Acute-onset delirium in intensive care COVID patients: association of imperfect brain repair with foodborne micro-pollutants.

BACKGROUND AND PURPOSE: COVID-19 affects the brain in various ways, amongst which delirium is worrying. An assessment was made of whether a specific, long-lasting, COVID-19-related brain injury develops in acute respiratory distress syndrome patients after life-saving re-oxygenation. METHODS: Ten COVID+ patients (COVID+) with unusual delirium associated with neuroimaging suggestive of diffuse brain injury and seven controls with non-COVID encephalopathy were studied. The assessment took place when the intractable delirium started at weaning off ventilation support. Brain magnetic resonance imaging (MRI) was performed followed by standard cerebrospinal fluid (CSF) analyses and assessment of CSF erythropoietin concentrations (as a marker for the assessment of tissue repair), and of non-targeted CSF metabolomics using liquid chromatography high resolution mass spectrometry. RESULTS: Patients were similar as regards severity scores, but COVID+ were hospitalized longer (25 [11.75; 25] vs. 9 [4.5; 12.5] days, p = 0.03). On admission, but not at MRI and lumbar puncture performance, COVID+ were more hypoxic (p = 0.002). On MRI, there were leptomeningeal enhancement and diffuse white matter haemorrhages only in COVID+. In the latter, CSF erythropoietin concentration was lower (1.73 [1.6; 2.06] vs. 3.04 [2.9; 3.91] mIU/ml, p = 0.01), and CSF metabolomics indicated (a) increased compounds such as foodborne molecules (sesquiterpenes), molecules from industrialized beverages and micro-pollutants (diethanolamine); and (b) decreased molecules such as incomplete breakdown products of protein catabolism and foodborne molecules (glabridin). At 3-month discharge, fatigue, anxiety and depression as well as MRI lesions persisted in COVID+. CONCLUSIONS: Some COVID+ are at risk of a specific delirium. Imperfect brain repair after re-oxygenation and lifestyle factors might influence long-lasting brain injuries in a context of foodborne micro-pollutants.

Environmental exposure to phthalates and dementia with Lewy bodies: contribution of metabolomics.

BACKGROUND: In neurodegenerative diseases, alongside genetic factors, the possible intervention of environmental factors in the pathogenesis is increasingly being considered. In particular, recent evidence suggests the intervention of a pesticide-like xenobiotic in the initiation of disease with Lewy bodies (DLB). OBJECTIVES: To test for the presence of pesticides or other xenobiotics in the cerebrospinal fluid (CSF) of patients with DLB. METHODS: A total of 45 patients were included in this study: 16 patients with DLB at the prodromal stage, 8 patients with DLB at the demented stage, 8 patients with Alzheimer's disease (AD) at the prodromal stage and 13 patients with AD at the demented stage. CSF was obtained by lumbar puncture and analysed by liquid chromatography-mass spectrometry. RESULTS: Among the compounds detected in greater abundance in the CSF of patients with DLB compared with patients with AD, only one had a xenobiotic profile potentially related to the pathophysiology of DLB. After normalisation and scaling, bis(2-ethylhexyl) phthalate was more abundant in the CSF of patients with DLB (whole cohort: 2.7-fold abundant in DLB, p=0.031; patients with dementia: 3.8-fold abundant in DLB, p=0.001). CONCLUSIONS: This study is the first reported presence of a phthalate in the CSF of patients with DLB. This molecule, which is widely distributed in the environment and enters the body orally, nasally and transdermally, was first introduced in the 1920s as a plasticizer. Thereafter, the first cases of DLB were described in the 1960s and 1970s. These observations suggest that phthalates may be involved in the pathophysiology of DLB.

[Chronic kidney failure and biotin: A combination inducing unusual results in thyroid and parathyroid investigations, report of 2 cases]. / Insuffisance rénale chronique et biotine : un duo propice aux bilans thyroïdiens et parathyroïdiens erronés, à propos de 2 cas.

In clinical chemistry, many immunoassays apply biotin and streptavidin in the assay principle. Presence of high levels of biotin in patient samples can produce negative or positive interference depending on the assay format. In this study, we describe 2 clinical cases with chronic kidney failure and with unusual thyroid and parathyroid function test results due to biotin interference. We studied the impact of biotin levels on thyroid stimulating hormone (TSH), free thyroxine (T4L) and parathormone (PTH) results with a pool of sera loaded with several concentrations of biotin. In sandwich assays (TSH and PTH), excess biotin displaces biotinylated antibodies resulting in apparently low concentration of the analyte. With competitive immunoassays (T4L), excess biotin competes with biotinylated analog for the binding sites on streptavidin resulting in low signal and falsely high concentration of the analyte. In conclusion, chronic kidney failure combined to therapeutic biotin is in favour of high levels of biotin which causes seriously misleading results in assays using biotin-streptavidin mechanisms.

Assessment of adrenal function in patients with acute hepatitis using serum free and total cortisol.

BACKGROUND: Adrenal dysfunction is frequently reported in severe acute hepatitis using serum total cortisol. AIMS: Because 90% of serum cortisol is bound to proteins that are altered during stress, we investigated the effect of decreased cortisol-binding proteins on serum total and free cortisol in severe acute hepatitis. METHODS: 43 severe and 31 non-severe acute hepatitis and 29 healthy controls were enrolled consecutively and studied prospectively. Baseline (T0) and cosyntropin-stimulated (T60) serum total and free cortisol concentrations were measured. RESULTS: T0 and T60 serum total cortisol did not differ significantly between severe, non-severe hepatitis and healthy controls. Conversely, serum free cortisol (T0p=0.012; T60p<0.001) concentrations increased from healthy controls to severe hepatitis, accompanied by a decrease in corticosteroid-binding globulin and albumin (all p<0.001). In acute hepatitis (n=74), patients with "low" corticosteroid-binding globulin (<28mg/L) had higher T0 serum free cortisol than others (103.1 [61.2-157] vs. 56.6 [43.6-81.9]nmol/L, p=0.0024). Analysis of covariance showed that at equal concentration of total cortisol, the free cortisol concentration was significantly higher in severe than in non-severe hepatitis (p<0.001) or healthy controls (p<0.001). CONCLUSIONS: In severe hepatitis, the decrease in cortisol-binding proteins impairs correct diagnosis of adrenal dysfunction. This could be corrected by measuring or estimating free cortisol.

[Clinical laboratory medicine: continuous amelioration with a book of objectives and satisfaction survey]. / Amélioration continue du DES de biologie médicale à l'aide d'un carnet de stage et d'un questionnaire d'évaluation de la satisfaction.

We report in this publication the use of two educational tools, a questionnaire of satisfaction and a training book, to improve the training of students during their internship in clinical laboratory at the "Pôle de biologie des Hôpitaux universitaires de Strasbourg" in France. First, the ongoing training was assessed by the interns with a questionnaire measuring satisfaction. The analysis of this questionnaire identified four key points to improve: 1) define the teaching objectives, 2) organize the training with a schedule, 3) revise certain teaching methods and 4) ensure better integration of the students in the team of medical biologists. After this assessment, we implemented a training book to answer these four points. Indeed, the training book presents the objectives, the schedule of training, and how to validate the educational objectives. A new assessment was performed again using the same methodology. Results showed an improvement in student satisfaction from 74 to 88 %. The questionnaire of satisfaction and the training book are presented in this article. The aim of the assessment of training combined with the training book is to incite the actors of the training (students and teachers) to continually improve the training. The objectives of the Pôle de Biologie are to obtain an 80 % satisfaction rate during the 6 months trainings and to reduce or eliminate dissatisfaction, and finally to ensure the validation by students of 80 to 100 % of their predetermined objectives.

Effect of the oestrogen receptor antagonist fulvestrant on the cirrhotic rat lung.

It has been postulated that cirrhosis-related lung vasodilatation and the subsequent hepatopulmonary syndrome are partly explained by an increased estradiol level through an enhanced endothelial formation of nitric oxide (NO). In this study, we assessed whether the oestrogen receptor antagonist fulvestrant (F) improves cirrhosis-related lung abnormalities. Cirrhosis was induced in rats by chronic bile duct ligation (CBDL). Four groups were studied: CBDL, CBDL+F, sham, and sham+F. Histological, immunohistochemical, and Western blot analyses were performed on lung samples. In the lung, the endothelial NO synthase and the nitrotyrosine protein expressions were increased in CBDL as compared to sham rats. Both parameters were significantly reduced by fulvestrant in the CBDL rats. Surprisingly, the level of pVASP (an indirect marker of NO formation and action) was decreased in CBDL rats, and fulvestrant had no effect on this parameter. The level of the vascular endothelial growth factor, the diameter of small lung vessels, and the number of macrophages were increased in CBDL lungs in comparison with sham lungs, and these parameters were unaffected by fulvestrant treatment. In conclusion, fulvestrant may not be relevant to improve lung abnormalities in cirrhosis because NO may not be biologically active and because key events contributing to the lung abnormalities are not affected by fulvestrant.

Extensive study of human insulin immunoassays: promises and pitfalls for insulin analogue detection and quantification.

BACKGROUND: Over the last few decades, new synthetic insulin analogues have been developed. Their measurement is of prime importance in the investigation of hypoglycaemia, but their quantification is hampered by variable cross-reactivity with many insulin assays. For clinical analysis, it has now become essential to know the potential cross-reactivity of analogues of interest. METHODS: In this work, we performed an extensive study of insulin analogue cross-reactivity using numerous human insulin immunoassays. We investigated the cross-reactivity of five analogues (lispro, aspart, glulisine, glargine, detemir) and two glargine metabolites (M1 and M2) with 16 commercial human insulin immunoassays as a function of concentration. RESULTS: The cross-reactivity values for insulin analogues or glargine metabolites ranged from 0% to 264%. Four assays were more specific to human insulin, resulting in negligible cross-reactivity with the analogues. However, none of the 16 assays was completely free of cross-reactivity with analogues or metabolites. The results show that analogue cross-reactivity, which varies to a large degree, is far from negligible, and should not be overlooked in clinical investigations. CONCLUSIONS: This study has established the cross-reactivity of five insulin analogues and two glargine metabolites using 16 immunoassays to facilitate the choice of the immunoassay(s) and to provide sensitive and specific analyses in clinical routine or investigation.

Thyroid-stimulating hormone and free thyroxine on the ADVIA Centaur immunoassay system: a multicenter assessment of analytical performance.

OBJECTIVES: We assessed the analytical performance of the TSH and FT4 assays on ADVIA Centaur in a multicenter national evaluation. DESIGN AND METHODS: A precision study and a method comparison were performed. Reference values stated by the manufacturer were checked from 379 normal subjects. RESULTS: For TSH and FT4, the intra-assay CVs were below 2.3 and 5.2%, respectively, and the inter-assay CVs below 4.4% and 7.2%, respectively. Therefore, the precision and reproducibility were acceptable. Bland-Altman bias plots revealed good correlation and agreement with Cobas assays. TSH and FT4 data yielded reference ranges of 0.64-3.24 mIU/L and 10.5-18.9 pmol/L, respectively. CONCLUSION: These assays demonstrate reliable characteristics. The reference ranges obtained can be used for interpretation of thyroid function.

Plasma copeptin, a possible prognostic marker in cirrhosis.

BACKGROUND & AIM: Copeptin, secreted stoichiometrically with vasopressin, demonstrated its prognostic role in various diseases other than cirrhosis. METHODS: We investigated the association between severity of cirrhosis and plasma concentrations of copeptin, and the prognostic value of copeptin in 95 non-septic cirrhotic patients (34 Child-Pugh A, 29 CP-B, 32 CP-C), 30 septic patients with a Child-Pugh >8 ('group D'), and 16 healthy volunteers. Patients were followed for at least 12 months to assess the composite endpoint death/liver transplantation. RESULTS: Median copeptin concentrations (interquartile range) increased through healthy volunteers group [5.95 (3.76-9.43) pmol/L] and 'group D' patients [18.81 (8.96-36.66) pmol/L; P < 0.001)]. During a median follow-up of 11.0 ± 6.1 months, 28 non-transplanted patients died and eight were transplanted. In receiver operated characteristic curves analysis, the area under the curve values were as follows: Child-Pugh score 0.80 (95% CI: 0.71-0.86), model of end-stage liver disease (MELD) score 0.80 (0.70-0.86), C-reactive protein (CRP) 0.71 (0.60-0.80) and copeptin 0.70 (0.57-0.79). By stratifying the values of these variables into tertiles, the risk of death/liver transplantation for patients belonging to the highest tertile of copeptin (>13 pmol/L) was high (Log-rank test: P = 0.0002) and 2.3-fold higher than for patients with lower concentrations after adjusting for MELD score (>21) and CRP (>24 mg/L) in a Cox model. Other potential predictors (age, total cholesterol, natraemia and serum free cortisol) did not reach a significant level. CONCLUSION: In cirrhotic patients, copeptin concentrations increased along with the severity of liver disease. In our cohort, the 1-year mortality or liver transplantation was predicted by high MELD score and high concentrations of CRP and copeptin.

Should functional sensitivity of a new thyroid stimulating hormone immunoassay be monitored routinely? The ADVIA Centaur TSH3-UL assay experience.

OBJECTIVES: We emphasize the importance of routine follow-up of subnormal TSH concentrations with QC materials. DESIGN AND METHODS: The functional sensitivity (FS) of the ADVIA Centaur system TSH assay was assessed. We report the values yielded for QC materials in two clinical laboratories. RESULTS: The FS was <0.02 mIU/L. The low-TSH QC (a serum pool) showed unacceptable between-lot imprecision (mean 0.0252 mIU/L, CV 22%). CONCLUSION: We do encourage healthcare laboratories to constitute low-TSH serum pools to ensure that the results they report meet 3rd-generation criteria.

Intermethod variability in TSH-receptor antibody measurement: implication for the diagnosis of Graves disease and for the follow-up of Graves ophthalmopathy.

BACKGROUND: We compared the analytical and clinical performance of 3 porcine thyroid receptor antibody (TRAb) methods (1 second- and 2 new third-generation systems) with the conventional TRAb assay based on the human recombinant TSH receptor (hTRAK). PATIENTS AND METHODS: We obtained sera from 86 patients with untreated Graves disease (GD) and 71 healthy controls. We measured TRAb concentrations by radioreceptor assay using the hTRAK (Brahms) or the porcine TSH receptor (pRRA) from Beckman-Coulter, by electrochemiluminescence immunoassay (ECLIA) with the Elecsys/Cobas (Roche), and by ELISA using the Medizym TRAb clone (Medipan). RESULTS: Between-run assay imprecision was < or =10% and < or =7.6% for hTRAK and ECLIA, but reached 14% and 14.9% for ELISA and pRRA, respectively. Maximal specificity and sensitivity close to 100% were obtained for hTRAK, ECLIA, and ELISA. pRRA failed to detect positive TRAbs in 5 GD patients. Although calibrated against the same reference standard 90/672, the assays displayed a high intermethod variability. The results were significantly higher by ECLIA and lower by ELISA and pRRA compared with hTRAK. Patients with ophthalmopathy had higher TRAb results by ELISA and pRRA than those without eye disease. CONCLUSIONS: Second- and third-generation TRAb assays had similar diagnostic sensitivities in the diagnostic evaluation of GD. Despite the use of the same reference standard for calibration, high intermethod variability in TRAb assay results was seen in untreated GD patients. Assay harmonization is necessary for correct interpretation in the follow-up of Graves ophthalmopathy.

Recovery from chronic demyelination by thyroid hormone therapy: myelinogenesis induction and assessment by diffusion tensor magnetic resonance imaging.

The failure of the remyelination processes in multiple sclerosis contributes to the formation of chronic demyelinated plaques that lead to severe neurological deficits. Long-term cuprizone treatment of C57BL/6 mice resulted in pronounced white matter pathology characterized by oligodendrocyte depletion, irreversible demyelination and persistent functional deficits after cuprizone withdrawal. The use of a combination of in vivo diffusion tensor magnetic resonance imaging (DT-MRI) and histological analyses allowed for an accurate longitudinal assessment of demyelination. Injection of triiodothyronine (T(3)) hormone over a 3 week interval after cuprizone withdrawal progressively restored the normal DT-MRI phenotype accompanied by an improvement of clinical signs and remyelination. The effects of T(3) were not restricted to the later stages of remyelination but increased the expression of sonic hedgehog and the numbers of Olig2(+) and PSA-NCAM(+) precursors and proliferative cells. Our findings establish a role for T(3) as an inducer of oligodendrocyte progenitor cells in adult mouse brain following chronic demyelination.

Use of insulin immunoassays in clinical studies involving rapid-acting insulin analogues: Bi-insulin IRMA preliminary assessment.

BACKGROUND: In clinical studies involving rapid-acting analogues (RAAs), insulin immunoreactivity is frequently measured, including endogenous, regular insulin (RI) and RAA immunoreactivities. Such a procedure implies equivalent cross-reactivities of all insulins present in serum. Commercially available human insulin immunoassays have been widely used, but their limitations (including hemolysis and anti-insulin antibodies) were not fully investigated. The aims of our study were to compare cross-reactivities of RI and RAAs in buffer and in serum and to investigate insulin immunoassay pitfalls. METHODS: Cross-reactivities were assessed using Bi-insulin IRMA (Schering Cis-Bio International) in phosphate-buffered saline (PBS)-1% bovine serum albumin (BSA) and in pools of sera spiked with RI and RAAs (lispro and aspart). To investigate the influence of hemolysis, a pool of sera spiked with RAA was mixed with a concentrated hemolysate (final hemoglobin concentration 10 g/L) and incubated for 3 h at room temperature. To determine interference by anti-insulin antibodies, insulin was removed using charcoal from 18 sera with anti-insulin antibodies and from 17 sera without detectable anti-insulin antibodies. These insulin-free samples were then spiked with RI and RAAs and the immunoreactivity was determined. RESULTS: Compared with buffer, cross-reactivity in serum for RI, lispro and aspart was lower (35%, 29% and 26% lower, respectively). Hemolysis degraded almost all RI and RAAs contained in the serum (>or=95%). Anti-insulin antibody interference was significant for RI and RAAs (p