Docking-Based Evidence for the Potential of ImmunoDefender: A Novel Formulated Essential Oil Blend Incorporating Synergistic Antiviral Bioactive Compounds as Promising Mpro Inhibitors against SARS-CoV-2.

Essential oils (Eos) have demonstrated antiviral activity, but their toxicity can hinder their use as therapeutic agents. Recently, some essential oil components have been used within safe levels of acceptable daily intake limits without causing toxicity. The "ImmunoDefender," a novel antiviral compound made from a well-known mixture of essential oils, is considered highly effective in treating SARS-CoV-2 infections. The components and doses were chosen based on existing information about their structure and toxicity. Blocking the main protease (Mpro) of SARS-CoV-2 with high affinity and capacity is critical for inhibiting the virus's pathogenesis and transmission. In silico studies were conducted to examine the molecular interactions between the main essential oil components in "ImmunoDefender" and SARS-CoV-2 Mpro. The screening results showed that six key components of ImmunoDefender formed stable complexes with Mpro via its active catalytic site with binding energies ranging from -8.75 to -10.30 kcal/mol, respectively for Cinnamtannin B1, Cinnamtannin B2, Pavetannin C1, Syzyginin B, Procyanidin C1, and Tenuifolin. Furthermore, three essential oil bioactive inhibitors, Cinnamtannin B1, Cinnamtannin B2, and Pavetannin C, had significant ability to bind to the allosteric site of the main protease with binding energies of -11.12, -10.74, and -10.79 kcal/mol; these results suggest that these essential oil bioactive compounds may play a role in preventing the attachment of the translated polyprotein to Mpro, inhibiting the virus's pathogenesis and transmission. These components also had drug-like characteristics similar to approved and effective drugs, suggesting that further pre-clinical and clinical studies are needed to confirm the generated in silico outcomes.

Hypericum Humifusum Leaves Attenuates Hepatic Ischemia-Reperfusion Injury in a Rat Model.

INTRODUCTION: Effective prevention strategies require specific actions during the different phases of ischemia-reperfusion (I-R) injury. The objective of our study is to evaluate the effect of aqueous extract of Hypericum humifusum leaves (HHL) on liver I-R model in Rat. MATERIAL AND METHODS: Animals were subjected to 90 min of hepatic ischemia followed by reperfusion (120 min). HHL extract (25 mg/mL/kg) was injected 15 min before reperfusion. To evaluate the effect of HHL extract on I-R, we have monitored transaminases levels, Malondialdehyde (MDA) concentration, histological lesions (apoptosis and necrosis) and compared the results to a reference oxidant vitamin E. RESULTS: The determination of total phenol extracts of HHL was 59.91 ± 0.35 mg of Gallic Acid/g dry plant material with higher antioxidant activity (91.73% ± 1.67) compared to vitamin E (87.42%). Using aqueous extract of HHL, we noted a significant decrease of AST and ALT [1129 UI (585/1995) and 768 UI (335/1375)] compared to no-treated group [5,585.5 UI (5,035/12,070) and 8,099.5 UI (5,040/12,326)] as a decrease in MDA content [85.7% protection (50.9/91.5)]. HHL extract reduce the damage induced by I-R of 48.7% (27/48.7) and 96.1% (95.7/96.5) for necrosis and apoptosis lesions respectively. CONCLUSION: HHL aqueous extract have potential to protect liver from the damage effect induced by I-R better than vitamin E solution.

[Antiepileptic drugs administration by nasogastric tube in comatose patients]. / Modalités d'administration des antiépileptiques par sonde nasogastrique chez des patients comateux : étude des connaissances, attitudes et pratiques.

AIM: To evaluate the modalities of administration of antiepileptic drugs (AED) with nasogastric tube (NGT) by nurses and to draw up recommendations. METHODS: Our study consisted on investigating the modalities of administration of AED's with NGT by nurses during four months. We prepared 10 questions including demographic information. Participation was voluntary and anonymous. The questionnaire was distributed in seven intensive care departments after authorization of each head of the department. Thus, 45 nurses were included. RESULTS: Nurses sex ratio was 1.5 and mean age was 31 years (25 to 37 years). Among the nurses, 60% mentioned that the NGT were silicone made and 4% that they were PVC made. The mean duration before replacing the NGT was thought to be 5±3 days. Among the nurses, 91% affirmed to clear the NGT after each use. All the nurses had agreed that the solid form is the most commonly used pharmaceutical form in the NGT. AED were associated with the enteral feeding solution in 56%. The AED should be crushed before administration for 98% of the nurses even in case of polymedication. Among them, 62% recommended to crush all of the associated drugs together. Before introducing the AED into the NGT, 93% of the nurses reported mixing with tap water. We have noticed that 62% of nurses felt the need to improve their knowledge AED administration with NGT. CONCLUSION: To optimize AED therapy, modalities of administration by NGT in epileptic comatose patients should be enhanced.

Progress and assessment of a contextualized teaching session of pharmacology.

BACKGROUND: Learning transfer, in medical teaching, remains an essential question and optimizing it is the main preoccupation of every trainer in medical sciences. Some learning methods showed their efficacy as the contextualized learning in the framework of a professional activity or in a situation recalling it in a realistic manner. AIM: To describe steps of planning and progress of a session of clarification, illustration, application et participation (CIAP) of pharmacology teaching students from second cycle of medical studies (DCEM) and to assess the session. METHODS: We performed a descriptive transversal study in April 2017 in the Faculty of Medicine of Tunis. Our work was composed of two parts. The first part consisted in a description of the preparation and the progress of the CIAP session entitled antiepileptic drugs, which is comprised in the pharmacology teaching of the certificate of Neurology to the students of DCEM. The second part consisted in an assessment of knowledge acquisition and the progress of the session by the students. RESULTS: We proceeded to a planning of the session which resulted in a contextualized teaching and induced an active participation and an interactivity of the students. Comparison of the results of the pretest and the posttest showed a statistically significant difference in terms of good responses. The assessment of the session progress was good. CONCLUSION: Our study demonstrated the feasibility of a session of contextualized teaching session or CIAP of pharmacology and its input in terms of knowledge to the students.

Therapeutic monitoring of antiepileptic drugs in comatose patients.

OBJECTIVE: In this study, we aimed to analyze the trough plasmatic levels (C0) of the antiepileptic drugs (AED) administered by nasogastric tubes (NGT) in comatose patients and to draw up recommendations for therapeutic drug monitoring (TDM) and for the modalities of AED administration by NGT. METHODS: We conducted a retrospective study on comatose patients addressed over six years and 10 months in Clinical Pharmacology for C0 measurement of AED administered by NGT. RESULTS: In this study, the sex-ratio was 2.38 (44 patients). The patients' median age was 24 years. There was 14.5% of children (≤16 years). Among the 103 samples, C0 measurement concerned valproic acid in 57%, phenobarbital in 28 % and carbamazepine in 15%. Two AED or more were associated in 42% of patients. AED were associated to other drugs in 85% of cases. The AED C0 were subtherapeutic in 71% of cases. C0/Dp lower than recommanded in 65 %. In these samples, 55% presented at least one drug association with the concerned AED. In 45% of the cases, there was no drug association but a non-respect of modalities of AED administration by NGT in patients. CONCLUSION:   The drug monitoring is a useful tool to assess drug-drug interactions and to control modalities of AED administration in comatose patients.

Response to clopidogrel and of the cytochrome CYP2C19 gene polymorphism.

INTRODUCTION: Clopidogrel (clopi) is a prodrug widely prescribed in the management of coronary artery disease and requires the intervention of hepatic cytochrome P450 2C19 (CYP2C19) for its activation. However, there is interindividual variability in response to clopi despite the use of recommended doses. Thus, the studies have highlighted the effect of the CYP2C19 gene polymorphism or Cyp2C19 gene on the response to clopi and particularly Cyp2C19 * 2 which may be associated with an increased risk of major cardiovascular events or MACE. OBJECTIVE: To evaluate the effect of Cyp2C19 * 2 polymorphism on MACE occurrence and hemorrhagic complications in patients treated with clopi. METHODS: We carried out a descriptive longitudinal study including 71 patients placed under clopi for a minimum duration of one month. Genotyping of the Cyp2C19 allele was performed by conventional polymerase chain reaction (PCR). After a follow-up period of 495 ± 183 days, we performed a statistical analysis to evaluate the association between the Cyp2C19 * 2 polymorphism and the occurrence of MACE or hemorrhagic complications. RESULTS: Among our patients, 51% had an angioplasty, 42% medical treatment and 7% a coronary artery bypass surgery. In our study population, 52% were heterozygous (HTZ), 28% homozygous (HMZ) healthy * 1 / * 1 and 20% HMZ had the loss of function allele * 2 / * 2. The allelic frequency of Cyp2C19 * 2 was 46%. Follow-up mean duration was of 495 ± 183 days. During this period, the prevalence of MACE was 11% and that of hemorrhagic complications was 13%. In our study, we did not observe a significant association between the occurrence of MACE or hemorrhagic complications with the genotype carrying the Cyp2C19 * 2 allele. CONCLUSION: Among patients treated with clopi, wearing a Cyp2C19 * 2 function loss allele didn't seem to be associated with a significantly higher risk of MACE, nor a significantly lower risk of hemorragic complications. This suggests the necessity of larger studies.

Protective effect of Ulva lactuca extract during hepatic cold preservation in rats.

Introduction In recent years, many marine resources have drew attention in the research for bio-active compounds to develop new drugs and health foods. (1) Marine algae are now considered as a rich source of antioxidants (2). It is known that seaweeds contain numerous bioactive substances that have the ability to lower cholesterol, reduce blood pressure, promote healthy digestion; and antioxidant activity (3). Natural antioxidants are interesting compounds due to their properties which help prevent oxidative stress (4), among other potentially beneficial actions. For instance, several biological effects have been attributed to flavonoids, such as anti-tumoral, anti-inflammatory, anti-ischemic and anti-aggregate plaquetary activities. These activities are believed to be in part related to the antioxidant properties of the compounds, namely in scavenging radical oxygen species (ROS). (5, 6) The cold ischemia constitute a situation of oxidative stress in touch with liberation of oxygenated radicals, these situations incited the researchers to find means for the improvement of the conservation of organs allowing to prolong the durations of the cold ischemia of certain organs (in particular the liver) with conservation of the maximum functional value. However, the constant efforts led by the teams of transplantation to develop transplants, the conservation of organs remains a problem to be resolved. (7) Conservation solution of organ appears as being a stemming to remedy the fatal effects of the ischemia-reperfusion. For our part, we think that seaweeds have not delivered their secrets and yet especially that the marine environment of the Tunisian coast still remains little exploited in spite of the big variety of the fauna and the flora of the coast. We envisage in this work, to study a sort of seaweed collected on the Tunisian quotation in the region of "Chott Meriem" (North West of Tunisia). The purpose of our work is to estimate the capacity of extracts stemming from the green seaweed Ulva lactuca to improve the conservation solution of organs against the hepatic effects of ischemia.

Animal model of liver ischemia reperfusion: biochemical and histological evaluation.

INTRODUCTION: During last years, significant progress was made in the comprehension of the hepatic lesions after Ischemia-Reperfusion episode in order to improve the Results in practice clinical. AIM: To avoid or reduce the damage induced by Ischemia-Reperfusion, we developed a model of hepatic Ischemia-Reperfusion with variable periods of reperfusion from 0 to 24 hours.  METHODS: Our study related to rats Wistar males.  Six various groups were studied: the first reference group (without neither ischemia and reperfusion), the second group with ischemia of 90 min and without reperfusion and the 3end , 4end, 5end and 6end groups in addition to ischemia, underwent a reperfusion of 30 min, 2h, 6h and 24h respectively.  The damage of hepatic Ischemia-Reperfusion was evaluated by a biochemical test based on the proportioning of transaminases and an anatomopathologic study by optical microscopy for the determination of the degree of hepatic attack.  RESULTS: The RESULTS obtained seem to show an aggravation of the liver lesions and an increase in the plasmatic rates of AST and ALT in relation with the duration of the reperfusion.  Indeed, the maximum of damage was observed after 2 hours of reperfusion. We observed a reduction in the lesions after 6h and 24h of reperfusion.  CONCLUSION: Our work enabled us to describe a simple model of hepatic Ischemia-Reperfusion with functional, biochemical and anatomopathologic tests.

[Therapeutic Drug Monitoring of Valproic Acid in Children: A Prospective Study of The Effect of The Compliance and The Economic Level on the Trough Plasmatic Concentrations and Epileptic Seizures]. / Suivi thérapeutique de l'acide valproïque chez l'enfant : étude prospective de l'effet de l'observance et du niveau économique sur les concentrations plasmatiques résiduelles et les crises épileptiques.

INTRODUCTION: Valproic acid (VA) is a widely used antiepileptic drug. Because of its pharmacokinetic variability and the influence of intrinsic and extrinsic factors such as the treatment compliance, VA therapeutic drug monitoring (TDM) is recommended in children. The aim of this study is to evaluate the effect of treatment compliance and the economic level on VA tough plasmatic concentration (TPC) and epileptic rhythm in children. MATERIAL AND METHODS: A one-year prospective study (August 2008-August 2009) concerning children (age≤5 years) regularly treated by VA who had a VA TDM. So, 276 plasmatic samples from 238 children were collected. The children were divided in two groups as following: the group 1 (G1) presenting a good compliance and a reliable questioning and the group 2 (G2) presenting a bad compliance and a non reliable questioning. We evaluated the interindividual variability by correlating the TPC to the dose. Then, we divided the hole group in function of their economic levels (low-medium-high). RESULTS: Sex ratio male/female was 1.3. Median age was 5 years+/-3,9. The mean TPC was 62 µg/mL [0.12-131 µg/mL]. VA TPC were in the therapeutic range (TR) in 62%. Adverse drug reactions were noted in 4.2% of the children. G1 represented 70% of the children and G2, 30%. The TPC were in the TR in 67% of G1 and 51% of G2 (p=0.02). There was a significant difference between the TPC in G1 and G2 (p=0.02).There was no significative difference in the TPC in function of the economic levels. There was no correlation between TPC and the administered doses. The epileptic seizures were more spaced in children with therapeutic TPC than those with TPC in the TR (p=0.002) and in G1 than in G2 (p=0.03). CONCLUSIONS: Compliance should be appropriate in order to optimize the TDM rule. A good compliance and a therapeutic TPC allow a better control of epileptic seizures.

Contribution of Therapeutic Monitoring in the Assessment of Toxic Adverse Effects of Mitotane: a Case Report.

Mitotane provided serious side effects and low doses seemed to be tolerated. Determination of mitotane concentration in plasma is recommended. We report the case of toxic plasma levels with low doses of mitotane in a 47-year-old man with adrenocortical cancer.

Pharmacokinetik population of methotrexate in tunisian population with acute lymphoblastic leukemia.

BACKGROUND: The use of high dose of MTX in the treatment of the leukemia is actually better controlled by renal preparation, control of plasma concentrations and administration of folinic acid. However, High dose MTX has been proven to cause substantial toxicity and have high intra-and inter-patient variability. Population pharmacokinetic analysis is a useful tool for identification of sources of pharmacokinetic variability during anticancer drug development and can aid the design of alternative dosing regimens to enhance their efficacy and safety. AIM: The aim of our study is to developed and validate a population pharmacokinetics model of our population. We hereby describe the clinical covariates (age, sex and clearance of the creatinine) that influence MTX pharmacokinetic for predicting optimal dose to reduce MTX toxicity. METHOD: It is a prospective study achieved between January 2005 to January 2012 in the Service of Clinical Pharmacology. Including 273 patients treated for acute lymphocytic leukaemia 2582 plasma concentration was achieved. The data have been analyzed with Nonmem© software (non linear regression to mixed effect). RESULTS: The age of our patients varied from 2 to 23 years with an average of 13 years. The patients received high dose MTX therapy (1 to 8 g/m2) in 24 hours infusion every 15 days. Three compartiment models describe the pharmacokinetic of MTX. The most important covariables affecting the model were clearance of the creatinine, age and weight. We obtained a good correlation between the predicted and the observed concentrations. CONCLUSION: The development of population pharmacokinetics model of MTX allows us to propose a therapeutic diagram adapted to every patient according to its morphological and pharmacological features while taking in consideration the therapeutic objective.

[Development and validation of a new HPLC method for determination of Lamotrigine and clinical application]. / Mise au point validation d'une method de dosage de la lamotrigine par chromatographie liquid à haute performance et application clinique.

BACKGROUND: Lamotrigine is an effective anticonvulsant drug used in the treatment of epilepsy. It has a narrow therapeutic range, a large inter and intra-individual pharmacokinetic variability and some concentration-dependent side effects. AIM: The aim of this study was to develop and validate a new method for lamotrigine quantitation in plasma using HPLC with UV/visible detection. METHODS: A rapid HPLC-UV method was developed for the determination of lamotrigine in plasma. All solvents used were HPLC grade. RESULTS: After liquid-liquid extraction, chromatographic separation was achieved using an RP 18 (250 mm) column. The mobile phase was composed of acetonitrile and 0.1 M potassium dihyrogenophosphate (25/75) (v/v). Barbital sodium was used as internal standard. This technique was linear over the 2 µg/mL to 50 µg/mL range (r= 0.99). Detection and quantification limits were 0.07 µg/mL and 0.21 µg/mL, respectively. Within-day coefficient of variation (13.37 to 16 %) and day-to-day coefficients of variation (15.68 to 16.63 %) at three different concentrations. Under these conditions, each analysis required no longer than 10 min. We finally evaluated the plasma concentrations of lamotrigine in Tunisian patients treated with this drug. CONCLUSION: The results found are similar to those previously described and the developed method is repeatable and reproducible. It can be used for clinical applications.

Vancomycin therapeutic drug monitoring in cerebrospinal fluid.

Vancomycin penetrates poorly through the blood-brain barrier. Determination of vancomycin concentration in plasma is recommended. In contrast, its determination in cerebrospinal fluid (CSF) is rarely performed. We report the case of a 74-year-old man with post traumatic meningitis with vancomycin concentration measured in CSF.

[Not Available]. / Y a-t-il intérêt à doser les métabolites de l'azathioprine chez les malades ayant une maladie inflammatoire chronique de l'intestin?

OBJECTIVE: The objective of our work is to search if there is a relation between azathioprine's metabolites (6-thioguanines nucleotides and 6-methyl mercaptopurines) and clinical efficacy and adverse effects of azathioprine in inflammatory bowel disease population. METHOD: We included patients with Crohn's disease or ulcerative colitis (UC) treated by azathioprine for a duration more than 1year. Each patient had a dosage of azathioprine metabolites. RESULTS: We included 43 Crohn's disease patients and 7 UC. Azathioprine was indicated for steroid dependancy in 23 cases, to prevent post-operative recurrence in 10 cases, to maintain clinical remission obtained by medical treatment in 17 patients. A clinical response to azathioprine (obtention of remission, absence of recurrence during the follow up) was observed in 34 patients. CONCLUSION: Our work confirms the relation between the doses of azathioprine metabolites and the myelotoxicity due to this molecule.

[Is there any interest to dose the azathioprine's metabolites during inflammatory bowel diseases?]. / Y a-t-il intérêt à doser les métabolites de l'azathioprine chez les malades ayant une maladie inflammatoire chronique de l'intestin ?

OBJECTIVE: The objective of our work is to search if there is a relation between azathioprine's metabolites (6-thioguanines nucleotides and 6-methyl mercaptopurines) and clinical efficacy and adverse effects of azathioprine in inflammatory bowel disease population. METHOD: We included patients with Crohn's disease or ulcerative colitis (UC) treated by azathioprine for a duration more than 1 year. Each patient had a dosage of azathioprine metabolites. RESULTS: We included 43 Crohn's disease patients and 7 UC. Azathioprine was indicated for steroid dependancy in 23 cases, to prevent post-operative recurrence in 10 cases, to maintain clinical remission obtained by medical treatment in 17 patients. A clinical response to azathioprine (obtention of remission, absence of recurrence during the follow up) was observed in 34 patients. CONCLUSION: Our work confirms the relation between the doses of azathioprine metabolites and the myelotoxicity due to this molecule.

The effects of the CYP3A5*3 variant on tacrolimus pharmacokinetics and outcomes in Tunisian kidney transplant recipients.

INTRODUCTION: Tacrolimus, exhibits interindividual pharmacokinetic variability and a narrow therapeutic index. The influence of the CYP3A5 6986A>G single nucleotide polymorphism (SNP) on this variability remains a topic of debate. AIM: To assess the impact of the aforementioned SNP on tacrolimus area under curve (AUC0-12h), adverse drug reactions (ADRs), and kidney graft outcomes. METHODS: Blood samples were collected from Tunisian kidney transplants over a five-year period during either the early (<3 months) or late (>3 months) post-transplant phases. Through blood concentration (C0) and AUC0-12h of tacrolimus were measured. Patients were prospectively followed to assess graft outcomes. Polymerase chain reaction of restriction fragment length polymorphism was used for CYP3A5 6986A>G genotyping. RESULTS: Fifty Tunisian kidney recipients receiving tacrolimus were enrolled in the study. Acute and chronic graft rejections were observed in eight and three patients, respectively. Twenty-one patients (42%) reported ADRs. C0 and AUC0-12h, showed a significant difference between CYP3A5*1 carriers (mean C0=4 ng.mL-1 and AUC0-12h=94.37 ng.h.mL-1) and CYP3A5*3/3 or poor metabolizers carriers (mean C0=7.45 ng.mL-1; AUC0-12h=151.27 ng.h.mL-1) (p=0.0001; p=0.003, respectively). Supratherapeutic tacrolimus levels were significantly more common in poor metabolizers (p=0.046; Odds-ratio =1.3; confidence interval 95% [1.12-1.66]). The impact of SNP was significant on C0, AUC0-12h, C0/Dose and AUC0-12h/Dose, only in the late phase (p=0.01, 0.002, 0.012, 0.003 respectively). CONCLUSION: CYP3A5*3 variant was significantly associated with tacrolimus pharmacokinetics but had no impact on graft outcomes.

Population pharmacokinetics and Bayesian estimation of cyclosporine in a Tunisian population of hematopoietic stem cell transplant recipient.

PURPOSE: Therapeutic drug monitoring of cyclosporine minimizes the risk of toxicity and acute rejection after transplantation. Areas under the curve (AUCs) rather than trough concentration-based monitoring are recommended. Population pharmacokinetics (PopPK) modeling and Bayesian estimation seem to be the best way to predict cyclosporine disposition and dose requirements to achieve the therapeutic target in an individual patient because of the possibility of predicting cyclosporine AUC using only a few blood samples. Our objectives were to build a PopPk model for cyclosporine in a Tunisian population of HSCT patients and to develop a Bayesian method for the estimation of individual cyclosporine AUC. PATIENTS AND METHODS: The PopPk of cyclosporine was studied using nonlinear mixed effects modeling (NONMEM) in 30 patients (index group) receiving cyclosporine on a twice-daily basis. Ten blood samples were collected after steady-state morning cyclosporine dose. Bayesian estimation of individual AUC was made on the basis of three blood concentration measurements in an independent group of 30 patients (test group). RESULTS: A two-compartment model with first-order absorption and a lag time provided the best fitting. The population mean estimate and interindividual variability from the final model for CL, Ka, Tlag, V1, V2, and Q were 25.4 L/h (CV = 38.72 %), 0.214 h(-1)(CV = 28.5 %), 0.382 h, 10.9 L (85.73 %), 496 L, and 5 L/h, respectively. Covariates had no discernible effects on cyclosporine pharmacokinetics in our population. Bayesian estimation provided an accurate estimation of AUC, although a bias was observed leading to slight underprediction of AUC (bias -1.03 %). A very satisfactory precision was observed (RMSE 12.07 %). CONCLUSION: We report a PopPK model for cyclosporine in Tunisian HSCT patients. Bayesian estimation using only three concentrations provides good prediction of cyclosporine exposure. These tools allow us to routinely estimate cyclosporine AUC in a clinical setting.

[Munchhausen syndrome by proxy revealed by falsely toxic methotrexate levels]. / Syndrome de Münchausen par procuration révélé par des méthotrexatémies toxiques artificielles.

Methotrexate is an antifolate drug used intravenously at high-dose in acute lymphocytic leukemia (ALL). Therapeutic drug monitoring is required to identify patients at risk of developing toxicity and to control folinic acid rescue. We report a case of Münchausen syndrome by proxy revealed by high and persistent falsely toxic methotrexate plasmatic levels. A 12 year-old child was treated with chemotherapy including methotrexate every 70 days for an ALL. The last methotrexate plasmatic level was 0.15 µmol/L at the 72th hour of the infusion. Then, he was treated by oral rout low-dose methotrexate. Ten days after methotrexate infusion, the patient consulted for asthenia, vomiting and presented a mucositis. Methotrexate plasmatic level was 2323 µmol/L. Renal function was normal. All drugs' intake was stopped. Folinic acid rescue was instituted. Even though there was no clinical sign of toxicity, therapeutic drug monitoring showed persistent high methotrexate plasmatic levels. Investigations eliminated measurement errors and pharmacokinetic problems. A deliberate methotrexate addition in each child blood sample brought by the mother was highly suspected. We confirmed this hypothesis by measuring methotrexate plasmatic levels in three samples: one brought by the mother, the second brought by the child's doctor and the last collected in our laboratory. Methotrexate plasmatic levels were respectively over 10,000 µmol/L (first sample) and lower than 0.02 µmol/L (the two others). The diagnosis of Munchausen's syndrome by proxy revealed by falsely toxic methotrexate plasmatic levels was made and the mother was addressed to the psychiatric department.

Humoral and Cellular Immunogenicity of Six Different Vaccines against SARS-CoV-2 in Adults: A Comparative Study in Tunisia (North Africa).

BACKGROUND: The mass vaccination campaign against SARS-CoV-2 was started in Tunisia on 13 March 2021 by using progressively seven different vaccines approved for emergency use. Herein, we aimed to evaluate the humoral and cellular immunity in subjects aged 40 years and over who received one of the following two-dose regimen vaccines against SARS-CoV-2, namely mRNA-1273 or Spikevax (Moderna), BNT162B2 or Comirnaty (Pfizer-BioNTech), Gam-COVID-Vac or Sputnik V (Gamaleya Research Institute), ChAdOx1-S or Vaxzevria (AstraZeneca), BIBP (Sinopharm), and Coronavac (Sinovac). MATERIAL AND METHODS: For each type of vaccine, a sample of subjects aged 40 and over was randomly selected from the national platform for monitoring COVID-19 vaccination and contacted to participate to this study. All consenting participants were sampled for peripheral blood at 3-7 weeks after the second vaccine dose to perform anti-S and anti-N serology by the Elecsys® (Lenexa, KS, USA) anti-SARS-CoV-2 assays (Roche® Basel, Switzerland). The CD4 and CD8 T cell responses were evaluated by the QuantiFERON® SARS-CoV-2 (Qiagen® Basel, Switzerland) for a randomly selected sub-group. RESULTS: A total of 501 people consented to the study and, of them, 133 were included for the cellular response investigations. Both humoral and cellular immune responses against SARS-CoV-2 antigens differed significantly between all tested groups. RNA vaccines induced the highest levels of humoral and cellular anti-S responses followed by adenovirus vaccines and then by inactivated vaccines. Vaccines from the same platform induced similar levels of specific anti-S immune responses except in the case of the Sputnik V and the AstraZeneca vaccine, which exhibited contrasting effects on humoral and cellular responses. When analyses were performed in subjects with negative anti-N antibodies, results were similar to those obtained within the total cohort, except for the Moderna vaccine, which gave a better cellular immune response than the Pfizer vaccine and RNA vaccines, which induced similar cellular immune responses to those of adenovirus vaccines. CONCLUSION: Collectively, our data confirmed the superiority of the RNA-based COVID-19 vaccines, in particular that of Moderna, for both humoral and cellular immunogenicity. Our results comparing between different vaccine platforms in a similar population are of great importance since they may help decision makers to adopt the best strategy for further national vaccination programs.