New ultra-sensitive immunoassay platform for blood-based neurodegenerative biomarker detection – Keystone Symposium 2023

Neurodegenerative disease markers like neurofilament light protein (NFL) and phosphorylated Tau 181 (p-Tau) can be detected in cerebrospinal fluid (CSF) and are already being used in diagnosis and to guide therapeutic development. However, broad adoption of these tests is hindered by the invasive nature and high cost of CSF sampling. Plasma-based biomarkers are much easier and more cost effective to implement but require significantly higher sensitivity for their reliable detection and have proven challenging for even the most sensitive proteomic technologies today. Here we describe a new proteomic technology, NULISA™ – with ultra-sensitive attomolar level detection.  The NULISA chemistry uses DNA-linked antibodies to convert immunocomplexes to reporter DNA molecules which can be quantified with quantitative real-time PCR (qPCR) or next-generation sequencing (NGS), enabling both ultra-high sensitivity and high multiplexing capacity. The NULISA protocol uniquely employs specially designed background suppression mechanisms to greatly enhance sensitivity and dynamic range.  We have developed NULISA assays for single markers NFL and phosphorylated tau proteins and a 200-plex panel targeting inflammation and immune response-related cytokines and chemokines. We demonstrate the superior performance in limit of detection with NULISA assays compared to existing immunoassays and the ability to generate comprehensive profiles of neuroinflammation in plasma samples. With full automation on the ARGO™ instrument and a wide range of multiplex levels, the ultra-sensitive NULISA technology holds great promise to enable blood-based neurodegenerative biomarkers for the early detection and monitoring of neurodegenerative diseases and aid in the development of new therapeutic approaches