Diabetes Mellitus and Cognition: A Pathway Analysis in the MEMENTO Cohort

OBJECTIVE: To assess the role of biomarkers of Alzheimer's Disease (AD), neurodegeneration and small vessel disease (SVD) as mediators in the association between diabetes mellitus and cognition. METHODS: The study sample was derived from MEMENTO, a cohort of French adults recruited in memory clinics and screened for either isolated subjective cognitive complaints or mild cognitive impairment. Diabetes was defined based on blood glucose assessment, use of antidiabetic agent or self-report. We used structural equation modelling to assess whether latent variables of AD pathology (PET mean amyloid uptake, Aβ(42)/Aβ(40) ratio and CSF phosphorylated tau), SVD (white matter hyperintensities volume and visual grading), and neurodegeneration (mean cortical thickness, brain parenchymal fraction, hippocampal volume, and mean fluorodeoxyglucose uptake) mediate the association between diabetes and a latent variable of cognition (five neuropsychological tests), adjusting for potential confounders. RESULTS: There were 254 (11.1%) participants with diabetes among 2,288 participants (median age 71.6 years; 61.8% women). The association between diabetes and lower cognition was significantly mediated by higher neurodegeneration (standardized indirect effect: -0.061, 95% confidence interval: -0.089; -0.032), but not mediated by SVD and AD markers. Results were similar when considering latent variables of memory or executive functioning. CONCLUSION: In a large clinical cohort in the elderly, diabetes is associated with lower cognition through neurodegeneration, independently of SVD and AD biomarkers

Total protein level in cerebrospinal fluid is stable in elderly adults

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The Pattern of Brain Amyloid Load in Posterior Cortical Atrophy Using 18F-AV45: Is Amyloid the Principal Actor in the Disease

Background: Posterior cortical atrophy (PCA) is characterized by progressive higher-order visuoperceptual dysfunction and praxis declines. This syndrome is related to a number of underlying diseases, including, in most cases, Alzheimer's disease (AD). The aim of this study was to compare the amyloid load with 18F-AV45 positron emission tomography (PET) between PCA and AD subjects. Methods: We performed 18F-AV45 PET, cerebrospinal fluid (CSF) biomarker analysis and a neuropsychological assessment in 11 PCA patients and 12 AD patients. Results: The global and regional 18F-AV45 uptake was similar in the PCA and AD groups. No significant correlation was observed between global 18F-AV45 uptake and CSF biomarkers or between regional 18F-AV45 uptake and cognitive and affective symptoms. Conclusion: This 18F-AV45 PET amyloid imaging study showed no specific regional pattern of cortical 18F-AV45 binding in PCA patients. These results confirm that a distinct clinical phenotype in amnestic AD and PCA is not related to amyloid distribution

1693P Incidence of NTRK genes fusion in adult brain tumours: A prospective cohort of 140 patients with cerebral gliomas and brain metastases

International audienceBackground: ImmTAC molecules are TCR-anti-CD3 bispecific fusion proteins that can redirect polyclonal T cell activation against cancer cells. Tebentafusp, a gp100-directed ImmTAC, has demonstrated survival benefit in metastatic uveal melanoma 1. Here, patient-derived tumour organoids (TO) 2 and 3-dimensional multicellular melanospheres were evaluated as tumour models to study ImmTAC activity. Methods: 3D melanospheres were generated by low adherence culture of melanoma cell lines (MEL202, MEL624, 92.1, MP-41, A375, IGR-1, Mewo) and their melanin synthesis genes were quantified by qPCR. The capacity of ImmTAC to redirect T cells against melanospheres was assessed in vitro using IFNg and granzyme B Elispots in the presence or absence of commercially sourced IFNa2 or IFNb. Patient derived TO were generated by Tempus 2 and screened for HLA-A*02:01 and antigen positivity. ImmTAC-mediated killing of relevant TO was assessed by 3D high content imaging. Results: Melanospheres formed from all melanoma cell lines tested, and upregulated melanin synthesis genes including PMEL, MITF, and MLANA. This translated into visible but heterogenous melanin expression. ImmTAC were capable of redirecting T cells against cells from melanospheres to produce IFNg (EC 50 23 pM-4.8 nM) and granzyme B (EC 50 130 pM-1.4 nM). Treatment of 3D cultures with IFNa2 or IFNb for 48 hours augmented ImmTAC-mediated redirection of IFNg secretion by a mean of 4.42-fold. To further assess ImmTAC-mediated T cell redirection against more complex in vitro cultures, TO were derived from patient tumours and co-cultured with PBMC for 96 hours. In these settings, clinically relevant doses of ImmTAC redirected T cells to induce cell lysis of antigen positive TO (EC 50 29.3 pM). Conclusions: 3D melanospheres and TO may provide useful models to study tumour biology, heterogeneity, and ImmTAC activity. ImmTAC were capable of redirecting T cells against these in vitro tumour models, which will allow for better understanding of mechanism of action. 1

An automated alert system based on the p-Tau/Tau ratio to quickly inform health professionals upon a suspected case of sporadic Creutzfeldt-Jakob disease.

International audienceIntroduction: Knowing the risk of potential sporadic Creutzfeldt-Jakob disease (sCJD) instrument-contamination is essential in hospitals. We examined the relevance of the p-Tau/Tau ratio to exclude a probable case of sCJD in clinical practice, and we established an alert system to quickly inform health professionals in case of positivity.Methods: This retrospective study was conducted on 143 cerebrospinal fluid samples from patients suspected for sCJD. The distinction between probable cases of sCJD and other patients was based on clinical, paraclinical and biological (14-3-3, Tau, p-Tau, Aβ 1-42) data. From this experience, the health professionals developed an alert system to be implemented upon a suspected case of sCJD.Results: A significant decrease in p-Tau/Tau ratio between sCJD and the other diseases was observed (p < 0 .001). The combined Tau test presented a sensitivity higher than 14-3-3 (100% versus 92.3%, p =0 .006) and an equivalent specificity (90% versus 96.1%). The time required for obtaining results was higher for 14-3-3 due to the centralization of investigations in some laboratories (3 weeks versus 2 h). In the presence of these elements, the triggering of the alert system was based on the p-Tau/Tau ratio. This system involves sending an automatic mail to the hospital department involved in the patient's care and the hospital hygiene team, which oversees the application of the procedures.Conclusion: The p-Tau/Tau concentrations present the desired criteria for use in current medical practice to fight against iatrogenic transmission. The alert system confirms a probable case of sCJD instantly to health professionals. Hygiene and sterilization measures can be applied immediately

Precuneus and Cingulate Cortex Atrophy and Hypometabolism in Patients with Alzheimer’s Disease and Mild Cognitive Impairment: MRI and 18F-FDG PET Quantitative Analysis Using FreeSurfer

International audienceOBJECTIVE:The objective of this study was to compare glucose metabolism and atrophy, in the precuneus and cingulate cortex, in patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI), using FreeSurfer.METHODS:47 individuals (17 patients with AD, 17 patients with amnestic MCI, and 13 healthy controls (HC)) were included. MRI and PET images using (18)F-FDG (mean injected dose of 185 MBq) were acquired and analyzed using FreeSurfer to define regions of interest in the hippocampus, amygdala, precuneus, and anterior and posterior cingulate cortex. Regional volumes were generated. PET images were registered to the T1-weighted MRI images and regional uptake normalized by cerebellum uptake (SUVr) was measured.RESULTS:Mean posterior cingulate volume was reduced in MCI and AD. SUVr were different between the three groups: mean precuneus SUVr was 1.02 for AD, 1.09 for MCI, and 1.26 for controls (p < 0.05); mean posterior cingulate SUVr was 0.96, 1.06, and 1.22 for AD, MCI, and controls, respectively (p < 0.05).CONCLUSION:We found graduated hypometabolism in the posterior cingulate cortex and the precuneus in prodromal AD (MCI) and AD, whereas atrophy was not significant. This suggests that the use of (18)F-FDG in these two regions could be a neurodegenerative biomarker

Vaginal Neoplasia Induced by an Unusual Papillomavirus Subtype in a Woman with Inherited Chromosomally Integrated Human Herpesvirus Type 6A

International audienceWe describe here a case of high-grade vaginal squamous lesion in a 54-year-old woman with a papillomaviruses (HPV) genital infection that developed from a cervical low-grade squamous intraepithelial lesion (SIL) to a high-grade SIL (HSIL) on cytological examination.A colposcopy exam led to the detection of suspect vaginal lesions with granulomatous infiltrations, which were classified as a Vaginal Intra-Epithelial Neoplasia grade 2 after pathologists’ analyses. After a laser vaginal surgery and a loop excision of the transformation zone, the analyses of the anatomical pieces using a nearcomplete HPV screening panel revealed an HPV-4 infection that was not detected before in cervical smears. This HPVinfection is associated with a high human herpesvirus type 6A (HHV-6A) viral load in the same anatomical piece. The presence of an inherited chromosomally integrated HHV-6A (iciHHV-6A) was proved in this patient by real-time polymerase chain reaction on hair follicles and nail. This case suggests reconsidering both thebenign nature of low-grade lesions in the female genital tract and the well-known “good” prognosis of low-risk HPV infection, especially when iciHHV-6A is diagnosed. This clinical course insists on the benefits of the multiplex panel use or global sequencing in order to optimize biological testing sensitivity, and so enhance clinical management of infection-induced neoplasi

: Histoire culturelle du corps - Discours, représentations, et épistémologies XIXe-XXIe siècles

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Utility of CSF biomarkers in psychiatric disorders: a national multicentre prospective study

International audienceAbstractBackgroundAffective and psychotic disorders are mental or behavioural patterns resulting in an inability to cope with life’s ordinary demands and routines. These conditions can be a prodromal event of Alzheimer’s disease (AD). The prevalence of underlying AD lesions in psychiatric diseases is unknown, and it would be helpful to determine them in patients. AD cerebrospinal fluid (CSF) biomarkers (amyloid β, tau and phosphorylated tau) have high diagnostic accuracy, both for AD with dementia and to predict incipient AD (mild cognitive impairment due to AD), and they are sometimes used to discriminate psychiatric diseases from AD. Our objective in the present study was to evaluate the clinical utility of CSF biomarkers in a group of patients with psychiatric disease as the main diagnosis.MethodsIn a multicentre prospective study, clinicians filled out an anonymous questionnaire about all of their patients who had undergone CSF biomarker evaluation. Before and after CSF biomarker results were obtained, clinicians provided a diagnosis with their level of confidence and information about the treatment. We included patients with a psychiatric disorder as the initial diagnosis. In a second part of the study conducted retrospectively in a followed subgroup, clinicians detailed the psychiatric history and we classified patients into three categories: (1) psychiatric symptoms associated with AD, (2) dual diagnosis and (3) cognitive decline not linked to a neurodegenerative disorder.ResultsOf 957 patients, 69 had an initial diagnosis of a psychiatric disorder. Among these 69 patients, 14 (20.2 %) had a CSF AD profile, 5 (7.2 %) presented with an intermediate CSF profile and 50 (72.4 %) had a non-AD CSF profile. Ultimately, 13 (18.8 %) patients were diagnosed with AD. We show that in the AD group psychiatric symptoms occurred later and the delay between the first psychiatric symptoms and the cognitive decline was shorter.ConclusionsThis study revealed that about 20 % of patients with a primary psychiatric disorder diagnosis before undergoing a CSF exploration for cognitive disorder displayed a CSF biomarker AD profile. In memory clinics, it seems important to consider AD as a possible diagnosis before finalizing a diagnosis of a psychiatric disorder

What is the clinical impact of cerebrospinal fluid biomarkers on final diagnosis and management in patients with mild cognitive impairment in clinical practice? Results from a nation-wide prospective survey in France

International audienceObjectives New diagnostic criteria for Alzheimer’s disease (AD) include cerebrospinal fluid (CSF) biomarkers that allow diagnosis at the stage of mild cognitive impairment (MCI). However, the impact of CSF biomarkers in MCI populations in clinical practice has been poorly evaluated. The objective of this study is to assess the use and impact in clinical practice of AD CSF biomarkers in French memory clinics. Design We performed a nation-wide, prospective survey between March 2012 and September 2014. Data over the same period was extracted from the French National Database (Banque Nationale Alzheimer, BNA) and compared with the results of the survey. Setting 29 secondary and tertiary memory clinics in France. Participants Clinicians prescribing lumbar puncture (LP) in order to measure AD CSF biomarkers. Clinicians completed a two-part questionnaire for each of their patients undergoing LP. Primary and secondary outcome measures Assessment of diagnosis, level of confidence before and after CSF biomarkers and impact on management in patients who underwent LP for CSF AD biomarkers in clinical routine. Results 977 questionnaires were completed, of which 61 were excluded because of unknown initial/final diagnosis or non-contributory CSF results. Of 916 patients reported, 153 (16.7%) had MCI as the initial diagnosis, of which 51 (33.3%) displayed an AD profile. CSF biomarkers resulted in a change in diagnosis in 44 patients (28.8%). Confidence level significantly increased after LP (8.3±1.4vs 6.73±1.18, p<0.0001), and CSF results modified management in 71/156 patients (46.4%), including 36 (23.5%) enrolled in clinical trials. Comparison of change in diagnosis with the BNA population revealed no difference (32.24%, p=0.4). Conclusion This nation-wide survey, reflecting clinical practice in French memory clinics, describes the impact of CSF AD biomarkers in patients with MCI in clinical practice