Cognitive Impairment, Dementia
Conditions
Brief summary
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.
Interventions
None listed
Sponsors
Azienda Usl di Bologna
Study design
Observational model
COHORT
Time perspective
OTHER
Eligibility
Sex/Gender
ALL
Age
40 Years to 90 Years
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| frequency of antibodies against neuronal antigens | at baseline | NSAb frequency will be calculated by dividing the number of patients with NSAb with the total number of patients |
| creation of a score that predicts the presence of NSAb | 24 months (108 weeks) | Based on logistic regression models including the clinical, imaging and biomarkers data. The minimum and maximum score is to be defined on the bases of the analyses of the clinical data at 24 months milestone.An higher score is expected to be associated with the antibody presence. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| changes of neurodegeneration biomarkers | at baseline | comparison of blood biomarkers from baseline to one year follow up in seropositive versus seronegative patients. The blood biomarkers are: phosphorylated tau protein 181 (p-tau 181) (pg/mL), Neurofilament Light chain (NfL) (pg/mL), Glial Fibrillary Acidic Protein (GFAP) (pg/mL). |
| changes of neuroanatomy | at baseline | comparison of Brain MRI from baseline to one year follow up in seropositive versus seronegative patients |
| changes of inflammatory biomarkers | at baseline | comparison of inflammatory biomarkers from baseline to one year follow up in seropositive versus seronegative patients. The inflammatory biomarkers are: Interferon alpha (IFN alpha) (pg/mL), Interferon gamma (IFN gamma) (pg/mL), Interleukin-1 beta (IL-1 beta) (pg/mL), Interleukin-2 (IL-2) (pg/mL), Interleukin-4 (IL-4) (pg/mL), Interleukin-5 (IL-5) (pg/mL), Interleukin-6 (IL-6) (pg/mL), Interleukin-8 (IL-8) (pg/mL), Interleukin-17A (IL-17A) (pg/mL), Tumor necrosis factor alpha (TNF alpha) (pg/mL), Interferon gamma-induced protein 10 (IP-10) known as C-X-C motif chemokine 10(CXCL10) (pg/mL), Monocyte chemoattractant protein-1 (MCP-1) known as C-C motif chemokine ligand 2 (CCL2) (pg/mL). |
| changes of brain blood barrier biomarkers | at baseline | comparison of brain blood barrier biomarkers from baseline to one year follow up in seropositive versus seronegative patients. The biomarkers are: S100 calcium-binding protein B (S-100b) (pg/mL), Glial Fibrillary Acidic Protein (GFAP) (pg/mL). |
Countries
Italy
Contacts
CONTACTMaria Pia Giannoccaro, Dr.
PRINCIPAL_INVESTIGATORMaria Pia Giannoccaro, Dr.
IRCCS Istituto delle Scienze Neurologiche di Bologna
Outcome results
None listed