This will not only advance our scientific knowledge, but really enable new therapeutic approaches, even novel diagnostics. So, with that, I'm excited. Let's dive into our talk. Mr. Fritsma: Fritsma: We continue with Part Two of our discussion. What have we learned about inflammation and thrombosis since the COVID-19 outbreak? And our Part 2 discussion is:

The Link between COVID-19 Infection, Thrombosis and Long COVID Mr. Fritsma: Doctor Henry, to start with, the symptoms of Long COVID are very broad, encompassing symptoms Mr. Fritsma: Doctor Henry, to start with, the symptoms of Long COVID are very broad, encompassing symptoms from head to toe, how do we classify these and are they related? Dr. Henry: Henry: Long COVID, like COVID, is an extremely heterogeneous disease, or better yet, group of still poorly defined diseases. The vast number of symptoms and different disease presentations makes classifying it very difficult, as is understanding if there are relationships between these different symptoms and different disease courses. Let's step back. Let's look at a little bit of data on symptomatology and what we see in Long COVID and then we can think about a bit of classification. So this is an excellent meta-analysis that was done that looked at the effects of Long COVID. It looked at a very large population, so it looked at a number of different studies and it put together a picture of the symptomatology that we see in Long COVID. And as you can see, the symptoms are very broad. Some of the most common are the fatigue, the headache and of course the brain fog that we've all heard about, going across nearly every system of the body. It really is a head-to-toe presentation, so this makes trying to understand what was driving this and how to classify it very difficult. We have everything from neurologic symptoms, psychiatric symptoms like paranoia and PTSD, to things like pulmonary fibrosis, chest pain, cough. So, it's a very broad picture that is Long COVID. We also can see here they also listed some laboratory values. They found D-dimer. We're looking at post COVID. 20% of people had elevated D-dimer, BNP [brain natriuretic peptide], CRP and of course the inflammatory biomarkers like serum ferritin, CRP, IL-6, procalcitonin, lactic acid, calprotectin, erythrocyte sedimentation rate [ESR]. So, indeed, it is a very heterogeneous picture and it makes one trying to understand what's driving this. How we classify this is very difficult. Is it one disease or is it several diseases? Do people have different progressions? Is it one thing? And this is a study that recently came out that I think gave me a little bit of pause. This study was done looking at a number of veterans using the US Department of Veteran Affairs database and it included over 180,000 participants who had a COVID-19 infection. They were looking particularly at the risk of developing diabetes. They found that those with COVID-19 were 40% more likely to develop diabetes up to a year later than were veterans in the control group. It just gives you an idea that we could be seeing long effects that affect many organs, many tissues and that we're just beginning to understand so, when we think about classification, the British put out their own very early-on guidelines, so they defined acute COVID which is within the first 4 weeks and then they define Long COVID as new or ongoing symptoms 4 weeks or more after the start of acute COVID, which that they divided into two groups, those for four to 12 weeks and 12 or more weeks. I don't think that classification really works too well but let me give my idea of how I classify this, at least in terms of what I'm doing about the pathophysiology. I think that we can really break it down into three groups of conditions: those are the prolonged symptomatic COVID, so these are people who have the prolonged symptoms, the cough, fever. Now, that doesn't really go away. And then we have the post-acute sequelae of SARS-CoV-2 infection. With this I'm thinking about things like myocardial infarction, stroke, diabetes, these new