Novel plasma biomarkers of amyloid plaque pathology and cortical thickness: Evaluation of the NULISA targeted proteomic platform in an ethnically diverse cohort

Topic/Product:
CNS Disease Panel 120, Neurology
Disease Area:
Alzheimer's Disease
Sample Type:
Plasma

Abstract

INTRODUCTION

Proteomic evaluation of plasma samples could accelerate the identification of novel Alzheimer’s disease (AD) biomarkers. We evaluated the novel NUcleic acid Linked Immuno-Sandwich Assay (NULISA) proteomic method in an ethnically diverse cohort.

METHODS

Plasma biomarkers were measured with NULISA in the Human Connectome Project, a predominantly preclinical biracial community cohort in southwestern Pennsylvania. Selected biomarkers were additionally measured using Simoa and Quest immunoassays and compared.

RESULTS

On NULISA, phosphorylated tau (p-tau217, p-tau231, and p-tau181), glial fibrillary acidic protein (GFAP), and microtubule-associated protein tau (MAPT-tau) showed the top significant association with amyloid beta (Aβ) positron emission tomography (PET) status, followed by the neuroinflammation markers C-C motif ligand 2 (CCL2), chitotriosidase 1 (CHIT1) and interleukin-8 (CXCL8), and the synaptic marker neurogranin (NRGN). Biomarkers associated with cortical thickness included astrocytic protein chitinase-3-like protein 1 (CHI3L1), cytokine CD40 ligand (CD40LG), brain-derived neurotrophic factor (BDNF), the Aβ-associated metalloprotein TIMP3 (tissue inhibitor of metalloprotein 3), and ficolin 2 (FCN2). Furthermore, moderate to strong between-platform correlations were observed for various assays.

DISCUSSION

NULISA multiplexing advantage allowed concurrent assessment of established and novel plasma biomarkers of Aβ pathology and neurodegeneration.

Highlights

  • Classical Alzheimer’s disease (AD) biomarkers measured using the NUcleic acid Linked Immuno-Sandwich Assay (NULISA) with next-generation sequencing readout (NULISAseq) CNS panel showed strong concordance with those measured using established immunoassay methods from Quanterix and Quest, with glial fibrillary acidic protein (GFAP) and neurofilament light (NfL) exhibiting the strongest correlation.
  • NULISAseq proteomic analysis identified several plasma biomarkers strongly associated with AD pathology in a biracial community cohort of older adults. Notably, phosphorylated tau-217 (p-tau217), GFAP, and p-tau231 displayed the strongest association with amyloid beta (Aβ) pathology, whereas brain-derived neurotrophic factor (BDNF) was strongly associated with neurodegeneration.
  • We demonstrate that plasma biomarker levels could be influenced by age, sex, apolipoprotein E (APOE) genotype, and self-identified race. Specifically, GFAP, NfL, and surfactant protein D (SFTPD) showed a strong association with age; CD63 and S100 calcium-binding protein B (S100B) with self-identified race; synaptosomal-associated protein 25 (SNAP25) with APOE genotype; and serum amyloid A1 (SAA1) and superoxide dismutase 1 (SOD1) with significant sex differences.

Steve Williams, MD, PhD

CSO

Dr. Willams serves as the company’s Chief Scientific Officer. He was previously Chief Medical Officer at Standard Biotools and at SomaLogic where he pioneered the discipline for discovery and validation of predictive, diagnostic and prognostic models using machine-learning applied to large-plex proteomics. 20 such tests were used for drug characterization, safety and efficacy when incorporated in clinical drug trials at Pharma/Biotech and 17 different multivariate tests were validated and translated into regulated healthcare uses. Prior to SomaLogic, Dr. Williams was at Pfizer in the UK and the USA as a clinical triallist in Translational Medicine, and subsequently as VP, Global Clinical Technology. He sat on the National Advisory Council for the National Institute of Biomedical Imaging and Bioengineering, the Executive Committee for the FNIH Biomarkers Consortium, and worked with FDA and PhRMA on developing evidentiary standards for biomarker qualification. Dr. William’s medical training was in London, at Charing Cross and Westminster Medical School, followed by a PhD in medicine/physiology at the same institution and training in Radiology at the University of Newcastle Upon Tyne. Steve is co-inventor on 26 proteomics patents and author/coauthor on multiple foundational proteomics manuscripts.

Justin McAnear

CFO

Mr. McAnear serves as the company’s Chief Financial Officer. He brings over 25 years of operational and financial leadership experience across various sectors and was instrumental in taking 10x Genomics public in 2019, serving as its CFO for over five years. Mr. McAnear served for over 3 years as Tesla’s VP of Worldwide Finance and Operations, supporting landmark initiatives such as the Model X and Model 3 launches and Solar City acquisition.  He also held various roles at Apple and J&J earlier in his career and served as a naval officer and aviator for over 9 years.