A Biomarker-chip Assay in Preserved Red Blood Cells for the Diagnosis of Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia, affecting approximately 35 million people worldwide. While several symptomatic treatments are available, there is currently no cure for advanced forms of AD. Early and accurate diagnosis is therefore essential, as it can help delay disease progression and improve patient management. Current diagnostic tools-clinical and neuropsychological assessments combined with neuroimaging and cerebrospinal fluid (CSF) biomarkers-are costly, invasive, and not easily accessible for large-scale screening. There is a pressing medical need for a simple, non-invasive, and reliable blood-based diagnostic test for AD.

The ADCHIP study (ST0067) aims to develop and validate a chip-based microfluidic assay that stabilizes human red blood cells for extended periods (weeks to months) to enable subsequent detection of blood biomarkers for Alzheimer's disease. The study is conducted under the Eurostars program (Grant E!9748 ADCHIP) and sponsored by Amoneta Diagnostics, in collaboration with Zellkraftwerk GmbH and the Leenaards Memory Center (CLM) at Lausanne University Hospital (CHUV).

This monocentric, non-interventional, prospective study will enroll 150 participants divided equally into three groups:

50 patients with Alzheimer's disease (AD),

50 patients with non-Alzheimer neurodegenerative disorders (NAD: frontotemporal dementia or Parkinson's disease), and

50 healthy controls (HC).

The primary objective is to evaluate the diagnostic performance of two proprietary Amoneta blood biomarkers-amyloid-β (Aβ) and protein kinase C (PKC)-detected in red blood cells using specific fluorescent probes and chip-cytometry technology. The secondary objective is to assess the diagnostic accuracy of emerging biomarkers, including candidate proteins, RNA signatures, and metabolomic/lipidomic profiles.

Participants will undergo a single study visit during which biological samples (blood and urine) will be collected. Pre-selection and diagnostic data (neuropsychological tests, imaging, and CSF biomarkers) will be obtained retrospectively when available. No investigational drug or medical device will be administered, and no follow-up visits are planned. The total duration of subject enrollment is approximately 22 months.

Analytical methods include flow cytometry and chip-cytometry for cellular biomarkers, ELISA for protein biomarkers, mass spectrometry for metabolomic/lipidomic signatures, and qPCR or NGS-based assays for RNA biomarkers. All samples will be collected and stored under standardized conditions for further analysis.

The primary outcome measure is the binary diagnostic classification (Yes/No for Alzheimer's disease) derived from the combined sensitivity and specificity of the blood biomarkers. Results will be compared with standard clinical diagnostic tools, including cognitive scores (e.g., MoCA, RLRI-16), structural MRI, and CSF biomarker results (Aβ42, total tau, phosphorylated tau).

Potential risks for participants are minimal and limited to standard blood and urine collection procedures (e.g., minor pain, bruising, or transient discomfort). MRI procedures are non-invasive and will only be performed if indicated by clinical necessity. All participants (or legal representatives when applicable) will provide written informed consent prior to inclusion. The study complies with the Declaration of Helsinki, ICH-GCP, and national ethical and regulatory requirements.

The ADCHIP study is expected to generate important new knowledge by validating a novel, rapid, and affordable blood-based diagnostic test for Alzheimer's disease. Such a test could substantially reduce diagnostic costs, enable population screening using stabilized blood samples, and improve patient stratification for therapeutic trials. Furthermore, the validated biomarkers, particularly Aβ and PKC, may serve as valuable tools for monitoring disease progression and assessing the efficacy of future AD therapeutics.

Inclusion criteria

General (all groups):

• Male or female participants aged 50 to 85 years.
• Signed and dated written informed consent (or consent from a legally authorized representative when applicable).

Alzheimer's Disease (AD) Group:

• Clinical diagnosis of Alzheimer's disease with a gradual and progressive decline in memory over at least 6 months.
• Objective evidence of an amnestic syndrome of the hippocampal type (based on RLRI-16, MoCA, or equivalent tests).
• Montreal Cognitive Assessment (MoCA) score between 15 and 23 (inclusive).
• Structural MRI compatible with a typical AD diagnosis (3D volumetric MRI required; amyloid PET if available).
• Retrospective CSF biomarker results showing at least 2 of 3 markers positive (Aβ1-42, total Tau, phosphorylated Tau).
• Patients with familial AD forms (mutations in APP, PSEN1, or PSEN2) may also be included.

Non-Alzheimer Neurodegenerative Disease (NAD) Group:

• 25 patients with frontotemporal dementia (FTD) and 25 patients with Parkinson's disease (PD) responsive to L-DOPA.
• Retrospective CSF biomarker results showing negative or non-AD profiles (≥2 of 3 markers negative).
• Neuroimaging compatible with respective diagnoses:

FTD: medial temporal atrophy and frontal atrophy score ≥2; MoCA 15-23. PD: evidence of dopaminergic neuron loss in substantia nigra; MoCA >23.

Healthy Control (HC) Group:

• Normal cognitive status (MoCA >23 and normal performance on RLRI-16 or equivalent neuropsychological tests).
• Normal structural MRI (and normal PET scan, if available).
• Negative CSF biomarkers (if available).

Exclusion criteria

General (all groups):

• Neutropenia (neutrophils <1,500/mm³) or thrombocytopenia (platelets <100,000/mm³).
• Education level below primary school.
• History of psychiatric disorders (schizophrenia, psychosis).
• Vascular dementia or mixed dementia.
• Active infectious or chronic inflammatory diseases affecting blood cell function.
• Active cancer or cancer under treatment, or treatment stopped within the last 3 months.
• Use of medications interfering with cognitive function or biomarkers of interest.
• Major sensory deficits (visual or auditory) affecting cognitive testing.
• Epilepsy.
• Known contraindication to MRI (e.g., stent or metallic implant).

Group-specific exclusions:

• AD group: Exclude vascular dementia, Lewy body dementia, mixed dementia, or any non-AD neurodegenerative disease.
• NAD group: Exclude Alzheimer's disease, vascular, or mixed dementia.
• HC group: Exclude any neurodegenerative disease, cognitive disorder, or abnormal cognitive testing.