Alzheimer’s Blood Tests Move Closer: Promise and Pitfalls for the Gulf

The US FDA has cleared the first blood-based tests for Alzheimer’s risk, including the Lumipulse G pTau217/β‑Amyloid 1‑42 Plasma Ratio in May 2025 and Roche’s Elecsys pTau181 test in October 2025 (FDA.gov, diagnostics.roche.com).

According to the FDA, these tests show high agreement with traditional PET scans but are approved only as supplementary tools, not stand-alone diagnostics.

Labcorp is now making Roche’s blood test widely available in US primary care (Labcorp), opening the door for broader, less invasive screening options.

Instead of a costly PET scan or spinal fluid test, patients over 55 with memory concerns now have blood test options to estimate if Alzheimer’s-related amyloid plaques are likely present (FDA.gov). The Roche test especially aims to help primary-care doctors quickly rule out those who don’t need more invasive procedures.

In studies cited by the FDA and Roche, these tests agreed over 90 percent of the time with established plaque detection methods. They are, however, not perfect. The Lumipulse test had indeterminate results in about 1 in 5 cases, and all results require further clinical evaluation to avoid misdiagnosis.

No blood test can confirm a diagnosis of Alzheimer’s disease alone. The FDA and Alzheimer’s Association stress these results should always be combined with medical history and cognitive tests done by specialists. A positive result means a higher probability of brain amyloid, not certain disease.

Misreading a result could push an otherwise healthy patient down an unnecessary, costly diagnostic path, and a negative result cannot rule out other causes of dementia. Cost and local availability also remain uncertain outside the US, especially as Gulf regulation typically lags FDA clearance.