Biomarkers for the diagnosis and monitoring of nitrous oxide intoxication: objectives and methodology of the SFBC Working Group.

The recreational use of nitrous oxide (N2O) is an emerging public health issue. Chronic N2O abuse may result in various clinical symptoms, encompassing neurological, psychiatric and cardiovascular outcomes. Despite the difficulties for the laboratory investigation of N2O intoxication, there is currently no guidelines in France to help both clinicians and biologists use appropriate biomarkers for the diagnosis and monitoring of patients with clinical symptoms potentially related to N2O intoxication.

Free hemoglobin determination at patients' bedside to evaluate hemolysis.

The authors report the relevance of using a point of care test (Helge) for free hemoglobin determination and concordance of the values the with Cobas 8000 and spectrophotometer methods. The within-run of the point of care test was <3%. Good correlations among the three methods were observed and an acceptable concordance for hemolysis index values from 50 mg/dl.

Use of dried blood spots for monitoring inflammatory and nutritional biomarkers in the elderly.

Objectives: Blood microsampling, particularly dried blood spots (DBSs), is an attractive minimally-invasive approach that is well suited for home sampling and predictive medicine associated with longitudinal follow-up of the elderly. However, diagnostic quantification of biomarkers from DBS poses a major challenge. Clinical mass spectrometry can reliably quantify blood proteins in various research projects.

Functional vitamin B deficiency is a consistent feature in hospital admissions for neurological disorders due to the use of nitrous oxide.

Misuse of inhaled nitrous oxide is a growing concern in France. It is known to alter concentrations of vitamin B which is required as a cofactor for methionine synthase and methylmalonyl-CoA mutase activity. Hence, measurement of the concentrations of cobalamin metabolism biomarkers, including vitamin B, homocysteine, and methylmalonic acid, could assist in the management of patients with a complex clinical presentation or in those who deny the consumption of nitrous oxide.

The pivotal role of HbA1c assay to detect hemoglobinopathies: A 5-year observational retrospective study in the population of Southern France.

Background And Aims: Mobility and migration flows are growing from different countries of the world to European countries, including France and in particular the Mediterranean basin. This study aimed to investigate the presence of hemoglobin (Hb) variants in outpatients/inpatients of the Montpellier Hospital (France) in whom an HbA1c assay had been performed and for which the country of birth had been informed.

Methods: This is a retrospective study from January 2016 to December 2020 based on all high-performance liquid chromatography (HPLC) chromatograms (Tosoh Bioscience HLC-723G8) having an alarm of suspected Hb variant during HbA1c measurement.

New Perspectives of Multiplex Mass Spectrometry Blood Protein Quantification on Microsamples in Biological Monitoring of Elderly Patients.

Blood microsampling combined with large panels of clinically relevant tests are of major interest for the development of home sampling and predictive medicine. The aim of the study was to demonstrate the practicality and medical utility of microsamples quantification using mass spectrometry (MS) in a clinical setting by comparing two types of microsamples for multiplex MS protein detection. In a clinical trial based on elderly population, we compared 2 µL of plasma to dried blood spot (DBS) with a clinical quantitative multiplex MS approach.

Frontal Intermittent Rhythmic Delta Activity Is a Useful Diagnostic Tool of Neurotoxicity After CAR T-Cell Infusion.

Background And Objectives: Chimeric antigen receptor (CAR) T-cell therapies have dramatically improved the prognosis of patients with relapsed or refractory hematologic malignancies; however, cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome (ICANS) occur in ∼100 and 50% of patients, respectively. This study aimed to determine whether EEG patterns may be considered as diagnostic tools for ICANS.

Methods: Patients who received CAR T-cell therapy at Montpellier University Hospital between September 2020 and July 2021 were prospectively enrolled.

Cystatin C for kidney function assessment in patients with facioscapulohumeral muscular dystrophy.

Background And Aims: Muscle mass (MM) impairment observed in facioscapulohumeral muscular dystrophy (FSHD) may bias estimated glomerular filtration rate (eGFR) based on creatinine (eGFRcreat). eGFR based on cystatin C (eGFRcys), produced by all nucleated cells, should be an interesting alternative. Main objectives were to compare eGFRcreat and eGRFcys for chronic kidney disease (CKD) staging and for annual eGFR evolution.

Cystatin C in addition to creatinine for better assessment of glomerular renal function decline in people with HIV receiving antiretroviral therapy.

Objective: To compare the estimated glomerular filtration rate (eGFR) using the creatinine equation (eGFRcreat) or the cystatin C equation (eGFRcys) in people with HIV (PWH) under antiretroviral drugs. We specifically included patients with an eGFRcreat around 60 ml/min per 1.73 m2 to evaluate agreement on stage 2 and 3 chronic kidney disease (CKD) classification.

Analytical Performances of the Novel i-STAT Alinity Point-of-Care Analyzer.

Many Point-of-Care devices have been released over the past decade. However, data regarding their analytical performances in real-world situations remains scarce. Herein, we aimed to assess the analytical performances of the i-STAT Alinity system.

Neutrophil extracellular traps have auto-catabolic activity and produce mononucleosome-associated circulating DNA.

Background: As circulating DNA (cirDNA) is mainly detected as mononucleosome-associated circulating DNA (mono-N cirDNA) in blood, apoptosis has until now been considered as the main source of cirDNA. The mechanism of cirDNA release into the circulation, however, is still not fully understood. This work addresses that knowledge gap, working from the postulate that neutrophil extracellular traps (NET) may be a source of cirDNA, and by investigating whether NET may directly produce mono-N cirDNA.

Persistence of neutrophil extracellular traps and anticardiolipin auto-antibodies in post-acute phase COVID-19 patients.

In the early phase of the pandemic, we were among the first to postulate that neutrophil extracellular traps (NETs) play a key role in COVID-19 pathogenesis. This exploratory prospective study based on 279 individuals showed that plasma levels of neutrophil elastase, myeloperoxidase and circulating DNA of nuclear and mitochondrial origins in nonsevere (NS), severe (S) and postacute phase (PAP) COVID-19 patients were statistically different as compared to the levels in healthy individuals, and revealed the high diagnostic power of these NETs markers in respect to the disease severity. The diagnostic power of NE, MPO, and cir-nDNA as determined by the Area Under Receiver Operating Curves (AUROC) was 0.

Analytical evaluation and bioclinical validation of new aldosterone and renin immunoassays.

Objectives: Aldosterone and renin determinations play an important role in the etiological diagnosis of secondary hypertension. The analytical performances of new aldosterone and renin immunoassays on the Lumipulse G600II system (Fujierbio) were investigated and compared with those of the iSYS system (IDS) on patients concerned by medical investigations in a context of suspected or proven Primary aldosteronism.

Methods: By using the Lumipulse G Aldosterone and Renin assays we performed imprecision study, linearity and method comparison (n=107).

A case of inter-assay HbA1c discrepancy due to Hemoglobin G-Copenhagen.

Background And Objective: A clinician was intrigued about HbA1c upper 9% (75 mmol/mol) in a 76 year-old women with normal glycemia. Further explorations were performed in order to understand this discordance.

Methods: First HbA1c test was performed on a HLC -723 G11 apparatus (Tosoh Bioscience) and thereafter compared to the HLC-723-G8 (Tosoh Bioscience), the Capillaris 3 Tera (Sebia) and the DCA Vantage point of care testing (POCT) (Siemens) apparatus.

Optimization of Patient Management in the Gynecology Emergency Department Using Point-of-Care Beta hCG.

Background: Point-of-care testing (POCT) provides shorter turn-around times and, in many cases, potentially improves medical decision making. The AQT90 FLEX® benchtop immunoanalyzer (Radiometer Medical ApS, Copenhagen, Denmark) allows for the determination of beta-human chorionic gonadotropin (βhCG) in 18 min. The main aim of this study was to evaluate the impact of measuring βhCG using the AQT90 analyzer in the gynecology emergency department (ED) compared to the standard practice of using central laboratory blood testing on the patient length of stay (LOS).

Biomarkers of Redox Balance Adjusted to Exercise Intensity as a Useful Tool to Identify Patients at Risk of Muscle Disease through Exercise Test.

The screening of skeletal muscle diseases constitutes an unresolved challenge. Currently, exercise tests or plasmatic tests alone have shown limited performance in the screening of subjects with an increased risk of muscle oxidative metabolism impairment. Intensity-adjusted energy substrate levels of lactate (La), pyruvate (Pyr), β-hydroxybutyrate (BOH) and acetoacetate (AA) during a cardiopulmonary exercise test (CPET) could constitute alternative valid biomarkers to select "at-risk" patients, requiring the gold-standard diagnosis procedure through muscle biopsy.

Fatal accidental lipid overdose with intravenous composite lipid emulsion in a premature newborn: a case report.

Background: Tenfold or more overdose of a drug or preparation is a dreadful adverse event in neonatology, often due to an error in programming the infusion pump flow rate. Lipid overdose is exceptional in this context and has never been reported during the administration of a composite intravenous lipid emulsion (ILE).

Case Presentation: Twenty-four hours after birth, a 30 weeks' gestation infant with a birthweight of 930 g inadvertently received 28 ml of a composite ILE over 4 h.

Evaluation of a new point-of-care testing for creatinine and urea measurement.

Point of care testing makes it possible to obtain results in an extremely short time. Recently, radiometer has expanded the panel of tests available on its ABL90 FLEX PLUS blood gas analyzer (ABL90) by adding urea and creatinine. The aim of this study was to verify the performance of these new parameters.