Like the heroic Argonauts of ancient Greek mythology, researchers worldwide are on a quest for “the golden fleece” of biofluid-based biomarker discovery, aiming to identify human disease at its early, more treatable stages. That’s why we named the NULISA high-throughput automated instrument the ARGO HT, and this series of Biomarker Edge blogs will focus on the ARGOnaut Club members’ early achievements with the technology in the past year. 

Young neuroscience investigators should view Dr. Thomas (Tommy) Karikari’s Biofluid Biomarkers Laboratory at the University of Pittsburgh School of Medicine as a prime example for rigorously discovering and validating clinical biomarkers in an academic setting.  

Dr. Karikari considers biomarkers from the standpoint of patients and clinicians: how can he facilitate routine, reproducible, and most importantly, accessible collections so that everyone can participate in and benefit from modern, evidence- and technology-driven medicine, whether they live in a large Western city or a small African village. Indeed, Dr. Karikari’s motivation stems from the desire to bring “this analysis to the village where he grew up in Ghana, so my father can be diagnosed.” 

Brain-derived tau in the spotlight 

We’re starting to see the first exciting reports using the brain-derived tau (BD-tau) isoform and its phosphorylated modifications (e.g., BD-pTau-217), which are the newest additions to Alamar’s NULISAseq CNS Disease Panel 120. Dr. Karikari and colleagues were the first to discover that a tau isoform lacking a splicing insert represents the primary tau in the brain, distinct from “big tau” that most immunoassays measure ​(Gonzalez-Ortiz et al., 2023)​. Conventional phosphorylated tau measured in the periphery thus fails to differentiate whether the tau originated in the brain or elsewhere in the body.  

In unpublished work, Dr. Karikari’s team elegantly demonstrates that teasing apart BD-pTau-217 from pTau-217 provides insights into co-morbidities associated with Alzheimer’s patients, who often present with kidney and/or heart pathologies. A ratio of BD-pTau-217 to amyloid beta proteins best predicts AD positivity in the absence of comorbidities, including diabetes and cardiovascular disease. His lab is busy identifying tau isoforms specific to kidney and heart tissue, providing researchers with additional tools for individualized diagnosis.  

Across the pond, Dr. Jonathan Schott of University College London and Alzheimer’s Research UK has been evaluating the performance of the new BD-tau singleplex assays (NULISApcr) in a British cohort. His goal is to accurately diagnose early-stage AD to predict which individuals will go on to develop clinical AD. Plasma pTau measurements play a role in identifying potential AD pathology in individuals with mild cognitive impairment. At this stage, anti-amyloid and other emerging drugs appear to provide the most therapeutic benefit.  

In “hot-off-the-press” data readouts, the NULISApcr BD-pTau-217 assay outperforms the Lumipulse pTau-217 assay from Fujirebio, currently used in UK clinical practice, in several key considerations: 

• Area under the curve predictive capacity for AD positivity (BD-pTau-217 AUC = 0.96) 

• Fold-change difference between AD+ and AD- (~15 vs 6) 

• Larger dynamic range, i.e., upper and lower cutoff points for positivity) 

• Reduced “gray zone,” i.e., levels of analyte are in between the upper and lower cutoff points for positivity (15% vs 19%)

Overall, these results suggest that the BD-tau assays meet the UK’s strict criteria for confirmatory testing. As further validation of BD-tau’s diagnostic and predictive capacity, recent findings on BD-pTau217 from the Insight 46 British birth cohort study — “the most well-characterized cohort in the world” — which has followed individuals born in the same week of March 1946, show promising results. Researchers can refer to this longitudinal study to better understand individuals with amyloid pathology who are close to developing cognitive impairment. BD-pTau217 was the top-performing assay in predicting this conversion, while both BD-pTau217 and BD-pTau181 outperform “big tau” in predicting disease severity (BRAAK stage).  

Powering neuroscience discovery with multiplexing 

Onto the European continent, Dr. Andrea Benedet of the University of Gothenburg uses NULISA as “a big hammer for lots of nails.” Her team has deployed the technology across a range of neuroscience applications, including long COVID, frontotemporal dementia (FTD), depression and behavior impairment, sleep, and neonatal brain injury. Hypoxic ischemic encephalopathy (HIE) occurs when cerebral blood flow is disrupted during birth. Therapeutic hypothermia (TH) is an effective remedy, but only if administered within six hours of birth, and up to a third of cases are missed. By leveraging NULISA’s low sample volume requirements and multiplexing capabilities, her lab identified a concentration-dependent marker with clinical implications.  

Two additional unpublished projects in Dr. Benedet’s lab reveal novel findings in AD diagnosis and progression. In predicting late-stage tau pathology, graduate student Guglielmo di Molfetta identified a panel of seven proteins that enhanced diagnostic accuracy beyond single-plex pTau-217 and could serve as BRAAK staging surrogates. By combining NULISAseq CNS Disease and Inflammation Panels with TSPO PET imaging to investigate neuroinflammation, a hallmark of AD, graduate student Ilaria Pola discovered that inflammatory biomarkers reflect different stages of AD progression and may serve as a proxy for TSPO PET. Therefore, fluid biomarkers might expand diagnostic options to a broader population while also pinpointing critical inflection points in disease progression. 

The first ARGO HT instrument in Asia is housed at the Hong Kong Center for Neurodegenerative Diseases at the University of Hong Kong, where Dr. Jason Jiang is studying AD biomarkers in the Chinese population. By leveraging the “happy medium” NULISA provides for achieving high-plex and high sensitivity, Dr. Jiang’s team employed machine learning methods to identify an eight-protein blood panel that strongly correlated with centiloid (CL) readings in amyloid-PET imaging. This signature showed high predictive accuracy in both early-stage detection (i.e., no CL versus intermediate CL) and disease staging (i.e., intermediate versus high CL).  

In AD, ancestry significantly influences genetic risk factors. For example, APOE status is not a strong risk factor in individuals with Chinese ancestry. Yet, the TREM2 H157Y variant is five times more common in the Chinese population compared to Western groups and carries a ninefold increased risk for developing AD, along with faster cognitive decline. NULISA multiplex capabilities can help decipher the phenotype resulting from the genotype. In a cohort of cognitively normal subjects, Dr. Jiang’s team reported that carriers of the H157Y variant exhibited markedly increased neurodegeneration and inflammation, as shown by NULISAseq CNS Disease Panel markers in blood, including neurofilament heavy chain (NfH) and Chitinase 1 (CHIT1), respectively ​(Tsui et al., 2025)​. The effect was evident regardless of amyloid status, suggesting TREM2 may modulate neurodegenerative and inflammatory processes that contribute to faster cognitive decline and brain atrophy in H157Y carriers. 

Democratizing biomarker discovery with miniaturization 

According to Dr. Schott, the motivation “to use blood biomarkers is to democratize diagnostics.” Both Dr. Karikari and Dr. Benedet are spearheading initiatives to deploy NULISA in microcapillary collection devices, such as dried blood and plasma spots (also see our tech note*). This “brain to blood” method improvement for discovering biomarkers and validating assays from small-volume collections allows for broader use. In remote locations, where delayed centrifugation, refrigeration, and logistics complicate traditional phlebotomy collections, the superior sensitivity of NULISA, along with enrichment steps to boost signals, ensures accurate results. In unpublished results, Dr. Benedet’s team has shown highly significant correlations between NULISAseq markers in venous blood and TelImmune cards, which separate blood into plasma, making them ideal for field-based collection.  

From brain to blood 

Dr. Karikari notes that “when it comes to blood testing in AD, we’ve moved very quickly from having nothing to being picky.” Along with Dr. Schott, Dr. Benedet, and Dr. Jiang, these pioneers are showing what the NULISA platform was designed to do: enable early biomarker discovery in the disease and facilitate translation into clinical practice.  

VP of Assay Development at Alamar, Dr. Binquing (BQ) Zheng, is “happy to learn about how our hard work paid off,” in describing her reactions to such groundbreaking achievements in neuroscience discovery. It certainly wasn’t easy to combine ultra-high sensitivity, multiplexed targets, as well as the simplicity and automation of the ARGO HT system and bioinformatics pipeline into the NULISA platform, but it is necessary for the protein biomarker field.