M2HepPrEP: study protocol for a multi-site multi-setting randomized controlled trial of integrated HIV prevention and HCV care for PWID.

BACKGROUND: Opioid use is escalating in North America and comes with a multitude of health consequences, including HIV and hepatitis C virus (HCV) outbreaks among persons who inject drugs (PWID). HIV pre-exposure prophylaxis (PrEP) and HCV treatment regimens have transformative potential to address these co-occurring epidemics. Evaluation of innovative multi-modal approaches, integrating harm reduction, opioid agonist therapy (OAT), PrEP, and HCV treatment is required. The aim of this study is to assess the effectiveness of an on-site integrated care model where delivery of PrEP and HCV treatment for PWID takes places at syringe service programs (SSP) and OAT programs compared with referring PWID to clinical services in the community through a patient navigation model and to examine how structural factors interact with HIV prevention adherence and HCV treatment outcomes. METHODS: The Miami-Montreal Hepatitis C and Pre-Exposure Prophylaxis trial (M2HepPrEP) is an open-label, multi-site, multi-center, randomized, controlled, superiority trial with two parallel treatment arms. A total of 500 persons who injected drugs in the prior 6 months and are eligible for PrEP will be recruited in OAT clinics and SSP in Miami, FL, and Montréal, Québec. Participants will be randomized to either on-site care, with adherence counseling, or referral to off-site clinics assisted by a patient navigator. PrEP will be offered to all participants and HCV treatment to those HCV-infected. Co-primary endpoints will be (1) adherence to pre-exposure prophylaxis medication at 6 months post-randomization and (2) HCV sustained virological response (SVR) 12 weeks post-treatment completion among participants who were randomized within the HCV stratum. Up to 100 participants will be invited to participate in a semi-structured interview regarding perceptions of adherence barriers and facilitators, after their 6-month assessment. A simulation model-based cost-effectiveness analysis will be performed to determine the comparative value of the strategies being evaluated. DISCUSSION: The results of this study have the potential to demonstrate the effectiveness and cost-effectiveness of offering PrEP and HCV treatment in healthcare venues frequently attended by PWID. Testing the intervention in two urban centers with high disease burden among PWID, but with different healthcare system dynamics, will increase generalizability of findings. TRIAL REGISTRATION: Clinicaltrials.gov NCT03981445 . Trial registry name: Integrated HIV Prevention and HCV Care for PWID (M2HepPrEP). Registration date: June 10, 201.

Toxicokinetics of bisphenol-S and its glucuronide in plasma and urine following oral and dermal exposure in volunteers for the interpretation of biomonitoring data.

The measurement of bisphenol-S (BPS) and its glucurono-conjugate (BPSG) in urine may be used for the biomonitoring of exposure in populations. However, this requires a thorough knowledge of their toxicokinetics. The time courses of BPS and BPSG were assessed in accessible biological matrices of orally and dermally exposed volunteers. Under the approval of the Research Ethics Committee of the University of Montreal, six volunteers were orally exposed to a BPS-d8 deuterated dose of 0.1 mg/kg body weight (bw). One month later, 1 mg/kg bw of BPS-d8 were applied on 40 cm2 of the forearm and then washed 6 h after application. Blood samples were taken prior to dosing and at fixed time periods over 48 h after treatment; complete urine voids were collected pre-exposure and at pre-established intervals over 72 h postdosing. Following oral exposure, the plasma concentration-time courses of BPS-d8 and BPSG-d8 over 48 h evolved in parallel, and showed a rapid appearance and elimination. Average peak values (±SD) were reached at 0.7 ± 0.1 and 1.1 ± 0.4 h postdosing and mean (±SD) apparent elimination half-lives (t½) of 7.9 ± 1.1 and 9.3 ± 7.0 h were calculated from the terminal phase of BPS-d8 and BPSG-d8 in plasma, respectively. The fraction of BPS-d8 reaching the systemic circulation unchanged (i.e. bioavailability) was further estimated at 62 ± 5% on average (±SD) and the systemic plasma clearance at 0.57 ± 0.07 L/kg bw/h. Plasma concentration-time courses and urinary excretion rate profiles roughly evolved in parallel for both substances, as expected. The average percent (±SD) of the administered dose recovered in urine as BPS-d8 and BPSG-d8 over the 0-72 h period postdosing was 1.72 ± 1.3 and 54 ± 10%. Following dermal application, plasma levels were under the lower limit of quantification (LLOQ) at most time points. However, peak values were reached between 5 and 8 h depending on individuals, suggesting a slower absorption rate compared to oral exposure. Similarly, limited amounts of BPS-d8 and its conjugate were recovered in urine and peak excretion rates were reached between 5 and 11 h postdosing. The average percent (±SD) of the administered dose recovered in urine as BPS-d8 and BPSG-d8 was about 0.004 ± 0.003 and 0.09 ± 0.07%, respectively. This study provided greater precision on the kinetics of this contaminant in humans and, in particular, evidenced major differences between BPA and BPS kinetics with much higher systemic levels of active BPS than BPA, an observation explained by a higher oral bioavailability of BPS than BPA. These data should also be useful in developing a toxicokinetic model for a better interpretation of biomonitoring data.

Kinetic time courses of lambda-cyhalothrin metabolites after dermal application of Matador EC 120 in volunteers.

A controlled kinetic study was conducted in volunteers dermally exposed to the widely used lambda-cyhalothrin pyrethroid pesticide to document the time courses of relevant biomarkers of exposure, in order to better assess biomonitoring data in workers. Matador® EC120 formulation (120 g/l) was applied on 40 cm2 of the forearm at a 0.25 mg/kg dose of lambda-cyhalothrin and left without occlusion or washing for 6 h. The application site was then washed thoroughly with soap and water. The kinetic time courses of cis-3-(2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropane carboxylic acid (CFMP) and 3-phenoxybenzoic acid (3-PBA) metabolites were determined in plasma and urine up to 84 h post-application. Results show that the fraction of lambda-cyhalothrin absorbed in the body was rapidly cleared following dermal contact. According to CFMP and 3-PBA plasma profiles, calculated mean apparent absorption half-lives (t1/2) were 3 and 7.3 h, respectively, and corresponding mean apparent elimination t1/2 were 11.2 and 7.6 h. These differences suggest some metabolism at the site-of-entry and storage of metabolites by the dermal route. Toxicokinetic parameters calculated from urinary profiles confirm the values of absorption and elimination rates. Metabolites were almost completely excreted over the 84-h period post-application and, on average, 0.12 and 0.08% of the applied lambda-cyhalothrin dose was recovered in the urine as CFMP and 3-PBA, respectively, indicating a low dermal absorption fraction of this pyrethroid. This study showed the potential use of CFMP and 3-PBA biomarkers for the assessment of dermal exposure to lambda-cyhalothrin pyrethroid.

Documenting the kinetic time course of lambda-cyhalothrin metabolites in orally exposed volunteers for the interpretation of biomonitoring data.

Lambda-cyhalothrin is a pyrethroid pesticide largely used in agriculture. Exposure assessment can be performed by measuring key urinary metabolites. For a proper use of biomonitoring data, it is however important to gain information on the toxicokinetics of these key biomarkers of exposure. A human volunteer study was performed to document the plasma and urinary time courses of major lambda-cyhalothrin metabolites. Seven volunteers ingested 0.025mgkg-1 body weight of lambda-cyhalothrin. Blood samples were withdrawn prior to dosing and at fixed time periods over the 72 h-period following ingestion and complete urine voids were collected pre-exposure and at pre-established intervals over 84h post-dosing. The cis-3-(2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylic acid (CFMP) and 3-phenoxybenzoic acid (3-PBA) metabolites were quantified in these samples. Plasma concentrations of CFMP and 3-PBA increased rapidly after ingestion, with average peak values at 3.1 and 4.0h post-dosing, respectively; subsequent elimination phase showed a rapid decay with a mean half-life (t½) of ≈5.3 and 6.4h for CFMP and 3-PBA, respectively. Urinary rate time courses displayed a profile similar to the plasma concentration-time curves with corresponding mean t½ of ≈4.2 and 5.9h. In the 84-h period post-treatment, on average 21% of lambda-cyhalothrin dose were excreted in urine as CFMP as compared to 30% as 3-PBA. Overall, CFMP and 3-PBA metabolites were confirmed to be major metabolites of lambda-cyhalothrin and exhibited similar kinetics with short half-lives; they thus both appear as useful biomarkers of exposure to lambda-cyhalothrin in humans.