YKL-40

A Marker of Astrocytic Activation and Neuroinflammatory Progression

Simoa® YKL-40 Advantage PLUS Assay (Item 105796)
YKL-40, also known as chitinase-3-like protein 1 (CHI3L1), is a glycoprotein secreted by activated astrocytes and other immune cells during inflammation and tissue remodeling. In the central nervous system (CNS), rising YKL-40 levels signal astrocytic reactivity, an early warning sign of neuroinflammatory activity that may precede neuronal damage and degeneration.

While GFAP indicates structural injury in astrocytes, YKL-40 reveals functional activation, reflecting the astrocyte’s active role in driving inflammation. Together, they form a powerful duo for staging neurodegenerative disease progression. YKL-40 is particularly valuable in research on Alzheimer’s disease (AD), multiple sclerosis (MS), and systemic inflammatory disorders, with elevated levels correlating with disease activity, treatment response, and prognosis.

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Data Sheet

Simoa YKL-40
Advantage PLUS
(HD-X)

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Key Benefits of the Simoa YKL-40 Assay

  • Astrocytic Activation Readout: Unlike structural injury markers like GFAP, YKL-40 captures secretory, inflammatory astrocyte behavior, signaling when cells are actively contributing to neuroinflammation.
  • Early-Stage Neuroinflammatory Marker: YKL-40 levels rise before overt damage, offering an earlier signal in the pathological timeline and supporting timely therapeutic interventions.
  • Monitoring Biomarker for Treatment Response: YKL-40 levels have been shown to decline with successful treatment in diseases like MS, highlighting its role in longitudinal monitoring.
  • Dual Utility in CNS and Systemic Inflammation: Produced by astrocytes, microglia, macrophages, and chondrocytes, YKL-40 functions as a bridge biomarker between CNS and systemic inflammation, ideal for multi-marker panels.
  • Complements GFAP: For researchers already using GFAP, YKL-40 adds functional depth, offering a paired strategy for tracking both astrocytic injury (GFAP) and astrocytic activity (YKL-40).

Biological and Clinical Relevance

  • Alzheimer’s Disease: CSF YKL-40 is elevated in AD and correlates with plaque-associated astrocyte activation. Adds a key “inflammation channel” to core AT(N) biomarker frameworks .
  • Multiple Sclerosis: Elevated in active disease; levels decline with effective immunosuppressive therapy. Correlates with lesion load on MRI.
  • Rheumatoid Arthritis and Systemic Inflammation: Serum YKL-40 is increased in RA, tracking with disease activity and therapeutic response, making it useful for systemic immune monitoring.

Powering Neuroinflammation Research with Simoa®

With unmatched sensitivity, scalability, and clinical research relevance, Quanterix’s YKL-40 Advantage PLUS Assay is an essential tool for:

  • Staging neurodegenerative disorders
  • Monitoring astrocytic activation
  • Evaluating inflammation-targeting therapies
  • Supporting biomarker-driven clinical trial design
  • Enhancing multi-marker disease panels

Applications and Intended Use

The Simoa YKL-40 Advantage PLUS Assay is a digital immunoassay intended for the quantification of YKL-40 in human CSF, serum, and EDTA plasma samples, enabling research in neurodegeneration, astrocyte biology, and systemic inflammation. This assay is for research use only.

Assay Specifications

  • Compatible Instruments: HD-X
  • Limit of Detection (LOD): 0.2108 ± 0.2 pg/mL
  • Detection Range: 0.0410 – 0.9040 pg/mL
  • Analytical Limit of Quantification (LOQ): 1.0300 pg/mL
  • Sample Types: Serum, EDTA plasma, CSF
  • Sample Volume Required: 130 µL

Kit Contents

The YKL-40 Advantage PLUS Assay Kit includes all reagents and controls required to perform 96 tests, ensuring reproducibility across studies.

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