A self-administered device to collect blood yields high-quality antibody samples and works successfully in a high proportion of users, according to a study of people with previous COVID-19 infection led by Seattle researchers.
The experimental device, made by Seattle-based startup Tasso, has the potential to supplant some blood draws normally taken from a vein in clinics.
The Tasso-SST device works on the upper arm, drawing blood from a network of capillaries under the skin. The patient pushes a button on the device, which pierces the skin with a spring-loaded lancet and creates a vacuum to help collect the blood.
Researchers from Tasso, the University of Washington and Fred Hutchinson Cancer Research Center tested the device in 99 study participants. One group had recovered from prior COVID-19 and were expected to have antibodies against the virus, and a second group had no history of the disease.
The test was designed to ask if patients made enough antibodies against the virus to donate to people with ongoing infections. Self-collected samples were compared with samples collected with the device under supervision and with blood drawn through a vein by a phlebotomist.
The antibody results for each participant were similar among all samples, the researchers found. That’s even though the Tasso-ST samples were subjected to conditions mimicking 48-hour shipping, compared to immediate processing for the phlebotomist-collected samples.
“There was nearly perfect correlation between the results from the venous blood and the capillary blood samples,” said lead author Chihiro Morishima in a UW press release. “The results were as good as we could have hoped for,” added Morishima, an associate professor of laboratory medicine and pathology.
The findings are in sync with previous research showing that antibodies tend to be stable in blood samples.
Though the samples were in good shape, some participants had to use the device twice to get enough blood. Eighty five participants (93.4%) generated enough blood for analysis with their first attempt, compared to 90 participants (98.9%) with a successful blood draw through a vein. Almost all participants had at least some college education.
The device is designed to collect more blood than the average finger prick — yielding on average about a 1/3 milliliters in the study. That’s enough for the the manual analysis performed in the study, though automated instruments may require more.
Other studies with Tasso-SST remain ongoing, including another COVID-19 antibody study at Fred Hutch funded in part by Amazon. Tasso VP of Product Nick End is also a former senior manager of product management at Amazon.
Last July the 9-year-old company raised $17 million on top of $13.1 million in prior grant funding from the Defense Advanced Research Projects Agency (DARPA), the Defense Threat Reduction Agency (DTRA) and the National Institute of Health (NIH).
Tasso also markets a device to self-collect store and transport small blood samples dried as dots on a strip. This device received clearance this May in the European Union for non-diagnostic uses, such as monitoring levels of blood components during clinical trials. That device uses similar technology as the Tasso-SST.
As more studies emerge demonstrating the usefulness of serology in COVID-19 management, “we believe that the FDA will recognize the clinical diagnostic value of these tests and open pathways for authorization,” said Tasso CTO Erwin Berthier in an email to GeekWire. He co-founded the company with fellow bioengineer and CEO Ben Casavant in 2011.
Tasso provided funding for the new study, was involved in the research and approved the final manuscript. The company was not involved in decisions on how to analyze or present the data, according to PLOS One, which published the study.
