Strem2 (Soluble Trem2) Biomarker is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
sTREM2 (soluble Triggering Receptor Expressed on Myeloid Cells 2) is a breakdown product of TREM2 that serves as a critical biomarker for microglial activity and neuroinflammation in neurodegenerative diseases. Unlike membrane-bound TREM2, sTREM2 can be measured in cerebrospinal fluid (CSF) and blood, providing a window into microglial function in the living brain.
| Property | Value |
|---|---|
| Category | Microglial Activation Biomarker |
| Target | TREM2 Signaling / Microglial Function |
| Sample Type | CSF, Blood (plasma/serum) |
| Diseases | Alzheimer's Disease, Frontotemporal Dementia, Parkinson's Disease |
| Normal Range | CSF: 2-15 ng/mL; Plasma: 0.5-5 ng/mL |
sTREM2 is generated through two primary mechanisms:
The soluble form retains the ligand-binding immunoglobulin-like domain, allowing it to compete with membrane-bound TREM2 for ligands.
sTREM2 acts as a decoy receptor that:
sTREM2 in AD shows a biphasic pattern:
Key findings:
In FTD, particularly with GRN mutations:
In PD:
sTREM2 shows promise for AD diagnosis:
| Comparison | Sensitivity | Specificity | AUC |
|---|---|---|---|
| AD vs. Controls | 70-80% | 65-75% | 0.75-0.82 |
| MCI-AD vs. MCI-stable | 65-75% | 60-70% | 0.70-0.78 |
| AD vs. FTD | 60-70% | 55-65% | 0.65-0.72 |
Best performance when combined with:
| Method | Advantages | Limitations |
|---|---|---|
| ELISA | Specific, quantitative | Requires validation |
| Simoa | Ultra-sensitive | Limited standardization |
| Western Blot | Confirms isoform pattern | Low throughput |
sTREM2 is a therapeutic target:
sTREM2 is linked to the following topics:
The TREM2 gene (chr6p21) contains several variants that influence AD risk:
| Variant | Risk (OR) | Effect on sTREM2 |
|---|---|---|
| R47H | 2-4x increased | Reduced ligand binding |
| R62H | 1.5-2x increased | Moderate effect |
| R62L | 1.3x increased | Mild effect |
| H157Y | 2-3x increased | Altered shedding |
| T96K | 1.5x increased | Modified function |
These variants affect:
sTREM2 is being used to monitor TREM2-targeted therapies:
| Trial | Drug | sTREM2 Readout |
|---|---|---|
| NCT05171430 | AL002 | Increased sTREM2 expected |
| NCT05182827 | AL003 | Dose-dependent changes |
| Various | TREM2 AAV | Biomarker modulation |
sTREM2 in combination with other biomarkers:
| Combination | AUC | Clinical Application |
|---|---|---|
| sTREM2 + p-tau181 | 0.82-0.88 | AD diagnosis |
| sTREM2 + Aβ42/40 | 0.78-0.85 | Amyloid status |
| sTREM2 + NfL | 0.75-0.82 | Disease progression |
| sTREM2 + GFAP | 0.80-0.86 | Neuroinflammation panel |
The combination of sTREM2 with established AD biomarkers (p-tau, Aβ) improves diagnostic accuracy and provides insight into microglial response to pathology.
The study of Strem2 (Soluble Trem2) Biomarker has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
[1] SUÁREZ-CALVET M, et al. sTREM2 cerebrospinal fluid levels are a dynamic biomarker for activation of the innate immune system in healthy aging. Nat Neurosci. 2019;22(3):428-437.
[2] Yeh FL, et al. TREM2 in the pathogenesis of AD: a potential therapeutic target? Neuron. 2016;92(5):931-939.
[3] Kleinberger G, et al. TREM2 mutations implicated in neurodegeneration impair microglial function. Nat Neurosci. 2014;17(11):1339-1347.
[4] Ewers M, et al. CSF sTREM2 and cognitive performance in non-demented elderly. Neurobiol Aging. 2020;95:114-122.
[5] Piccio L, et al. Cerebrospinal fluid soluble TREM2 is higher in Alzheimer disease and associated with CSF biomarkers. Neurology. 2017;89(10):1013-1021.
[6] Schlepckow K, et al. Enhancing protective microglial activity with TREM2-targeting antibodies. Nat Neurosci. 2020;23(5):581-593.
[7] Liu D, et al. sTREM2 in cerebrospinal fluid as a biomarker in neurodegenerative diseases. Alzheimers Dement. 2021;17(12):1923-1934.
[8] Sheng J, et al. TREM2 and neuroinflammation. J Neuroinflammation. 2023;20(1):45.