Implication of Central Nervous System Barrier Impairment in Amyotrophic Lateral Sclerosis: Gender-Related Difference in Patients.

Central nervous system (CNS) barrier impairment has been reported in amyotrophic lateral sclerosis (ALS), highlighting its potential significance in the disease. In this context, we aim to shed light on its involvement in the disease, by determining albumin quotient (QAlb) at the time of diagnosis of ALS in a large cohort of patients. Patients from the university hospital of Tours (n = 307) were included in this monocentric, retrospective study. In total, 92 patients (30%) had elevated QAlb levels. This percentage was higher in males (43%) than in females (15%). Interestingly, QAlb was not associated with age of onset, age at sampling or diagnostic delay. However, we found an association with ALS functional rating scale-revised (ALSFRS-r) at diagnosis but this was significant only in males. The QAlb levels were not linked to the presence of a pathogenic mutation. Finally, we performed a multivariate survival analysis and found that QAlb was significantly associated with survival in male patients (HR = 2.3, 95% CI = 1.2-4.3, p = 0.009). A longitudinal evaluation of markers of barrier impairment, in combination with inflammatory biomarkers, could give insight into the involvement of CNS barrier impairment in the pathogenesis of the disease. The gender difference might guide the development of new drugs and help personalise the treatment of ALS.

Quality consideration for the validation of urine TMA and TMAO measurement by nuclear magnetic resonance spectroscopy in Fish Odor Syndrome.

OBJECTIVES: Trimethylaminuria, also known as Fish Odor Syndrome (FOS), is a condition characterized by the presence of high concentrations of trimethylamine (TMA) in urine, sweat and expired air of affected patients. Diagnosis of this benign but unpleasant disease is mainly based on clinical presentation and assessment of TMA and its metabolite, TMAO (trimethylamine-N-oxide), concentrations in urine of patients. MATERIAL AND METHODS: We here described the validation of an analytical method for measurement of TMA and TMAO in urine using nuclear magnetic resonance (NMR) according to the specifications of the ISO 15189 norm. We used a fast validation protocol, based exactitude profile method, enabling to determine accuracy, intra and inter-day precision from a limited number of samples. RESULTS: The linearity was established from 2.5 to 100 mg/L for TMA measurement and from 10 to 1000 mg/L for TMAO measurement, with good analytical performances i.e. accuracy, intra and inter-day precision. We also report a case diagnose for FOS from this method. CONCLUSIONS: This method validation ensures the robustness of NMR in routine use for diagnosis of trimethylaminuria, as part of the reference center for inherited metabolic diseases at the Tours hospital.

Assessment of the glomerular filtration rate (GFR) in kidney transplant recipients using Bayesian estimation of the iohexol clearance.

Background Plasma iohexol clearance (CLiohexol) is a reference technique for glomerular filtration rate (GFR) determination. In routine practice, CLiohexol is calculated using one of several formulas, which have never been evaluated in kidney transplant recipients. We aimed to model iohexol pharmacokinetics in this population, evaluate the predictive performance of three simplified formulas and evaluate whether a Bayesian algorithm improves CLiohexol estimation. Methods After administration of iohexol, six blood samples were drawn from 151 patients at various time points. The dataset was split into two groups, one to develop the population pharmacokinetic (POPPK) model (n = 103) and the other (n = 48) to estimate the predictive performances of the various GFR estimation methods. GFR reference values (GFRref) in the validation dataset were obtained by non-compartmental pharmacokinetic (PK) analysis. Predictive performances of each method were evaluated in terms of bias (ME), imprecision (root mean square error [RMSE]) and number of predictions out of the ±10% or 15% error interval around the GFRref. Results A two-compartment model best fitted the data. The Bayesian estimator with samples drawn at 30, 120 and 270 min allowed accurate prediction of GFRref (ME = 0.47%, RMSE = 3.42%), as did the Brøchner-Mortensen (BM) formula (ME = - 0.0425%, RMSE = 3.40%). With both methods, none of the CL estimates were outside the ±15% interval and only 2.4% were outside the ±10% for the BM formula (and none for the Bayesian estimator). In patients with GFR ≤30 mL/min/1.73 m2, the BM formula performed very well, while the Bayesian method could not be evaluated in depth due to too small a number of patients with adequate sampling times. Conclusions GFR can be estimated with acceptable accuracy in kidney transplant patients using the BM formula, but also using a Bayesian algorithm.

Glomerular Hyper- and Hypofiltration During Acute Circulatory Failure: Iohexol-Based Gold-Standard Descriptive Study.

OBJECTIVE: To assess glomerular filtration rate in the early phase of acute circulatory failure by measuring iohexol plasma clearance. DESIGN: Interventional prospective multicentric study. SETTING: Three French ICUs in tertiary teaching hospitals. PATIENTS: Patients with acute circulatory failure within 12 hours after ICU admission. INTERVENTIONS: IV administration of a nontoxic 5-mL dose of iohexol. Collection of nine arterial blood samples over 24 hours for iohexol plasma concentration measurements. Iohexol clearance calculation with a population pharmacokinetic model. Iohexol clearance was an estimation of the mean glomerular filtration rate over 24 hours. MEASUREMENTS AND MAIN RESULTS: Among 99 included patients, we could calculate iohexol clearance for 85. The median iohexol clearance was 31 mL/min (interquartile range, 16-44). According to iohexol clearance, 41 patients (48%) had severe hypofiltration (clearance, < 30 mL/min), 29 (34%) had moderate hypofiltration, and 10 (12%) had mild hypofiltration (clearance, 30-60 and 60-90 mL/min, respectively). Four patients (5%) had normal glomerular filtration rate, and only one (1%) showed hyperfiltration (clearance, > 130 mL/min). Urinary creatinine clearance underestimated renal impairment in one patient out of two; the bias of iohexol clearance toward 24-hour urinary creatinine clearance over the same period was -18.1 mL/min (limits of agreement, -73.5 to 37.4). CONCLUSIONS: We demonstrated the feasibility of iohexol clearance measurement in unstable critically ill patients. Normal kidney function is exceptional during the early phase of acute circulatory failure. Glomerular filtration rate estimation by urinary creatinine clearance frequently fails to detect renal impairment. Hyperfiltration is very infrequent.

Endogenous metabolites that are substrates of organic anion transporter's (OATs) predict methotrexate clearance.

Variable pharmacokinetics of high-dose-methotrexate (MTX) is responsible for severe toxicities. Unpredictable overexposure still occurs during some courses despite having controlled the main factors known to play a role in its elimination. The aim of our study was to evaluate whether the urine metabolomic profile measured at the time of MTX administration is predictive of the drug's clearance and/or of treatment-related toxicity. We analyzed the urine content of endogenous metabolites before MTX administration in a cohort of adult patients treated for lymphoid malignancies. Individual MTX clearance (MTXCL) was estimated from population pharmacokinetic analyses of therapeutic drug monitoring data. We determined the urine metabolite content by gas chromatography-mass spectrometry (GC-MS) and applied Partial Least Square (PLS) analysis to assess the relationship between the urine metabolome and MTXCL. External validation was applied to evaluate the performances of the PLS model. We used orthogonal partial least squares discriminant analysis (OPLS-DA) to distinguish patients with normal or delayed elimination, and patients with or without toxicity. Sixty-two patients were studied. We obtained a very good prediction of individual MTX clearance using a set of 28 metabolites present in patient urine at baseline. The mean prediction error and precision were -0.36% and 21.4%, respectively, for patients not included in the model. The model included a set of endogenous organic anions, of which the tubular secretion depends on organic anion transporter (OAT) function. Our analyses did not allow us to discriminate between patients with or without delayed elimination or those who did or did not experience toxicity. Urinary metabolomics can be informative about an individual's ability to clear MTX. More broadly, it paves the way for the development of a biomarker of tubular secretion, easily measurable from endogenous substances.

A Time-Dependent Model Describes Methotrexate Elimination and Supports Dynamic Modification of MRP2/ABCC2 Activity.

BACKGROUND: Multidrug resistance protein-2 encoded by the ABCC2 gene (MRP2/ABCC2), an efflux transporter expressed at the proximal renal tubule, is rate-limiting for urine excretion of coproporphyrin (UCP) isomers I and III, translating in high UCP [I/(I + III)] ratio in MRP2-deficient patients presenting with the Dubin-Johnson Syndrome. MRP2 is also a major contributor to methotrexate (MTX) clearance. As MTX is both a substrate and an inhibitor of MRP2, time course of the concentrations of MTX in blood could induce functional modification of MRP2 over time, which in turn can modify its own elimination rate. METHODS: A 3-parameter time-dependent MTX population pharmacokinetic (PK) model based on a power function accounting for nonlinearity in its clearance was developed using Pmetrics in a first cohort of 41 patients (76 PK profiles) and compared with a previously published 2-compartment model developed with NONMEM and a 3-compartment model developed with ITSIM. In a second cohort (62 patients and 62 PK profiles), the association between the UCP [I/(I + III)] ratio at 3 periods [before MTX administration (P1), at the end of infusion (P2), and at hospital discharge (P3)] and the time-dependent PK parameters of MTX was investigated. Effects of genetic polymorphisms and of coadministered drugs were also studied. RESULTS: The model developed tightly fitted the data in both cohorts. A significant inverse correlation was found between log (k1) (ie, the rate constant explaining MTX concentration decrease) and the difference in UCP [I/(I + III)] ratio between P3 and P2 (DP3) (ß ± SD = -0.025 ± 0.008, P = 0.00443). CONCLUSIONS: Self-inhibition of the MRP2-dependent secretion of MTX is a plausible explanation for the time-dependent PKs of this drug. Additional studies specifically designed to evaluate this hypothesis are required.

Iohexol clearance in unstable critically ill patients: a tool to assess glomerular filtration rate.

BACKGROUND: Acute kidney injury (AKI) is associated with significant morbidity and mortality, particularly in unstable critically ill patients. In this context, serum creatinine concentration is an imperfect tool for estimating glomerular filtration rate (GFR), an index of renal function. The objective of this pilot study was to evaluate the feasibility of measuring iohexol clearance for GFR assessment in critically ill patients with acute circulatory failure at intensive care unit (ICU) admission. METHODS: ICU patients were prospectively included within 12 h of acute circulatory failure; a non-toxic dose of iohexol (5 mL) was infused intravenously and iohexol plasma concentration decrease was measured over 24 h. Urinary iohexol concentration was measured in urine samples collected four times, every 6 h for 24 h. The Kidney Disease Improving Global Outcome score, measuring AKI, was calculated each day. RESULTS: Among 18 patients with acute circulatory failure, AKI developed in 15; 14 showed decreased serum creatinine concentration during the first 24 h even though 10 presented AKI. The absolute variation in serum creatinine concentration was correlated with fluid balance over 24 h. Median [min; max] plasma clearance of iohexol was 39.4 mL/min [6.1; 154.0] and iohexol urinary clearance 32.8 mL/min [0.8-170.4]. The correlation between plasma and urinary clearance was ρ=0.97, p<0.0001. CONCLUSIONS: GFR may be estimated by plasma iohexol clearance in unstable critically ill patients. This method is reliable, correlates very well with urinary iohexol clearance and does not depend on input/output fluid balance and fluid infusion, as compared with serum creatinine concentration.

Urinary coproporphyrin I/(I + III) ratio as a surrogate for MRP2 or other transporter activities involved in methotrexate clearance.

AIMS: The urinary coproporphyrin I/(I + III) ratio may be a surrogate for MRP2 activity. We conducted a prospective study in patients receiving methotrexate (MTX) to examine the relationship between this ratio and the pharmacokinetics of a MRP2 substrate. METHODS: Three urine samples were collected from 81 patients for UCP I/(I + III) ratio determination: one before (P1), one at the end of MTX infusion (P2), and one on the day of hospital discharge (P3). Three polymorphisms of ABCC2 were analysed and their relationships with basal UCP I/(I + III) ratio values assessed. All associated drugs were recorded and a drug interaction score (DIS) was assigned. Population pharmacokinetic analysis was conducted to assess whether MTX clearance (MTXCL) was associated with the basal UCP I/(I + III) ratio, its variation during MTX infusion, the DIS or other common covariates. RESULTS: The basal UCP I/(I + III) ratio was not associated with ABCC2 polymorphisms and did not differ according to the DIS. Significant changes in the ratio were observed over time, with an increase between P1 and P2 and a decrease at P3 (P < 0.001). No association was found between basal UCP I/(I + III) ratio and MTXCL. The final model indicates that MTXCL was dependent on the change in the ratio between P1 and P3, DIS and creatinine clearance. CONCLUSION: The basal UCP I/(I + III) ratio is not predictive of MTXCL. However, it is sensitive to the presence of MTX, so it is plausible that it reflects a function modified in response to the drug.

Increased acylcarnitines in infant heart failure indicate fatty acid oxidation inhibition: towards therapeutic options?

AIMS: Heart failure in adults is characterized by reduction of long-chain fatty acid oxidation in favour of carbohydrate metabolism. This adaptive phenomenon becomes maladaptive because energy conversion decreases and lipid toxic derivatives known to impair cardiac function are accumulating. No data are available concerning metabolic modification in heart failure in children. METHODS AND RESULTS: In order to evaluate the fatty acid oxidation in children suffering from heart failure, acylcarnitine profiles on dried blood spots were obtained from children under 16 years old with dilated cardiomyopathy and clinical heart failure (DCM-HF) and control children. Nine children were included in the DCM-HF group and eight in the control group. Acylcarnitine profiles revealed a significant 3.1-fold increase of total acylcarnitines (sum of C3 to C18 acylcarnitine species) in DCM-HF children compared with controls. This result persisted considering the sum of long-chain acylcarnitines (sum of C14 to C18 species), medium-chain acylcarnitines (sum of C8 to C12 species), and short-chain acylcarnitines (sum of C3 to C6 species), respectively, 2.0-, 2.6-, and 1.9-fold increase compared with the control group. A significant linear correlation was found between left ventricular dilatation or ejection fraction and acylcarnitines accumulation. Finally, acylcarnitine ratio C16OH/C16 and C18OH/C18 enhanced in the DCM-HF group, suggesting a diminution of the long-chain hydroxyl acyl-CoA dehydrogenase activity. CONCLUSIONS: Our results suggest down-regulation of fatty acid oxidation in children with heart failure. Such lipidomic alteration could worsen heart function and may suggest considering a metabolic treatment of heart failure in children.

Sweet ending: When genetics prevent a dramatic CDG diagnostic mistake.

Herein, we described the case of a newborn male, from consanguineous parents, who developed, at day 11 of life, an obstructive hydrocephalus resulting from bilateral cerebellar hemorrhage without evident cause. Then, at 1 month, he developed a fulminant hepatitis with hyperammonia, hyperlactatemia and metabolic acidosis. Infectious and first line metabolic explorations were normal. Screening for congenital disorder of glycosylation (CDG) was performed using capillary electrophoresis and western blot of serum transferrin. Abnormal results were evocative of mannose-phosphate isomerase deficiency (MPI-CDG or CDG-Ib) as it can be responsible for fulminant hepatitis, digestive disease, developmental delay, and coagulopathy. However, trio whole exome sequencing revealed a pathogenic variant at the homozygous state in ALDOB, responsible for hereditary fructose intolerance (HFI), an inherited metabolic disorder with excellent prognosis under a fructose-free diet. HFI had not been previously evoked in view of the absence of diet diversification, but meticulous inquiry revealed that parents systematically added white sugar to the bottle milk of their child, unintentionally triggering potentially fatal HFI decompensations. Early genetic analysis upsetted both diagnosis and prognosis for this infant who had excellent development after fructose removal. This full-of-surprises diagnostic approach illustrates the importance of an integrative collaboration between clinicians, biochemists, and geneticists.

A case of severe toxicity during coadministration of vincristine and piperacillin: are drug transporters involved in vincristine hypersensitivity and drug-drug interactions?

Neurotoxicity is frequent with vincristine treatment, but severe autonomic neuropathy is rare. A decreased activity of drug transporters in the presence of an interacting drug may favor such events by increasing systemic or tissue exposure to the drug. We encountered severe autonomic neuropathy and cholestasis in a child receiving vincristine, after the introduction of piperacillin-tazobactam. A causality assessment of the adverse reaction identified the antibiotic as the most probable cause of the observation. The patient was heterozygous for several common polymorphisms of ABCC2 (multidrug-related protein-2), CYP3A5, and ABCB1 (multidrug-related protein-1, P-glycoprotein), but their role in the toxicity cannot be ascertained.

Routine determination of GFR in renal transplant recipients by HPLC quantification of plasma iohexol concentrations and comparison with estimated GFR.

Estimated glomerular filtration rate (eGFR) methods are not sufficiently reliable in renal transplant recipients (RTR) and should be replaced by iohexol plasma clearance measurement. However, this method has poor availability in health centers. The aim of our study was to develop a high-performance liquid chromatography (HPLC) method for plasma iohexol measurement in routine practice and to evaluate its plasma clearance as a reference of GFR. We developed an HPLC method using UV detection. We evaluated sample storage conditions to provide recommendations for routine practice. Then, we compared GFRbased on plasma iohexol clearance (GFR-iohexol) to eGFR using modification of diet in renal disease, Cockcroft and Gault, and CDK-EPIequations in 40 RTR. The method was validated over a concentration range of 15-300 µg/l. Excellent linearity (r > 0.998), inter- and intraday precision (CV < 3.3%), and accuracy (>96.8%) were complied with ICH guidelines. We also demonstrated excellent samples stability (9 days). Although eGFR methods are not references in RTR, we found a correct concordance between eGFR and GFR-iohexol in our population. To conclude, our method is simple, rapid, accurate, and reliable for routine clinical and research use especially in RTR.

Inflammatory mediators, lipoproteins and apolipoproteins in early diagnosis of amyotrophic lateral sclerosis.

There is currently no diagnostic or prognostic biomarker available in clinical practice for Amyotrophic Lateral Sclerosis (ALS). The objective of this study was to monitor a combination of various inflammatory markers, lipids, and apolipoproteins alterations in ALS patients at the time of diagnosis, to assess their role as early diagnostic or prognostic biomarker candidates. C-reactive protein, orosomucoid, prealbumin, calprotectin, lipids and apoliproteins were determined in the blood of all subjects (25 ALS patients, 23 controls) as routinely performed in our laboratory. Inflammatory mediators were evaluated by a bead-based multiplex assay. A two-step approach was used for each analytical strategy: univariate analysis followed by multivariate analysis. Eight features were significantly different between ALS patients and controls, sometimes with important fold changes. The supervised Partial least Squares Discriminant Analysis separated ALS and controls with great accuracy (94 %) and the permutation test was significant (p < 0.01), ensuring the robustness of the model. The prediction model leads to a mean sensitivity and specificity of 90 (+/- 10) and 78 (+/- 10) %, respectively, with a mean predictive positive value and negative predictive value of 80 (+/- 8.9) and 89 (+/- 11.8) %, respectively. However, the models did not discriminate subgroups of ALS patients based on ALS characteristics. This study highlights the usefulness of evaluating a combination of multiple pathways rather than focusing on a single target. These promising results suggest the need for the longitudinal monitoring of these candidates to determine their role in disease evolution.

Urinary elimination of coproporphyrins is dependent on ABCC2 polymorphisms and represents a potential biomarker of MRP2 activity in humans.

MRP2 encoded by ABCC2 gene is involved in the secretion of numerous drugs and endogenous substrates. Patients with Dubin-Johnson syndrome due to mutation in ABCC2 gene have elevated urinary coproporphyrin ratio (UCP I/(I + III)). Here we investigated whether this ratio could serve as a biomarker of MRP2 function. Phenotype-genotype relationships were studied in 74 healthy subjects by measuring individual UCP I/(I + III) ratio obtained on 24-hour urine and by analyzing five common SNPs in ABCC2 gene. The UCP I/(I + III) ratio varied from 14.7% to 46.0% in our population. Subjects with 3972TT genotype had a higher ratio (P = .04) than those carrying the C allele. This higher UCP I/(I + III) ratio was correlated with a higher level of isomer I excretion. This study provides a proof of concept that UCP I/(I + III) ratio can be used as a biomarker of MRP2 function in clinical studies as it provides quantitative information about the in vivo activity of MRP2 in a given patient.

Some CSF Kynurenine Pathway Intermediates Associated with Disease Evolution in Amyotrophic Lateral Sclerosis.

The aim of this study was to evaluate the kynurenine pathway (KP) and amino acids profile, using mass spectrometry, in the cerebrospinal fluid (CSF) of 42 amyotrophic lateral sclerosis (ALS) patients at the diagnosis and 40 controls to detect early disorders of these pathways. Diagnostic and predictive ability (based on weight loss, forced vital capacity, ALS Functional Rating Scale-Revised evolution over 12 months, and survival time) of these metabolites were evaluated using univariate followed by supervised multivariate analysis. The multivariate model between ALS and controls was not significant but highlighted some KP metabolites (kynurenine (KYN), kynurenic acid (KYNA), 3-Hydroxynurenine (3-HK)/KYNA ratio), and amino acids (Lysine, asparagine) as involved in the discrimination between groups (accuracy 62%). It revealed a probable KP impairment toward neurotoxicity in ALS patients and in bulbar forms. Regarding the prognostic effect of metabolites, 12 were commonly discriminant for at least 3 of 4 disease evolution criteria. This investigation was crucial as it did not show significant changes in CSF concentrations of amino acids and KP intermediates in early ALS evolution. However, trends of KP modifications suggest further exploration. The unclear kinetics of neuroinflammation linked to KP support the interest in exploring these pathways during disease evolution through a longitudinal strategy.

[POCT-management during the first wave of Covid-19 in France. Results of a national survey leaded by the SFBC-POCT Working Group]. / Gestion de la biologie délocalisée lors de la première vague de Covid-19 en France. Résultats de l'enquête nationale menée par le groupe de travail des EBMD de la SFBC.

During the first wave of Covid-19 in France, in spring 2020, healthcare institution's laboratory had to adapt itself quickly to the growing demand for emergency biology, in particular by reorganizing their POCT analyzers: redeployment of analyzers and/or new installations. In order to analyze this management, a subgroup of 15 hospital biologists from the SFBC Working Group "Biochemical markers of Covid-19" sent, in fall 2020, an on-line survey to French hospital laboratories using POCT. Answers analysis (n = 86) shows a territorial disparity related to the severity of the first wave: increased activity essentially in red zones, management of unexpected situations, training of additional nursing staff for 40 % of the laboratories... The survey also showed simplification of aspects related to accreditation those periods of health crisis. An additional survey, carried out in the spring of 2021, showed good overall satisfaction of the healthcare services (n = 139) concerning the services provided by biology in the POCT sector. Because of their great adaptation capacity, the laboratories and their POCT-teams have played a key role in the management of the first wave of Covid-19 in France. However, the success of these organizations requires an essential collaboration between laboratories and healthcare services. The results of this survey are fundamental in the context of the prolongation of the pandemia throughout the world with a POCT sector appearing to be growing.

Influence of methotrexate exposure on outcome in patients treated with MBVP chemotherapy for primary central nervous system lymphoma.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Although treated using the same high-dose methotrexate (HD-MTX)-based multiagent chemotherapy, patients with primary central nervous system lymphoma (PCNSL) have significant differences in outcome. However, little information has been published about factors influencing outcome in PCNSL. As it is known that the pharmacokinetics of MTX vary considerably between subjects leading to different exposure in patients receiving the same dose, it is important to evaluate its role in response to chemotherapy. WHAT THIS STUDY ADDS: This study is the first to evaluate the exposure-response relationship in patients treated with MBVP chemotherapy. We found that patients who were early non-responders to MBVP chemotherapy had poor survival, whatever the salvage regimen. Tumour response at early evaluation was not associated with MTX pharmacokinetics and increasing the dose would probably not improve results. AIMS: Although the standard treatment for primary central nervous system lymphoma (PCNSL) consists of three cycles of MBVP (methotrexate, BCNU, VP16, methylprednisolone) and radiotherapy, early failure of treatment may require modification of the treatment. However, our understanding of the outcome in such patients and of the factors involved in early failure of treatment is poor. In addition to known prognostic factors, we evaluated the influence of methotrexate (MTX) exposure on the response to MBVP chemotherapy in patients treated for PCNSL after the first two cycles. METHODS: We retrospectively analyzed all patients with PCNSL treated with the MBVP regimen over the previous 10 years. Clinical, personal data and known prognostic factors were studied. The parameters of MTX exposure were estimated using a population pharmacokinetic approach with NONMEM. Objective response (OR), overall survival (OS) and failure-free survival (FFS) were evaluated in all patients. RESULTS: Thirty-seven patients were studied. We observed lower FFS and OS (0.49 years) in patients who were not able to receive the planned treatment (group 1, n=12) than in those who received three cycles (8.04 years) (group 2, n=25). Known prognostic factors were comparable in both groups, but mean dose of MTX and mean AUC tended to be lower in patients who failed prematurely or showed no response after two cycles. CONCLUSIONS: We found that patients who were early non-responders to MBVP chemotherapy had poor survival, without major influence of MTX exposure. It is thus probably unlikely that increasing the dose of MTX would improve outcome.

History, extensive characterization and challenge of anti-tetanus serum from World War I: exciting remnants and deceived hopes : Centenarian IgGs lost their neutralization capacity.

During World War I (WWI), infectious diseases including tetanus were among the most important causes of death. Even though its efficacy was somewhat controversial before the war, tetanus antiserum played a key role in reducing the mortality of this disease. A vial of tetanus antiserum dating back from WWI, left behind on the French battlefield by the US Army, was borrowed from a private collection and opened. The serum contained within was characterized by orthogonal biochemical techniques to determine if any neutralizing IgGs could remain after 100 years of storage. In vitro analysis by Size Exclusion Chromatography and Serum Protein Electrophoresis suggested the presence of residual IgG. In spite of our hopes, these IgGs were not able to protect mice against tetanus toxin challenge in a neutralizing assay. Even though our results indicate the presence of remaining IgGs inside the serum, they were functionally disabled. These results show that obscurity alone is insufficient to protect IgGs from degradation over very long periods of time at room temperature. HIGHLIGHTS: Tetanus antiserum found its place in the therapeutic arsenal during World War I A century-old vial of tetanus antiserum was opened for biochemical and in vivo characterization Biochemical assays revealed the presence of proteins having all the characteristics of IgGs The serum was unable to protect mice against toxinic challenge.

The specific metabolome profiling of patients infected by SARS-COV-2 supports the key role of tryptophan-nicotinamide pathway and cytosine metabolism.

The biological mechanisms involved in SARS-CoV-2 infection are only partially understood. Thus we explored the plasma metabolome of patients infected with SARS-CoV-2 to search for diagnostic and/or prognostic biomarkers and to improve the knowledge of metabolic disturbance in this infection. We analyzed the plasma metabolome of 55 patients infected with SARS-CoV-2 and 45 controls by LC-HRMS at the time of viral diagnosis (D0). We first evaluated the ability to predict the diagnosis from the metabotype at D0 in an independent population. Next, we assessed the feasibility of predicting the disease evolution at the 7th and 15th day. Plasma metabolome allowed us to generate a discriminant multivariate model to predict the diagnosis of SARS-CoV-2 in an independent population (accuracy > 74%, sensitivity, specificity > 75%). We identified the role of the cytosine and tryptophan-nicotinamide pathways in this discrimination. However, metabolomic exploration modestly explained the disease evolution. Here, we present the first metabolomic study in SARS-CoV-2 patients which showed a high reliable prediction of early diagnosis. We have highlighted the role of the tryptophan-nicotinamide pathway clearly linked to inflammatory signals and microbiota, and the involvement of cytosine, previously described as a coordinator of cell metabolism in SARS-CoV-2. These findings could open new therapeutic perspectives as indirect targets.

[Determination of thresholds values for platelet serotonin and urinary 5-HIAA concentrations for the biological diagnosis of digestive neuroendocrine tumors]. / Quelles valeurs de référence pour la concentration de la sérotonine plaquettaire et du 5-HIAA urinaire pour le diagnostic des tumeurs neuroendocrines digestives ?

OBJECTIVES: Platelet serotonin and its urinary metabolite 5-HIAA (5-hydroxyindolacetic acid) are the main biomarkers measured for the detection of neuroendocrine tumors (NET). We observe in our laboratory many false positives or false negatives for the 2 assays using threshold values given by the manufacturer. We aim to determine our own local threshold values for a better detection of gastrointestinal NETs. METHODS: We studied patients with measurement of platelet serotonin and/or urinary 5-HIAA in University Hospital of Tours between January 2005 and June 2016. We established an « index ¼ cohort with 75% of patients to determine local threshold value for the 2 parameters. A "validation" cohort constituted with 25% of remaining patients allowed us to compare the performances of manufacturer's values with local threshold values. RESULTS: Two hundred ninety patients were included, with 19 suffering from NETs. Local threshold value for platelet serotonin was determined at 5.13 amol/platelet, the one for urinary 5-HIAA at 3.60 µmol/mmol urinary creatinine. Platelet serotonin specificity was better with local threshold value for identical sensibility (0.75). Urinary 5-HIAA sensibility was improved with local threshold value (1 vs 0.667) for identical specificity (0.902). CONCLUSION: Using our local threshold value for platelet serotonin and urinary 5-HIAA improved diagnostic performances of these biochemical markers to detect NETs.