It is becoming increasingly clear that Covid-19 is often more than severe pneumonia. Study results now show, for example, that strokes, pulmonary embolism and severe vascular inflammation can also be part of the clinical picture.
Other organs and tissues are also damaged.
At first it looked different. “Beginning” was only five months ago. Health authorities in Wuhan, China, reported at the time that an extraordinarily aggressive form of pneumonia, apparently caused by a virus, was being diagnosed more and more frequently, especially among 40- to 69-year-olds.
More than just pneumonia
Today, almost 300,000 deaths later, it is not just the virus that is known. You also know how it affects the body and can describe the course of the disease of most infected people well. The latter, however, also means that “pneumonia” is often a somewhat too simple definition. Because there are now several indications that Sars-CoV-2 triggers more than just mild to severe respiratory infections.
More about the corona virus:
Above all, it is becoming increasingly clear that vascular cells can also be affected. And that this is often more than collateral damage to the virus is also clear: Because, according to the current study situation, these attacks could be the cause of almost a quarter of all fatal infections.
Overall, such findings are still relatively rare, because the overwhelming number of those infected develop respiratory infections. And it still applies that most of them are harmless to mild. However, in some people – including younger people who are not at risk – doctors and pathologists are increasingly observing changes that they are only beginning to understand. These include vascular disorders in children similar to Kawasaki syndrome observed in New York and Italy. Small and medium-sized arteries ignite suddenly and violently for reasons that have not yet been clarified. This often results in potentially dangerous lumps near the heart. However, it is not proven whether there is actually a connection to a corona infection.
Formerly suspected
And then there are the not uncommon, atypical, difficult courses for pneumonia as the cause. A doctor who suspected that some deaths were different at an early age is Nils Kucher, a specialist in thrombosis and pulmonary embolism at the University of Zurich. “I was astonished for the first time when we found out that out of the over 1200 deaths in Switzerland involving eight million people, the vast majority, probably 75 percent, do not die in the hospital but at home,” said Kucher weeks ago Daily mirror. In the case of initially harmless courses, the condition sometimes apparently worsens so suddenly that those affected cannot even make an emergency call.
There were also reports from the Netherlands, for example: In a study at two university hospitals, the researchers found blood clots in 18 percent of the patients. In a clinic in Milan, pulmonary embolism was found in 388 Covid-19 patients in almost eight percent. A short time later, the German Neurological Society warned that a third of 214 Chinese Covid-19 patients had neurological failures and increased strokes.
[Alle aktuellen Entwicklungen in Folge der Coronavirus-Pandemie finden Sie hier in unserem Newsblog. Über die Entwicklungen speziell in Berlin halten wir Sie an dieser Stelle auf dem Laufenden]
These early observations are now confirmed, among other things, by first autopsy studies from Hamburg. The legal doctors from the University Hospital Eppendorf (UKE) actually wanted to wait until they had examined significantly more – maybe twenty or fifty – deceased people. But after only twelve autopsies, they decided to publish their findings in the journal “Annals of Internal Medicine”. What they saw seemed too important to them for the further treatment of other patients: seven of the 12 autopsies had thromboses. Four of them had not died of pneumonia, but of pulmonary embolism. These occur when blood clots migrate to the lungs and settle there.
Many thromboses
“We were amazed that we had already discovered so many cases of thrombosis after examining so few patients,” said Jan Sperhake, senior physician at the Institute of Forensic Medicine, when the study was presented on Friday in Hamburg. This finding has now been confirmed by a total of 192 forensic medical examinations at the UKE.
It coincides with the observations that other pathologists make at their institutes. In principle, says David Horst from the Institute of Pathology at the Charité in Berlin, there are three main causes of death. In addition to lung failure, these are bacterial superinfections. In addition, there would be “just the blood clots in the vessels”. Often, says Horst, these blood clots would form in the legs, then migrate to the lungs and there lead to a sudden cardiac arrest.
The data are far from definitive, as is their possible interpretation: At the moment, one can only estimate that “of the Covid 19 patients, a quarter, maybe even 30 or 35 percent, will develop thrombosis or pulmonary embolism during the hospital stay” , says Stavros Konstantinides, Medical Director of the Center for Thrombosis and Hemostasis (CTH) at the University Hospital Mainz, opposite the “Science Media Center”.
Different organs and tissues, same molecular doors
Ultimately, however, the findings are not surprising. In fact, they are very plausible – and that also has to do with the detailed knowledge of the virus and the disease mechanisms, which is growing rapidly despite all the problems and despite the fact that the knowledge of the virus has only been growing rapidly for five months. Because the molecules, which serve as doors for the viruses and allow them access to the pharynx and lung cells, also sit on the inner walls of the vascular cells and kidneys.
Once the virus has damaged the lungs so far that it gets into the bloodstream, it can continue to work there and ensure that the blood vessels also become inflamed. On the one hand, this leads to an even stronger immune response, which may end in the cytokine storm feared by many doctors, in which the immune system starts to work completely uncontrollably and no longer fights the virus, but the body itself.
On the other hand, it ensures that the blood coagulation cascade begins, which is actually there to close wounds. Doctors agree that they measure high levels of blood clotting factors when patients are seriously ill.
Kidney failure
The formation of blood clots could also be linked to the increasingly observed strokes, believes David Horst from the Charité. So far, he has examined eight Covid-19 bodies – strictly according to the rules of an autopsy: first looking at the outside, then opening the body and finally looking at the organs. And there, too, he encounters vascular occlusions. “We also often see small blood clots in the organs themselves, for example in the kidneys, which then cause the tissue to die,” says Horst. In fact, a survey of eleven intensive care centers that treat Covid 19 patients shows that an average of one third of the patients suffered acute kidney failure.
This observation by pathologists is likely to be of far-reaching importance – not only for the deceased. Because such clots in organs can also form in survivors and damage the kidneys or other organs in the long term and impair their function. The rate of moderate to serious kidney damage is “20 to 30 percent,” said Eric Hoste, chairman of the European Society of Intensive Care Medicine.
A register for better understanding
Many would have to go on dialysis. As a preventive measure, specialist societies recommend treating patients with blood thinners. But according to Stavros Konstantinides (Mainz) nobody knows which dosage is the right one.
Almost all of the new findings currently raise new questions. A virus that leads to severe respiratory infections gradually becomes a much more complex clinical picture. To understand it, the world’s first national register for Covid autopsies was set up in Aachen. There, all essential clinical diagnoses and course during life and the pathological diagnoses that are recorded by the autopsy should be anonymized. “This register,” hopes the Berlin pathologist Horst, “will hopefully help to find further answers.”
–
