[Miocarditis in Patients with COVID 19 Confirmed by Immunohistochemical]
Aim Despite the regular heart damage in patients with coronavirus pneumonia caused by SARS Cov 2, a possibility of developing lymphocytic myocarditis as a part of COVID 19 remains unsubstantiated. The aim of this study was to demonstrate a possibility of lymphocytic myocarditis and to study its morphological features in patients with the novel coronavirus infection (COVID 19) with a severe course.Material and methods Postmortem data were studied for 5 elderly patients (74.8+ 4.4 years; 3 men and 2 women) with the novel coronavirus infection and bilateral, severe polysegmental pneumonia (stage 3 4 by computed tomography) COVID 19 was diagnosed based on the typical clinical presentation and positive polymerase chain reaction test in nasopharyngeal swabs. All patients were treated in different hospitals repurposed for the treatment of patients with COVID 19. A standard histological study was performed with hematoxylin and eosin, toluidine blue, and van Gieson staining. Serial paraffin slices were studied immunohistochemically with antibodies to CD3, SD68, CD20, perforin, and toll like receptors (TLR) 4 and 9.Results In none of the cases, myocarditis was suspected clinically, added to the diagnosis or indicated as a possible cause of death. IHD and acute myocardial infarction were mentioned as error diagnoses not confirmed by the postmortem examination. The morphological examination of the heart identified signs of lymphocytic myocarditis consistent with Dallas criteria for this diagnosis. Myocardial infiltrate was characterized in detail, and a combined inflammatory damage of endocardium and pericardium was described. The immunohistochemical study with cell infiltrate typing confirmed the presence of CD3 positive T lymphocytes and the increased expression of TLR 4. A picture of coronaritis, including that with microvascular thrombosis, was found in all cases.Conclusion A possibility for development of lymphocytic viral myocarditis in COVID 19 was confirmed morphologically and immunohistochemically. Specific features of myocarditis in COVID 19 include the presence of coronaritis and a possible combination of myocarditis with lymphocytic endo and pericarditis.
Kardiologiia