Importance of relative binding of bisphenol A and bisphenol S to plasma proteins for predicting their in vivo potencies.

Many studies suggest that the potential impact of bisphenol S (BPS) as an endocrine disruptor is comparable to that of bisphenol A (BPA). However, in vitro-to-in vivo and from animal to human extrapolations require knowledge of the plasma free fraction of the active endocrine compounds. The present study aimed to characterise BPA and BPS binding to plasma proteins both in humans and different animal species. The plasma protein binding of BPA and BPS was assessed by equilibrium dialysis in plasma from adult female mice, rats, monkeys, early and late pregnant women as well as paired cord blood, early and late pregnant sheep and foetal sheep. The fraction of free BPA was independent of plasma concentrations and ranged between 4% and 7% in adults. This fraction was 2 to 3.5 times lower than that of BPS in all species except sheep, ranging from 3% to 20%. Plasma binding of BPA and BPS was not affected by the stage of pregnancy, BPA and BPS free fractions representing about 4% and 9% during early and late human pregnancy, respectively. These fractions were lower than the free fractions of BPA (7%) and BPS (12%) in cord blood. Our results suggest that similarly to BPA, BPS is extensively bound to proteins, mainly albumin. The higher fraction of free BPS compared to BPA may have implications for human exposure assessment since BPS free plasma concentrations are expected to be 2 to 3.5 times higher than that of BPA for similar plasma concentration.

Efficacy of teicoplanin monotherapy following initial standard therapy in Enterococcus faecalis infective endocarditis: a retrospective cohort study.

PURPOSE: Teicoplanin is often used in Enterococcus faecalis infective endocarditis as a relay in case of penicillin side effects, or in outpatients. We assessed the efficacy of teicoplanin used as continuation therapy after initial standard treatment of E. faecalis endocarditis. METHODS: All adult patients consecutively diagnosed between 1997 and 2016 for E. faecalis endocarditis were retrospectively reviewed. Patients who received standard therapy (ST) were compared to those switched to teicoplanin to complete the treatment (teicoplanin therapy, TT). RESULTS: Seventy-one patients were enrolled: 34 in the ST group and 37 in the TT group. Amoxicillin was replaced by teicoplanin after a median duration of 18 days (IQ25 - 75 12-21). Teicoplanin (5.8 ± 2.3 mg/kg) was administered for a median duration of 29 days (IQ25 - 75 25-34). Gentamicin therapy was similar. Overall duration of antimicrobial therapy was 42 days (IQ25 - 75 35-43) in the ST group, and 46 days (IQ25 - 75 43-49) in the TT group (p = 0.001). Global and endocarditis-related mortality rates were 22/34 (65%) and 13/34 (38%) in the ST group, and 14/37 (38%) and 3/37 (8%) in the TT group (p ≤ 0.05). Relapses occurred in 2/26 patients who survived the treatment phase in the ST group (8%) and in 3/37 in the TT group (8%, p = 0.68). All relapses in the TT group occurred in patients presenting prosthetic valve endocarditis. Finally, 20 patients were cured in the ST group (59%), and 33 patients in the TT group (89%, p = 0.003). CONCLUSIONS: In E. faecalis endocarditis, the switch to teicoplanin in selected patients following an initial phase of standard treatment represents an alternative, particularly for outpatient therapy. Caution should be exercised in cases of prosthetic valve endocarditis.

Analytical assays and bootstrap resampling method to validate performance of the Roche Elecsys STAT highly sensitive troponin T assay and its application for the 'rule-out' part of ESC guidelines for NTSTEMI.

BACKGROUND: The European Society of Cardiology (ESC) guidelines recommend a dynamic (0-1h) cardiac troponin (cTn) determination for non-ST elevation myocardial infarction diagnosis. For patients with low cTn levels, a discharge from emergency can be considered. Nevertheless, cTn cutoffs for discharge are lower than the limits of quantification proposed by laboratory reagent suppliers. AIM: Validate cTn assay on the Elecsys STAT kit. MATERIALS AND METHODS: Precision, trueness, repeatability and within-laboratory variability were calculated from internal quality control and plasma pooled at 5.78 and 10.73 ng/L. Accuracy was calculated from external quality control. Uncertainty of measurement was calculated from (i) the uncertainty of the standard and control values and (ii) by precision from pooled plasma. Distribution of precision results from pooled plasma has been evaluated by bootstrap simulations. Dilution linearity tests with patient plasma were performed to evaluate the method for values near 5 ng/L. RESULTS: Precision and trueness ranged from 1.35 to 4.45% and from 0.14 to -3.74%, respectively. Accuracy results ranged from 101.40 to 104.90%. Within laboratory variability was 2.91%. Uncertainty ranged from 3.66% to 19.90% for higher (2188) to lower values (5.78 ng/L). Bootstrap simulations allowed utilization of precision data from pooled plasma to evaluate cTn assay. The method was linear from 4.48 to 39.80 ng/L. A linear regression model best described the data. CONCLUSION: Elecsys STAT method provides accurate cTn results, including patients with cTn results categorizing them as 'rule-out' in the ESC guidelines.

Non-O1/non-O139 Vibrio cholerae bacteremia and hepatitis in diabetic patient, France, winter 2019.

OBJECTIVES: Vibrio cholerae non-O1/non-O139 (NOVC) bacteremia is infrequently reported in Western countries and is associated with unfavorable outcome. PATIENT/METHOD: We describe here the case of a diabetic patient with hepatic cytolysis and NOVC bacteremia following an episode of diarrhea. RESULT: The patient was paucisymptomatic and had a favorable resolution with oral ciprofloxacin. CONCLUSION: NOVC should be systematically sought in stool samples, particularly in immunocompromised patients, due to an increased risk of infection occurrence.

Urine toxicological screening method using an immunoenzymatic assay based on a biochip array technology: comparative study with immunochromatography and Liquid chromatography­mass spectrometry / Criblage toxicologique urinaire par une méthode automatisée immunoenzymatique multiparamétrique basée sur une technique de biopuce : comparaison à de l'immunochromatographie et de la chromatographie liquide couplée à de la spectrométrie de masse

Multiparametric toxicology research is mainly based on immunochromatography [IC] and chromatography methods. A new automated method using an immunoenzymatic (IE) assay based on a biochip array technology combines short turning around time and analytical performances close to chromatography in terms of positivity cut-off. The aim of our study was to compare IE versus IC and chromatography methods using urines samples from clinical cases. Seventy-two samples were analyzed by IC (amphetamines, opiates, benzodiazepines, THC, methadone, cocaine), IE and chromatography (previous classes plus opioids and cathinone). Immunochromatography results were read by at least 7 operators to assess reading subjectivity. Immunoenzymatic, IC, and chromatrography results were compared with each other. Chromatographic quantification was analyzed to understand discrepancies. Significant discrepancies (29-64%) were observed between IC and IE for most of the drug families investigated except for benzodiazepines, methadone and opiates. These discrepancies were not identified between IE and chromatography, except for some substances (28% to 67% discrepancies for buprenorphine, tramadol and oxycodone, 100% for cathinone). In contrast to IC, the performance of IE approached those of chromatography, except for some substances for which cross-reactions must be investigated. Reading discrepancies were frequent with IC (33% of samples) and made robust result output challenging. In conclusion, the Multistat® is an interesting method for first-line toxicological screening for laboratories without chromatography method.

La recherche des toxiques multiparamétrique repose principalement sur des méthodes immunochromatographie [IC] et de chromatographie (CL). Une nouvelle méthode automatisée immunoenzymatique (IE) (Multistat®) en biopuce, combine un rendu de résultats rapide et des performances analytiques, en termes de seuils de positivité, proche de la CL. L'objectif de notre étude a été de comparer l'IE à des méthodes d'IC et de CL sur des échantillons hospitaliers. Soixante-douze échantillons ont été analysés par IC (amphétamines, opiacés, benzodiazépines, THC, méthadone, cocaïne), IE et CL (classes précédentes plus opioïdes et dérivés de la cathinone). Les résultats d'IC étaient lus par au moins 7 personnes pour évaluer la subjectivité des lectures. Les résultats d'IE, d'IC et de CL étaient comparés entre eux. La quantification en CL était exploitée pour expliquer les discordances. Une forte proportion de discordances (de 29 à 64 %) était observée entre IC et IE sur la plupart des toxiques explorées sauf pour les benzodiazépines, la méthadone et les opiacés. Ces discordances n'étaient pas retrouvées entre IE et CL, hormis pour certaines substances (28 % à 67 % de divergences pour buprénorphine, tramadol et oxycodone, 100 % pour les dérivés de la cathinone). À l'inverse de l'IC, les performances de l'IE se rapprochaient de celles de la CL, sauf pour certaines substances pour lesquelles des réactions croisées doivent être recherchées. Les discordances de lecture étaient fréquentes en IC et rendent difficile un rendu de résultat robuste. En conclusion, le Multistat® est une méthode intéressante pour un criblage en première intention pour les laboratoires sans CL.

Comparing ultrafiltration and equilibrium dialysis to measure unbound plasma dolutegravir concentrations based on a design of experiment approach.

Dolutegravir therapeutic drug monitoring (TDM) could be improved by measuring the unbound dolutegravir plasma concentration (Cu), particularly in patients experiencing virological failure or toxicity despite achieving appropriate DTG total plasma concentrations. Equilibrium dialysis (ED) is the gold standard to measure Cu, but ED is time consuming, precluding its use in clinical practice. In contrast, ultrafiltration is applicable to TDM, but is sensitive to numerous analytical conditions. In order to evaluate measurements of Cu by ultrafiltration, ultrafiltration conditions were validated by comparison with ED. DTG concentrations were measured by LC-MS/MS. Three ultrafiltration factors (temperature, duration and relative centrifugal force [RCF]) were evaluated and compared to ED (25/37 °C), using a design of experiment strategy. Temperature was found to influence Cu results by ED (p = 0.036) and UF (p = 0.002) when results were analysed with ANOVA. Relative centrifugal force (2000 g) and time (20 min) interacted to influence Cu (p = 0.006), while individually they did not influence Cu (p = 0.88 and p = 0.42 for RCF and time). Ultrafiltration conditions which yielded the most comparable results to ED were 37 °C, 1000 g for 20 min. Ultrafiltration results greatly depended on analytical conditions, confirming the need to validate the method by comparison with ED in order to correctly interpret DTG Cu.

Plasma Hepatitis E Virus Kinetics in Solid Organ Transplant Patients Receiving Ribavirin.

Hepatitis E virus (HEV) infection causes chronic hepatitis in solid organ transplant (SOT) recipients. Antiviral therapy consists of three months of ribavirin, although response rates are not optimal. We characterized plasma HEV kinetic patterns in 41 SOT patients during ribavirin therapy. After a median pharmacological delay of three (range: 0-21) days, plasma HEV declined from a median baseline level of 6.12 (3.53-7.45) log copies/mL in four viral kinetic patterns: (i) monophasic (n = 18), (ii) biphasic (n = 13), (iii) triphasic (n = 8), and (iv) flat-partial response (n = 2). The mean plasma HEV half-life was estimated to be 2.0 ± 0.96 days. Twenty-five patients (61%) had a sustained virological response (SVR) 24 weeks after completion of therapy. Viral kinetic patterns (i)-(iii) were not associated with baseline characteristics or outcome of therapy. A flat-partial response was associated with treatment failure. All patients with a log concentration decrease of plasma HEV at day seven of >15% from baseline achieved SVR. In conclusion, viral kinetic modeling of plasma HEV under ribavirin therapy showed, for the first time, four distinct kinetic profiles, a median pharmacologic delay of three days, and an estimated HEV half-life of two days. Viral kinetic patterns were not associated with response to therapy, with the exception of a flat-partial response.

The Electronic Pharmaceutical Record: A new method for medication reconciliation.

RATIONALE, AIM, AND OBJECTIVE: There are several ways to establish an accurate medication list in the hospital admission medication reconciliation (MedRec). The challenge for MedRec lies in the availability, reliability, and completeness of the data used. In France, the Electronic Pharmaceutical Record (ePR) was developed to register each medication taken by ambulatory patients, primarily to make dispensation in community pharmacies safe. We evaluated the suitability of this tool in the MedRec when patients were admitted to the hospital. METHOD: We conducted a 6-month pilot study of 249 MedRec files from a hospital diabetology department. The analysis was supplemented by the ePR for any patient for whom this information was recorded. The study evaluated the ePR as a new MedRec tool, as well as the clinical impact (CI) of the new data collected. RESULTS: The ePR was contributory for 28% of the patients. Discrepancies were associated with polypharmacy, most of which had a CI = 1. Medication omission was the most frequently found discrepancy (72%), but self-medication (8%) and lack of medication adherence (9%) were also observed. CONCLUSION: This tool provided added value for reconciliation, as it quickly identifies regular medications, adherence, and self-medication behaviour. The ePR is essential for conducting a thorough MedRec.

Determination of dolutegravir's unbound fraction in human plasma using validated equilibrium dialysis and LC-MS/MS methods.

Assessment of the unbound pharmacologically active fraction (fu; as the ratio of unbound to total concentration) of dolutegravir could improve therapeutic drug monitoring (TDM) in patients that experience virological failure or toxicity, despite receiving adequate total concentrations. This study evaluated (i) dolutegravir's fu through equilibrium dialysis (ED), (ii) the pre-analytical parameters that influence fu, and (iii) fu's inter-individual variability in HIV patients. Validation of the LC-MS/MS method followed FDA guidelines. The results, based on coefficients of variation (results from nominal concentrations <15%), allowed accurate measurement of unbound and total dolutegravir concentrations. Equilibrium during ED was obtained in 4h. Sparse non-specific binding (9%) was observed, allowing results interpretation without interference. Steps before analysis (e.g., conservation at +4°C, freeze/thaw cycles) did not influence fu, allowing easy integration of fu analysis within laboratory routines. Anticoagulants from samples (citrated versus heparinized; p<0.001) and hemolysis (p=0.007) influenced fu and could lead to misinterpretation. Developed was then performed to the HIV-patients' plasma (n=54). Results, expressed as median InterQuartile Range [25%;75%] were 0.45% IQR [0.38; 0.55] for fu, 9.26µg/L IQR [4.62; 15.14] for unbound, and 2035µg/L IQR [878.5; 2640] for total concentration. The high inter-individual variability observed in the unbound form from HIV patients was a first step towards integrating dolutegravir TDM.

Is the unbound concentration of atazanavir of interest in therapeutic drug monitoring?

To date, therapeutic drug monitoring (TDM) is carried out with antiretrovirals and is usually based on total concentrations (Ct ). However, for some patients, TDM does not reflect efficacy or the avoidance of toxicity as is the case for atazanavir (ATV), a HIV protease inhibitor. As the unbound concentration (Cu ) is the pharmacological active form, the aim of the study was to evaluate the value of Cu and the unbound fraction (fu , fu = Cu /Ct ) for the TDM of ATV. The variability of Cu and the corresponding fu of ATV was explored in 43 patients treated with ATV for an average of 13.5 months. Cu was determined by coupling ultrafiltration and liquid chromatography. As ATV is highly bound to alpha-1 acid glycoprotein (AAG), the correlation between fu and AAG was also evaluated. The viral load was monitored to evaluate the patients' virologic response, while total plasma bilirubin and unconjugated plasma bilirubin were used as biomarkers of ATV toxicity. Median trough Cu and Ct were 37.9 µg/L (Interquartile range (IQR) 20.6-94.9 µg/L) and 628.6 µg/L (IQR 362.7-1078.1 µg/L), respectively. fu , Cu and Ct showed high variability, but the fu variability was not correlated with the AAG level. The unbound concentration and fraction were unrelated to the virologic response (P = 0.21 and P = 0.65 for Cu and fu , respectively) nor to the unconjugated bilirubin (Pearson correlation coefficient (ρ), ρ = 0.22; P = 0.17 for Cu ). Neither total nor unbound concentrations of ATV fully explained hyperbilirubinaemia or virologic failure. From this study, we conclude that unbound ATV did not appear to be more relevant than Ct .

Impact of CYP2C19 genetic polymorphisms on voriconazole dosing and exposure in adult patients with invasive fungal infections.

Voriconazole (VCZ) use is limited by its narrow therapeutic range and significant interpatient variability in exposure. This study aimed to assess (i) the impact of CYP2C19 genotype on VCZ exposure and (ii) the doses required to achieve the therapeutic range in adult patients with invasive fungal infections (IFIs). Therapeutic drug monitoring (TDM) of VCZ, based on trough concentration measurement, and CYP2C19 genotyping were used to guide VCZ dosing in Caucasian patients with IFIs. The two common polymorphisms in Caucasians (CYP2C19*2 and *17), associated with decreased or increased CYP2C19 activity, respectively, were correlated with the daily VCZ dose, pharmacokinetic parameters and concentration-to-dose ratio. In total, 111 trough concentration measurements from 35 genotyped patients were analysed using linear mixed-effect models. The mean VCZ doses required to achieve target concentrations were significantly higher in CYP2C19*17 carriers compared with CYP2C19*1/*1 individuals (P<0.001): 2.57±0.25mg/kg twice daily in CYP2C19*1/*1 patients versus 3.94±0.39mg/kg and 6.75±0.54mg/kg in *1/*17 and *17/*17 patients, respectively. In addition, exposure to VCZ correlated with the CYP2C19*17 variant. Indices of exposure for CYP2C19*2 carriers were in line with the functional effect of this polymorphism compared with CYP2C19*1/*1 individuals, however comparisons of doses required to achieve target concentrations were not statistically different. The CYP2C19*17 allele predicted both VCZ exposure and dose required to achieve effective and non-toxic concentrations. CYP2C19 genotyping appears useful to guide VCZ initial dosing when coupled with TDM and to explain subtherapeutic concentrations frequently observed in clinical practice.

An Early Viral Response Predicts the Virological Response to Ribavirin in Hepatitis E Virus Organ Transplant Patients.

BACKGROUND: Ribavirin is efficient at treating chronic hepatitis E virus infection in solid-organ transplant patients. However, the early kinetics of viral replication under therapy and the impact of immunosuppressant regimens on viral replication are unknown: thus, determining the aim of our study. METHODS: Thirty-five patients with a solid-organ transplant and chronic hepatitis E virus infection were given ribavirin for 3 months. The hepatitis E virus (HEV) RNA concentrations were determined before treatment, at days 7, 15, and 21 and at months 1, 2, and 3 during therapy and after ribavirin cessation. RESULTS: A sustained virological response (SVR) occurred in 63%. Decreased viral concentration within the first week post-ribavirin therapy was an independent predictive factor for SVR, and a decreased HEV concentration of 0.5 log copies/mL or greater had an 88% positive predictive value. No correlation between ribavirin trough level on day 7 or at month 2 with a virological response or an SVR was observed. Before therapy, HEV RNA concentration was significantly greater in patients receiving mechanistic target of rapamycin inhibitor-based immunosuppression compared to patients given calcineurin inhibitors. The use of mycophenolic acid did not impact on the response to ribavirin. CONCLUSION: An early response to ribavirin can be used to define the optimal duration of therapy in the setting of HEV infection.

Ceftazidime dosage recommendations in burn patients: from a population pharmacokinetic approach to clinical practice via Monte Carlo simulations.

BACKGROUND: Ceftazidime dosage regimen recommendations based on pharmacokinetic/pharmacodynamic approaches are not available for burn patients. OBJECTIVE: The goal of this study was to propose a continuous dosage regimen of ceftazidime in burn patients, taking into account different MICs and pharmacokinetic covariates. METHODS: The population pharmacokinetic analysis was conducted by using software dedicated to the analysis of nonlinear mixed effects models. The population pharmacokinetic model was first developed and validated in 70 adult burn patients. Taking into account various MICs of pathogens, 3 Monte Carlo simulation trials were conducted by using target concentration intervals (10-100, 20-100, and 40-100 mg/L). The recommended dosages were defined as the minimum dose leading to the highest percentage of patients whose ceftazidime concentrations were included in the target interval. RESULTS: Serum creatinine and age were identified as covariates of ceftazidime clearance. Age was also involved in volume of distribution. The simulations showed that a dose of 6 g/d did not allow achievement of the target interval in most patients. Regardless of dosage regimen, age, and serum creatinine, the mean percentage of patients reaching the 10- to 100-mg/L and the 20- to 100-mg/L target intervals were 99.4% (0.3%) and 96.1% (0.8%), respectively. For the 40- to 100-mg/L target interval, this percentage was only 76.4% (2.1%) (range, 65%-80%). CONCLUSIONS: Age and serum creatinine level can be used at the bedside to determine the initial doses of ceftazidime. These Monte Carlo simulations highlight the need of a reappraisal of ceftazidime's use in burn patients. Doses between 3 and 16 g/d are proposed, taking into account the pathogens' MICs. However, for sepsis caused by a pathogen with an MIC ≥ 8 mg/L, an insufficient percentage of burn patients will reach the therapeutic target with the recommended dosages.