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New T-Cell Test to Detect COVID-19 Infection Risk and Sheds Light on the Future of Diagnostic Testing in Health Care

April 19, 2021

By Julie Gould 

Dr. Sudeb Dalai, MD PhD, is a physician-scientist-innovator specializing in Infectious Diseases at Stanford University and the Palo Alto Medical FoundationSudeb Dalai, MD, PhD, senior medical director, Adaptive Biotechnologies, discusses a recent T-cell test that was developed to help detect recent or past COVID-19 infection, explains how the test works, and details what this newly developed test means for the world of diagnostics in health care.

Can you talk a little about T-cells and how they are currently being used in the care of patients? 

T cells are specialized cells of the immune system. They move around in the blood looking for threats to help us detect, fight and remember most diseases. Virtually every disease has its own unique T-cell signature.

T cells are our frontlines of defense against infectious disease, cancer and autoimmune disorders. They arise earlier than antibodies and can persist in the blood for longer.

We can now use T cells to detect disease in large populations of people which would not have been possible 5-10 years ago. That’s why we partnered with Microsoft to leverage AI and machine learning to help identify and map the T-cell immune response to many different diseases, including COVID-19. 

How have you helped changed the testing landscape by utilizing T-cells in order to test for COVID-19? 

T-Detect™ COVID is the first in a new class of tests to receive FDA Emergency Use Authorization (EUA) for recent or prior COVID-19 infection. T-Detect COVID takes an entirely new approach to determining past infection by looking an individual’s T cell immune response to SARS-CoV-2, the virus that causes COVID-19.   

The test works by analyzing at the T-cell response to a broad portion of the virus. Antibody tests analyze the immune response to only specific parts of the virus like the spike protein.

T-Detect COVID correctly confirmed recent or prior COVID-19 infections 97.1% of the time with 100% specificity in cases that had confirmed RT-PCR diagnosis. 

What does this newly developed test mean for the world of diagnostics in health care? 

The authorization of T-Detect COVID represents a breakthrough for patients and a pivotal milestone for the diagnostic testing paradigm in human disease.   

We have proven that it is possible to read how T cells detect disease in the blood in order to create new diagnostic tests, and this is just the beginning of a pipeline of tests for many other diseases. For example, we have ongoing research in Lyme disease and Crohn’s disease.

By applying Microsoft’s AI, machine learning, and cloud computing to our science and next generation sequencing, we are turning biology into data and we’re using that data to discover and develop tests and treatments for many other diseases.

Based on this test, how do you think the future of care will change? 

Our platform transforms the genetics of the immune system into data, and we take that data, and turn it into tests and treatments for almost any disease.

T-Detect COVID, our T-cell diagnostic test, is a prime example. It’s one test with many potential indications powered by the data from our body’s immune system. 

The massive and growing amount of immune system data that we generate is at the center of what we do. 

We’re using that data to create a pipeline of novel diagnostics and therapeutics based on how the immune system detects and manages disease, which could transform how we currently diagnose and treat a broad spectrum of diseases.  

What do you want other health care professionals to know about this test? How can they apply it to their clinical practice routine? 

T-Detect COVID can help patients determine if they had recent or prior COVID-19 infection particular to those who:  

  • Have lingering symptoms and wonder if they previously had COVID-19
  • May have been exposed to SARS-CoV-2, but were never tested and are concerned that they might have had COVID-19
  • Were tested, but are concerned it may have been a false negative result 

T-Detect COVID should not be used to diagnose current SARS-CoV-2 infection. 

Except for a blood draw, everything can be completed online at, including getting a prescription and receiving test results via a secure portal. Patients can sign up to have their blood drawn at one of 2,000+ Labcorp facilities or have a mobile phlebotomist come to their home. Results are sent via secure email in 7-10 days.

Patients can order T-Detect COVID online at by answering a few eligibility questions through a secure portal. 

Any final thoughts?

With Microsoft, we are building a map of the immune system called the TCR-Antigen Map. This approach uses immunosequencing, proprietary computational modeling and machine learning to map T-cell receptor sequences to disease-associated antigens for infectious diseases, autoimmune disorders and cancer.

Understanding the adaptive immune system is not only an important step in diagnosing many different diseases but also may ultimately help to develop novel, immune-based treatments.

Dr Sudeb Dalai, MD PhD, is a physician-scientist specializing in Infectious Diseases at Stanford University and the Palo Alto Medical Foundation. As a Senior Medical Director at Adaptive, he also leads the clinical development strategy and execution for the T-Detect infectious disease program. He is a member of the teaching faculty at Stanford School of Medicine and was formerly a Medical Director at Karius Inc, where he contributed to the development of genome-based diagnostics for infectious diseases. Dr. Dalai remains highly active in outpatient and inpatient clinical care, in addition to teaching, research, and industry innovation.   

Dr Dalai’s expertise includes complex infections, sepsis, epidemiology/clinical research, data science, and genomics. He holds degrees from Stanford, MIT, and UC Berkeley School of Public Health.  He has received numerous teaching and leadership awards, directs multiple academic and industry research studies, and has authored an array of publications. Dr Dalai was elected to serve on the MIT Board of Trustees and provides healthcare and strategy consulting for industry ventures and companies at all growth stages in the areas of biotechnology / life sciences, diagnostic and pharmaceutical development, and healthcare technology/innovation. He is an internationally-invited speaker and has delivered lectures in the US/North America, Europe, and Africa.

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