bioRxiv: Artificial lungs help reveal the causes of blood clogs in PATIENTs with COVID19.

9, 2020 /--- In a recent study, EPFL scientists are using technology to better understand how coronavirus causes blood clots in some patients.
they developed a simplified lung model that allowed them to see for the first time how viruses attack cells located in blood vessels.
the exact incidence is still unclear, COVID-19 can sometimes cause blood clots.
a recent study showed that about 10 percent of hospitalized patients developed this complication.
still not sure why the virus causes this reaction - in the worst cases, blood clots can cause strokes.
to gain insight into the phenomenon, EPFL scientists have developed a microfl flow control chip that simulates a person's lungs and replicates part of its structure to study COVID-19 infections.
the chip can hold lung endocial cells, vascular cells and immune system cells, and allow scientists to see directly how SARS-CoV-2 attacks human cells and triggers the formation of blood clots.
(Photo: www.pixabay.com) suspect that two mechanisms are at work.
is the overproductive production of cytokines, proteins that play a role in immune cell signaling.
coronaviruses can cause "cytokine storms" in which overactive immune system responses can damage blood vessels and lead to blood clot formation, which can be fatal.
another possible mechanism is damage to the inner walls of blood vessels or endothial tissue in the lungs.
many of these tissues in the lungs, and once damaged, blood can easily clot and form clots.
, what mechanism are the possible culprits? To find out, doctors need to be able to observe the progress of lung infections on an hourly basis.
this is almost impossible in living patients, nor is it feasible in laboratory culture, where the culture usually contains only one cell and does not provide a sufficiently realistic indication of the entire lung system.
john McKinney's lab have been supported by the EPFL COVID-19 Working Group.
led by dr. Vivek Thacker, a postdoctoral doctor in the lab, they now use on-chip lung devices and model them to simulate steps of SARS-CoV-2 lung infection.
the device contains a microflow channel that feeds nutrients to cells on the chip that are arranged to rebuild a portion of the lungs.
more specifically, the chip contains a layer of endothial cells or cells that cover the lungs, as well as a layer of endothial cells or cells lined with blood vessels.
two layers are separated by the membrane.
scientists introduced SARS-CoV-2 into their devices, the virus first attacked the outer layer of the endocyst cells, just like a natural infection.
they worked with Dr. Jessica Sordet Dessimoz and his team at the histological core facility to find that the virus reached the inner layer of endostrote cells within a day and caused considerable damage in the following days.
Vivek Thacker said: "There is enough destructive power to damage the endoskin and expose blood from blood vessels to the air, leading to the formation of blood clots.
through our system, we found that the virus could cause blood clots by directly attacking the endoskin.
, that doesn't mean cytokines don't work.
" EPFL device reveals a phenomenon that cannot be observed using conventional methods because SARS-CoV-2 does not proliferate well in endoskin cell monocultures.
also found in the endeskin of infected patients, but in small numbers, " said Thaker, a government analyst.
" team will then use their single lung and actual blood samples so they can directly observe the formation of blood clots.
it's not as simple as it sounds - blood clots quickly outside the body, so "we have to be fast and accurate," explains Thaker.
they plan to add anticoagulants to the sample and then add it to the device before injecting it.
team will deal with this complex process over the next few weeks.
(bioon.com) Source: lung helpers researchers how COVID-19 causes blood clots Original source: Vivek V Thacker et al. Rapid endothelialitis and vascular contente SARS-CoV-2 infect in human lung-on-chip model, bioRxiv (2020). DOI: 10.1101/2020.08.10.243220.