First blood test for Alzheimer’s in primary care

Labcorp has launched what it describes as the first FDA-cleared blood test for Alzheimer’s disease assessment in primary care settings nationwide.

The Elecsys pTau-181 helps clinicians rule out the neurodegenerative disorder by identifying which symptomatic patients aged 55 and older are unlikely to have amyloid pathology, abnormal protein build-up in the brain associated with the disease.

Patients with negative results can be evaluated for other potential causes of cognitive decline, while patients with positive results can be referred for additional testing.

The diagnostic was developed by Roche Diagnostics and cleared by the US Food and Drug Administration in 2025.

Brian Caveney, chief medical and scientific officer at Labcorp, said: “Primary care clinicians are often the first point of contact for patients with concerns related to cognitive symptoms, yet Alzheimer’s testing has historically required a visit to a specialist.

“By making this first-of-its-kind blood test available nationwide, Labcorp is giving primary care clinicians a powerful tool to help patients get answers sooner and guide next steps with confidence.”

The Elecsys pTau-181 offers 97.9 per cent negative predictive value, a measure of how accurately it can rule out the condition in symptomatic patients, according to the company.

The diagnostic is performed via a simple blood draw, which can be completed in a doctor’s office or at any of Labcorp’s more than 2,200 patient service centres nationwide.

It provides an alternative to traditional approaches that require brain scans or lumbar punctures, procedures to collect spinal fluid, which can be costly, invasive or difficult to access.

The company says it can help reduce unnecessary referrals amid a national shortage of neurologists, supporting timely evaluation of other causes of cognitive decline.

An estimated 7.2 million Americans live with the disease.

Labcorp’s portfolio includes blood-based biomarker diagnostics for Alzheimer’s disease and other forms of dementia.