At AAIC 2026, an Alzheimer's blood test measuring disease proteins in blood raised primary-care accuracy from 65% to 93%. It remains a triage aid for symptomatic patients, not a stand-alone screen, because positive results still need brain-scan or spinal-fluid confirmation.
The data came from a Swedish study of 1,310 people with mild cognitive impairment or dementia, including 383 seen in primary care. Mild cognitive impairment means memory or thinking problems that are noticeable but not severe. AAIC 2026 was held July 12-15 in London and online and highlighted the results as a major finding, according to the Alzheimer's Association in its conference overview.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- What the Swedish study tested
- How much did accuracy improve?
- How did results change care decisions?
- Which rules decide appropriate use?
- Which tests are cleared and what should patients discuss?
What the Swedish study tested
The study enrolled 1,310 Swedish patients with mild cognitive impairment or dementia, with 383 in primary care and 927 in specialty care. Physicians made a diagnosis before and after seeing blood-test results, with 165 physicians taking part. Lead researcher Sebastian Palmqvist of Lund University used the PrecivityAD2 test.
PrecivityAD2 measures amyloid-beta ratios and p-tau217 in blood. Amyloid-beta and p-tau217 are proteins linked to Alzheimer's disease in the brain. The test result was reported as negative, likely positive or positive.
How much did accuracy improve?
Among primary-care patients, accuracy rose from 65% before blood results to 93% after, according to the Alzheimer's Association in its release on the primary-care study. Dementia specialists reached 94% accuracy in the same study. In head-to-head comparison, both groups were about 90% accurate.
The greatest primary-care value was in ruling out Alzheimer's disease. A negative result helped physicians look for other causes of memory problems. A positive or likely-positive result pointed toward further Alzheimer's evaluation.
How did results change care decisions?
After seeing results, physicians changed the diagnosis in about one-third of patients. They changed planned care or examinations in over half of patients. That included referrals, added tests and treatment plans.
For primary-care patients, this meant fewer missed Alzheimer's cases and fewer wrong Alzheimer's labels. It also meant clearer next steps for families facing new symptoms. Results guided who needed specialty follow-up and who needed workup for other conditions.
Which rules decide appropriate use?
The 2025 Alzheimer's Association guideline sets performance bars for blood tests used as triage aids. A triage test needs at least 90% sensitivity and 75% specificity in symptomatic specialty-care patients. Sensitivity means finding true cases, while specificity means correctly ruling out people without the disease.
To replace brain PET scans or spinal-fluid testing, a blood test must reach 90% for both measures, according to the Alzheimer's Association in its guideline release. PET is a brain scan that shows Alzheimer's plaques. Spinal-fluid testing measures the same markers through a lumbar puncture.
Which tests are cleared and what should patients discuss?
By August 2026, the FDA had cleared four tests for symptomatic use: Lumipulse G, Elecsys pTau181, PrecivityAD2 for ages 40 and older, and Elecsys pTau217 for ages 55 and older in primary and specialty care. Clearances cover only adults with symptoms, and positive or intermediate results still need PET or spinal-fluid confirmation, according to NPACE in its primary-care update.
The AAIC results were interim findings from Sweden. Patients with new memory concerns can use these points to plan a visit: Bring a family member who has seen the changes, and ask what follow-up test is available locally.
- describe symptoms, timing and effect on daily tasks to the primary-care clinician
- ask whether a cleared symptomatic-use blood test fits as a triage step
- ask what a negative, likely-positive or positive result would change
- plan for PET or spinal-fluid confirmation if the result is not clearly negative
You Might Also Like
- FDA’s 2026 PrecivityAD2 Alzheimer’s Blood Test Clearance: What Changed and What Comes Next for Memory Clinic Patients
- The NIA 2026 Dementia Care and Caregiving Summit Report: A 2026 Follow-Up Checklist for Long-Distance Caregivers
- Strengths-Based Dementia Care in the 2026 NIA Report: What the Report Establishes and Leaves Unanswered for Long-Distance Caregivers
