Evaluation of a Liquid Chromatography-Tandem Mass Spectrometry Assay for Second-line Tuberculosis Drug Concentrations in Small Hair Samples

Abstract Abstract Background Treatment monitoring of multidrug-resistant (MDR) and extensively drug-resistant tuberculosis (XDR-TB) in resource-limited settings is challenging. We developed a multi-analyte assay for eleven anti-TB drugs in small hair samples as an objective metric of drug exposure. Methods Small hair samples were collected from participants at various timepoints during directly-observed MDR/XDR-TB treatment at an inpatient tertiary referral facility in South Africa (DR-TB cohort). We assessed an LC-MS/MS index panel assay including isoniazid, ethambutol, pyrazinamide, levofloxacin, moxifloxacin, ethionamide, prothionamide, linezolid, clofazimine, pretomanid, and bedaquiline against a reference standard of inpatient treatment records. Because treatment regimens prior to hospitalization were not available, we also analyzed specificity (for all drugs except isoniazid) using an external cohort of HIV-positive patients treated for latent TB infection with daily isoniazid (HIV/LTBI cohort) in Uganda. Results Among the 57 DR-TB patients (58% with pre-XDR/XDR-TB; 70% HIV-positive) contributing analyzable hair samples, the sensitivity of the investigational assay was 94% or higher for all drugs except ethionamide (58.5%, 95% confidence interval [CI], 40.7-99.9). Assay specificity was low across all tested analytes within the DR-TB cohort; conversely, assay specificity was 100% for all drugs in the HIV/LTBI cohort. Conclusions We developed an 11-drug panel assay to quantitatively ascertain drug exposure within second- and third-line DR-TB treatment regimens. Because hair concentrations reflect long-term exposure, multiple successive regimens commonly employed in DR-TB treatment may result in apparent false-positive qualitative and falsely elevated quantitative hair drug levels when prior treatment histories are not known.

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Diagnostic Accuracy of a Liquid Chromatography-Tandem Mass Spectrometry Assay for Rifampin-resistant Tuberculosis Drug Concentrations in a Routine Care Setting

10.21203/rs.2.14805/v2 ◽

2020 ◽

Author(s):

John Metcalfe ◽

Peter Bacchetti ◽

Ali Esmail ◽

Andrew Reckers ◽

David Aguilar ◽

...

Keyword(s):

Drug Exposure ◽

Limit Of Detection ◽

Routine Care ◽

Hiv Positive ◽

Treatment Regimens ◽

Tb Treatment ◽

Resistant Tuberculosis ◽

Drug Concentrations ◽

Hair Samples ◽

Latent Tb Infection

Abstract BackgroundTreatment monitoring of drug-resistant tuberculosis (DR-TB) in resource-limited settings is challenging. We developed a multi-analyte assay for eleven anti-TB drugs in small hair samples as an objective metric of drug exposure.MethodsSmall hair samples were collected from participants at various timepoints during directly observed RR-TB treatment at an inpatient tertiary referral facility in South Africa (DR-TB cohort). We assessed qualitative determination (i.e., detection above limit of detection) of bedaquiline, linezolid, clofazimine, pretomanid, levofloxacin, moxifloxacin, pyrazinamide, isoniazid, ethambutol, ethionamide, and prothionamide in an LC-MS/MS index panel assay against a reference standard of inpatient treatment records. Because treatment regimens prior to hospitalization were not available, we also analyzed specificity (for all drugs except isoniazid) using an external cohort of HIV-positive patients treated for latent TB infection with daily isoniazid (HIV/LTBI cohort) in Uganda.ResultsAmong the 57 DR-TB patients (58% with pre-XDR/XDR-TB; 70% HIV-positive) contributing analyzable hair samples, the sensitivity of the investigational assay was 94% or higher for all drugs except ethionamide (58.5%, 95% confidence interval [CI], 40.7-99.9). Assay specificity was low across all tested analytes within the DR-TB cohort; conversely, assay specificity was 100% for all drugs in the HIV/LTBI cohort.ConclusionsHair drug concentrations reflect long-term exposure, and multiple successive regimens commonly employed in DR-TB treatment may result in apparent false-positive qualitative and falsely elevated quantitative hair drug levels when prior treatment histories within the hair growth window are not known.

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Diagnostic accuracy of a liquid chromatography-tandem mass spectrometry assay in small hair samples for rifampin-resistant tuberculosis drug concentrations in a routine care setting

BMC Infectious Diseases ◽

10.1186/s12879-020-05738-5 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

John Metcalfe ◽

Peter Bacchetti ◽

Ali Esmail ◽

Andrew Reckers ◽

David Aguilar ◽

...

Keyword(s):

Drug Exposure ◽

Limit Of Detection ◽

Routine Care ◽

Hiv Positive ◽

Treatment Regimens ◽

Tb Treatment ◽

Resistant Tuberculosis ◽

Drug Concentrations ◽

Hair Samples ◽

Latent Tb Infection

Abstract Background Treatment monitoring of drug-resistant tuberculosis (DR-TB) in resource-limited settings is challenging. We developed a multi-analyte assay for eleven anti-TB drugs in small hair samples as an objective metric of drug exposure. Methods Small hair samples were collected from participants at various timepoints during directly observed RR-TB treatment at an inpatient tertiary referral facility in South Africa (DR-TB cohort). We assessed qualitative determination (i.e., detection above limit of detection) of bedaquiline, linezolid, clofazimine, pretomanid, levofloxacin, moxifloxacin, pyrazinamide, isoniazid, ethambutol, ethionamide, and prothionamide in an LC-MS/MS index panel assay against a reference standard of inpatient treatment records. Because treatment regimens prior to hospitalization were not available, we also analyzed specificity (for all drugs except isoniazid) using an external cohort of HIV-positive patients treated for latent TB infection with daily isoniazid (HIV/LTBI cohort) in Uganda. Results Among the 57 DR-TB patients (58% with pre-XDR/XDR-TB; 70% HIV-positive) contributing analyzable hair samples, the sensitivity of the investigational assay was 94% or higher for all drugs except ethionamide (58.5, 95% confidence interval [CI], 40.7–99.9). Assay specificity was low across all tested analytes within the DR-TB cohort; conversely, assay specificity was 100% for all drugs in the HIV/LTBI cohort. Conclusions Hair drug concentrations reflect long-term exposure, and multiple successive regimens commonly employed in DR-TB treatment may result in apparent false-positive qualitative and falsely elevated quantitative hair drug levels when prior treatment histories within the hair growth window are not known.

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Diagnostic Accuracy of a Liquid Chromatography-Tandem Mass Spectrometry Assay for Rifampin-resistant Tuberculosis Drug Concentrations in a Routine Care Setting

10.21203/rs.2.14805/v3 ◽

2021 ◽

Author(s):

John Metcalfe ◽

Peter Bacchetti ◽

Ali Esmail ◽

Andrew Reckers ◽

David Aguilar ◽

...

Keyword(s):

Drug Exposure ◽

Limit Of Detection ◽

Routine Care ◽

Hiv Positive ◽

Treatment Regimens ◽

Tb Treatment ◽

Resistant Tuberculosis ◽

Drug Concentrations ◽

Hair Samples ◽

Latent Tb Infection

Abstract BackgroundTreatment monitoring of drug-resistant tuberculosis (DR-TB) in resource-limited settings is challenging. We developed a multi-analyte assay for eleven anti-TB drugs in small hair samples as an objective metric of drug exposure. MethodsSmall hair samples were collected from participants at various timepoints during directly observed RR-TB treatment at an inpatient tertiary referral facility in South Africa (DR-TB cohort). We assessed qualitative determination (i.e., detection above limit of detection) of bedaquiline, linezolid, clofazimine, pretomanid, levofloxacin, moxifloxacin, pyrazinamide, isoniazid, ethambutol, ethionamide, and prothionamide in an LC-MS/MS index panel assay against a reference standard of inpatient treatment records. Because treatment regimens prior to hospitalization were not available, we also analyzed specificity (for all drugs except isoniazid) using an external cohort of HIV-positive patients treated for latent TB infection with daily isoniazid (HIV/LTBI cohort) in Uganda.ResultsAmong the 57 DR-TB patients (58% with pre-XDR/XDR-TB; 70% HIV-positive) contributing analyzable hair samples, the sensitivity of the investigational assay was 94% or higher for all drugs except ethionamide (58.5%, 95% confidence interval [CI], 40.7-99.9). Assay specificity was low across all tested analytes within the DR-TB cohort; conversely, assay specificity was 100% for all drugs in the HIV/LTBI cohort. ConclusionsHair drug concentrations reflect long-term exposure, and multiple successive regimens commonly employed in DR-TB treatment may result in apparent false-positive qualitative and falsely elevated quantitative hair drug levels when prior treatment histories within the hair growth window are not known.

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Time for a change: considering regimen changes in analyses of observational drug-resistant TB treatment cohort data

The International Journal of Tuberculosis and Lung Disease ◽

10.5588/ijtld.20.0076 ◽

2020 ◽

Vol 24 (11) ◽

pp. 1151-1155

Author(s):

M. F. Franke ◽

C. D. Mitnick

Keyword(s):

Observational Studies ◽

Drug Exposure ◽

Randomized Clinical Trials ◽

Multidrug Resistant ◽

Drug Resistant ◽

Treatment Regimens ◽

Tb Treatment ◽

Mdr Tb ◽

Therapeutic Research ◽

Do So

Randomized clinical trials represent the gold standard in therapeutic research. Nevertheless, observational cohorts of patients treated for multidrug-resistant TB (MDR-TB) or rifampin-resistant TB (RR-TB) also play an important role in generating evidence to guide drug-resistant TB care. Generally, summary exposure classifications (e.g., ‘ever vs. never´, ‘exposed at baseline´) have been used to characterize drug exposure in the absence of detailed longitudinal data on MDR-TB regimen changes. These summary classifications, along with an absence of data on covariates that change throughout the course of treatment, constrain researchers´ ability to answer the most relevant questions while accounting for known biases. In this paper, we highlight the importance of regimen changes in improving inference from observational studies of longer MDR-TB treatment regimens, and offer an overview of the data and analytic strategies required to do so.

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Measuring TB drug levels in the hair in adults and children to monitor drug exposure and outcomes

The International Journal of Tuberculosis and Lung Disease ◽

10.5588/ijtld.20.0574 ◽

2021 ◽

Vol 25 (1) ◽

pp. 52-60

Author(s):

V. Mave ◽

D. Kadam ◽

S. Gaikwad ◽

A. Kinikar ◽

D. Aguilar ◽

...

Keyword(s):

Treatment Failure ◽

Treatment Outcomes ◽

Drug Exposure ◽

Treatment Success ◽

Cox Proportional Hazards ◽

Tb Treatment ◽

Drug Concentrations ◽

Hair Samples ◽

Adults And Children ◽

Lower Hazard

INTRODUCTION: Testing for anti-TB drugs in small hair samples may serve as a non-invasive tool to measure cumulative drug exposure and/or adherence, as these determine treatment success. We aimed to assess how well hair assays of TB drugs predict TB treatment outcomes.METHODS: A small thatch of hair, ~30 strands, was cut from the occipital region in adults and children from a prospective TB cohort in India. Isoniazid (INH), acetyl-INH and pyrazinamide (PZA) were extracted from the hair samples and quantified using liquid-chromatography-tandem mass spectrometry. The relationship between drug concentrations in hair and time to unfavourable outcomes was assessed using Cox-proportional hazards regression models.RESULTS: A two-fold increase in hair acetyl-INH concentrations in the 264 participants in our cohort with hair assays for TB drugs indicated a lower hazard of unfavourable TB treatment outcomes (aHR 0.67, 95%CI 0.44–1.02) and TB treatment failure (aHR 0.65, 95%CI 0.42–1.01). Higher summed concentrations (a summed measure of INH and acetyl-INH) indicated a lower hazard of treatment failure (aHR 0.69, 95%CI 0.45–1.05)CONCLUSION: Hair levels of INH and its metabolite may predict TB treatment outcomes, indicating the potential utility of this measure to assess and optimise TB treatment outcomes.

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Correlation of hair and plasma efavirenz concentrations in HIV-positive South Africans

Southern African Journal of HIV Medicine ◽

10.4102/sajhivmed.v20i1.881 ◽

2019 ◽

Vol 20 (1) ◽

Author(s):

Jenna Johnston ◽

Lubbe Wiesner ◽

Peter Smith ◽

Gary Maartens ◽

Catherine Orrell

Keyword(s):

Drug Exposure ◽

Controlled Trial ◽

Correlation Coefficients ◽

Plasma Samples ◽

Measuring Device ◽

Resource Limited ◽

Study Results ◽

Hair Samples ◽

Liquid Chromatography Tandem Mass ◽

Randomised Controlled

Background: Antiretroviral concentrations in hair provide a longer window of drug detection and are useful for measuring longer-term drug exposure. Efavirenz is an important component of first-line treatment in resource-limited settings, but its concentrations in hair have not been well studied.Methods: This study is a supplementary to a randomised controlled trial of an adherence intervention using an electronic adherence measuring device. Hair and plasma samples were collected from human immunodeficiency virus-positive patients in Cape Town, South Africa. Previously validated liquid chromatography tandem mass spectrometry methods were used to measure efavirenz concentrations in the collected hair and plasma samples. CYP2B6 genotyping of participants was also performed. Data analysis was performed using descriptive and comparative statistics as well as regression modelling.Results: Hair samples were collected from 59% of patients enrolled in the parent study. Results indicated that hair efavirenz concentrations were significantly influenced by participants’ CYP2B6metaboliser status. Median efavirenz concentrations for extensive, intermediate and slow metaboliser genotypes were 3.54 ng/mg, 5.11 ng/mg and 10.66 ng/mg, respectively. A strong correlation was observed between the efavirenz concentrations measured in hair and plasma samples (Spearman’s correlation coefficients, 0.672–0.741, p < 0.0001). No relationship between hair efavirenz concentrations and virological failure or adherence measured using an electronic adherence was shown.Conclusion: The results from this study provide further insight into the potential of using hair as a matrix for measuring antiretroviral concentrations. However, challenges experienced in collecting hair samples suggest that this adherence measure may have limited utility in an African population.

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Tuberculosis: Development of New Drugs and Treatment Regimens

Jurnal Respirasi ◽

10.20473/jr.v7-i.1.2021.36-45 ◽

2021 ◽

Vol 7 (1) ◽

pp. 36

Author(s):

Soedarsono Soedarsono

Keyword(s):

Treatment Guidelines ◽

New Drugs ◽

World Health ◽

Health Crisis ◽

Treatment Regimens ◽

Tb Treatment ◽

Repurposed Drugs ◽

Latent Tb Infection ◽

Health Organization ◽

Who Guideline

Tuberculosis (TB) still becomes a public health crisis. Drug-resistant TB (DR-TB) becomes a concern as the increasing DR-TB cases in countries with high TB burden. The 2017 World Health Organization (WHO) guideline recommended a combination of TB treatment consisting of 2 months of intensive phase with isoniazid (H), rifampisin (R), pyrazinamid (Z), and ethambutol (E), followed by 4 months of continuation phase with HR daily. WHO has updated DR-TB treatment guidelines several times. In 2016, WHO recommended shorter regimen and individual regimen based on certain conditions. The most updated 2020 WHO guideline recommended the short regimen consisting of all oral drugs as well as changes in the grouping of medicines used in DR-TB regimens in longer/individual regimens. Bedaquiline, delamanid, pretomanid, and sutezolid are new drugs which have been studied for their uses as anti-TB drugs (ATD). Bedaquilin and delamanid, which have passed phase 3 trials, have been approved and recommended by WHO for DR-TB treatment. Repurposed drugs have been used for DR-TB treatment during the time of evaluation of drugs list and regimens for DR-TB treatment. Fluoroquinolones, clofazimine, linezolid, carbapenem, amoxicillin/clavulanic acid are repurposed drugs. TB and DR-TB management will be updated at any time, based on the latest findings in studies, to evaluate and improve the effectiveness of current treatments. Prevention of active TB disease by the treatment of latent TB infection (LTBI) is also a critical component of the end TB strategy by WHO. Therefore, the development of new drugs for the LTBI treatment is also needed.

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Population pharmacokinetics of efavirenz in HIV and TB/HIV coinfected children: the significance of genotype-guided dosing

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkz238 ◽

2019 ◽

Vol 74 (9) ◽

pp. 2698-2706 ◽

Cited By ~ 1

Author(s):

Wael A Alghamdi ◽

Sampson Antwi ◽

Anthony Enimil ◽

Hongmei Yang ◽

Albert Dompreh ◽

...

Keyword(s):

Drug Exposure ◽

Compartment Model ◽

Mixed Effects ◽

Large Variability ◽

Linear Mixed Effects ◽

Tb Treatment ◽

Drug Concentrations ◽

Wide Variability ◽

Model Weight ◽

A Prospective Study

Abstract Objectives The current WHO weight-based dosing recommendations for efavirenz result in a wide variability of drug exposure in children. Our objectives are to characterize the effects of rifampicin- and isoniazid-containing anti-TB therapy and CYP2B6 activity on efavirenz concentrations in children, using non-linear mixed-effects modelling. Methods This is a pharmacokinetic (PK) substudy of a prospective study that examined the interactions between anti-TB therapy and efavirenz in HIV-infected children with and without TB. PK samples were obtained 4 weeks after starting efavirenz (PK1) and repeated 4 weeks after completing TB therapy (PK2) in TB/HIV coinfected patients. Drug concentrations were measured using LC-MS/MS. Composite CYP2B6 516/983/15582 genotype was determined. Population PK modelling was performed in Monolix. Simulations were performed to obtain the predicted mid-dose concentrations (C12). Results One hundred and five HIV-infected Ghanaian children (46 with TB/HIV) were included. The median age and weight were 7 years and 19 kg. The efavirenz concentrations over time were adequately described using a one-compartment model. Weight, composite CYP2B6 genotype and PK visit had a significant influence on the PK parameters, while TB therapy had no significant effect. Simulations showed adequate C12 for intermediate composite CYP2B6 metabolizers only. Conclusions Our model showed that rifampicin- and isoniazid-containing anti-TB therapy does not influence efavirenz PK parameters. On the other hand, it describes the effect of efavirenz autoinduction after completing TB treatment. In addition, dosing efavirenz in children based only on weight results in a large variability in drug exposure. We propose dose adjustments for slow and extensive composite CYP2B6 metabolizers.

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Multidrug-resistant tuberculosis (MDR-TB) and multidrug-resistant HIV (MDR-HIV) syndemic: challenges in resource limited setting

BMJ Case Reports ◽

10.1136/bcr-2019-230628 ◽

2019 ◽

Vol 12 (8) ◽

pp. e230628 ◽

Cited By ~ 1

Author(s):

Christian Francisco ◽

Mary Ann Lansang ◽

Edsel Maurice Salvana ◽

Katerina Leyritana

Keyword(s):

Psoas Abscess ◽

Multidrug Resistant ◽

Health Concern ◽

Tb Treatment ◽

Resistant Tuberculosis ◽

Multidrug Resistant Tuberculosis ◽

Resource Limited ◽

Persons Living With Hiv ◽

Mdr Tb ◽

Living With Hiv

Tuberculosis (TB) is common among persons living with HIV. This public health concern is aggravated by infection with multidrug-resistant organisms and adverse effects of polypharmacy. There are few published cases of multidrug-resistant tuberculosis (MDR-TB) in multidrug-resistant HIV (MDR-HIV) infected patients. We report a case of a 29-year-old Filipino man with HIV on zidovudine (AZT)-containing antiretroviral therapy (ART) but was eventually shifted to tenofovir due to anaemia. He presented with left flank tenderness, which was found to be due to an MDR-TB psoas abscess, and for which second-line anti-TB treatment was started. HIV genotyping showed MDR-HIV infection susceptible only to AZT, protease inhibitors and integrase inhibitors. Subsequently, he developed neck abscess that grew Mycobacterium avium complex and was treated with ethambutol and azithromycin. ART regimen was revised to AZT plus lamivudine and lopinavir/ritonavir. Erythropoietin was administered for recurrent AZT-induced anaemia. Both abscesses resolved and no recurrence of anaemia was noted.

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Multidisciplinary advisory teams to manage multidrug-resistant tuberculosis: the example of the French Consilium

The International Journal of Tuberculosis and Lung Disease ◽

10.5588/ijtld.18.0779 ◽

2019 ◽

Vol 23 (10) ◽

pp. 1050-1054

Author(s):

L. Guglielmetti ◽

J. Jaffré ◽

C. Bernard ◽

F. Brossier ◽

N. El Helali ◽

...

Keyword(s):

Multidrug Resistant ◽

New Drugs ◽

World Health ◽

Advisory Committees ◽

Treatment Regimens ◽

Tb Treatment ◽

Resistant Tuberculosis ◽

Multidrug Resistant Tuberculosis ◽

Mdr Tb ◽

Health Organization

SETTING: The World Health Organization (WHO) recommends that multidrug-resistant tuberculosis (MDR-TB) treatment should be managed in collaboration with multidisciplinary advisory committees (consilia). A formal national Consilium has been established in France since 2005 to provide a centralised advisory service for clinicians managing MDR-TB and extensively drug-resistant (XDR-TB) cases.OBJECTIVE: Review the activity of the French TB Consilium since its establishment.DESIGN: Retrospective description and analysis of the activity of the French TB Consilium.RESULTS: Between 2005 and 2016, 786 TB cases or contacts of TB cases were presented at the French TB Consilium, including respectively 42% and 79% of all the MDR-TB and XDR-TB cases notified in France during this period. Treatment regimens including bedaquiline and/or delamanid were recommended for 42% of the cases presented at the French TB Consilium since 2009. Patients were more likely to be presented at the French TB Consilium if they were born in the WHO Europe Region, had XDR-TB, were diagnosed in the Paris region, or had resistance to additional drugs than those defining XDR-TB.CONCLUSION: The French TB Consilium helped supervise appropriate management of MDR/XDR-TB cases and facilitated implementation of new drugs for MDR/XDR-TB treatment.

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