As new diagnostic assays are cleared by regulators, clinical laboratories will play a key role in identifying appropriate patients for new less-invasive Alzheimer’s tests
With multiple companies racing to develop a blood-based test for Alzheimer’s disease (AD), clinical laboratories may soon have new less-invasive diagnostic assays for AD on their menus.
Why a race? Because a less-invasive clinical laboratory test that uses a venous blood draw (as opposed to a spinal tap)—and which has increased sensitivity/specificity—has a potentially large market given the substantial numbers of elderly predicted to develop Alzheimer’s over the next decade. It has the potential to be a high volume, high dollar diagnostic test.
In fact, Mordor Intelligence estimates that the market for Alzheimer’s disease therapeutics will grow from $7.7 billion in 2024 to $10.10 billion by 2029.
Alzheimers.gov, an official website of the US government, says, “Researchers have made significant progress in developing, testing, and validating biomarkers that detect signs of the disease process. For example, in addition to PET scans that detect abnormal beta-amyloid plaques and tau tangles [abnormal forms of tau protein] in the brain, NIH-supported scientists have developed the first commercial blood test for Alzheimer’s. This test and others in development can not only help support diagnosis but also be used to screen volunteers for research studies.”
Additionally, the US Food and Drug Administration (FDA) is clearing new Alzheimer’s drugs for clinical use. The pharma companies behind these drugs need clinical laboratory tests that accurately diagnosis the disease and confirm that it would be appropriate for the patient to receive the new therapeutic drugs, a key element of precision medicine.
“The big promise for blood tests is that they will eventually be accessible, hopefully, cost-effective, and noninvasive,” Rebecca Edelmayer, PhD (above), Vice President, Scientific Engagement, Alzheimer’s Association, told USA Today. “The field is really moving forward with use of these types of tests,” she added. Clinical laboratories may soon have these new assays on their test menus. (Photo copyright: Alzheimer’s Association.)
Companies in the Race to Develop Blood-based Alzheimer’s Tests
Researchers found that C2N’s blood test can detect brain amyloid status with “sensitivity, specificity, positive and negative predictive values that approximate those of amyloid positron emission tomography (PET) imaging,” according to a news release.
“The PrecivityAD2 blood test is intended for use in patients aged 55 and older with signs or symptoms of mild cognitive impairment or dementia who are undergoing evaluation of Alzheimer’s disease or dementia. Only a healthcare provider can order the PrecivityAD2 test,” the news release noted.
“The PrecivityAD2 blood test showed strong clinical validity with excellent agreement with brain amyloidosis by PET,” the researchers wrote.
The PrecivityAD2 test, which is mailed directly by C2N to doctors and researchers, is performed at the company’s CLIA-certified lab, according to USA Today, which added that the cost of $1,450 is generally not covered by insurance plans.
Expanding Test Access with IVD Companies
ALZpath, Inc. has a different approach to the Alzheimer’s disease test market. The Carlsbad, Calif.-based company, set up an agreement with in vitro diagnostics (IVD) company Roche Diagnostics for use of its phosphorylated tau (pTau)217 antibody “to develop and commercialize an Alzheimer’s disease diagnostic blood test that will be offered on the Roche Elecsys platform,” according to a news release.
Roche received FDA breakthrough device designation on the Elecsys pTau217 test earlier this year and will work with pharmaceutical company Eli Lilly to commercialize the test.
Estimates show 75% of dementia cases go undetected—a number which could grow to 140 million by 2050, according to data shared by Roche with Fierce Biotech.
“We plan to leverage our installed base of diagnostic systems, which is the largest in the world, to ensure we are able to create access to this test for those who need it the most,” Matt Sause, CEO, Roche Diagnostics, told Fierce Biotech.
Another IVD company, Beckman Coulter, recently signed an agreement to use ALZpath’s pTau217 antibody test in its DxI 9000 Immunoassay Analyzer. In a news release, Kathleen Orland, SVP and General Manager of the Clinical Chemistry Immunoassay Business Unit at Beckman Coulter, said that the test had “high performance in detecting amyloid pathology” and could “integrate into our advanced DxI 9000 platform to support broad-based testing.”
Clinical Laboratory Participation
The FDA is drafting new guidance titled, “Early Alzheimer’s Disease: Developing Drugs for Treatment” that is “intended to assist sponsors in the clinical development of drugs for the treatment of the stages of sporadic Alzheimer’s disease (AD) that occur before the onset of overt dementia.”
Pharma companies intent on launching new drugs for Alzheimer’s will need medical laboratory tests that accurately diagnosis the disease to confirm the medications would be appropriate for specific patients.
Given development of the aforementioned pTau217 antibody tests, and others featuring different diagnostic technologies, it’s likely clinical laboratories will soon be performing new assays for diagnosing Alzheimer’s disease.
Proof-of-concept study may eventually lead to new clinical laboratory urine tests for fast, non-invasive detection of cancer
Here is the latest example of researchers finding useful biomarkers in urine for diagnosing certain cancers. The discovery comes from the University of Michigan Health Rogel Cancer Center, where, in a proof-of-concept study, scientists developed a urine-based test that screens for circulating free DNA (cfDNA) fragments (aka, cell-free DNA) released by tumors in the head and neck. If they confirm these findings, it’s possible the technology could be adapted into a non-invasive clinical laboratory test for selected cancers.
One such cancer is human papillomavirus (HPV) which, though “widely recognized for causing cervical cancer” is “increasingly found to cause cancers in the mouth, throat, and other head and neck regions,” according to a U-M Medical School press release.
The U-M study findings could lead to an early, non-invasive test for the detection of cancer, as compared to traditional urine or blood-based liquid biopsy testing.
“In this study, we provide evidence to support the hypothesis that conventional assays do not detect ultrashort fragments found in urine since they are designed to support longer DNA fragments. Our team used an unconventional approach to develop a urine test for HPV-positive head and neck cancer ctDNA detection,” said Chandan Bhambhani, PhD (above), Research Lab Specialist Intermediate at University of Michigan and co-first author of the study, in a news release. Clinical laboratories may soon have a new urine-based test for detecting cancer. (Photo copyright: LinkedIn.)
According to the researchers, benefits of urine testing include:
Testing with urine is convenient for people who may be unable to access healthcare and phlebotomy services.
Urine has low biohazard risk and may be easily collected in large amounts, compared with blood.
Ongoing collection of urine could make way for TR-ctDNA “kinetics to be used as a high time-resolution biomarker” to monitor patients’ response to treatment.
However, urine, the researchers cautioned, must be analyzed in a different manner if it is to be comparable in efficiency to blood-based ctDNA testing.
“There have been mixed reports on the efficiency of TR-ctDNA detection compared with that of blood ctDNA. A potentially crucial factor for the analysis of TR-ctDNA is knowing the length of TR-ctDNA fragments present in urine, because this affects assay design for optimal sensitivity in TR-ctDNA detection,” the researchers explained.
New Assay Detects Ultrashort DNA Fragments
To complete their study, the U-M researchers developed an ultrashort HPV droplet digital PCR (polymerase chain reaction) assay that enabled detection of TR-ctDNA from HPV-associated oropharyngeal squamous cell carcinoma (HPV OPSCC), BioTechniques reported.
The assay was made to target the HPV16 E6 (Human papillomavirus 16) gene and to measure TR-ctDNA in patients with HPV OPSCC, the JCI Insight paper noted.
“The HPV16 E6 gene represents a highly recurrent ctDNA target in the population of patients with HPV OPSCC,” the researchers wrote in JCI Insight, adding:
Targeting ultrashort fragments was essential “for robust TR-ctDNA detection.”
Results in urine with patients with HPV OPSCC was consistent with results from plasma ctDNA.
The test, still in the discovery phase, was mailed to patients who were being treated for the disease and who reside within 100 miles of Ann Arbor, Mich. They returned urine samples for testing at the U-M lab and to get insights into possible post-treatment needs.
“Using longitudinal urine samples from a small case series, we showed proof of concept for early detection of cancer recurrence. Thus, our results indicate that by targeting ultrashort DNA fragments, TR-ctDNA becomes a viable approach for HPV OPSCC detection and potentially for cancer recurrence monitoring after treatment,” the authors wrote.
Further Studies, Possible Test Expansion
HPV infection—and especially HPV type 16—is a growing risk factor for oropharyngeal cancers, according to the National Cancer Institute.
The U-M Rogel Cancer Center scientists plan more studies to leverage the information urine may carry about an individual’s health. The researchers intend to expand the scope of their new test to other cancers including breast cancer and acute myeloid leukemia.
“The test that has been developed has detected cancer far earlier than would typically happen based on clinical imaging. As such, these promising results have given us the confidence to broaden the scope of this study, seeking to expanding distribution even further,” said J. Chad Brenner, PhD, Associate Professor of Otolaryngology-Head and Neck Surgery, U-M Medicine, and co-senior author of the study, in the news release.
The University of Michigan Health study exemplifies scientists’ commitment to new categories of biomarkers that can be used for medical laboratory tests and prescription drugs. And by focusing on urine, the researchers made it possible for patients to collect specimens themselves and send them to the medical laboratory for analysis and reporting.
Researchers used CRISPR-based assays to develop new clinical laboratory point-of-care blood test which boasts accuracy, affordability, and accessibility
According to UPI, the test can “distinguish between influenza A and influenza B—the two main types of seasonal flu—as well as identifying more virulent strains like H1N1 and H3N2.”
Many research teams are working to develop paper-based diagnostic screening tests because of their lower cost to produce and usefulness in remote locations. Should this near-patient point-of-care test become clinically viable, it could mean shorter times to answer, enabling speedier diagnoses and earlier start of treatment.
It also means patient specimens do not have to be transported to a clinical laboratory for testing. And reduced cost per test makes it possible to test more people. This serves the public health aspect of monitoring outbreaks of influenza and other diseases and gives hope for improved treatment outcomes.
“Being able to tease apart what strain or subtype of influenza is infecting a patient has repercussions both for treating them and public health interventions, said Jon Arizti Sanz, PhD, co-lead study author and postdoctoral researcher at the Broad Institute of Harvard and MIT, in a Broad Institute news release.
“Ultimately, we hope these tests will be as simple as rapid antigen tests, and they’ll still have the specificity and performance of a nucleic acid test that would normally be done in a laboratory setting,” Cameron A. Myhrvold, PhD (above), Assistant Professor of Molecular Biology at Princeton University in New Jersey, told CIDRAP. Influenza tests that can be performed at the point of care and in remote locations may reduce the number of screening tests performed by clinical laboratories. (Photo copyright: Michael James Butts/Hertz Foundation.)
Her team developed their tests using Streamlined Highlighting of Infections to Navigate Epidemics (SHINE), “a clustered regularly interspaced short palindromic repeats (CRISPR)-based RNA detection platform,” the researchers wrote in their Journal of Molecular Diagnostics paper.
“SHINE has a runtime of 90 minutes, can be used at room temperature and only requires an inexpensive heat block to heat the reaction. The SHINE technology has previously been used to identify SARS-CoV-2 and later to distinguish between the Delta and Omicron variants,” Bioanalysis Zone reported.
“The test uses genetically engineered enzymes to identify specific sequences of viral RNA in samples,” the researchers told UPI. Originally designed to detect COVID-19, the team adapted the technology to detect influenza in 2022 “with the aim of creating a screening tool that could be used in the field or in clinics rather than hospitals or high-tech diagnostic labs,” they said.
Influenza A and B as well as H1N1 and H3N2 subtypes were the targets of the four SHINE assays. “When tested on clinical samples, these optimized assays achieved 100% concordance with quantitative RT-PCR. Duplex Cas12a/Cas13a SHINE assays were also developed to detect two targets simultaneously,” the researchers wrote in their paper.
The team used “20 nasal swabs from people with flu-like symptoms during the 2020-2021 flu season, nasal fluid from healthy people as the control, and 2016-2021 influenza sequences downloaded from the National Center for Biotechnology Information Influenza (NICB) database. They compared the results with those from quantitative reverse transcription-polymerase chain reaction (RT-PCR) tests,” CIDRAP reported.
The original 2020 test (shown above) takes 90 minutes to develop at room temperature. The test developers aim to drop this down to 15 minutes. In comparison, typical polymerase chain reaction (PCR) testing requires medical laboratories to have specialized equipment, trained staff, and prolonged processing times, the Broad Institute news release notes. (Photo copyright: Broad Institute.)
Implications of the New Tests
The ease of the new tests is an important development since approximately only 1% of individuals who come down with the flu see doctors for testing, according to the news release. And researchers had this in mind, looking at speed, accuracy, and affordability as a means to “improve outbreak response and infection care around the world,” UPI reported.
There are great benefits to strain differentiation that be achieved with the new test. Doctors are hopeful the test will help dial in the best treatment plans for patients since some strains are resistant to the antiviral medication oseltamivir (Tamiflu), UPI noted. This is significant since Tamiflu “is a common antiviral,” said Sanz in the Broad Institute news release.
“These assays have the potential to expand influenza detection outside of clinical laboratories for enhanced influenza diagnosis and surveillance,” the Journal of Molecular Diagnostics paper noted. This allows for more strategic treatment planning.
“Using a paper strip readout instead of expensive fluorescence machinery is a big advancement, not only in terms of clinical care but also for epidemiological surveillance purposes,” said Ben Zhang, an MD candidate in the Health Sciences and Technology at Harvard and co-first author of the study, in the Broad Institute news release.
Future Plans for Tests
“With further development, the test strip could be reprogrammed to distinguish between SARS-CoV-2 and flu and recognize swine flu and avian flu, including the H5N1 subtype currently causing an outbreak in US dairy cattle,” the study authors told CIDRAP.
The team is also looking at ways to help prevent H5N1 from crossing into human contamination, Sanz told UPI.
The new Princeton/MIT/Harvard tests echo the trend to bring in affordability and ease-of-use with accurate results as an end goal. Faster results mean the best treatments for each person can start sooner and may render the transport of specimens to a clinical laboratory as a second step unnecessary.
As research teams work to develop paper-based viral tests for their plethora of benefits, clinical laboratories will want to pay close attention to this development as it can have a big implication on assisting with future outbreaks.
Additional research is needed before these tests are going to be commonplace in homes worldwide, but this first step brings inspiration and hope of what’s to come.
Development of the Critical Values system redefined what STAT means in clinical laboratory testing turnaround times
Where did the concept of critical values and having clinical laboratories report them to referring physicians originate? How did the concept blossom into a standard practice in laboratory medicine? Given the importance of critical values, a lookback into how this aspect of laboratory medicine was developed is helpful to understand how and why this has become an essential element in the practice of medicine and an opportunity for labs to add value in patient care.
According to Stanford Medicine, critical/panic values are defined as “values that are outside the normal range to a degree that may constitute an immediate health risk to the individual or require immediate action on the part of the ordering physician.”
What you’ll read below is an insider’s account of the “birth of critical values reporting.”
According to Lundberg, an unaccompanied man was brought to the hospital in a coma and an examination revealed a laceration to his scalp. The patient was admitted to the neurosurgical unit where clinical laboratory tests were performed, including a complete blood count (CBC) analysis, urinalysis, and serum electrolytes. All the test results came back normal except the patient’s serum glucose (blood sugar level) which was 6 mg% in concentration.
“The hard-copy laboratory results were returned to the ward of origin within two hours of receipt of the specimens in the laboratory. However, the results were not noticed by the house officers who were busy with several other seriously ill patients. Ward personnel also failed to communicate the lab results to the responsible physicians,” Lundberg wrote.
When hospital staff did finally notice the test result the next morning glucose was immediately administered to the patient, but it was too late to prevent irreversible brain damage. The man soon passed away.
Following this incident, the hospital developed a “Critical Value Recognition and Reporting System.” The system generated new numbers that were termed “Panic Values.”
However, “critics complained that good doctors should never panic, so the name was changed to Critical Values,” Lundberg explained.
When any of these critical test values were out of the norm, “we required the responsible laboratory person to quickly verify the result and use the telephone (long before laboratory computers) to personally notify a responsible individual (no messages left) who agreed to find a physician who could quickly act on the result. All was documented with times and names,” he wrote.
“We understand that when a physician wants something, he/she wants it, no matter what. Well, in this patient-focused approach, the physician cannot have it, except as offered by the patient-focused approach, based on TAT [turnaround times of clinical laboratory tests],” wrote George Lundberg, MD (above), President and Chair of the Board of Directors of the Lundberg Institute, and Clinical Professor of Pathology at Northwestern University in an article he penned for the National Medical Journal of India (Photo copyright: Dark Intelligence Group. Shows Dr. Lundberg in 2011 addressing the Executive War College on Diagnostics, Clinical Laboratory, and Pathology Management.)
New Clinical Laboratory Standards
Recognition of the urgency to adopt new hospital standards related to certain clinical laboratory test results came swiftly. In 1972, Lundberg was invited to publish an article explaining the new Critical Value Recognition and Reporting System in Medical Laboratory Observer.
According to Lundberg, “most laboratory tests that are done do not need to be done; the results are either negative, normal, or show no change from a prior result. But some are crucial.”
The original set of Critical Values included the following testing results:
The list of values were later expanded to include “vital values.” These values describe lab results for which “action” is important, but where timing is less urgent. Examples of vital values include:
Lundberg and his colleagues went on to redefine what constitutes a laboratory test and what renders a test successful. They discussed laboratory procedures with committees of clinicians, lab personnel and patients, and reorganized hematology, chemistry, and toxicology based on the turnaround time (TAT) of tests.
“We ‘started the clock’—any and all days/times 24×7—when a specimen arrived at some place within the laboratory, and stopped the clock when a final result was available somewhere in the laboratory,” Lundberg wrote in NMJI. “We categorized all tests as: less than one hour, less than four hours, less than 24 hours, and more than 24 hours, guaranteed, 24×7. As a trade-off, we abolished the concept of ‘STAT’ orders … NO EXCEPTIONS. The rationale of each TAT was the speed with which a result was needed to render proper medical care that mattered to the welfare of the patient, and, of course, that was technically possible.”
Since then, very little has changed for the Critical Values System over the past 50 years. The majority of values added have fallen under the “Vital” category and not the “Critical” category. Today, most health systems and clinical laboratories create their own internal processes and procedures regarding which values need to be reported immediately (critical), which values are not urgent (vital), and how those results should be handled.
Clinical laboratories nationwide could follow Yale’s example and enact programs to bring much needed lab services to traditionally underserved communities
Ever since the COVID-19 pandemic drove up demand for telehealth medical services, mobile clinical laboratories have grown in popularity as well, especially among residents of remote and traditionally underserved communities. Now, several divisions of Yale University are getting in on the trend.
“Using a van retrofitted with laboratory-grade diagnostic equipment, the mobile clinic will employ SalivaDirect—a saliva-based COVID-19 PCR test developed at YSPH—to facilitate on-site testing with a turnaround time of two to three hours,” Yale Daily News reported.
Funded by a federal grant, the initial goal was to provide 400 free COVID-19 tests, but the program has exceeded that number. By April 10, the mobile lab had been deployed more than 60 times, appearing at events and pop-up sites throughout various communities in Connecticut, including regular stops at the WHEAT Food Pantry of West Haven.
“[The clinical laboratory-in-a-van] is a brilliant way to reduce the barriers to testing, instead taking the lab to communities who may be less likely—or unable—to access the necessary clinic or labs,” microbiologist Anne Wyllie, PhD, a research scientist who helped develop the PCR test deployed by the mobile lab told Yale Daily News. Wyllie works in the Department of Epidemiology of Microbial Diseases at Yale School of Public Health. “We are actively working with our community partners to identify how we can best serve their communities,” she added. (Photo copyright: Yale School of Medicine.)
Mobile Lab’s Capabilities
Collecting samples, processing, and delivering same-day COVID-19 results was the initial goal but that plan has expanded, Yale School of Medicine noted in a news release.
“Same-day onsite delivery of test results is an added benefit for communities and individuals without access to Wi-Fi or the ability to receive private health information electronically,” Yale added.
The mobile van is staffed with trained clinical laboratory technicians as well as community health navigators who provide both healthcare information and proper follow-up connections as needed for patients who receive positive COVID-19 results. The van runs off power from outdoor electrical outlets at each location and currently serves historically underserved populations in Hartford, Middlesex, Fairfield, New Haven, and New London counties, Yale noted.
“The van allows us to bring our services, as well as healthcare information, directly to communities where they are needed,” said Angelique Levi, MD, Associate Professor, Vice Chair and Director of Pathology Reference Services, and CLIA Laboratory Medical Director in the Department of Pathology at Yale University School of Medicine in a news release.
Launch of a High Complexity Molecular Lab on Wheels
YPL and YSPH collaborated to make the mobile lab a reality. YSPH created the saliva-based COVID-19 test and YPL “provided clinical validation necessary to get the testing method ready for emergency use authorization by the US Food and Drug Administration,” Yale noted.
“YPL recognized the need to be closer to the front lines of patient care and that retrofitting a fully licensed, high complexity molecular laboratory into a consumer-sized van was the right next step,” Chen Liu, MD, PhD, Chair of the Department of Pathology at Yale School of Medicine, noted in a Yale news release. This “gives us options to efficiently deliver accurate diagnostic information when and where it’s needed,” he added.
Throughout the COVID-19 pandemic, the Connecticut Department of Public Health, the City of New Haven, and various community organizations partnered with YPL, YSPH, and the SalivaDirect team to offer free SARS-CoV-2 testing to the public at two different sites in New Haven.
Principal investigators Levi and microbiologist Anne Wyllie, PhD, who helped develop the PCR test deployed by the mobile, lab led the Yale lab-in-a-van research project.
Flambeau Diagnostics, a biomedical company that specializing in mobile lab testing, worked with the Yale team to design and implement the mobile lab van.
“According to Wyllie, the new YSPH and YPL initiative utilizes one of the former Flambeau vans that had been retrofitted for clinical testing,” a Yale news release noted.
Kat Fajardo, Laboratory Manager at Yale University, added custom pieces of equipment to ensure seamless PCR testing. One was a Magnetic Induction Cycler (Mic) measuring only six by six inches. The Mic allowed for measurement of 46 biological specimens, while it’s diminutive size freed up space on the van’s countertop. This allowed lab techs to process specimens concurrently while also providing COVID-19 testing, according to a Yale news release.
Additionally, the van has a Myra portable robotic liquid handler which is “designed to automate the process of moving clinical specimens between vials,” the news release notes.
“What we wanted to do is run high complexity testing in the van, with a reduced timeframe, and then be able to get the results out to the patients as soon as we possibly could,” Fajardo stated.
Exploring the Mobile Laboratory’s Potential
According to a news release, YPL and YSPH consult with community partners to select locations for the mobile lab to visit. These partners include:
APT Foundation (New Haven County, in addition to others.
Although the van was initially used to provide SalivaDirect COVID-19 testing to vulnerable populations, YPL is working with its partners in those communities to identify other testing needs beyond COVID.
The Yale team is considering additional offerings and support such as the addition of a social worker as well as expanding lung health awareness beyond COVID-19 to other respiratory diseases. Also under consideration:
Vaccinations including for COVID-19 and Hepatitis B, and
Health education and materials for harm reduction and STI prevention, a Yale news release noted.
Yale’s Laboratory-in-a-Van program is a consumer-facing effort that is bringing much needed clinical lab services to traditionally underserved communities in Connecticut. Clinical laboratories throughout the nation could do the same with remote or homebound patients who cannot reach critical care.
