Revolutionary Blood Test Detects Early Alzheimer’s Disease with Exceptional Accuracy: A Breakthrough in Alzheimer’s Detection
In a significant breakthrough, researchers from the University of Gothenburg, in collaboration with colleagues from the University of Lund and Montreal, Canada, have introduced a groundbreaking blood test that holds immense potential as an indicator for detecting Alzheimer’s disease. This innovative approach utilizes a blood biomarker known as p-tau217 and has been found to demonstrate exceptional accuracy in detecting or ruling out brain amyloidosis, a crucial early sign of Alzheimer’s.
Over the past few years, there has been substantial research dedicated to developing blood biomarkers for Alzheimer’s disease. One area of focus has been the tau protein, specifically its phosphorylated form (p-tau), which plays a vital role in the pathology of Alzheimer’s disease.
Blood-based p-tau biomarkers, including p-tau217, show great promise as practical tools for screening individuals experiencing memory issues or early cognitive symptoms associated with Alzheimer’s disease. However, concerns have been raised regarding the potential for misdiagnosis and the high costs and medical risks associated with initiating treatments in individuals who do not have the disease.
To address these concerns, the researchers at the University of Gothenburg and their collaborators have devised a new two-step approach for using blood biomarkers in clinical practice. The primary step involves a diagnostic model that takes into account plasma p-tau217, age, and APOE e4 status to categorize patients with mild cognitive impairment based on their risk of having amyloid PET positivity. The second step involves confirmatory testing with CSF Ab42/40 ratio, performed only when the results of the first step are unclear.
To evaluate the efficacy of this approach, the researchers tested the workflow on 348 individuals with mild cognitive impairment from the Swedish BioFINDER studies at Lund University. The results were then confirmed in a separate TRIAD cohort at McGill University in Montreal, Canada, using a different method to analyze plasma p-tau217.
The model was assessed using three threshold strategies to categorize participants into low, intermediate, high-risk, and high-risk groups for having Alzheimer’s disease-type pathology. At the lower probability thresholds, aimed at prioritizing sensitivity to avoid missing patients with amyloid beta (Aβ) positive results, only 6.6% of false negatives were identified. Similarly, at the higher specificity threshold, aimed at minimizing the misclassification of Aβ negative patients as ‘high risk,’ only 2.3% false positives were observed.
When applying these stringent thresholds, 41% of patients fell into the intermediate risk category, compared to 29% using a less stringent threshold. Further assessments of this intermediate group using CSF Aβ42/40 showed a strong agreement of 86% with amyloid PET results.
This study highlights a two-step model that utilizes a blood test (p-tau217) to categorize patients with mild cognitive impairment into high, low, and intermediate risk for brain amyloidosis and early Alzheimer’s disease. The first step of the test accurately identifies high-risk patients who may benefit from early diagnosis and treatment initiation or specialist referral for future treatment. Moreover, the low-risk group effectively rules out Alzheimer’s disease, saving on healthcare expenses, while the intermediate group reduces the need for costly confirmatory tests.
The development of this revolutionary blood test brings hope for improved and accurate detection of early Alzheimer’s disease, potentially leading to earlier interventions and enhanced patient outcomes.
