Contributed Commentary by Dr. Christopher Bird, Beckman Coulter Diagnostics
March 20, 2026 | If you had asked me 20 years ago whether a simple blood draw could one day help diagnose Alzheimer’s disease with the same accuracy as PET imaging or cerebrospinal fluid analysis, I would have said you were getting ahead of the science. The gold standard tests — PET scans that visualize amyloid plaques and cerebral spinal fluid (CSF) assays that measure core biomarkers directly — have long been the backbone of accurate Alzheimer’s diagnoses. They remain incredibly effective, powerful tools, but they have limitations. For example, PET imaging requires specialized equipment, resulting in a significant cost burden — consequently, only premier institutions have access. Additionally, CSF testing requires an invasive lumbar puncture, necessitating specialized skillsets and procedures that many patients understandably hesitate to undergo, and certainly not without risk.
Next-generation Alzheimer’s blood-based biomarkers are now producing accuracy levels in the greater than 90% sensitivity range, roughly on par with PET and CSF. This is not just a scientific milestone — it feels like a shift in what is possible for everyday clinical practice. Suddenly, biology that once required specialty care (specialized clinicians, facilities, and equipment) can now be captured in a standard blood draw.
I’ve spent almost three decades in diagnostics, molecular medicine, and precision therapeutics. In that time, I’ve seen major breakthroughs. Occasionally, technology transcends publication activity (solely) and can result in reshaping care at scale. Blood-based Alzheimer’s testing is one of those breakthroughs.
If we want this technology to make a real difference in people’s lives, we must be honest about where we are today.
A Lesson from Oncology: Breakthroughs Don’t Implement Themselves
Before I transitioned into diagnostics leadership, I spent years working in oncology during the rise of precision medicine. Back then, the big “Eureka!” moments came fast: new biomarkers, new assays, new targeted therapies. But the real progress didn’t happen just because science advanced. It happened when clinicians learned how to use these tools effectively—when testing moved from academic centers into community clinics, when guidelines clarified who should be tested, and when reporting formats became clear and actionable.
There’s a parallel here with Alzheimer’s disease today.
A single blood test will never be a “silver bullet”. And that’s okay. Biology is complicated. In oncology, we eventually embraced complexity: multiple biomarkers, multiple modalities, and integrated interpretations. Alzheimer’s diagnostics is heading down that same path, and much like oncology, it will require a shift in thinking.
The Indeterminate Result: Frustration or Opportunity?
One of the biggest challenges in today’s Alzheimer’s blood-based tests is that up to 30% of patients fall into what we call the indeterminate zone. That means the test doesn’t point clearly toward a positive or negative result. It leaves clinicians with a gray area.
I’ve spent enough time with clinicians to know that gray areas can be deeply frustrating. Patients want answers. Doctors want clarity. An indeterminate result can feel like neither.
Early in my oncology career, I learned not to fear the gray. I remember the early days of EGFR mutation testing for lung cancer, when inconclusive results were annoyingly common. We didn’t know yet how to fine-tune thresholds or how to interpret borderline biomarker levels. But those “inconclusives” told us something important: we were measuring the right biology. We just needed better tools.
And we built them. Over time, those indeterminate rates dropped dramatically.
That same inflection point is happening in Alzheimer’s diagnostics right now. Indeterminate results aren’t evidence that the tests don’t work. They’re evidence the science is progressing — fast. They show us where to refine assays, where to sharpen cutoffs, and where to integrate additional markers.
If we want blood-based Alzheimer’s tests to reach their full potential (not just as laboratory innovations but as tools that change lives), we need to focus on three things.
- Reducing the indeterminate zone
We need assays that more clearly separate positive from negative, so fewer patients end up in diagnostic limbo. PET and CSF testing remain crucial benchmarks here—they help confirm borderline cases and anchor the accuracy of new biomarkers. They aren’t being replaced; they’re guiding the next generation.
- Equipping clinicians with practical guidance
The reality is that most Alzheimer’s testing happens in primary care clinics, not academic centers. A family doctor with a packed schedule shouldn’t be expected to interpret complex biomarker readouts without support. We need clear guidelines, easy-to-use algorithms, and reporting formats that translate biology into actionable decisions. We learned this lesson in oncology. Once clinicians were given practical tools, not academic lectures, testing took off and patient care improved.
- Building integrated “smart panels”
There is no single biomarker that fully covers Alzheimer’s disease. And that’s a strength, not a weakness. Multiple biomarkers give us a richer, more complete picture of disease biology. The future isn’t a single test. It’s smart combinations that consider patient history, comorbidities, and disease stage.
A Breakthrough Is Only the First Step
When I talk to clinicians using these tests today, I hear a mix of excitement and caution—the same mix I heard in oncology years ago. The excitement comes from possibility: earlier detection, better patient stratification, and the chance to intervene before symptoms and pathophysiology spiral out of control. The caution comes from reality: what do we do with borderline results? How do we counsel patients? How do we build care pathways around these tests?
These are the questions we need to answer now.
We’re not just developing tests. We’re shaping the future of how Alzheimer’s is detected, understood, monitored, and ultimately treated. PET scans and CSF tests gave us the foundation. Blood tests are giving us reach and scalability. Together, they’re building a pathway that could change millions of lives.
Breakthroughs get the headlines. Systems change the outcomes. And the next chapter of Alzheimer’s diagnostics will depend on our ability to build those systems thoughtfully, responsibly, and urgently.
Dr. Christopher Bird, Chief Medical Officer at Beckman Coulter Diagnostics, oversees advancing medical excellence and delivering meaningful medical impact across key disease areas through integrated evidence generation and medical education. Chris joined Beckman Coulter in 2025, bringing more than 25 years of leadership experience spanning diagnostics, molecular medicine, and cell therapy. His background includes serving as Chief Medical Officer at BioPorto, leading Medical & Scientific Affairs at Roche Diagnostics, North America, and co-founding and leading the cell therapy company, Chimeris. Chris holds a Bachelor of Science in Physiology from Brigham Young University, a Master of Science in Biochemistry and Molecular Biology from University of California, Los Angeles, and a Doctor of Philosophy in Molecular Immunology from the University of Oxford as an Abraham Scholar. In addition, he has graduate business degrees from London Business School and ESADE. He can be reached at cbird02@dhdiagnostics.com.