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. A multi-disciplinary Working Group, carried out under the auspices of the French Society of Clinical Biology (SFBC) and in collaboration with the French Societies of Emergency Medicine (SFMU), Analytical Toxicology (SFTA), Hemostasis and Thrombosis (SFTH), Vitamins and Biofactors (SFVB), and the French Federation of Neurology (FFN), was recently implemented to elaborate practical guidelines. The methodology of the Working Group is based on the critical analysis of the literature, and raising concerns and objectives are grouped into five working packages. The present manuscript primarily aims to expound upon the methodology and objectives of the ongoing SFBC Working Group on N2O.

Iron and Vitamin B12 Deficiency in Patients with Autoimmune Gastritis and Helicobacter pylori Gastritis: Results from a Prospective Multicenter Study.

INTRODUCTION: Iron and vitamin B12 deficiencies are common in patients with atrophic gastritis, but there are limited data on the prevalence of these deficiencies in different types of atrophic gastritis. METHODS: This multicenter, prospective study assessed micronutrient concentrations in histologically confirmed autoimmune gastritis (AIG, n = 45), Helicobacter pylori-related non-autoimmune gastritis (NAIG, n = 109), and control patients (n = 201). A multivariate analysis was performed to determine factors influencing those deficiencies. RESULTS: The median vitamin B12 concentration was significantly lower in AIG (367.5 pg/mL, Q1, Q3: 235.5, 524.5) than in NAIG (445.0 pg/mL, Q1, Q3: 355.0, 565.0, p = 0.001) and control patients (391.0 pg/mL, Q1, Q3: 323.5, 488.7, p = 0.001). Vitamin B12 deficiency was found in 13.3%, 1.5%, and 2.8% of AIG, NAIG, and control patients, respectively. Similarly, the median ferritin concentration was significantly lower in AIG (39.5 ng/mL, Q1, Q3: 15.4, 98.3 ng/mL) than in NAIG (80.5 ng/mL, Q1, Q3: 43.6, 133.9, p = 0.04) and control patients (66.5 ng/mL, Q1, Q3: 33.4, 119.8, p = 0.007). Iron deficiency and iron deficiency adjusted to CRP were present in 28.9% and 33.3% of AIG, 12.8% and 16.5% of NAIG, and 12.9% and 18.4% of controls, respectively. Multivariate analysis demonstrated that AIG patients had a higher risk of developing vitamin B12 deficiency (OR: 11.52 [2.85-57.64, p = 0.001]) and iron deficiency (OR: 2.92 [1.32-6.30, p = 0.007]) compared to control patients. Factors like age, sex, and H. pylori status did not affect the occurrence of vitamin B12 or iron deficiency. CONCLUSION: Iron and vitamin B12 deficiencies are more commonly observed in patients with AIG than in those with NAIG or control patients. Therefore, it is essential to screen for both iron and vitamin B12 deficiencies in AIG patients and include the treatment of micronutrient deficiencies in the management of atrophic gastritis patients.

Insulin: Know what your immunoassay detects. Evaluation of two new immunoassays.

BACKGROUND: Insulin is essential for glycemic regulation but diseases can cause a default or an excess of insulin secretion leading to dysregulated glycemia. Hence, measurement of insulinemia is useful to investigate hypoglycemia, determine the pathogenesis of diabetes and evaluate ß-cell function. Thus, diabetic patients need supplementation with recombinant human insulin and/or insulin analogues. Analogues have primary sequences different from native human insulin and may not be detected by some immunoassays. The objective of our study was to evaluate new insulin immunoassays by determining their ability to detect different types of human insulin or analogues. METHODS: This study compared the reactivity of two new insulin immunoassays with five well-established immunoassays on ten commercial insulins. We also measured insulin in blood samples from diabetic or pancreas transplant patients with known treatment. RESULTS: Contrary to recombinant human insulin, there were differences in the specificity to insulin analogues. We distinguished three immunoassay categories: those recognizing all types of insulin such as the non-specific BI-INS-IRMA®, Architect® and Access® immunoassays; those recognizing human insulin only (Cobas®); and those recognizing human insulin and analogues in variable proportions (Liaison XL®, iFlash® and Maglumi®). CONCLUSION: An accurate biological interpretation of insulinemia relies on knowledge of the specificity of the immunoassay used.

Atrophic Gastritis and Autoimmunity: Results from a Prospective, Multicenter Study.

Despite a global decrease, gastric cancer (GC) incidence appears to be increasing recently in young, particularly female, patients. The causal mechanism for this "new" type of GC is unknown, but a role for autoimmunity is suggested. A cascade of gastric precancerous lesions, beginning with chronic atrophic gastritis (CAG), precedes GC. To test the possible existence of autoimmunity in patients with CAG, we aimed to analyze the prevalence of several autoantibodies in patients with CAG as compared to control patients. Sera of 355 patients included in our previous prospective, multicenter study were tested for 19 autoantibodies (anti-nuclear antibodies, ANA, anti-parietal cell antibody, APCA, anti-intrinsic factor antibody, AIFA, and 16 myositis-associated antibodies). The results were compared between CAG patients (n = 154), including autoimmune gastritis patients (AIG, n = 45), non-autoimmune gastritis patients (NAIG, n = 109), and control patients (n = 201). ANA positivity was significantly higher in AIG than in NAIG or control patients (46.7%, 29%, and 27%, respectively, p = 0.04). Female gender was positively associated with ANA positivity (OR 0.51 (0.31-0.81), p = 0.005), while age and H. pylori infection status were not. Myositis-associated antibodies were found in 8.9% of AIG, 5.5% of NAIG, and 4.4% of control patients, without significant differences among the groups (p = 0.8). Higher APCA and AIFA positivity was confirmed in AIG, and was not associated with H. pylori infection, age, or gender in the multivariate analysis. ANA antibodies are significantly more prevalent in AIG than in control patients, but the clinical significance of this finding remains to be established. H. pylori infection does not affect autoantibody seropositivity (ANA, APCA, AIFA). The positivity of myositis-associated antibodies is not increased in patients with CAG as compared to control patients. Overall, our results do not support an overrepresentation of common autoantibodies in patients with CAG.

Serum pepsinogens can help to discriminate between H. pylori-induced and auto-immune atrophic gastritis: Results from a prospective multicenter study.

BACKGROUND: Serum pepsinogen (PG) testing is recommended by the European guidelines for diagnosis of chronic atrophic gastritis (CAG). However, wide variations in diagnostic performances are observed, due to the differences in the extent of gastric atrophy, and possibly in its origin (Helicobacter pylori-, autoimmune (AIG)). AIM: To analyze the diagnostic performances of PGs testing according to these different parameters, using enzyme-linked-immunosorbent serologic assay (ELISA) and chemiluminescent immunoassay (CLEIA). METHODS: Serum samples from patients having undergone gastroscopy with biopsies in five French centers were collected prospectively. Sensitivity (Se), specificity (Sp), and Area Under Curve were analyzed according to the extent and origin of CAG. RESULTS: Overall, 344 patients (156 males [45%]; mean age 58.8 [±14.2] years) were included, among whom 44 had AIG. Diagnostic performances of PG I for the detection of corpus CAG were excellent, with Se and Sp of 92.7% and 99.1% for ELISA and 90.5% and 98.2% for CLEIA, respectively. For AIG, corresponding values were 97.7% and 97.4% for ELISA, and 95.6% and 97.1% for CLEIA. In multivariate analysis, PG levels were associated with the auto-immune origin (p<0.001) but not with the extent of the atrophic gastritis. CONCLUSIONS: Pepsinogens are highly efficient for the diagnosis of corpus-limited CAG and allow to discriminate AIG from H. pylori-induced gastritis.

Psychological stress induces an increase in cholinergic enteric neuromuscular pathways mediated by glucocorticoid receptors.

Introduction: Repeated acute stress (RASt) is known to be associated with gastrointestinal dysfunctions. However, the mechanisms underlying these effects have not yet been fully understood. While glucocorticoids are clearly identified as stress hormones, their involvement in RASt-induced gut dysfunctions remains unclear, as does the function of glucocorticoid receptors (GR). The aim of our study was to evaluate the involvement of GR on RASt-induced changes in gut motility, particularly through the enteric nervous system (ENS). Methods: Using a murine water avoidance stress (WAS) model, we characterized the impact of RASt upon the ENS phenotype and colonic motility. We then evaluated the expression of glucocorticoid receptors in the ENS and their functional impact upon RASt-induced changes in ENS phenotype and motor response. Results: We showed that GR were expressed in myenteric neurons in the distal colon under basal conditions, and that RASt enhanced their nuclear translocation. RASt increased the proportion of ChAT-immunoreactive neurons, the tissue concentration of acetylcholine and enhanced cholinergic neuromuscular transmission as compared to controls. Finally, we showed that a GR-specific antagonist (CORT108297) prevented the increase of acetylcholine colonic tissue level and in vivo colonic motility. Discussion: Our study suggests that RASt-induced functional changes in motility are, at least partly, due to a GR-dependent enhanced cholinergic component in the ENS.

Serum Pepsinogens Combined with New Biomarkers Testing Using Chemiluminescent Enzyme Immunoassay for Non-Invasive Diagnosis of Atrophic Gastritis: A Prospective, Multicenter Study.

BACKGROUND: Analysis of serum biomarkers for the assessment of atrophic gastritis (AG), a gastric precancerous lesion, is of growing interest for identification of patients at increased risk of gastric cancer. The aim was to analyze the diagnostic performance of serum pepsinogen testing using another method, chemiluminescent enzyme immunoassay (CLEIA), as well as of other new potential biomarkers. MATERIAL AND METHODS: The sera of patients considered at increased risk of gastric cancer and undergoing upper endoscopy collected in our previous prospective, multicenter study were tested for pepsinogen I (PGI) and II (PGII), interleukin-6 (IL-6), human epididymal protein 4 (HE-4), adiponectin, ferritin and Krebs von den Lungen (KL-6) using the CLEIA. The diagnostic performance for the detection of AG was calculated by taking histology as the reference. RESULTS: In total, 356 patients (162 men (46%); mean age 58.6 (±14.2) years), including 152 with AG, were included. For the detection of moderate to severe corpus AG, sensitivity and specificity of the pepsinogen I/II ratio were of 75.0% (95%CI 57.8-87.9) and 92.6% (88.2-95.8), respectively. For the detection of moderate to severe antrum AG, sensitivity of IL-6 was of 72.2% (95%CI 46.5-90.3). Combination of pepsinogen I/II ratio or HE-4 showed a sensitivity of 85.2% (95%CI 72.9-93.4) for the detection of moderate to severe AG at any location. CONCLUSION: This study shows that PG testing by CLEIA represents an accurate assay for the detection of corpus AG. Additionally, IL-6 and HE-4 may be of interest for the detection of antrum AG. MINI-ABSTRACT: Pepsinogens testing by chemiluminescent enzyme immunoassay is accurate for the detection of corpus atrophic gastritis. IL-6 and HE-4 maybe of interest for the detection of antrum atrophic gastritis.

Induction of Human Trophoblast Stem Cells from Somatic Cells and Pluripotent Stem Cells.

Human trophoblast stem cells (hTSCs) derived from blastocysts and first-trimester cytotrophoblasts offer an unprecedented opportunity to study the placenta. However, access to human embryos and first-trimester placentas is limited, thus preventing the establishment of hTSCs from diverse genetic backgrounds associated with placental disorders. Here, we show that hTSCs can be generated from numerous genetic backgrounds using post-natal cells via two alternative methods: (1) somatic cell reprogramming of adult fibroblasts with OCT4, SOX2, KLF4, MYC (OSKM) and (2) cell fate conversion of naive and extended pluripotent stem cells. The resulting induced/converted hTSCs recapitulated hallmarks of hTSCs including long-term self-renewal, expression of specific transcription factors, transcriptomic signature, and the potential to differentiate into syncytiotrophoblast and extravillous trophoblast cells. We also clarified the developmental stage of hTSCs and show that these cells resemble day 8 cytotrophoblasts. Altogether, hTSC lines of diverse genetic origins open the possibility to model both placental development and diseases in a dish.

A panel of stomach-specific biomarkers (GastroPanel®) for the diagnosis of atrophic gastritis: A prospective, multicenter study in a low gastric cancer incidence area.

BACKGROUND: Analysis of serum biomarkers for the assessment of atrophic gastritis (AG), considered as gastric precancerous lesion, is of growing interest and recommended by current guidelines. Our aim was to evaluate the diagnostic performance of a panel of biomarkers (GastroPanel®) for the detection of AG in France, a country of a low gastric cancer (GC) incidence. MATERIAL AND METHODS: In this prospective, multicenter, cross-sectional study, consecutive patients considered at increased risk of GC and undergoing upper endoscopy with gastric biopsies were included. Blood samples were collected for the analysis of GastroPanel® (association of Pepsinogens I and II, Gastrin-17, and Helicobacter pylori serology) using ELISA. The results of GastroPanel® were compared to the results of histology considered as the reference. RESULTS: Between 2016 and 2019, 344 patients (148 cases with AG, 196 controls without AG) were included. Sensitivity, specificity, positive, and negative predictive values for the detection of AG by GastroPanel® were of 39.9% (95% CI 31.9; 48.2), 93.4% (95% CI 88.9; 96.4), 81.9 (95% CI 71.1; 90.0), and 67.3 (95% CI 61.4; 72.8), respectively. The sensitivity was significantly higher for the detection of severe AG [60.8% (95% CI 46.1; 74.6) P = .015] and corpus AG [61.0% (95% CI 49.2; 72.0), P = .004]. Diagnostic performances of GastroPanel® tended to be better than those of Pepsinogen I alone, but the difference did not reach statistical significance (P = .068). CONCLUSION: Serum pepsinogen and GastroPanel® tests show promising results for the detection of AG, especially of corpus AG and severe AG, in patients at high risk of GC in France.

Abnormally Elevated Follicle-Stimulating Hormone (FSH) Level in an Infertile Woman.

We report a case of 33-year-old woman with a 4-year primary infertility. A high isolated follicle-stimulating hormone (FSH) level was conflicting with the clinical situation and with other hormonal markers which were in favor of polycystic ovarian syndrome. We followed a strategy used to identify immune complexes involving FSH. The PEG precipitation test revealed that the high FSH level was almost exclusively due to the presence of autoimmune FSH immunoglobulin complex (macro-FSH). The profile obtained by gel filtration chromatography confirmed the presence of an FSH-immunoglobulin complex. Such immunological dysregulation could be explored in cases of unexplained infertility and recurrent IVF failure.