OBJECTIVES:The pharmaco-epidemiological research program in kidney transplantation (PERP-KT) aims to evaluate, for the principal maintenance immunosuppressive drugs (MISDs): the influence of model-informed precision dosing on graft and patient survival; long-term exposure-effects relationships; and the benefit-harm balance of their combinations and time sequences in patient groups or clinical settings not adequately evaluated in comparative randomized clinical trials. It also aims to develop a hybrid, dynamic, deep learning model capable of predicting the rate of renal graft function decline, thereby providing a platform for individualized prediction of the benefits and risks associated with MISDs. PATIENTS AND METHODS:After obtaining all regulatory andd ethical approvals, de-identified extracts of three national databases were linked to create the nationwide PERP-KT dataset, which is hosted within the highly secure environment of the French Health Data Hub. RESULTS:CRISTAL (the exhaustive registry of the French Agence de la Biomédecine) comprises data from 49 886 kidney donors and the corresponding 47 842 transplant recipients between 2005 and 2020. Following iterative deterministic matching and extensive quality control procedures, CRISTAL data were successfully linked to: the French national Health Data System (SNDS), which records reimbursed healthcare utilization, for 30 782 kidney transplant recipients; and to ISBA, a web-based platform for Bayesian dose adjustment of MISDs that contains pharmacological data, for 17 700 kidney grafts and 17 576 recipients. PERSPECTIVES:More than 20 pharmaco-epidemiological studies will leverage the database's extensive follow-up, large population size and richness of clinical, healtcare-utilization, and pharmacological data.

BACKGROUND:The constant emergence of novel psychoactive substances (NPS) poses significant analytical challenges due to their structural diversity, low concentrations in complex biological matrices, and the limited availability of certified reference materials. This review summarizes current and emerging analytical strategies for detecting novel substances and evaluates the contribution of innovative technologies for toxicological surveillance. METHODS:Studies addressing analytical techniques for NPS detection including chromatographic, spectrometric, ambient ionization, and artificial intelligence (AI)-assisted methods were systematically reviewed, with emphasis on applicability, sensitivity, and adaptability in clinical, forensic, and environmental contexts. RESULTS:Conventional techniques such as liquid chromatography coupled with tandem mass spectrometry and immunoassays provide reliable detection of known compounds but are limited by their targeted scope for detecting newly synthesized analogs. High-resolution mass spectrometry, nuclear magnetic resonance, and direct ionization approaches offer broader detection capabilities but remain resource-intensive. Recent advances in AI-including spectral prediction, structural classification, and de novo compound generation-offer promising new avenues for untargeted screening and early compound identification. In addition, emerging tools such as molecular networking, wastewater-based epidemiology, and portable mass spectrometry devices further enhance real-time monitoring and surveillance capacity. CONCLUSIONS:An integrated, adaptive analytical framework combining high-resolution mass spectrometry, ambient ionization, and AI-driven data analysis will help address the fast-evolving NPS landscape. Standardization of reference materials, harmonization across laboratories, and interdisciplinary collaboration between chemists, clinicians, and regulatory agencies will be key to improving the speed, sensitivity, and public health impact of NPS detection.

Objectifs Caractériser l’impact d’une multi-exposition post-natale à un mélange de pesticides sur le statut oxydatif et l’intégrité tissulaire en explorant la réversibilité des dommages. Méthode Un modèle murin juvénile a été exposé durant 21jours à un mélange de pesticides (organochlorés, organophosphorés, pyréthrinoïdes, herbicides et fongicides) calibré sur les quartiles (Q1, Q2, Q3) d’imprégnation réelle mesurés dans le sang de cordon et le lait maternel de la cohorte Pmetox. La croissance pondérale, les poids relatifs des organes, les marqueurs de stress oxydant rénaux (MDA, GSH, SOD, catalase) et l’examen histopathologique ont été analysés à J21 et après une phase de récupération de 60jours. Résultats L’exposition induit un ralentissement significatif de la vitesse de croissance pondérale durant le traitement (p=0,032). Une hypertrophie rénale dose-dépendante est observée, avec un poids relatif passant de 1,17 à 0,03g/100g (témoins) à 1,61 à 0,02g/100g (Q3, p<0,001). Sur le plan biochimique, le stress oxydant est caractérisé par une augmentation du MDA (p=0,021 pour Q3) et une chute du GSH, déclenchant une induction compensatoire de la SOD et de la catalase (p<0,05). L’analyse histopathologique à J21 montre une gradation lésionnelle: néphropathie interstitielle aiguë (NIA) en Q1, évoluant vers une nécrose tubulaire aiguë (NTA) focale en Q3. Après 60jours de récupération, les paramètres biochimiques et pondéraux se normalisent. Toutefois, l’évaluation tissulaire révèle une récupération incomplète: une réparation tubulaire est amorcée en Q1 et Q2 malgré une inflammation persistante, le groupe Q3 présente une intensification de la NTA, marquant une chronicité des lésions malgré l’arrêt de l’exposition. Conclusion La sévérité de la toxicité observée résulte d’interactions critiques. En situation de mono-exposition, les PYR sont rapidement hydrolysés par les carboxylestérases. Toutefois, la présence d’OP (profénofos) inhibe irréversiblement ces enzymes par liaison covalente, augmentant la biodisponibilité et la demi-vie des PYR (Tang et al., 2008). Ce mécanisme de potentialisation est aggravé par la présence de fongicides triazoles, inhibiteurs des cytochromes P450 (CYP3A/CYP2C), limitant davantage le métabolisme oxydatif des toxiques. Inversement, les OC agissent comme de puissants inducteurs du CYP450, risquant de générer des métabolites réactifs secondaires (Kefi et al., 2021). Cette compétition enzymatique et ces inhibitions réciproques, couplées à l’immaturité des systèmes de défense néonataux, créent une charge oxydative excessive. L’hétérogénéité des effets observés en conditions réelles s’explique par ce réseau complexe d’interactions fonctionnelles qui surpasse les capacités de résilience organique. Ces résultats démontrent qu’une exposition post-natale à un mélange complexe de pesticides, aux doses environnementales réelles, provoque une toxicité rénale médiée par le stress oxydant. Si les signes systémiques et biochimiques semblent réversibles, la persistance et l’aggravation des lésions histologiques aux fortes doses soulignent un risque de séquelles rénales à long terme. Ce projet a été réalisé avec l’assistance financière de Centre de recherche pour le développement international (CRDI) et du ministère de l’Enseignement supérieur, de la Recherche et de l’Innovation (MESRI) à travers le FIRST, dans le cadre du programme de financement SGCI2.

Chronic liver disease (CLD) affects millions worldwide, yet accurately staging its progression without liver biopsy remains a major clinical challenge. Human serum albumin (HSA), the most abundant blood protein synthesized exclusively by the liver, undergoes measurable structural modifications as liver disease advances, making it a potential molecular marker of disease severity. Using high-resolution liquid chromatography-mass spectrometry (LC-HR-MS), we quantified native HSA and nine modified isoforms in plasma from 172 CLD patients spanning all fibrosis stages and 82 healthy controls. Native HSA declined markedly with disease severity, reaching 4.1-4.2 g/L in decompensated cirrhosis versus 12.2 g/L in controls. Modified isoforms showed stage-specific patterns, and their ratios to native HSA amplified the diagnostic signal for advanced disease. A machine learning classifier trained on the full albumin spectral profile achieved substantial agreement with standard staging, and demonstrated higher accuracy than FIB-4 index (81.5% vs. 59.3% accuracy). Within the study cohort, these results were reproduced on two independent instruments from different manufacturers (McNemar p = 0.149), confirming the reproducibility across different platforms of the albumin signature. These findings establish HSA spectral profiling as a promising non-invasive staging tool for CLD, with cross-platform reproducibility supporting its potential for translation to multicenter clinical practice.

Objectifs Optimiser les paramètres de chromatographie et d’acquisition spectrale permettant un couplage innovant de chromatographie en fluide supercritique (SFC) avec un spectrométre de masse haute résolution (HRMS), et appliquer celui-ci à la recherche et au dosage de produits stupéfiants dans la salive. Méthode Les dérivés amphétaminiques, cocaïniques et opiacés tels que définis dans l’arrêté du 13 décembre 2016 ayant trait à la conduite automobile ont été considérés. Le système analytique était constitué d’un système SFC couplé à un système HRMS de type QTOF (Nexera UC et LCMS-9050 ; Shimadzu, France). Dans un premier temps, un plan d’expérience a permis de déterminer le choix de la colonne chromatographique, les conditions d’élution en phase supercritique, et de tester différents modes d’acquisition spectrale ciblés (single ion monitoring [SIM] ; multiple reaction monitoring [MRM/MS-MS]) et non ciblés (data independant/dependant acquisition [DIA/DDA] ; Full-Scan MS). Puis, une validation de la méthode a été menée selon une procédure interne répondant aux exigences de la norme ISO 15189 en termes de linéarité, limite de détection et quantification, répétabilité, reproductibilité et exactitude. Enfin, la nouvelle méthode a été comparée à une méthode de LC-MS/MS en analysant 30 échantillons issus de l’activité de routine de toxicologie médico-légale du laboratoire. Résultats La séparation chromatographique était réalisée dans une colonne Diol II (Shimpack, France) maintenue à 25°C et à une pression de 150 bars, en utilisant du CO2 supercritique comme phase mobile principale, associé à un co-solvant méthanol contenant 2mM de formiate d’ammonium (solvant B). Un flux make-up de méthanol à 0,080mL/min était ajouté post-colonne afin d’optimiser l’ionisation. L’élution était effectuée selon un gradient de 2 % à 80 % de solvant B en 12minutes, avec un débit de 1,0mL/min, permettant une séparation efficace des composés d’intérêt. L’acquisition spectrale était réalisée, après ionisation en Electrospray positif, par un mode full-scan MS (approche non ciblé de 100 à 500uma ; MS1) suivi d’un mode MSMS (approche ciblée avec les ions précurseurs des molécules d’intérêt et leurs étalons internes deutérés). La méthode a été entièrement validée pour une gamme dynamique de 5 à 500ng/mL. La LOD était de 1ng/mL pour l’ensemble des molécules. Dans l’échantillon de 30 salives prélevées chez des conducteurs automobiles, une parfaite concordance entre les résultats observés avec la méthode SFC-HRMS et la méthode de référence par LC-MS/MS a été observée, peu importe que le cas soit positif ou négatif. Conclusion Les conditions analytiques permettant de synchroniser un système de SFC et un HRMS ont été définis. Dans cette étude de faisabilité, ce couplage a permis d’atteindre des LOD faibles pour un panel de produits stupéfiants recherchés dans la salive. Ce couplage SFC-HRMS constitue une plateforme analytique originale, certainement polyvalente et respectueuse de l’environnement, s’inscrivant dans une démarche de réduction de l’empreinte environnementale liée aux solvants organiques.

BACKGROUND:The aim of this study was to assess the presence of pyrethroid metabolites in the urine of mothers and their full-term newborns during the first days of life and to investigate the correlation between maternal and neonatal urinary concentrations. It also explores potential clinical and environmental factors influencing these levels. METHODS:Creatinine-adjusted urinary concentrations of 5 pyrethroid metabolites, 3-phenoxybenzoic acid, 4-fluoro-3-phenoxybenzyl acid (FPBA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-carboxylic acid, and cis and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (Cis-dimethylcyclopropane-1-carboxylic acid), and (Trans-dimethylcyclopropane-1-carboxylic acid), were measured within the first 3 days postpartum in mothers and their children. RESULTS:The study included 88 mothers and 91 full-term newborns. At least 1 pyrethroid metabolite was detected in 99% of mothers and 77% of newborns. A significant (P < 0.05) correlation was observed between maternal and neonatal urinary concentrations of dimethylcyclopropane-carboxylic acid, a metabolite specific to deltamethrin, supporting the hypothesis of placental transfer. Newborns born during winter had considerably lower urinary metabolite concentrations compared with those born in other seasons. No significant correlations were found for the other metabolites, likely due to the diversity of their parent compounds. CONCLUSIONS:This study provides evidence of transplacental transfer of deltamethrin, while the lack of 3-phenoxybenzoic acid correlation suggests differential metabolic or exposure pathways for nonspecific metabolites. The seasonal variation in metabolite levels suggests environmental or behavioral factors influencing exposure. These findings emphasize the need to investigate dietary and domestic pesticide exposure as key contributors to perinatal pyrethroid exposure, as well as longitudinal studies to assess the evolution of metabolite concentrations and their potential health effects on mothers and infants.

Aim French law requires roadside drug testing with an immunological kit, with positive results confirmed using oral fluid collected by a FLOQSwab® (FsW). However, this swab is designed for oral mucosa sampling, not for oral fluid collection. This study aimed to examine how buccal cell content, collected using FsW during roadside testing, affects the quantification of delta-9-tetrahydrocannabinol (THC), cocaine (C), and its metabolites (benzoylecgonine [BZE] and ecgonine methyl ester [EME]) Method Briefly, in the first step, a phosphate buffer was used to extract molecules from the swab. After ultrasound treatment, a homogenate was obtained. For the present works, we applied two treatments to this homogenate: either centrifugation, which produced a pellet (a dense sediment containing concentrated buccal cells), or compression of the FLOQSwab®, resulting in an extract product. THC, C, BZE, and EME were quantified at various stages of the protocol using a fully validated (ISO15189) liquid chromatography-mass spectrometry method. The limits of detection were 0.15ng/mL for THC and 3ng/mL for C, BZE and EME. In parallel, buccal cells were counted using a Malassez counting chamber in the homogenate and the pellet for the comparison of the different measurements. Results A total of 150 Driving Under the Influence of Drugs (DUID) cases were analyzed for THC, along with 86 cases for cocaine and its metabolites. For THC, concentrations were consistently higher in the pellet, showing an average increase of 4.3-fold. Additionally, the pellet contained a mean of 3.5 times more cells than the homogenate. A significant positive correlation was also observed (R2=0.79) between the number of buccal cells and the increase in concentration. In 5.3% of cases, THC was detected in the pellet but not in the homogenate. For cocaine, an average 1.4-fold increase in concentration was observed in the extract product in 43 out of 52 cases, with similar increases of 1.4 for BZE and 1.2 for EME. The extraction process identified 5 additional positive cases compared to the homogenate analysis, representing 9.6% of the samples. Conclusion A strong correlation between the number of buccal cells and THC concentration highlights their critical role in enabling detection, especially in cases where THC might otherwise remain undetectable. For cocaine and its metabolites, efficient compound extraction from swab fibers proved essential, increasing measurable concentrations and identifying additional cases. Tailored pretreatment methods are therefore fundamental for enhancing the sensitivity and reliability of oral fluid drug testing in DUID cases.

Probe Electrospray Ionization (PESI) is an atmospheric pressure ionization method that can be directly coupled with a mass spectrometer to allow ultrafast analyses without chromatographic separation and with minimal sample preparation. Using the particular case of cocaine and its metabolites in human oral fluid, the main objective of the present study was to test the feasibility of a new hybrid system combining a PESI source and a quadrupole time-of-flight (QTOF). The best results were obtained for a sample preparation with a simple dilution of 100 mu L of oral fluids in an ethanol / 10 mM ammonium formate buffer (50/50) and 10 mu L deposited on a dedicated sample plate and introduced into the PESI source. For HRMS acquisition, an approach consisting in a full-mass scan ("untargeted approach" from 100 to 500 m / z ; MS1) followed by a targeted scheduled MSMS acquisition (precursor ions of the 3 molecules of interest and their 3 internal standards; MS2) gave the best signals. The total time of analysis was 0.45 min and the method was validated according to ISO15189 standard for a 5-100 ng/mL range, including accuracy and precision (inter-day and intra-day precision and bias values were lower than 15 %), matrix effect, carryover and specificity (no interference with a mixture of 119 psychotropic drugs spiked at 1 mg/L). The LLOD values were 1 ng/mL for the 3 cocaine derivatives and 83 Driving Under the Influence of Drug (DUID) cases sent to our Lab for the determination of illicit drugs in oral fluid were analyzed using the PESI-QTOF method and compared to a LC-MS/MS method. A perfect agreement was observed between the 2 methods, whether the cases were positive or negative. Cocaine was detected in 51 out of these 83 real cases (61.6 %). BZE and EME were also simultaneously detected in 50 of them (98.5 %). This feasibility study reports the first analytical method based on a coupling of a PESI source to a QTOF mass spectrometer. Adding the major advantage of high specificity through HRMS is a step forward for PESI technology.

OBJECTIVES:The aims were to investigate the presence of pyrethroid metabolites (MetaPyr) in the urine of mothers and their premature newborns, and assess potential transplacental transmission and the evolution of these compounds in the early days of life. METHODS:In this prospective study, the first urine samples were collected from 63 premature infants and 55 mothers (<34 weeks' gestation) between Sept 2021 and Oct 2022. The MetaPyr concentrations were determined using liquid chromatography-tandem mass spectrometry. RESULTS:At least 1 MetaPyr was detected in the urine of 98.2% of mothers. At least 1 MetaPyr was detected within the first 3 days of life in 70% of newborns. The most frequently detected metabolites in the newborns were trans-DCCA and DBCA. Metabolites detected in newborns are generally present in maternal samples. Longitudinal urine analysis of 47 premature infants showed variable MetaPyr trends over time. Notably, FPBA was present in some infants but absent in all maternal urine samples, appearing from day 8 onward. DISCUSSION:The results emphasized the maternal-fetal transmission of MetaPyr and the complexity of its metabolism and excretion in early life. The detection of these biomarkers in the first urine samples of 80% of preterm neonates may be explained by 2 hypotheses: (1) direct maternal-fetal transmission of MetaPyr through maternal blood, as the mother may have been exposed during pregnancy, and (2) transfer of parent pyrethroids to the fetus, followed by fetal metabolism and urinary excretion. CONCLUSIONS:This pilot study suggested prenatal exposure to pyrethroids in premature newborns, highlighting the need to monitor pesticide exposure from birth, particularly in vulnerable populations. This phenomenon, described as "exposure capital at birth," occurs before any environmental contact. This is followed by uninterrupted environmental exposure during the first days of life.

BACKGROUND:Mycophenolate mofetil is widely used in liver transplantation but poses dosing challenges owing to the narrow therapeutic window and high pharmacokinetic variability of its active moiety, mycophenolic acid (MPA). Overexposure increases the risk of adverse effects, whereas underexposure increases the risk of rejection and graft loss. The ImmunoSuppressant Bayesian Dose Adjustment (ISBA) platform estimates the MPA area under the curve (AUC) 0-12h using 3 post-dose samples (20 minutes, 1 hour, 3 hours) and provides dose recommendations to target an AUC 0-12h of 30-60 mg·h/L. The aim of this study was to describe the MPA AUC 0-12h and assess the impact of ISBA-guided dose adjustments. METHODS:MPA concentrations were measured at each visit, and AUCs were estimated in real time during routine clinical follow-up. All data collected from liver-transplant recipients aged ≥18 years from October 2005 to May 2020 were retrospectively analyzed. Dosing recommendations were adjusted proportionally to reach the AUC target of 45 mg.h/L. RESULTS:A total of 3632 requests involving 1872 patients were analyzed, making this the largest real-world cohort of this population reported to date. Among them, 658 patients benefited from at least 2 successive dose adjustments, allowing for a comparison between the results obtained without any prior use of the online platform and those obtained after the first visit (AUC of the second visit). At the first visit (before any dose recommendation) during the first year after transplantation, the median AUC 0-12h (interquartile range) was 27 (16-39) mg·h/L (n = 422). After dose adjustment recommendation, the median AUC 0-12h increased significantly to 38 (30-49) mg·h/L (n = 205, P < 0.001). The proportion of patients within the therapeutic target range (30-60 mg.h/L) increased from 40% to 61% (+21%, P < 0.001). CONCLUSIONS:Many patients were underexposed to MPA before dose adjustment. The ISBA recommendations significantly improved target attainment rates.

Micafungin is an important echinocandin for invasive fungal infections, but its pharmacokinetics (PK) in critically ill patients is highly variable. This study aimed to characterize micafungin population PK in intensive care unit (ICU) patients, identify clinical covariates influencing exposure, and evaluate practical PK/pharmacodynamic (PD) indices, steady-state area under the curve (AUCss) and trough concentration (Cmin), as alternatives to the traditional AUC/minimum inhibitory concentration (MIC) ratio for therapeutic drug monitoring (TDM). Sixty critically ill adults received 100 mg/day intravenous micafungin, with rich PK sampling on Days 0, 4, and 14. Data were analyzed using a two-compartment model with first-order elimination in Monolix, and covariates were identified via forward–backward stepwise selection. The typical clearance was 1.56 L/h with high interindividual variability (coefficient of variation 59.9

ObjectifsLorsqu’il s’agit de contrôle routier, la loi prévoit une confirmation d’une consommation de stupéfiants par l’envoi d’un second prélèvement salivaire à un laboratoire utilisant des méthodes de spectrométrie de masse (MS). Notre objectif était de développer une méthode de dosage de la cocaïne et de ses métabolites (benzoylecgonine, BZE et ecgonine-methylester, EME) dans la salive en couplant une source de type Probe ElectroSpray Ionization (PESI) à un spectromètre de masse haute résolution (HRMS) de type quadripôle à temps de vol (QTOF). En effet, la source PESI est une méthode d’ionisation à pression atmosphérique permettant de s’affranchir d’une séparation en chromatographie et ainsi d’obtenir des résultats en un temps très court (Griffeuille, P. et al. Journal of Analytical Toxicology 2023;47(1):89-95)MéthodeDes optimisations devaient être réalisées pour déterminer les conditions de préparation des échantillons permettant une ionisation optimale dans la source PESI et pour synchroniser le mouvement séquentiel de l’aiguille (période/fréquence d’ionisation) avec les temps d’événement du QTOF. L’acquisition spectrale a été réalisé selon un mode “MS/MS” (ciblé) avec des transitions de confirmation pour la cocaïne et ses 2 métabolites. Conformément à la norme ISO 15189 (COFRAC), la validation a inclus notamment une détermination des limites de détection (LDD) et de quantification (LDQ), de la justesse et de la précision, de l’effet matrice, du carry over et de la spécificité. Les performances de cette approche par PESI-QTOF ont été comparées à celle d’une méthode de LC-MS/MS déjà accréditée, grâce à l’analyse de 83 échantillons confiés au laboratoire pour recherche de stupéfiants dans le cadre de la conduite automobile.RésultatsLes meilleures conditions de préparation d’échantillon ont été obtenues pour une dilution de la salive (ou son équivalent) dans un tampon éthanol/formiate d’ammonium 10mM (50/50). Après ajout des étalons deutérés (1 pour chacun des 3 composés d’intérêt), 10μL d’échantillon sont déposés sur une plaque d’échantillonnage dédiée introduite dans la source PESI. Les meilleurs signaux pour chacun des 6 composés (3 dérivés de la cocaïne et 3 étalons internes) ont été obtenus pour des événements MS1 de 0,050seconde et des événements MS2 de 0,050seconde, ainsi qu’une fréquence de 2,3Hz pour l’aiguille. Le temps d’analyse totale était de 45secondes. Les résultats de la validation étaient conformes aux exigences de la norme ISO 15189, avec notamment des LDD comprises entre 1 et 3ng/mL (exigences légales : <10ng/mL). Pour les 83 échantillons analysés, une parfaite concordance a été observée entre la méthode PESI-QTOF et la méthode LC-MS/MS : 51 cas « positifs », dont 49 avec détection des 3 dérivés, 1 avec uniquement cocaïne et BZE, et 1 avec uniquement de la cocaïne.ConclusionCette étude présente le premier couplage entre une source PESI et un spectromètre de masse de type QTOF. Cette étude de faisabilité qui se limite à l’analyse des cocaïniques dans la salive montre qu’il est possible d’obtenir d’excellentes LDD en combinant les qualités d’une source PESI (peu ou pas de préparation d’échantillon, pas de séparation chromatographique et temps d’analyse extrêmement court) avec la spécificité d’une approche par HRMS.

Despite increasing debates about their potential side effects on human health, data concerning the risks and the impacts associated with pesticides remains scarce. Analytical tools allowing the measurement of most pesticides and/or their metabolites to which the population can be exposed are also of need. In the present study, the limits of detection (LODs) of 3 different screening procedures based on either Low-Resolution and High-Resolution Mass Spectrometry (LR-MS and HR-MS) for the determination of pesticides in serum (among which carbamates, dithiocarbamates, neonicotinoids, organochlorines, organophosphates and pyrethroids) were explored. For HR-MS, a quadrupole time-of-flight was used in positive and negative electrospray ionization modes and data were obtained from either a targeted scheduled MSMS acquisition (HR-MSMS) or a data-independent acquisition (HR-DIA). For LR-MS, a triple quadrupole was used and data were acquired with a classical multiple-reaction monitoring (MRM) mode. Depending on the approach, the LOD values varied from 0.05 to 10ng/mL. For the lowest concentrations, the proportion of molecules detected was systematically greater for the LR-MS approach, while those of HR-MSMS were better than those of HR-DIA. These differences in the LOD values were confirmed in a sample of 174 serums in which LR-MRM detected 89 compounds while HR-MSMS and HR-DIA detected 79 and 75 compounds, respectively. Nevertheless, for environmental and occupational purposes, HRMS approach could probably be efficient to detect most of pesticides and their metabolites in human serum and could be suitable for human biomonitoring studies or fundamental research exploring the impact of exposure to pesticides on human health.

Background: Legally prescribed benzodiazepines (BZDs) and designer BZDs are widely misused and must be determined in multiple contexts (eg, overdose, drug-facilitated sexual assaults, or driving under the influence of drugs). This study aimed to develop a method for measuring serum BZD levels using probe electrospray ionization (PESI) mass spectrometry and an isotope dilution approach. Methods: A tandem mass spectrometer equipped with a probe electrospray ionization source in multiple reaction monitoring mode was used. Isotope dilution was applied for quantification using a deuterated internal standard at a fixed concentration for alprazolam, bromazepam, diazepam, nordiazepam, oxazepam, temazepam, zolpidem, and zopiclone. This method included designer BZDs: clonazolam, deschloroetizolam, diclazepam, etizolam, flualprazolam, flubromazepam, flubromazolam, meclonazepam, nifoxipam, and pyrazolam. Sample preparation was done by mixing 10 µL of serum with 500 µL of an ethanol/ammonium formate 0.01 mol/L buffer. Complete validation was performed, and the method was compared with liquid chromatography coupled with mass spectrometry (LC-MS/MS) and immunoassays (IC) by analyzing 40 real samples. Results: The analysis time for identification and quantification of the 18 molecules was 2.5 minutes. This method was fully validated, and the limits of quantification varied from 5 to 50 mcg/L depending on the molecule. In the 40 real samples, 100% of molecules (n = 89) were detected by both LC-MS/MS and PESI-MS/MS, and regression analysis showed excellent agreement between the 2 methods (r2 = 0.98). On IC, bromazepam and zolpidem were not detected in 2 and 1 cases, respectively. Conclusions: PESI-MS/MS allows serum BZD detection and measurement. Given the isotope dilution approach, a calibration curve was not required, and its performance was similar to that of LC-MS/MS, and its specificity was higher than that of IC.

Les analyses présentées concernent le cas d'un homme retrouvé mort à son domicile. Une première expertise est effectuée avec une méthode de screening toxicologique sur matrices biologiques : humeur vitrée, sang cardiaque, bile et contenu gastrique. L'issu de ces analyses est un résultat positif pour la présence de pyrimiphos-méthyl dans le contenu gastrique uniquement. Ces mêmes prélèvements sont envoyés au laboratoire de pharmacologie et de toxicologie du CHU de Limoges pour confirmation. Une recherche spécifique du pyrimiphos-méthyl et de ses métabolites, 2-Diethylamino-6-methyl-4-Pyrimidinol (métabolite spécifique) et dialkylphosphates (métabolites communs aux organophosphorés), est effectué en LC-MS/MS (LC-TQ), puis par LC-HRMS (LC-QTOF). Lors de la première analyse, une présence de pyrimiphos-méthyl est effectivement observée dans le contenu gastrique, avec une concentration de 14 μg/L. Cependant il n'est pas retrouvé de pyrimiphos-méthyl, ni de ses métabolites dans les autres matrices. Lors de l'analyse en LC-HRMS, aucun signal n'a été détecté ni pour le pyrimiphos-méthyl, ni pour ses métabolites. Les résultats obtenus par analyse en LC-MS/MS de basse résolution ont orienté les premières conclusions vers une présence de pyrimiphos-méthyl dans le contenu gastrique. Cependant, l'hypothèse d'une intoxication mortelle semblait en contradiction avec l'absence du composé et de ses métabolites dans le sang cardiaque. De plus, la concentration observée dans le liquide gastrique (14 μg/L), paraissait insuffisantes pour expliquer un décès par ingestion du fait des valeurs toxiques du pyrimiphos-méthyl (DJA de 4 μg/kg/j et NOAEL de 0,25 mg/kg/2 fois par jour). Dans ce contexte, l'analyse de confirmation par LC-HRMS a permis de lever l'ambiguïté. La LC-HRMS est donc un puissant outil de confirmation permettant de limiter le risque de faux positifs.

Amid the early 2020 SARS-CoV-2 crisis, severe hand sanitizer shortages led to OMS local production recommendations, inviting a diverse array of alcohol producers to contribute. However, not all followed mandatory controls for API-grade alcohol. We conducted a study to ensure the safety of the received alcohols, focusing on methanol and acetaldehyde levels. All samples were well below Ph. Eur guidelines, affirming their safety for use. Furthermore, no additional impurities were detected, reinforcing the quality and safety of the assessed hand sanitizers. Our findings, amidst the scarcity of the SARS-CoV-2 era, highlight the importance of rigorous safety assessments during local hand sanitizer production.

Early and sensitive biomarkers of liver dysfunction and drug-induced liver injury (DILI) are still needed, both for patient care and drug development. We developed the Serum Enhanced Binding (SEB) test to reveal post-transcriptional modifications (PTMs) of human serum albumin resulting from hepatocyte dysfunctions and further evaluated its performance in an animal model. The SEB test consists in spiking serum ex-vivo with ligands having specific binding sites related to the most relevant albumin PTMs and measuring their unbound fraction. To explore the hypothesis that albumin PTMs occur early during liver injury and can also be detected by the SEB test, we induced hepatotoxicity in male albino Wistar rats by administering high daily doses of ethanol and CCl4 over several days. Blood was collected for characterization and quantification of albumin isoforms by high-resolution mass spectrometry, for classical biochemical analyses as well as to apply the SEB test. In the exposed rats, the appearance of albumin isoforms paralleled the positivity of the SEB test ligands and histological injuries. These were observed as early as D3 in the Ethanol and CCl4 groups, whereas the classical liver tests (ALT, AST, PAL) significantly increased only at D7. The behavior of several ligands was supported by structural and molecular simulation analysis. The SEB test and albumin isoforms revealed hepatocyte damage early, before the current biochemical biomarkers. The SEB test should be easier to implement in the clinics than albumin isoform profiling.

Well-characterized biomarkers using reliable quantitative methods are essential for the management of various pathologies such as diabetes, kidney, and liver diseases. Human serum albumin (HSA) isoforms are gaining interest as biomarkers of advanced liver pathologies. In view of the structural alterations observed for HSA, insights into its isoforms are required to establish them as reliable biomarkers. Therefore, a robust absolute quantification method seems necessary. In this study, we developed and validated a far more advanced top-down liquid chromatography-mass spectrometry (LC-MS) method for the absolute quantification of HSA isoforms, using myoglobin (Mb) as an internal standard for quantification and for mass recalibration. Two different quantification approaches were investigated based on peak integration from the deconvoluted spectrum and extracted ion chromatogram (XIC). The protein mixture human serum albumin/myoglobin eluted in well-shaped separated peaks. Mb allowed a systematic mass recalibration for every sample, resulting in extremely low mass deviations compared to conventional deconvolution-based methods. In total, eight HSA isoforms of interest were quantified. Specific-isoform calibration curves showing good linearity were obtained by using the deconvoluted peaks. Noticeably, the HSA ionization behavior appeared to be isoform-dependent, suggesting that the use of an enriched isoform solution as a calibration standard for absolute quantification studies of HSA isoforms is necessary. Good repeatability, reproducibility, and accuracy were observed, with better sensitivity for samples with low albumin concentrations compared to routine biochemical assays. With a relatively simple workflow, the application of this method for absolute quantification shows great potential, especially for HSA isoform studies in a clinical context, where a high-throughput method and sensitivity are needed.