented by HCWs. Patient engagement could improve ADR detection and potentially strengthen the pharmacovigilance system. High ADR-risk patients ought to be monitored regularly to enable early detection and management.

Alcohol Use and the Risk of Communicable Diseases

The body of knowledge on alcohol use and communicable diseases has been growing in recent years. Using a narrative review approach, this paper discusses alcohol's role in the acquisition of and treatment outcomes from four different communicable diseases: these include three conditions included in comparative risk assessments to date-Human Immunodeficiency Virus (HIV)/AIDS, tuberculosis (TB), and lower respiratory infections/pneumonia-as well as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) because of its recent and rapid ascension as a global health concern. Alcohol-attributable TB, HIV, and pneumonia combined were responsible for approximately 360,000 deaths and 13 million disability-adjusted life years lost (DALYs) in 2016, with alcohol-attributable TB deaths and DALYs predominating. There is strong evidence that alcohol is associated with increased incidence of and poorer treatment outcomes from HIV, TB, and pneumonia, via both behavioral and biological mechanisms. Preliminary studies suggest that heavy drinkers and those with alcohol use disorders are at increased risk of COVID-19 infection and severe illness. Aside from HIV research, limited research exists that can guide interventions for addressing alcohol-attributable TB and pneumonia or COVID-19. Implementation of effective individual-level interventions and alcohol control policies as a means of reducing the burden of communicable diseases is recommended.

Factors associated with non-completion of latent tuberculosis infection treatment in Rio de Janeiro, Brazil: A non-matched case control study

INTRODUCTION

There are scarce data on the routine latent tuberculosis infection treatment (LTBIT) and factors associated with a non-completion in high tuberculosis burden countries. Therefore, in this study we aimed to evaluate the factors associated with non-completion of LTBIT.

MATERIALS AND METHODS

This was a non-matched case control study conducted at a University Hospital in Rio de Janeiro, Brazil. A total of 114 cases and 404 controls were enrolled between January/1999 and December/2009. Cases were close contacts who did not complete the LTBIT and controls were the contacts that completed it. Multivariate analysis was used to investigate risk factors associated with non-completion of LTBIT among contacts in two different periods of recruitment.

RESULTS

Factors associated with non-completion LTBIT included: drug use (OR 23.33, 95% CI 1.83-296.1), TB treatment default by the index case (OR 16.97, 95% CI 3.63-79.24) and drug intolerance. TB disease rates after two years of follow up varied from 0.4% to 1.9%. The number necessary to treat to prevent one TB case among contacts was 116.

CONCLUSIONS

Non-completion treatment by the index case and illicit drug use were associated with not completing latent tuberculosis infection treatment and no tuberculosis disease was identified among those who completed latent tuberculosis infection treatment.

Adherence to nine-month isoniazid for latent tuberculosis infection in healthcare workers: a prospective study in a tertiary hospital

Poor adherence to medication can lead to treatment failure in healthcare workers (HWCs) with latent tuberculosis infection (LTBI) who are at high risk of developing active tuberculosis. However, the factors associated with non-completion of nine-month LTBI treatment with isoniazid (9 H) have not been well studied. We investigated the completion rate and factors affecting adherence to LTBI treatment with 9 H among HCWs. A prospective cohort study of 114 HCWs who were diagnosed with LTBI by QuantiFERON-TB Gold In-Tube tests were performed in a single university hospital between June 2016 and December 2017. All patients received the 9 H LTBI treatment. At each visit, treatment adherence and development of adverse reactions to isoniazid were evaluated via a standard questionnaire. To evaluate the impact of the severity of hepatotoxicity on non-completion of LTBI treatment, we classified hepatotoxicity into two groups: severe hepatotoxicity was defined as alanine aminotransferase >3.0 times the upper normal limit (UNL) with symptoms or  = 5.0 times the UNL. Mild hepatotoxicity was defined as alanine aminotransferase>UNL, but not meet the definition of severe hepatotoxicity. Overall, 71 HCWs (62.3%) completed LTBI treatment with 9 H while 43 HCWs (37.7%) discontinued their treatment. Most discontinuation (81.4%, 35/43) occurred during the first three months of treatment. There were no significant differences in age, sex, occupation, or comorbidities between the HCWs who completed and those who discontinued LTBI treatment. However, HCWs who discontinued LTBI treatment had more hepatotoxicity than those who completed treatment (44.2% vs. 11.3%, P < 0.001). Cox proportional hazard analysis revealed that hepatotoxicity is the only factor significantly associated with discontinuation of 9 H LTBI treatment (unadjusted HR = 2.89, 95% CI = 1.62–5.46). In multivariable analysis, not only severe hepatotoxicity (adjusted HR = 7.99, 95% CI = 3.05–20.94) but also mild hepatotoxicity was significantly associated with discontinuation of LTBI treatment (adjusted HR = 2.34, 95% CI = 1.05–5.21). The completion rate of 9 H LTBI treatment was 62.3% among HCWs. While age, sex, occupation, and pretreatment comorbidities were not associated with treatment completion, isoniazid-induced hepatotoxicity significantly affected adherence.

Latent tuberculosis treatment completion rates from prescription drug administrative data

OBJECTIVE

In the province of Manitoba, Canada, given that latent tuberculosis infection (LTBI) treatment is provided at no cost to the patient, treatment completion rates should be optimal. The objective of this study was to estimate LTBI treatment completion using prescription drug administrative data and identify patient characteristics associated with completion.

METHODS

Prescription drug data (1999-2014) were used to identify individuals dispensed isoniazid (INH) or rifampin (RIF) monotherapy. Treatment completion was defined as being dispensed INH for ≥ 180 days (INH180) or ≥ 270 days (INH270) or RIF for ≥ 120 days (RIF120). Logistic regression models tested socio-demographic and comorbidity characteristics associated with treatment completion.

RESULTS

The study cohort comprised 4985 (90.4%) persons dispensed INH and 529 (9.6%) RIF. Overall treatment completion was 60.2% and improved from 43.1% in 1999-2003 to 67.3% in 2009-2014. INH180 showed the highest completion (63.8%) versus INH270 (40.4%) and RIF120 (27.0%). INH180 completion was higher among those aged 0-18 years (68.5%) compared with those aged 19+ (61.0%). Sex, geography, First Nations status, income quintile, and comorbidities were not associated with completion.

CONCLUSIONS

Benchmark 80% treatment completion rates were not achieved in Manitoba. Factors associated with non-completion were older age, INH270, and RIF120. Access to shorter LTBI treatments, such as rifapentine/INH, may improve treatment completion.

Beyond pills and tests: addressing the social determinants of tuberculosis

Poverty drives tuberculosis (TB) rates but the approach to TB control has been disproportionately biomedical. In 2015, the World Health Organization's End TB Strategy explicitly identified the need to address the social determinants of TB through socio-economic interventions. However, evidence concerning poverty reduction and cost mitigation strategies is limited. The research described in this article, based on the 2016 Royal College of Physicians Linacre Lecture, aimed to address this knowledge gap. The research was divided into two phases: the first phase was an analysis of a cohort study identifying TB-related costs of TB-affected households and creating a clinically relevant threshold above which those costs became catastrophic; the second was the design, implementation and evaluation of a household randomised controlled evaluation of socio-economic support to improve access to preventive therapy, increase TB cure, and mitigate the effects of catastrophic costs. The first phase showed TB remains a disease of people living in poverty - 'free' TB care was unaffordable for impoverished TB-affected households and incurring catastrophic costs was associated with as many adverse TB treatment outcomes (including death, failure of treatment, lost to follow-up and TB recurrence) as multidrug resistant (MDR) TB. The second phase showed that, in TB-affected households receiving socio-economic support, household contacts were more likely to start and adhere to TB preventive therapy, TB patients were more likely to be cured and households were less likely to incur catastrophic costs. In impoverished Peruvian shantytowns, poverty remains inextricably linked with TB and incurring catastrophic costs predicted adverse TB treatment outcome. A novel socio-economic support intervention increased TB preventive therapy uptake, improved TB treatment success and reduced catastrophic costs. The impact of the intervention on TB control is currently being evaluated by the Community Randomized Evaluation of a Socio-economic Intervention to Prevent TB (CRESIPT) study.

Beyond pills and tests: addressing the social determinants of tuberculosis

Poverty drives tuberculosis (TB) rates but the approach to TB control has been disproportionately biomedical. In 2015, the World Health Organization's End TB Strategy explicitly identified the need to address the social determinants of TB through socio-economic interventions. However, evidence concerning poverty reduction and cost mitigation strategies is limited. The research described in this article, based on the 2016 Royal College of Physicians Linacre Lecture, aimed to address this knowledge gap. The research was divided into two phases: the first phase was an analysis of a cohort study identifying TB-related costs of TB-affected households and creating a clinically relevant threshold above which those costs became catastrophic; the second was the design, implementation and evaluation of a household randomised controlled evaluation of socio-economic support to improve access to preventive therapy, increase TB cure, and mitigate the effects of catastrophic costs. The first phase showed TB remains a disease of people living in poverty - 'free' TB care was unaffordable for impoverished TB-affected households and incurring catastrophic costs was associated with as many adverse TB treatment outcomes (including death, failure of treatment, lost to follow-up and TB recurrence) as multidrug resistant (MDR) TB. The second phase showed that, in TB-affected households receiving socio-economic support, household contacts were more likely to start and adhere to TB preventive therapy, TB patients were more likely to be cured and households were less likely to incur catastrophic costs. In impoverished Peruvian shantytowns, poverty remains inextricably linked with TB and incurring catastrophic costs predicted adverse TB treatment outcome. A novel socio-economic support intervention increased TB preventive therapy uptake, improved TB treatment success and reduced catastrophic costs. The impact of the intervention on TB control is currently being evaluated by the Community Randomized Evaluation of a Socio-economic Intervention to Prevent TB (CRESIPT) study.

Three months of weekly rifapentine plus isoniazid is less hepatotoxic than nine months of daily isoniazid for LTBI

SETTING

Nine months of daily isoniazid (9H) and 3 months of once-weekly rifapentine plus isoniazid (3HP) are recommended treatments for latent tuberculous infection (LTBI). The risk profile for 3HP and the contribution of hepatitis C virus (HCV) infection to hepatotoxicity are unclear.

OBJECTIVES

To evaluate the hepatotoxicity risk associated with 3HP compared to 9H, and factors associated with hepatotoxicity.

DESIGN

Hepatotoxicity was defined as aspartate aminotransferase (AST) >3 times the upper limit of normal (ULN) with symptoms (nausea, vomiting, jaundice, or fatigue), or AST >5 x ULN. We analyzed risk factors among adults who took at least 1 dose of their assigned treatment. A nested case-control study assessed the role of HCV.

RESULTS

Of 6862 participants, 77 (1.1%) developed hepatotoxicity; 52 (0.8%) were symptomatic; 1.8% (61/3317) were on 9H and 0.4% (15/3545) were on 3HP (P < 0.0001). Risk factors for hepatotoxicity were age, female sex, white race, non-Hispanic ethnicity, decreased body mass index, elevated baseline AST, and 9H. In the case-control study, HCV infection was associated with hepatotoxicity when controlling for other factors.

CONCLUSION

The risk of hepatotoxicity during LTBI treatment with 3HP was lower than the risk with 9H. HCV and elevated baseline AST were risk factors for hepatotoxicity. For persons with these risk factors, 3HP may be preferred.

Initiation and completion rates for latent tuberculosis infection treatment: a systematic review

BACKGROUND

Control of latent tuberculosis infection (LTBI) is an important step towards tuberculosis elimination. Preventive treatment will prevent the development of disease in most cases diagnosed with LTBI. However, low initiation and completion rates affect the effectiveness of preventive treatment. The objective was to systematically review data on initiation rates and completion rates for LTBI treatment regimens in the general population and specific populations with LTBI.

METHODS

A systematic review of the literature (PubMed, Embase) published up to February 2014 was performed.

RESULTS

Forty-five studies on initiation rates and 83 studies on completion rates of LTBI treatment were found. These studies provided initiation rates (IR) and completion rates (CR) in people with LTBI among the general population (IR 26-99 %, CR 39-96 %), case contacts (IR 40-95 %, CR 48-82 %), healthcare workers (IR 47-98 %, CR 17-79 %), the homeless (IR 34-90 %, CR 23-71 %), people who inject drugs (IR 52-91 %, CR 38-89 %), HIV-infected individuals (IR 67-92 %, CR 55-95 %), inmates (IR 7-90 %, CR 4-100 %), immigrants (IR 23-97 %, CR 7-86 %), and patients with comorbidities (IR 82-93 %, CR 75-92 %). Generally, completion rates were higher for short than for long LTBI treatment regimens.

CONCLUSION

Initiation and completion rates for LTBI treatment regimens were frequently suboptimal and varied greatly within and across different populations.

Latent tuberculous infection in the United States and Canada: who completes treatment and why?

OBJECTIVES

To assess latent tuberculous infection (LTBI) treatment completion rates in a large prospective US/Canada multisite cohort and identify associated risk factors.

METHODS

This prospective cohort study assessed factors associated with LTBI treatment completion through interviews with persons who initiated treatment at 12 sites. Interviews were conducted at treatment initiation and completion/cessation. Participants received usual care according to each clinic's procedure. Multivariable models were constructed based on stepwise assessment of potential predictors and interactions.

RESULTS

Of 1515 participants initiating LTBI treatment, 1323 had information available on treatment completion; 617 (46.6%) completed treatment. Baseline predictors of completion included male sex, foreign birth, not thinking it would be a problem to take anti-tuberculosis medication, and having health insurance. Participants in stable housing who received monthly appointment reminders were more likely to complete treatment than those without stable housing or without monthly reminders. End-of-treatment predictors of non-completion included severe symptoms and the inconvenience of clinic/pharmacy schedules, barriers to care and changes of residence. Common reasons for treatment non-completion were patient concerns about tolerability/toxicity, appointment conflicts, low prioritization of TB, and forgetfulness.

CONCLUSIONS

Less than half of treatment initiators completed treatment in our multisite study. Addressing tangible issues such as not having health insurance, toxicity concerns, and clinic accessibility could help to improve treatment completion rates.