Alzheimer’s blood tests poised to lead

Summary

Blood-based biomarkers for Alzheimer’s disease, including the FDA-approved Lumipulse G pTau 217/β-Amyloid 1-42 and Elecsys pTau181 tests, are revolutionizing diagnosis and treatment. These less invasive tests offer earlier detection, improved accessibility, and potential for broader patient reach. However, challenges remain, including understanding their performance in diverse populations, addressing potential interferences, and educating clinicians on their use and interpretation.

Karen Titus

March 2026—For a pathology that is invariably associated with dimming—of memory, of relationships, of personality—Alz-heimer’s disease has been linked to remarkably bright news as of late. Blood-based biomarkers, including two that garnered FDA approval last year, have cracked open the door to earlier diagnoses and therapeutic interventions, as well as the potential to reach more patients.

In May 2025, the Lumipulse G pTau 217/β-Amyloid 1-42 plasma ratio test (Fujirebio Diagnostics) was approved to aid in diagnosing Alz-heimer’s disease, specifically for early detection of Alzheimer’s-associated amyloid plaques in patients 55 and older who exhibit signs/symptoms of the disease. And last October, the FDA cleared the Elecsys pTau181 plasma test (Roche Diagnostics) for use in primary care settings, to rule out Alzheimer’s disease in patients 55 and older who are exhibiting signs/symptoms of cognitive decline.

Even if no one is humming “Blue Skies” as the soundtrack for the field, the optimism among laboratory experts is tangible, and has in turn been taken up by their clinical colleagues.

At his former institution of the University of California, Davis, Nam K. Tran, PhD, says that when the laboratory looked at deploying a blood-based biomarker for AD, the only recurring question from clinical colleagues was, When can we go live? “The neurologists were really excited—and I understand completely,” says Dr. Tran, who is professor and associate dean for biobanking, University of Pittsburgh School of Medicine, as well as vice chair for biobanking and medical director, point-of-care testing, Department of Pathology, UPMC.

So does Leslie M. Shaw, PhD. “The science behind this is rock solid,” says Dr. Shaw, professor and director of the toxicology laboratory and director of the biomarker research laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania.

And Hans Frykman, MD, PhD, spares no superlatives, suggesting the biomarkers are “probably the most important clinical chemistry test since troponin. It’s of that magnitude.” Even the first-generation troponin “was obviously an outstanding biomarker and huge improvement from what we had before,” says Dr. Frykman, chief scientific officer, Neurocode Laboratory, a Bellingham, Wash.-based high-complexity lab focused on neuroimmunology and biomarkers in neuro-degeneration. “And I feel the same way about p-tau217. It should be celebrated that we’ve got this biomarker. It’s such a huge improvement over anything prior.”

Improvements also bring challenges. “It’s exciting, but it also comes with its own problems,” says Dr. Frykman. He pauses, then quickly adds, “But I just have to reiterate: This really is groundbreaking.”