Autoimmune Dementia: Predictors of Neuronal Synaptic Antibodies in Patients With New-ONset Cognitive Impairment

Official title

Autoimmune Dementia: Predictors of Neuronal Synaptic Antibodies in Patients With New-ONset Cognitive Impairment and Their Relevance in Non-encephalitic formS: The ADONIS Study

Overview

The goal of this observational study is to investigate the frequency and the possible pathogenic role of neuronal synaptic antibodies (NSAb) in patients with cognitive impairment (CI). The main questions it aims to answer are: 1. the frequency and associated features of NSAb in patients with CI and the usefulness of a clinical score in improving autoimmune dementia (AID) diagnosis; 2. the clinical significance of NSAb in patients with CI not fulfilling the autoimmune encephalitis (AE) criteria and serum NSAb (NSAb-pos-CI); 3. the impact of blood-brain-barrier (BBB) dysfunction on their pathogenicity.

Detailed description

AE can mimic dementia and, contrarily to neurodegenerative dementia syndromes, affected patients can improve with timely immunotherapies. Consensus-based diagnostic criteria for AE help to select patients for antibody testing. However, encephalitis signs can be absent, particularly in the elderly, and AE can present with slowly progressing CI mimicking classical neurodegenerative diseases, misleading the diagnostic process. Data on the prevalence of NSAb and AE in unselected patients with CI are sparse and mostly affected by retrospective design, small cohorts, and antibody assay shortcomings. There is an urgent need to define the frequency of NSAb and AE in CI patients and elucidate the associated clinical, laboratory and imaging features. Filling these gaps is the first aim of this project. This will allow the early identification and the best management of patients with AID. On the other hand, a proportion of CI patients have NSAb and do not fit the AE criteria (NSAb-pos-CI).

These NSAb are often in the serum, and not in the Cerebrospinal Fluid (CSF), or belong to the Immunoglobulin A/M (Ig A/M) subclasses, as opposite to the AE-associated Immunoglobulin G (IgG) subclass, thus triggering questions about their clinical and therapeutic implications. As NSAb can be found at low titers in the serum of healthy controls, a hypothesis explaining their pathogenicity relies on dysfunctions of the BBB, in a context of indolent inflammation, that might allow the antibodies to reach the Central Nervous System (CNS). Alternatively, NSAb may not be directly pathogenic and could even be secondary to an ongoing neurodegenerative process. However, even in this context, known and unknown NSAb, could still contribute to the clinical phenotype, modulating the disease progression or the presence of additional clinical features (i.e. psychiatric symptoms). Understanding if these serum NSAb, along with other factors such as inflammation and BBB alterations, have a role in modifying the disease trajectory, i.e. accelerating the neurodegeneration and CI progression, is the other main goal. This project will represent a chance to clarify the role of NSAb in NSAb-pos-CI and potentially help to identify a subgroup of patients with specific phenotypes, who could benefit from immunotherapies. The identification of such patients will allow their best clinical management.

Primary outcome measures

• frequency of antibodies against neuronal antigens [Time frame: at baseline]
• frequency of antibodies against neuronal antigens [Time frame: 12 months (54 weeks)]
• creation of a score that predicts the presence of NSAb [Time frame: 24 months (108 weeks)]

Secondary outcome measures (8)

• changes of neurodegeneration biomarkers [Time frame: at baseline]
• changes of neurodegeneration biomarkers [Time frame: 1 year (54 weeks)]
• changes of neuroanatomy [Time frame: at baseline]
• changes of neuroanatomy [Time frame: 1 year (54 weeks)]
• changes of inflammatory biomarkers [Time frame: at baseline]
• changes of inflammatory biomarkers [Time frame: 1 year (54 weeks)]
• changes of brain blood barrier biomarkers [Time frame: at baseline]
• changes of brain blood barrier biomarkers [Time frame: 1 year (54 weeks)]

Eligibility criteria

Inclusion criteria

• both sexes
• adult (aged between 40 and 90 years)
• patients with a diagnosis of new-onset neurocognitive disorders (major and minor), as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria, with onset within the previous 24 months

Exclusion criteria

\- presence of a history of seizures within 4 weeks from onset.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

Italy · 3 centers

• IRCCS Istituto delle Scienze Neurologiche di Bologna — Bologna
• Istituto Auxologico Italiano IRCCS — Milan
• Fondazione IRCCS Istituto Neurologico Carlo Besta — Milan

Publications

• Bartels F, Stronisch T, Farmer K, Rentzsch K, Kiecker F, Finke C. Neuronal autoantibodies associated with cognitive impairment in melanoma patients. Ann Oncol. 2019 May 1;30(5):823-829. doi: 10.1093/annonc/mdz083. PMID 30840061
• Brunkhorst R, Pfeilschifter W, Foerch C. Astroglial proteins as diagnostic markers of acute intracerebral hemorrhage-pathophysiological background and clinical findings. Transl Stroke Res. 2010 Dec;1(4):246-51. doi: 10.1007/s12975-010-0040-6. Epub 2010 Aug 28. PMID 24323552
• Castillo-Gomez E, Oliveira B, Tapken D, Bertrand S, Klein-Schmidt C, Pan H, Zafeiriou P, Steiner J, Jurek B, Trippe R, Pruss H, Zimmermann WH, Bertrand D, Ehrenreich H, Hollmann M. All naturally occurring autoantibodies against the NMDA receptor subunit NR1 have pathogenic potential irrespective of epitope and immunoglobulin class. Mol Psychiatry. 2017 Dec;22(12):1776-1784. doi: 10.1038/mp.2016.12 PMID 27502473
• Constantinescu R, Krysl D, Bergquist F, Andren K, Malmestrom C, Asztely F, Axelsson M, Menachem EB, Blennow K, Rosengren L, Zetterberg H. Cerebrospinal fluid markers of neuronal and glial cell damage to monitor disease activity and predict long-term outcome in patients with autoimmune encephalitis. Eur J Neurol. 2016 Apr;23(4):796-806. doi: 10.1111/ene.12942. Epub 2016 Jan 29. PMID 26822123
• Dubey D, Kothapalli N, McKeon A, Flanagan EP, Lennon VA, Klein CJ, Britton JW, So E, Boeve BF, Tillema JM, Sadjadi R, Pittock SJ. Predictors of neural-specific autoantibodies and immunotherapy response in patients with cognitive dysfunction. J Neuroimmunol. 2018 Oct 15;323:62-72. doi: 10.1016/j.jneuroim.2018.07.009. Epub 2018 Jul 25. PMID 30196836
• Dubois B, Villain N, Frisoni GB, Rabinovici GD, Sabbagh M, Cappa S, Bejanin A, Bombois S, Epelbaum S, Teichmann M, Habert MO, Nordberg A, Blennow K, Galasko D, Stern Y, Rowe CC, Salloway S, Schneider LS, Cummings JL, Feldman HH. Clinical diagnosis of Alzheimer's disease: recommendations of the International Working Group. Lancet Neurol. 2021 Jun;20(6):484-496. doi: 10.1016/S1474-4422(21)00066-1. E PMID 33933186
• Flanagan EP, McKeon A, Lennon VA, Boeve BF, Trenerry MR, Tan KM, Drubach DA, Josephs KA, Britton JW, Mandrekar JN, Lowe V, Parisi JE, Pittock SJ. Autoimmune dementia: clinical course and predictors of immunotherapy response. Mayo Clin Proc. 2010 Oct;85(10):881-97. doi: 10.4065/mcp.2010.0326. PMID 20884824
• Giannoccaro MP, Cossins J, Sorland K, Fluge O, Vincent A. Searching for Serum Antibodies to Neuronal Proteins in Patients With Myalgic Encephalopathy/Chronic Fatigue Syndrome. Clin Ther. 2019 May;41(5):836-847. doi: 10.1016/j.clinthera.2019.04.001. Epub 2019 May 1. PMID 31053295

Identifiers

NCT: NCT06321588 · GR-2021-12373134

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗