{"id":5084,"date":"2023-11-06T19:03:01","date_gmt":"2023-11-07T00:03:01","guid":{"rendered":"https:\/\/ccna-ccnv.ca\/ccna_publication\/a-two-step-workflow-based-on-plasma-p-tau217-to-screen-for-amyloid-%ce%b2-positivity-with-further-confirmatory-testing-only-in-uncertain-cases-2\/"},"modified":"2024-12-03T14:58:30","modified_gmt":"2024-12-03T19:58:30","slug":"a-two-step-workflow-based-on-plasma-p-tau217-to-screen-for-amyloid-%ce%b2-positivity-with-further-confirmatory-testing-only-in-uncertain-cases-2","status":"publish","type":"ccna_publication","link":"https:\/\/ccna-ccnv.ca\/fr\/ccna_publication\/a-two-step-workflow-based-on-plasma-p-tau217-to-screen-for-amyloid-%ce%b2-positivity-with-further-confirmatory-testing-only-in-uncertain-cases-2\/","title":{"rendered":"A two-step workflow based on plasma p-tau217 to screen for amyloid \u03b2 positivity with further confirmatory testing only in uncertain cases"},"content":{"rendered":"<h2 class=\"title\">Abstract<\/h2>\n<div id=\"eng-abstract\" class=\"abstract-content selected\">\n<p>Cost-effective strategies for identifying amyloid-\u03b2 (A\u03b2) positivity in patients with cognitive impairment are urgently needed with recent approvals of anti-A\u03b2 immunotherapies for Alzheimer&rsquo;s disease (AD). Blood biomarkers can accurately detect AD pathology, but it is unclear whether their incorporation into a full diagnostic workflow can reduce the number of confirmatory cerebrospinal fluid (CSF) or positron emission tomography (PET) tests needed while accurately classifying patients. We evaluated a two-step workflow for determining A\u03b2-PET status in patients with mild cognitive impairment (MCI) from two independent memory clinic-based cohorts (n = 348). A blood-based model including plasma tau protein 217 (p-tau217), age and APOE \u03b54 status was developed in BioFINDER-1 (area under the curve (AUC) = 89.3%) and validated in BioFINDER-2 (AUC = 94.3%). In step 1, the blood-based model was used to stratify the patients into low, intermediate or high risk of A\u03b2-PET positivity. In step 2, we assumed referral only of intermediate-risk patients to CSF A\u03b242\/A\u03b240 testing, whereas step 1 alone determined A\u03b2-status for low- and high-risk groups. Depending on whether lenient, moderate or stringent thresholds were used in step 1, the two-step workflow overall accuracy for detecting A\u03b2-PET status was 88.2%, 90.5% and 92.0%, respectively, while reducing the number of necessary CSF tests by 85.9%, 72.7% and 61.2%, respectively. In secondary analyses, an adapted version of the BioFINDER-1 model led to successful validation of the two-step workflow with a different plasma p-tau217 immunoassay in patients with cognitive impairment from the TRIAD cohort (n = 84). In conclusion, using a plasma p-tau217-based model for risk stratification of patients with MCI can substantially reduce the need for confirmatory testing while accurately classifying patients, offering a cost-effective strategy to detect AD in memory clinic settings.<\/p>\n<\/div>\n","protected":false},"author":19,"featured_media":0,"template":"","meta":{"_acf_changed":false},"studies-relation":[],"class_list":["post-5084","ccna_publication","type-ccna_publication","status-publish","hentry"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v25.8 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>A two-step workflow based on plasma p-tau217 to screen for amyloid \u03b2 positivity with further confirmatory testing only in uncertain cases - CCNA - CCNV<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/ccna-ccnv.ca\/fr\/ccna_publication\/a-two-step-workflow-based-on-plasma-p-tau217-to-screen-for-amyloid-%ce%b2-positivity-with-further-confirmatory-testing-only-in-uncertain-cases-2\/\" \/>\n<meta property=\"og:locale\" content=\"fr_CA\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"A two-step workflow based on plasma p-tau217 to screen for amyloid \u03b2 positivity with further confirmatory testing only in uncertain cases - 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