Clinical reporting following the quantification of cerebrospinal fluid biomarkers in Alzheimer's disease: An international overview

Introduction: The current practice of quantifying cerebrospinal fluid (CSF) biomarkers as an aid in the diagnosis of Alzheimer's disease (AD) varies from center to center. For a same biochemical profile, interpretation and reporting of results may differ, which can lead to misunderstandings and raises questions about the commutability of tests. Methods: We obtained a description of (pre-)analytical protocols and sample reports from 40 centers worldwide. A consensus approach allowed us to propose harmonized comments corresponding to the different CSF biomarker profiles observed in patients. Results: The (pre-)analytical procedures were similar between centers. There was considerable heterogeneity in cutoff definitions and report comments. We therefore identified and selected by consensus the most accurate and informative comments regarding the interpretation of CSF biomarkers in the context of AD diagnosis. Discussion: This is the first time that harmonized reports are proposed across worldwide specialized laboratories involved in the biochemical diagnosis of AD

Long-term prognosis of cerebral amyloid angiopathy-related inflammation versus the typical type: worse or not?

6th Congress of the European-Academy-of-Neurology (EAN), ELECTR NETWORK, MAY 23-26, 2020International audienc

Long-term prognosis of cerebral amyloid angiopathy-related inflammation versus the typical type: worse or not?

6th Congress of the European-Academy-of-Neurology (EAN), ELECTR NETWORK, MAY 23-26, 2020International audienc

Diagnosis associated with Tau higher than 1200 pg/mL: Insights from the clinical and laboratory practice

International audienceContext: Cerebrospinal fluid (CSF) biomarkers are valuable tools for the diagnosis of neurological diseases. We aimed to investigate within a retrospective multicentric study the final diagnosis associated with very high CSF Tau levels and to identify patterns of biomarkers that would differentiate them in clinical practice, to help clinical biologists into physicians' counseling.Patients and methods: Within the national multicentric network ePLM, we included 1743 patients from January 1, 2008, to December 31, 2013, with CSF biomarkers assayed by the same Innotest assays (protein Tau, phospho-Tau [pTau], and Aβ 1-42). We identified 205 patients with protein Tau concentration higher than 1200 pg/mL and final diagnosis.Results: Among those patients, 105 (51.2%) were suffering from Alzheimer's disease, 37 (18%) from sporadic Creuztfeldt-Jakob disease, and 63 (30.7%) from other neurological diseases including paraneoplastic/ central nervous system tumor, frontotemporal dementia, other diagnoses, amyloid angiopathy, Lewy body dementia, and infections of the central nervous system. Phospho-Tau, Aβ1-42 and Aβ1-42/pTau values differed significantly between the three groups of patients (p 60 pg/mL.Conclusion: This work emphasizes the interest of a well-thought-out interpretation of CSF biomarkers in neurological diseases, particularly in the case of high Tau protein concentrations in the CSF

Different Clinical Outcomes between Cerebral Amyloid Angiopathy-Related Inflammation and Non-Inflammatory Form.

International audienceOBJECTIVE: Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a rare manifestation related to CAA, thought to be more severe. We aimed to compare the clinical and radiological outcomes of CAA-ri and non-inflammatory CAA. MATERIALS AND METHODS: We retrospectively included all patients with CAA-ri from 13 French centers. We constituted a sex- and age-matched control cohort with non-inflammatory CAA and similar disease duration. Survival, autonomy and cognitive evolution were compared after logistic regression. Cerebral microbleeds (CMB), intracerebral hemorrhage, cortical superficial siderosis and hippocampal atrophy were analyzed as well as CSF biomarker profile and APOE genotype when available. Outcomes were compared using Kaplan-Meier curves and log-rank tests. RESULTS: Data from 48 CAA-ri patients including 28 already reported and 20 new patients were analyzed. Over a mean of 3.1~years, 11 patients died (22.9%) and 18 (37.5%) relapsed. CAA-ri patients were more frequently institutionalized than non-inflammatory CAA patients (30% vs 8.3%, p\,<\,0.001); mortality rates remained similar. MMSE and modified Rankin scale scores showed greater severity in CAA-ri at last follow-up. MRI showed a higher number of CMB at baseline and last follow-up in CAA-ri (p\,<\,0.001 and p\,=\,0.004, respectively). CSF showed lower baseline levels of A\ss 42 in CAA-ri than non-inflammatory CAA (373.3~pg/ml vs 490.8~pg/ml, p\,=\,0.05). CAA-ri patients more likely carried at least one APOE \epsilon4 allele (76% vs 37.5%, adjusted p\,=\,0.05) particularly as homozygous status (56% vs 6.2%, p\,<\,0.001). INTERPRETATION: CAA-ri appears to be more severe than non-inflammatory CAA with a significant loss of autonomy and global higher amyloid burden, shown by more CMB and a distinct CSF profile. This burden may be partially promoted by \epsilon4 allele

J Alzheimers Dis

BACKGROUND: Pathogenic variants in the autosomal dominant genes PSEN1, PSEN2, or APP, APOE4 alleles, and rare variants within TREM2, SORL1, and ABCA7 contribute to early-onset Alzheimer's disease (EOAD). However, sporadic EOAD patients have been insufficiently studied to define the probability of being a carrier of one of these variants. OBJECTIVE: To describe the proportion of each genetic variation among patients with very young-onset sporadic AD. METHODS: We first screened PSEN1, PSEN2, and APP in 154 EOAD patients with an onset before 51 years and a negative family history. Among 99 patients with no mutation (NMC), whole exome sequencing (WES) was performed. We analyzed the APOE genotype and rare protein-truncating or missense predicted damaging variants of TREM2, SORL1, and ABCA7. Neurological examination and cerebrospinal fluid (CSF) biomarkers were systematically retrieved. RESULTS: Nineteen (12.3%) mutation carriers (MC) harbored an APP or PSEN1 pathogenic or likely pathogenic variant. Among the NMC, 54/99 carried at least one genetic risk factor, including 9 APOE4/E4 homozygous, 37 APOE4 heterozygous, and 14 with a rare variant in another risk factor gene: 3 SORL1, 4 TREM2, and 9 ABCA7. MC presented an earlier disease onset (p < 0.0001) and associated neurologic symptoms more frequently (p < 0.002). All but one patient had at least 2 CSF biomarkers in abnormal ranges. CONCLUSION: The genetic component of very early sporadic EOAD gathers a substantial proportion of pathogenic variants in autosomal dominant genes and an even higher proportion of patients carrying genetic risk factors, suggesting an oligogenic determinism, even at this range of ages

Clinical reporting following the quantification of cerebrospinal fluid biomarkers in Alzheimer's disease: An international overview

International audienceIntroduction: The current practice of quantifying cerebrospinal fluid (CSF) biomarkers as an aid in the diagnosis of Alzheimer's disease (AD) varies from center to center. For a same biochemical profile, interpretation and reporting of results may differ, which can lead to misunderstandings and raises questions about the commutability of tests.Methods: We obtained a description of (pre-)analytical protocols and sample reports from 40 centers worldwide. A consensus approach allowed us to propose harmonized comments corresponding to the different CSF biomarker profiles observed in patients.Results: The (pre-)analytical procedures were similar between centers. There was considerable heterogeneity in cutoff definitions and report comments. We therefore identified and selected by consensus the most accurate and informative comments regarding the interpretation of CSF biomarkers in the context of AD diagnosis.Discussion: This is the first time that harmonized reports are proposed across worldwide specialized laboratories involved in the biochemical diagnosis of AD