Alzheimer's disease biomarkers

biomarkers() a dataset of curated biomarkers relevant to Alzheimer's disease (AD) and related neurodegenerative conditions. Each row corresponds to a defined biomarker, including both directly measured biomarkers and derived indicators such as ratios. Variables include identification of the biomarker (bmk_id and bmk_name), reference(s) to underpinning analyte(s) (analyte_ids), and classification details.

Usage

biomarkers()

Value

A tibble with the following columns:

bmk_id

Short identifier for the biomarker (e.g., "ab42", "ptau181_ab42_ratio").

bmk_name

Human-readable label (e.g., "Aβ42 / Aβ40", "Amyloid PET").

bmk_category

Top-level role: "core", "non-specific", or "co-pathology".

bmk_class

Stage or use-tier within category (e.g., "core 1", "core 2").

bmk_subclass

Biological process aligned with the ATNISV framework (e.g., "A", "T1", "N").

bmk_modality

Measurement domain: "fluid" or "imaging".

bmk_type

Whether the biomarker is "original" (directly measured) or "derived" (e.g., ratios).

analyte_ids

List of one or more analyte IDs underpinning the biomarker definition.

bmk_desc

Short description of what the biomarker measures or represents.

Details

Biomarkers are organized into a structured, three-tier classification system that reflects their biological role, pathogenic target, and stage in the disease process:

• bmk_category: the highest level of classification, reflecting the biomarker's overall diagnostic role. Categories include:

  • "core": biomarkers of AD neuropathologic change (ADNPC), essential for diagnosis and staging;

  • "non-specific": biomarkers relevant to AD pathophysiology but not specific to AD;

  • "co-pathology": markers that capture common comorbid pathologies frequently co-occurring with AD.

• bmk_class: a subdivision of the category level, used to distinguish between earlier- and later-appearing markers in the course of disease progression.

  For example:

  • "core 1" includes A and T1 markers that become abnormal early and support diagnosis;

  • "core 2" includes T2 markers that become abnormal later and support disease staging.

• bmk_subclass: identifies the specific biological process or proteinopathy the biomarker represents, aligned with the updated ATNISV framework:

  • "A": amyloid-beta proteinopathy;

  • "T1": soluble tau fragments (e.g., p-tau181, p-tau217, p-tau231);

  • "T2": tau aggregates (e.g., tau PET, MTBR-tau243);

  • "N": neurodegeneration;

  • "I": inflammation and immune activation;

  • "S": synucleinopathy;

  • "V": vascular brain injury.

In contrast, the bmk_modality field is not part of the classification hierarchy but denotes the technical measurement domain—either "fluid" (e.g., CSF, plasma) or "imaging" (e.g., PET, MRI). This distinction is critical because the same biological process (e.g., amyloid pathology) may be captured through multiple modalities, which differ in their temporal resolution, biological specificity, and clinical application. The updated criteria explicitly reject the assumption of equivalence between fluid and imaging biomarkers, hence the need to treat modality separately.

See also

analytes(), assays()

Examples

biomarkers()
#> # A tibble: 23 × 9
#>    bmk_id     bmk_name bmk_category bmk_class bmk_subclass bmk_modality bmk_type
#>    <chr>      <chr>    <chr>        <chr>     <chr>        <chr>        <chr>   
#>  1 ab40       Aβ40     core         core 1    A            fluid        original
#>  2 ab42       Aβ42     core         core 1    A            fluid        original
#>  3 ab42_ab40… Aβ42 / … core         core 1    A            fluid        derived 
#>  4 amyloid_p… Amyloid… core         core 1    A            imaging      original
#>  5 t_tau      Total t… core         core 1    T1           fluid        original
#>  6 ptau217    p-tau217 core         core 1    T1           fluid        original
#>  7 ptau181    p-tau181 core         core 1    T1           fluid        original
#>  8 ptau231    p-tau231 core         core 1    T1           fluid        original
#>  9 ptau181_a… p-tau18… core         core 1    T1           fluid        derived 
#> 10 ptau217_n… p-tau21… core         core 1    T1           fluid        derived 
#> # ℹ 13 more rows
#> # ℹ 2 more variables: analyte_ids <list>, bmk_desc <chr>