Independent Research Finds Underlying Method for C₂N’s p-Tau217 RatioBlood Test Outperforms Other Tau Blood Tests Used for Alzheimer’s Diagnoses
ST. LOUIS — September 14, 2022 — A group of distinguished Alzheimer’s disease researchers has affirmed, in a new study published online in the journal Brain, the superiority of the methods that are the basis of C₂N Diagnostics’ new p[hospho]-tau217 ratio test. Currently available as a unique research tool in Alzheimer’s clinical studies, C₂N’s p-tau217 ratio test is nearing completion of development as a clinical lab test that will help healthcare providers better diagnose Alzheimer’s disease, particularly when combined with amyloid beta (Ab) measures from C₂N’s existing PrecivityAD™ clinical blood test.
The head-to-head comparison measured the diagnostic performance of 10 different tests that quantify plasma phosphorylated-tau concentrations, including the methods underlying C₂N’s p-tau217 ratio blood test, to detect abnormal brain amyloid-β status and predict future progression to Alzheimer's dementia. The different tests compared in the round-robin study ranged from using mass spectrometry (MS)-based methods to immunoassays to detect one of three phosphorylated tau markers, including p-tau181, p-tau217, and p-tau231.
The article, titled “Head-to-head comparison of 10 plasma phospho-tau assays in prodromal Alzheimer's disease,” explained that the study involved 135 patients with “baseline diagnosis of mild cognitive impairment (mean age 72.4 years; 60.7% women) who were followed for an average of 4.9 years.” The research team explained that it “found that the mass spectrometry-based p-tau217 [from Dr. Bateman at Washington University] exhibited significantly better performance than all other plasma p-tau biomarkers when detecting abnormal Aβ status (AUC = 0.947; pdiff < 0.015) or progression to Alzheimer's dementia (AUC = 0.932; pdiff < 0.027).” Dr. Randall Bateman is a scientific co-founding member of C₂N Diagnostics.
The C₂N p-tau Multi-Analyte Assay (p-tau MAA) blood test, which contains the p-tau217 ratio measurement, is underpinned by the MS assay that Dr. Bateman and his team developed at Washington University. C₂N, under a technology transfer agreement with Washington University, optimized those methods and commercialized the p-tau MAA as a Research Use Only tool for use in Alzheimer’s clinical research. At this year’s AAIC annual meeting, the company reported its first clinical research experience combining its p-tau217 ratio blood test with its Ab 42/40 ratio blood test to identify amyloid pathology in individuals with cognitive impairment or dementia. The integration of these two measures into a single score resulted in a test that achieved an AUC performance of 0.96 and accuracy of 90% when compared with quantitative amyloid PET results to identify the presence of brain amyloid plaques.
The researchers from the new round robin study further stated that “mass spectrometry-based measures of p-tau217 perform best when identifying mild cognitive impairment patients with abnormal brain Aβ or those who will subsequently progress to Alzheimer's dementia. The results further indicate that the highest performing assays have performance metrics that rival the gold standards of Aβ-PET and CSF.” A possible explanation for this may be that MS-based detection methods are highly accurate and potentially more so than immunoassays. Therefore, they could more reliably quantify low abundance proteins like p-tau protein forms and also Ab in protein-rich matrices such as blood.
Dr. Joel Braunstein, C₂N president and CEO, says, “This latest research is an important finding that adds to other independent studies that have demonstrated remarkable performance of our proprietary blood testing methods. It is clear from these studies that the specific type of assay used and biomarker measured matters when the goal is to reliably detect brain pathology among individuals experiencing cognitive impairment. This data will enable health care providers to make more informed decisions as they consider which blood-based biomarker tests to incorporate into the memory care of their patients in the future.”
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About C₂N Diagnostics, LLC
C₂N Diagnostics is a leader in advanced brain health diagnostics with a vision to bring Clarity Through Innovation™. C₂N strives to provide exceptional laboratory services and products in the field of brain health. C₂N’s biomarker services and products are used for: clinical decision making to improve patient care, including diagnosis and treatment monitoring; maximizing the quality and efficiency of clinical trials that test novel treatments for neurodegeneration; and providing innovative tools to help healthcare researchers better understand novel mechanisms of disease, identify new treatment targets, and conduct important epidemiologic studies to improve global public health. For more information visit www.C2N.com.