Adaptive Biotech received FDA emergency use authorization for T-Detect™ COVID, its test used to detect past COVID-19 infections using genetic techniques to interrogate T cells.
To be simple and clear, this is a very sensitive blood test to look for past COVID infections, but not an active infection. For that, you still need to do a nasal or other swabs.
Why this approach of looking at T cells might be especially important in CLL patients is because while we may have less robust T cell function than someone with a normal immune system, we are particularly bad at forming antibodies. So standard antibody tests may miss past COVID-19 infections in us.
As a reminder, B cells form antibodies and CLL is a cancer of B cells. Antibody formation is part of our “adaptive” immune system, that adapts to a new threat such as SARS-CoV-2, in contrast to the innate immunity which is the first generic responder to any threat. Many of us with CLL make low levels of antibodies, confirmed by low blood levels of immunoglobulins on blood tests, and our poor response to vaccines as documented by this research from Dr. Pleyer at the NIH.
T cells, specifically helper T cells (CD4), are also part of the adaptive immune system, that can respond and remember past threats and help launch a co-ordinate response to an active virus or other threat and have us well prepared should the same virus try to re-infect us. In fact, CD4 T cells arise (and are detectable) very early following infection to “help” the B cells to make antibodies that target the virus.
Both antibodies and T cells that target SARS-CoV-2 tend to fall off over time if they rise at all in CLL patients. But virus-specific T cells appear to be detectable for longer periods of time using sensitive technologies. This makes tests that evaluate the T cell response to infections or other diseases a valuable addition to the tools available to clinicians and patients.
For CLL patients, this is a particularly attractive option as I would not count on the absence of antibodies to correlate with the absence of past infection. The truth is we don’t yet know how well T-Detect™ COVID will work in CLL patients, but there is reason to be optimistic.
The science, mathematics, Artificial Intelligence (AI), and machine learning used to sort through billions of genetic sequences behind all this is an amazing story in itself. But it is a topic for a whole other nerdy post.
Here is the FDA official press release: Coronavirus (COVID-19) Update: FDA Authorizes Adaptive Biotechnologies T-Detect COVID Test
Here is some scientific background from Adaptive: New T-Detect COVID Test Shows the Power of Combining Adaptive’s Immune Medicine Platform with Microsoft’s AI and Machine Learning.
The role of this testing in the clinical and research space is still being developed, and I for one am glad to have this new option to better understand if I and fellow CLL patients have been previously infected with COVID-19.
Stay strong. We are all in this together.
Brian Koffman MDCM (retired) MS Ed
Co-Founder, Executive VP and Chief Medical Officer
CLL Society, Inc.