Impact of Age on Outcome of Rifapentine-Based Weekly Therapy for Latent Tuberculosis Infection

Dermatology practice updates in mycobacterial disease

Atypical mycobacterial infections are commonly acquired through exposure to water, and tuberculosis remains highly endemic in many parts of the world. In this era of global connection, travel, and immigration, it is more important than ever to maintain a high index of suspicion for infection from cutaneous tuberculosis and atypical mycobacteria. Epidemics related to surgical procedures have been related to inadequate sterilization, as almost 50% of public water supplies harbor mycobacteria. Improved diagnostic techniques for these microbes, including Auramine-Rhodamine staining and rapid detection of mycobacteria and drug susceptibilities through PCR and MALDI-TOF, have improved detection and treatment outcomes. Given an increasing number of patients on immunosuppressive therapies, clinicians must remain vigilant.

Uptake and Completion of Tuberculosis Preventive Treatment Using 12-Dose, Weekly Isoniazid-Rifapentine Regimen in Bangladesh: A Community-Based Implementation Study

BACKGROUND

The United Nations high-level meeting (UNHLM) pledged to enroll 30 million in tuberculosis preventive treatment (TPT) by 2022, necessitating TPT expansion to all at tuberculosis (TB) risk. We assessed the uptake and completion of a 12-dose, weekly isoniazid-rifapentine (3HP) TPT regimen.

METHODS

Between February 2018 and March 2019 in Dhaka, community-based TPT using 3HP targeted household contacts of 883 confirmed drug-sensitive pulmonary TB patients. Adhering to World Health Organization guidelines, contacts underwent active TB screening before TPT initiation.

RESULTS

Of 3193 contacts who were advised health facility visits for screening, 67% (n = 2149) complied. Among these, 1804 (84%) received chest X-rays. Active TB was diagnosed in 39 (2%) contacts; they commenced TB treatment. Over 97% of 1216 contacts began TPT, with completion rates higher among females, those with more education and income, non-slum residents, and those without 3HP-related adverse events. Adverse events, mainly mild, occurred in 5% of participants.

CONCLUSIONS

The 3HP regimen, with its short duration, self-administered option, and minimal side effects, achieved satisfactory completion rates. A community-focused TPT approach is feasible, scalable nationally, and aligns with UNHLM targets.

Isoniazid level and flu-like symptoms during rifapentine-based tuberculosis preventive therapy: A population pharmacokinetic analysis

AIM

A population pharmacokinetic (PPK) study of the correlation of adverse drug reactions (ADRs) with the 3HP regimen (weekly high-dose rifapentine plus isoniazid for 12 doses) for latent tuberculosis infection (LTBI) remains lacking. The purpose of this study is to determine the association of rifapentine or isoniazid concentration and ADRs.

METHODS

This prospective, multicentre, observational study enrolled LTBI contacts receiving 3HP treatment between January 2017 and August 2020. The concentrations of rifapentine, isoniazid and their metabolites (25-desacetyl-rifapentine and acetyl-isoniazid) in plasma samples collected monthly after 3HP treatment were determined. A PPK model was constructed to predict the maximum concentration (C_max ) and area under the concentration-time curve from 0 to 24 h (AUC). Their association with ADRs was evaluated by applying three multivariate logistic regression models with adjustment for various covariates.

RESULTS

A total of 415 LTBI cases were ultimately enrolled; 355 (85.5%) completed the 3HP treatment. Among them, 47 (11.3%) experienced systemic drug reactions and 291 (70.0%) experienced one or more flu-like symptom. The plasma concentration-time profiles of isoniazid, rifapentine and their metabolites were adequately described by the developed models. A higher C_max of isoniazid was significantly correlated with a higher risk of any ADR (adjusted odds ratio and 95% confidence interval: 3.04 [1.07-8.65]) and any or at least two flu-like symptoms (all severity grades) (2.76 [1.06-7.17]).

CONCLUSIONS

Isoniazid may be responsible for ADRs, especially flu-like symptoms, during 3HP treatment.

Whole-blood 3-gene Signature as a Decision Aid for Rifapentine-based TB Preventive Therapy

Background

Systemic drug reaction (SDR) is a major safety concern with weekly rifapentine plus isoniazid for 12 doses (3HP) for latent tuberculosis infection (LTBI). Identifying SDR predictors and at-risk participants before treatment can improve cost-effectiveness of the LTBI program.

Methods

We prospectively recruited 187 cases receiving 3HP (44 SDRs and 143 non-SDRs). A pilot cohort (8 SDRs and 12 non-SDRs) was selected for generating whole-blood transcriptomic data. By incorporating the hierarchical system biology model and therapy–biomarker pathway approach, candidate genes were selected and evaluated using reverse-transcription quantitative polymerase chain reaction (RT-qPCR). Then, interpretable machine learning models presenting as SHapley Additive exPlanations (SHAP) values were applied for SDR risk prediction. Finally, an independent cohort was used to evaluate the performance of these predictive models.

Results

Based on the whole-blood transcriptomic profile of the pilot cohort and the RT-qPCR results of 2 SDR and 3 non-SDR samples in the training cohort, 6 genes were selected. According to SHAP values for model construction and validation, a 3-gene model for SDR risk prediction achieved a sensitivity and specificity of 0.972 and 0.947, respectively, under a universal cutoff value for the joint of the training (28 SDRs and 104 non-SDRs) and testing (8 SDRs and 27 non-SDRs) cohorts. It also worked well across different subgroups.

Conclusions

The prediction model for 3HP-related SDRs serves as a guide for establishing a safe and personalized regimen to foster the implementation of an LTBI program. Additionally, it provides a potential translational value for future studies on drug-related hypersensitivity.

Completion Rate and Safety of Programmatic Screening and Treatment for Latent Tuberculosis Infection in Elderly Patients With Poorly Controlled Diabetic Mellitus: A Prospective Multicenter Study

BACKGROUND

Poor control of diabetes mellitus (DM) increases active tuberculosis (TB) risk. Understanding risk factors for latent TB infection (LTBI) in this population and intervention completion rates is crucial for policy making.

METHODS

Under a collaborative multidisciplinary team consisting of public health professionals, endocrinologists, and pulmonologists, patients aged >45 years with poorly controlled DM (pDM), defined as having a glycated hemoglobin level of ≥9% within the preceding year, were enrolled by endocrinologists from 2 hospitals; these patients underwent LTBI screening by using QuantiFERON (QFT). Once-weekly isoniazid and rifapentine for 12 weeks (3HP) or daily isoniazid for 9 months (9H) was administered by pulmonologists. QFT-positivity predictors were evaluated using logistic regression. Completion rates and safety were also investigated.

RESULTS

Among 980 patients with pDM (age: 64.2 ± 9.7 years), 261 (26.6%) were QFT-positive. Age, DM duration, chronic kidney disease stage ≥3, and dipeptidyl peptidase-4 inhibitor use, not using metformin, were associated with QFT-positivity. Preventive therapy (3HP: 138; 9H: 62) was administered in 200 (76.6%) QFT-positive patients. The completion rates of 3HP and 9H were 84.1% and 79.0%, respectively (P = .494). Nine (6.5%) and zero patients in the 3HP and 9H groups, respectively, developed systemic drug reactions (P = .059); 78.3% and 45.2% had ≥1 adverse drug reactions (P < .001); and post-treatment QFT conversion rates were 32% and 20%, respectively (P = .228).

CONCLUSIONS

LTBI prevalence exceeds 25% in elderly patients with pDM. Under care from a collaborative multidisciplinary team, the completion rate of preventive therapy, regardless of regimen could approach, or even exceed 80% in this population.

High rate of completion for weekly rifapentine plus isoniazid treatment in Chinese children with latent tuberculosis infection-A single center study

Three months of weekly rifapentine plus isoniazid (3HP) is a short course regimen for latent tuberculosis infection treatment with satisfied safety and efficacy. However, research on its use in children is limited. In this study, we evaluated the completion rate and safety of the 3HP regimen among children in China. Participants aged 1–14 years receiving 3HP for TB prevention at Shanghai Public Health Clinical Center were followed from December 2019 to November 2020 to evaluate the safety and completion rate of the treatment. Thirty-one children were eligible for inclusion, but five were excluded from the analysis (three were treated with a lower than recommended dose, and two were lost to follow-up). Of the 26 children included in the analysis, the treatment completion rate was 100%. Adverse drug reactions (ADRs) were reported in 38.5% (10/26) of the patients. The most common ADRs were gastrointestinal symptoms (19.2%,5/26), and all ADRs were rated as Grade 1. The 3HP regimen has a high completion rate, and it seems well tolerated in our study population. However, further randomized controlled clinical trial with larger sample size are warranted.