Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio test measures blood biomarkers associated with the disease
Clinical laboratories could soon find themselves playing a significant role in Alzheimer’s care as the US Food and Drug Administration (FDA) announced its first-ever clearance of a blood test to assist in diagnosing the cognitive disease.
The agency issued a 510(k) clearance for the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio test from Fujirebio Diagnostics, Inc. The test is intended for “the early detection of amyloid plaques associated with Alzheimer’s disease in adult patients, aged 55 years and older, exhibiting signs and symptoms of the disease,” according to an FDA press release.
“Nearly seven million Americans are living with Alzheimer’s disease, and this number is projected to rise to nearly 13 million,” said FDA Center for Devices and Radiological Health Director Michelle Tarver, MD, PhD, in the press release. “Today’s clearance is an important step for Alzheimer’s disease diagnosis, making it easier and potentially more accessible for US patients earlier in the disease.”
“Alzheimer’s disease impacts too many people, more than breast cancer and prostate cancer combined,” said FDA Commissioner Martin A. Makary, MD, MPH, in the FDA press release.
“Knowing that 10% of people aged 65 and older have Alzheimer’s, and that by 2050 that number is expected to double, I am hopeful that new medical products such as this one will help patients,” said FDA Commissioner Martin A. Makary, MD, MPH, in the FDA press release. (Photo copyright: Johns Hopkins University.)
Blood Protein Test Details
Fujirebio’s test calculates the ratio of two blood proteins, pTau217 and β-amyloid 1-42. “This ratio is correlated to the presence or absence of amyloid plaques in the patient’s brain, reducing the need for a PET scan,” the press release states.
The FDA said it has already authorized or cleared similar tests that use cerebrospinal fluid (CSF) samples obtained through an invasive spinal tap. “This new Lumipulse test only requires a simple blood draw, making it less invasive and much easier for patients to access,” the FDA said.
In granting the clearance, the agency looked at data from a clinical study of 499 adults displaying signs of cognitive impairment. Close to 92% of participants with positive test results had amyloid plaques as determined by amyloid PET scan or CSF test results. Approximately 97% with negative results from the Lumipulse test were also shown to be negative in the PET scan or CSF test. Fewer than 20% of the patients received indeterminate results, which would require additional testing.
The primary risks of the test are false positive or false negative results, the federal agency noted.
“Importantly, the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio is not intended as a screening or stand-alone diagnostic test and other clinical evaluations or additional tests should be used for determining treatment options,” the FDA said.
‘Wild West’ Marketplace
In their reporting of this story,MedPage Today and the Associated Press both noted that some laboratory-developed tests can already measure plasma biomarkers associated with Alzheimer’s.
“But those tests aren’t reviewed by the FDA and generally aren’t covered by insurance,” the AP reported. “Doctors have also had little data to judge which tests are reliable and accurate, leading to an unregulated marketplace that some have called a ‘wild west.’”
Neurologist Richard S. Isaacson, MD, told CNN that he’s already using the test for research purposes. “It can provide better clarity into whether a person experiencing memory loss may have Alzheimer’s disease,” he said.
However, he cautioned that more research is needed to allow doctors to make best use of the test.
“I think the next step as a field is, we need to advance education about what these tests mean and what they don’t and who they should be used for,” he told CNN. “Because they mean different things in different people depending on their risk factors and whether they have symptoms. So, we’re still early.”
“The results must be interpreted in conjunction with other patient clinical information,” the FDA acknowledged in their press release.
Other Alzheimer’s Tests
The FDA said it reviewed the Lumipulse test through the 510(k) premarket notification pathway, in which the federal agency determines if a device is “substantially equivalent to a legally marketed predicate device.”
In this case, the agency found that the test is substantially equivalent to Fujirebio’s Lumipulse G β-amyloid Ratio (1-42/1-40), which measures the same proteins in CSF samples. The FDA authorized that device in 2022, according to a Fujirebio press release. That test uses Fujirebio’s automated Lumipulse G1200 instrument system.
Other companies including Roche, Eli Lilly, and C2N Diagnostics are also developing Alzheimer’s tests they intend to submit for FDA review, the AP reported.
However, effective communication can bring more harmony to medical lab managers and scientists when it comes to compliance
Depending on how lab professionals view it, clinical laboratory regulations can be characterized as a series of checklists to fill out or an opportunity to grow an organization.
Leaning into the latter option will preserve regulatory compliance while also ensuring the operational health of the clinical laboratory.
At the Lab Manager Leadership Summit, Kelly VanBemmel, MS, MB(ASCP)CM (above) pressed attendees to open the lines of communication between bench scientists and lab managers when it comes to clinical laboratory regulations. (Photo copyright: Scott Wallask.)
‘There’s a Gap’ in How Both Sides View Regulatory Compliance
VanBemmel spent her presentation aiming to bridge the rift between how bench scientists look at clinical laboratory regulations compared to the views of medical lab managers.
“There’s a gap between how staff experience regulations and how management does,” she noted. “Staff typically think of compliance as a checklist to do their jobs.” Managers, however, need to understand a wider compliance picture. She illustrated her point by comparing views on the following regulatory bodies.
Staff understand that the FDA clears tests and devices for use in non-research environments, though not all consumables or equipment are in that setting.
Managers understand that the FDA develops rules and guidance for CLIA complexity categorization.
Communication Leads to Common Ground with Clinical Laboratory Regulations
Given the above differences among managers and staff, VanBemmel explained that both sides must frequently talk to each other to fill in the missing details.
“When you’re in the thick of regulations, communication becomes critical,” she said.
For example, bench staff may feel it is solely their manager’s responsibility to comply with clinical laboratory regulations. Savvy lab leaders will point out non-compliant conditions—such as diagnostic analyzer malfunctions and sample cross contamination—over which bench staff have direct control, helping workers better understand their responsibility when it comes to compliance.
On the other hand, lazy communication from managers to their bench scientists can stunt compliance efforts. She recalled a prior supervisor who often answered questions about regulations by asking: What does the standard operation procedure state?
“That answer wasn’t particularly helpful,” VanBemmel recalled. “That made me think that my supervisor didn’t understand nuance.”
Thorough communication builds greater trust, and seasoned clinical laboratory professionals of all ranks will quickly recognize the compliance benefits when the worker-manager relationship gels.
Clinical laboratories should closely watch the Trump administration as it contemplates a court appeal, a revised LDT rulemaking, or abandoning the rule altogether
With a US District Court judge’s decision to vacate the Food and Drug Administration’s (FDA) rule on laboratory-developed tests (LDTs), perhaps the most intriguing aspect for clinical laboratories is what the next move will be by the federal government.
It’s hard to predict whether the administration of President Donald Trump will either appeal the judge’s decision, direct the FDA to come up with a new version of the rule that passes legal muster, or simply back off further scrutiny of LDTs.
Let’s look more closely at the options for clinical laboratory professionals to monitor.
US District Court Judge Sean Jordan, JD (above), vacated the federal Food and Drug Administration’s final rule to regulate laboratory-developed tests (LDTs) on March 31, 2025. In a lawsuit, the Association for Molecular Pathologists and the American Clinical Laboratory Association accused the FDA of overstepping its legal authority in issuing the LDT rule in 2024. The outcome of this ruling will affect clinical laboratories’ future development their own tests. (Photo copyright: Jackson Walker LLP.)
Will the Trump Administration Appeal the LDT Decision?
The FDA’s final rule—which came out in 2024 and was about to hit its first compliance milestone on May 6, 2025—had been discussed for at least 10 years prior, covering multiple presidential administrations. Because the final rule was published by the FDA under former President Joe Biden, it surprised some observers to see Trump’s Department of Justice defend the FDA’s right to implement the rule during oral arguments in February before Judge Sean Jordan in US District Court for the Eastern District of Texas.
That hearing was the culmination of a combined lawsuit from American Clinical Laboratory Association (ACLA) and the Association for Molecular Pathology (AMP) challenging the LDT rule. The suit sought summary judgment on the matter, which Jordan granted on March 31 in his decision to vacate the FDA’s rule.
“The Court vacates and sets aside, in its entirety, the FDA’s final rule titled Medical Devices; Laboratory Developed Tests,” Jordan wrote. “The Court remands this matter to the secretary of Health and Human Services for further consideration.”
Trump’s legal team set a precedent early in the president’s second term to aggressively challenge any court decisions that buck his authority. From that perspective, an appeal of the LDT judgment seems probable, although there is no official word yet about that.
Trump ran on an anti-regulatory, smaller government platform. In that sense, the DOJ’s defense of the FDA’s standing to carry out the LDT rule was a surprise.
Will the FDA Create a Revised Version of the LDT Rule?
The court sent the rule back to the FDA, which leaves the door open for the agency to construct and issue a new rule.
The clinical laboratory industry argued that LDTs should not be classified as medical devices, which the rule instead emphasized. That could be an area where a new version of the rule bends.
Congress could also step in here. For many years, a proposed bill known as the VALID Act (formally the Verifying Accurate Leading-Edge IVCT Development Act) was filed in the House of Representatives to increase LDT oversight.
But then—after the FDA’s LDT rule came out—the VALID Act looked to be the lesser of two evils to lab professionals. It’s possible labs and lawmakers could work out a new version of the VALID Act to avoid another potentially onerous FDA-issued rulemaking.
Will Trump and the FDA Do Nothing?
Even though it would go against the current pattern of challenging court decisions, the Trump administration could simply step back and choose to do nothing with the FDA’s vacated rule.
In that case, presumably LDTs would continue to be overseen by the Clinical Laboratory Improvement Amendments of 1988 (CLIA). The medical lab industry has long preferred to see CLIA reform as the pathway to regulating LDTs in the future rather than formal FDA involvement. The FDA referred to this arrangement as “enforcement discretion,” as LDT oversight has always been on the books at the FDA, but the agency deferred to CLIA for many years.
Of related interest was a news release last week from the federal Department of Health and Human Services (HHS) announcing a sweeping number of layoffs under its individual agencies. The FDA is slated to lose 3,500 employees, although the “reduction will not affect drug, medical device, or food reviewers, nor will it impact inspectors,” HHS noted in a fact sheet.
Revisiting an LDT rule that will require more reviewers and inspectors seems at odds with a shrinking FDA.
Clinical Labs Must Monitor the Near-term Future of LDTs
After coming out ahead in one of the biggest court showdowns in clinical lab history, medical laboratory scientists and industry leaders now must keep their eyes on the various avenues that LDT regulation could head down in the near future.
Watch for further analysis of the business implications of this court decision in The Dark Report.
Single genetic test can identify multiple pathogens and can be used by the UCSF clinical laboratory team to help physicians identify difficult to diagnose diseases
Continuing improvements in gene sequencing technologies and analytical software tools are enabling clinical laboratorians to diagnosis patients who have challenging symptoms. One such example is a new genomic test developed by researchers at University California, San Francisco (UCSF). The single test analyzes both RNA and DNA to detect almost any type of pathogen that may be the cause of specific illnesses.
The test uses a genomic sequencing technique known as metagenomics next-generation sequencing (mNGS). It works by sequencing genetic material found in blood, tissue, or body fluid samples and compares the sequenced data against a broad database of known pathogens to seek a match. Instead of looking for just one pathogen at a time, mNGS analyzes all of the nucleic acids, RNA, and DNA present in a sample simultaneously to detect nearly all pathogens, including viruses, bacteria, fungi, and parasites.
The mNGS test is not intended to replace existing clinical laboratory tests, but to help physicians diagnose an illness in cases where patients are experiencing severe symptoms, and where initial, commonplace tests are ineffective. In such cases, medical professionals require additional information to achieve a proper diagnosis.
“Our technology is deceptively simple,” said Charles Chiu, MD, PhD (above), professor of laboratory medicine and infectious diseases at UCSF and senior author of the studies in a news release. “By replacing multiple tests with a single test, we can take the lengthy guesswork out of diagnosing and treating infections.” The new technology may help physicians diagnose patients who have challenging symptoms and where current clinical laboratory testing is ineffective at identifying specific pathogens. (Photo copyright: University California San Francisco.)
Diagnostic Armamentarium for Physicians
According to an article published by the American Society for Microbiology (ASM) titled, “Metagenomic Next Generation Sequencing: How Does It Work and Is It Coming to Your Clinical Microbiology Lab?” mNGS is “running all nucleic acids in a sample, which may contain mixed populations of microorganisms, and assigning these to their reference genomes to understand which microbes are present and in what proportions. The ability to sequence and identify nucleic acids from multiple different taxa [plural for taxon] for metagenomic analysis makes this a powerful new platform that can simultaneously identify genetic material from entirely different kingdoms of organisms.”
The researchers developed the mNGS test years ago and it has produced promising results, including:
Diagnosing cases of encephalitis in transplant recipients to yellow fever in their organ donors.
Helping to identify the cause of a meningitis outbreak in Mexico among surgical patients.
Detecting a case of leptospirosis in a patient who was in a medically induced coma, which prompted doctors to prescribe penicillin and resulted in the full recovery of the patient.
Identifying the cause of neurological infections such as meningitis and encephalitis. The test successfully diagnosed 86% of neurological infections in more than 4,800 spinal fluid samples.
“Our mNGS test performs better than any other category of test for neurologic infections,” said Charles Chiu, MD, PhD, professor of laboratory medicine and infectious diseases at UCSF and senior author of the two studies, in a UCSF news release. “The results support its use as a critical part of the diagnostic armamentarium for physicians who are working up patients with infectious diseases.”
FDA Breakthrough Device Designation
The UCSF test has not yet been approved by the federal Food and Drug Administration (FDA), but it was granted a “breakthrough device” designation by the agency. This classification authorizes labs to use the test as a valid diagnosis method due to its potential ability to benefit patients.
Chiu told NBC News that the test costs about $3,000 per sample and fewer than 10 labs routinely use it due to several issues.
“Traditionally, it’s been used as a test of last resort, but that’s primarily because of issues involving, for instance, the cost of the test, the fact that it’s only available in specialized reference laboratories, and it also is quite laborious to run,” he said.
This type of lab testing is not feasible for most hospitals as it is costly and complicated, and because physicians may need assistance from clinical laboratory personnel who have the appropriate expertise to properly read test results.
“This just is not something that a clinical lab will be doing until somebody commercially puts it in a box with an easy button,” Susan Butler-Wu, PhD, associate professor of clinical pathology at the University of Southern California (USC), told NBC News. “It’s not a one-stop shop. It just can be helpful as an additional tool.”
Although the technology has some limitations, Chiu says the research performed by his team “raises the possibility that we perhaps should be considering running this test earlier” in symptomatic patients. He hopes the test will be used on a widespread basis in hospitals to diagnose various illnesses in the future.
“We need to get the cost down and we need to get the turnaround times down as well,” he told NBC.
Definitive Tool for Pathogen Detection
To increase access to the technology, Chiu and his colleagues founded Delve Bio, which is now the exclusive provider of the mNGS tool created at UCSF. In December, the company announced the commercial launch of Delve Detect, a metagenomic test for infectious diseases. According to its website, Delve Detect “offers genomic testing of cerebrospinal fluid (CSF) for more than 68,000 pathogens, with 48-hour turnaround time and metagenomics experts readily available to discuss results.”
“These findings support including mNGS as a core tool in the clinical workup for CNS [central nervous system] infections,” said Steve Miller, MD, PhD, UCSF volunteer clinical professor, laboratory medicine, and chief medical officer of Delve Bio in the UCSF news release. “mNGS offers the single most unbiased, complete and definitive tool for pathogen detection. Thanks to its ability to quickly diagnose an infection, mNGS helps guide management decisions and treatment for patients with meningitis and encephalitis, potentially reducing healthcare costs down the line.”
This mNGS test may prove to have the potential to greatly improve medical care for some infections and possibly expedite the detection of new viral threats. It is probable that clinical laboratories will soon be learning about and performing more tests of this nature in the future.
New guidelines come on the heels of recommendations covering post-market modifications to AI products, including those incorporated into systems used by clinical laboratories
Artificial intelligence (AI) is booming in healthcare, and as the technology finds its way into more medical devices and clinical laboratory diagnostic test technologies the US Food and Drug Administration (FDA) has stepped up its efforts to provide regulatory guidance for developers of these products. This guidance will have an impact on the development of new lab test technology that uses AI going forward.
In December, the FDA issued finalized recommendations for submitting information about planned modifications to AI-enabled healthcare products. Then, in January, the federal agency issued draft guidance that covers product management and marketing submission more broadly. It is seeking public comments on the latter document through April 7.
“The FDA has authorized more than 1,000 AI-enabled devices through established premarket pathways,” said Troy Tazbaz, director of the Digital Health Center of Excellence at the FDA’s Center for Devices and Radiological Health, in a press release announcing the draft guidance.
This guidance “would be the first to provide total product life cycle recommendations for AI-enabled devices, tying together all design, development, maintenance and documentation recommendations, if and when finalized,” Healthcare IT News reported.
“Today’s draft guidance brings together relevant information for developers, shares learnings from authorized AI-enabled devices, and provides a first point-of-reference for specific recommendations that apply to these devices, from the earliest stages of development through the device’s entire life cycle,” said Troy Tazbaz (above), director of the Digital Health Center of Excellence at the FDA Center for Devices and Radiological Health, in a press release. The new guidance will likely affect the development of new clinical laboratory diagnostic technologies that use AI. (Photo copyright: LinkedIn.)
Engaging with FDA
One key takeaway from the guidance is that manufacturers “should engage with the FDA early to ensure that the testing to support the marketing submission for an AI-enabled device reflects the agency’s total product lifecycle, risk-based approach,” states an analysis from consulting firm Orrick, Herrington and Sutcliffe LLP.
Another key point is transparency, Orrick noted. For example, manufacturers should be prepared to offer details about the inputs and outputs of their AI models and demonstrate “how AI helps achieve a device’s intended use.”
Manufacturers should also take steps to avoid bias in data collection for these models. For example, they should gather evidence to determine “whether a device benefits all relevant demographic groups similarly to help ensure that such devices are safe and effective for their intended use,” Orrick said.
New Framework for AI in Drug Development
On the same day that FDA announced the device guidelines, the agency also proposed a framework for regulating use of AI models in developing drugs and biologics.
“AI can be used in various ways to produce data or information regarding the safety, effectiveness, or quality of a drug or biological product,” the federal agency stated in a press release. “For example, AI approaches can be used to predict patient outcomes, improve understanding of predictors of disease progression and process, and analyze large datasets.”
The press release noted that this is the first time the agency has proposed guidance on use of AI in drug development.
These include “bias and reliability problems due to variability in the quality, size, and representativeness of training datasets; the black-box nature of AI models in their development and decision-making; the difficulty of ascertaining the accuracy of a model’s output; and the dangers of data drift and a model’s performance changing over time or across environments. Any of these factors, in FDA’s thinking, could negatively impact the reliability and relevancy of the data sponsors provide FDA.”
The FDA also plans to participate in direct testing of AI-enabled healthcare tools. In October, the FDA and the Department of Veterans Affairs (VA) announced that they will launch “a joint health AI lab to evaluate promising emerging technologies,” according to Nextgov/FCW.
Elnahal said the facility will allow federal agencies and private entities “to test applications of AI in a virtual lab environment.” The goal is to ensure that the tools are safe and effective while adhering to “trustworthy AI principles,” he said.
“It’s essentially a place where you get rapid but effective evaluation—from FDA’s standpoint and from VA’s standpoint—on a potential new application of generative AI to, number one, make sure it works,” he told Nextgov/FCW.
He added that the lab will be set up with safeguards to ensure that the technologies can be tested safely.
“As long as they go through the right security protocols, we’d essentially be inviting parties to test their technology with a fenced off set of VA data that doesn’t have any risk of contagion into our actual live systems, but it’s still informative and simulated,” he told Nextgov/FCW.
There has been an explosion in the use of AI, machine learning, deep learning, and natural language processing in clinical laboratory diagnostic technologies. This is equally true of anatomic pathology, where AI-powered image analysis solutions are coming to market. That two federal agencies are motivated to establish guidelines on working relationships for evaluating the development and use of AI in healthcare settings tells you where the industry is headed.
