Blood Biomarkers for Alzheimer Disease and Neuro-injury to Estimate the Association With Cognitive/Functional Decline and Mortality in a Real-world Population of GERiatric Hospitalized Patients (BAD-GER)

Blood levels of amyloid ß-42 (Aß42), total and phosphorylated tau protein (t- and p-tau) associated with other biomarkers of neuro-injury, i.e. neurofilament light (NfL) chain and with biomarkers of neuroinflammation, such as CXCL8, CXCL12 and glial fibrillary acidic protein (GFAP), and metabolites analyzable with metabolomic approach, can provide information not only on neuro-injury, but also on risk of re-hospitalization and mortality. The investigators called these biomarkers BAD-GER biomarkers. The BAD-GER study is a multicenter, prospective, three-arm observational study designed to validate a prognostic biomarker algorithm for mortality and hospital readmission. This algorithm will be derived from a retrospective analysis of Alzheimer's Disease and neurodegeneration biomarkers within an existing discovery cohort of 700 geriatric patients. By integrating clinical data, routine laboratory parameters, immunophenotypes, and specific BAD-GER biomarkers into a minimal dataset, the study will assess associations with functional/cognitive status, as well as short-term and one-year mortality and rehospitalization rates.

• collection of blood samples (Other): Serum and EDTA-plasma samples will be collected at baseline

Primary outcomes

• All-cause Mortality [12 months from enrollment]: To validate the prognostic value of a biomarker algorithm derived from a retrospective analysis of Alzheimer's disease and neurodegeneration biomarkers within an existing discovery cohort of 700 geriatric inpatients.
• Number of hospital readmission [12 months from enrollment]: To validate the prognostic value of a biomarker algorithm derived from a retrospective analysis of Alzheimer's disease and neurodegeneration biomarkers within an existing discovery cohort of 700 geriatric inpatients.

Secondary outcomes

• Comprehensive geriatric assessment by INTERRAI-MDS-AC/VAOR-AC instrument [At baseline]: Identification information, personal data at admission, assessment date, cognitive function, communication and vision, mood and behaviour, physical function, incontinence, diagnosis of the disease, health conditions, oral and nutrition status, skin conditions, medications, treatment and procedures, advanced directives, discharge potential, discharge, assessment information, anamnestic-clinical data, standardised clinical assessment, physical performance tests
• Levels of amyloid ß-42 [At baseline]: The levels of plasma amyloid ß-42 (Aß42) are assessed.
• Assessment of cognitive function [At baseline]: Cognitive function will be assessed using the Mini Mental State Examination (MMSE). Score ranges 0-30, with higher score indicating better cognitive function.
• Assessment of cognition [At baseline]: Clinical Dementia Rating Scale (CDR) is a cognitive test that is used to assess the severity of dementia. It evaluates six cognitive and functional domains, where the scores are summed to provide a total score from 0 (no cognitive impairment) to 30 (severe impairment).
• Assessment of frailty [At baseline]: It will be assessed by the Clinical Frailty Scale (CFS). This descriptive scale divides the older participants into 9 classes based on the information provided by them and their relatives: between 1 and 3 the patient is non-frail, pre-frail if 4, he is frail from 5 to 9.
• Levels of tau proteins [At baseline]: Plasma levels of total tau (t-tau) and phosphorylated tau (p-tau) will be quantified.
• Marker of neuro-injury [At baseline]: Neurofilament light chain (NfL) levels will be assessed in plasma
• Neuroinflammation [At baseline]: The plasma pro-inflammatory chemokine CXCL8 (Interleukin-8) and the homeostatic chemokine CXCL12 (SDF-1) will be measured
• Marker of astrocyte activation [At baseline]: Plasma concentrations of glial fibrillary acidic protein (GFAP) will be quantified

Sex: All, ages: 65 Years to any

GROUP 1: Patients hospitalized for acute neurological disorders

Inclusion criteria:

* Inpatients with one of the following diagnoses: ischemic or hemorrhagic stroke, delirium, status epilepticus, encephalitis/meningitis

Exclusion criteria:

* no informed consent

GROUP 2: Patients hospitalized for non-neurological diseases with dementia

Inclusion criteria:

* inpatients with diagnosis of major neurocognitive disorder according to DSM-5 criteria (2013)

Exclusion criteria:

* Inpatients with one of the following diagnoses: ischemic or hemorrhagic stroke, delirium, status epilepticus, encephalitis/meningitis
* no informed consent

GROUP 3: Patients hospitalized for non-neurological diseases without dementia

Inclusion criteria:

* inpatients with non-neurological diseases

Exclusion criteria:

* inpatients with one of the following diagnoses: ischemic or hemorrhagic stroke, delirium, status epilepticus, encephalitis/meningitis
* diagnosis of dementia
* no informed consent

• Fabiola Olivieri, Professor, Study chair, IRCCS INRCA, Ancona, Italy