192 CMAAO CORONA FACTS and MYTH COVID : Autopsy reports of COVID 19 patients
Dr K Aggarwal
With input from Dr Monica Vasudev
1064: Medscape excerpts
1. Every organ in the body is pretty much affected.
2. Conducting COVID autopsies has been like going to a police line up where one might not be able to definitively pick out the perpetrator but unlikely suspects can be eliminated
3. We've learned through autopsy that there's no direct tissue pathology to account for the acute symptoms that are seen" in the heart, the kidney, and the brain
4. Pathologists have postulated a handful of hypotheses about the causes of extensive organ damage in COVID-19, including that hypoxia resulting from compromised lung function may be causing secondary injuries
5. obesity pre-disposes the infected to worse morbidity and mortality. Obesity in and of itself is a pathologic state, that it leads to atherosclerosis, increased clotting, fatty liver disease, and often, enlarged hearts.
6. SARS-CoV-2 is exhibiting a selectivity for the lungs. In one decedent, bone marrow response was observed with many myeloid precursors in the peripheral blood vessels typical in an overwhelming infection.
7. The cells that SARS-CoV-2 may be targeting are the type II pneumocytes
8. Those lung surface cells secrete a fatty substance to keep the lobes pliable. And that, precipitates the diffuse alveolar damage and acute respiratory failure that we are observin
9. Immunohistochemistry testing and electron microscopy "confirmed viral tropism for pulmonary II pneumocytes.
10. Viral antigen in lung tissue was higher than with SARS or MERS.
11. Extensive detection in epithelial cells of the upper respiratory tract is unique among these highly pathogenic coronaviruses
12. COVID-19 autopsies have confirmed clinicians' reports of increased clotting. The virus may very well be infiltrating the endothelium and causing injury to the blood vessel.
13. Myocarditis is typical of viral diseases, but it has been frustratingly inconsistent in COVID-19 autopsies. Most have reported very little inflammation of the heart muscle. At least one death has been directly attributed to COVID-19–induced lymphohistiocytic and eosinophilic myocarditis. And German researchers report in JAMA Cardiology that 60 of 100 patients who had recovered from COVID-19 had ongoing myocardial inflammation, as measured by cardiovascular magnetic resonance imaging (MRI). Many collegiate football programs, reporting evidence of myocarditis in athletes who have recovered from COVID-19, said they would postpone their seasons.
14. But, looks like, what they are seeing by [MRI] is not true myocarditis but something else as per Richard S. Vander Heide, MD, PhD, MBA, a professor of pathology at Louisiana State University Health Sciences Center in New Orleans
15. So far, autopsy studies have found no typical myocarditis in nearly every case.
16. Vander Heide and colleagues published cardiopulmonary findings from 10 autopsies conducted on African Americans who died from COVID-19 in The Lancet in May and updated it with an additional 12 cases in Circulation in July. Six of the 22 had a history of heart disease. All had diffuse alveolar damage — a histopathologic marker of Acute Respiratory Distress Syndrome (ARDS) — in addition to pulmonary thrombi and microangiopathy. In all the cases, the virus was not found in the heart muscle cells and there was no evidence of what the authors called "typical lymphocytic myocarditis. In the newer study, Vander Heide and colleagues used electron microscopy to find what appeared to be viral particles in the vascular cells in the heart, lungs, and kidneys. Vander Heide, whose primary research interest is myocardial cell injury and adaptation, believes the infection of these endothelial cells is leading to clotting abnormalities in the heart's small vessels, causing inflammation. The heart cells are dying, but not from myocarditis. Instead, he thinks it's likely that the clotting is causing cell death from ischemia.
17. Some pathologists are looking at vascular changes, which are "among the distinctive features of COVID-19," write Maximilian Ackermann, MD, and colleagues in an article published in May in the New England Journal of Medicine.
18. They compared lungs of seven patients who died from COVID-19 with seven who died from ARDS secondary to influenza, as well as those from 10 age-matched, uninfected patients. The COVID-19 lungs exhibited severe endothelial injury, which appeared to be associated with intracellular SARS-CoV-2 virus.
19. There also was widespread vascular thrombosis with microangiopathy and occlusion of alveolar capillaries and significant new vessel growth from an unusual form of angiogenesis called intussusceptive angiogenesis — a reactive formation of new vessels where one splits into two, said co-author William W. Li, MD, president and medical director of the Angiogenesis Foundation.
20. Venous thromboembolism has also been observed in patients, including in a study at the University Medical Center Hamburg-Eppendorf in Germany that was published in May in the Annals of Internal Medicine.
21. Coronavirus infections may be a trigger for venous thromboembolism
22. Several potential mechanisms include endothelial dysfunction, systemic inflammation, and a pro-coagulatory state.
23. Researchers at Hospital Graz II in Graz, Austria, also homed in on thrombosis, with evidence of it in all 11 autopsies they conducted, according to an article published in Annals of Internal Medicine.
24. Pathologists were initially reluctant to take on COVID-19 autopsies, especially any that would involve aerosol-generating procedures. The College of American Pathologists attempted to allay fears with guidelines that recommend techniques that minimize those procedures, including using hand shears or other alternatives to an oscillating bone saw (also recommended by the CDC) or using a vacuum shroud with the bone saw.
25. Williamson pointed out that there have been no reported cases of SARS-CoV-2 transmission from a corpse to any pathologist, morgue technician, or assistant. Still, his informal survey in March of pathologists on a LISTSERV he manages found that only six out of 50 respondents were conducting autopsies. A month later, that number had risen to 30.
26. The CDC recommends autopsies be done in a negative pressure suite, which are more common at academic centers.