ECP 2023 Abstracts

S302 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 E-PS-14-007 SARS-CoV-2 spike glycoprotein and nucleocapsid protein expres- sion in cerebral vessels of COVID-19 patients with microcircula- tory disorders S. Gychka*, S. Nikolaienko, V. Vasylyk, M.S.A. Tuffaha, Y. Suzuki *Bogomolets National Medical University, Ukraine Background & objectives: In case of severe COVID-19, various forms of cerebral blood circulatory disorders may develop including stroke. This study describes clinical case series of patients died of COVID-19 aiming to demonstrate the connection between the viral load and brain microcirculation disorders. Methods: Formalin-fixed, paraffin-embedded post-mortem brain tissue samples of five COVID-19 patients were studied with light microscopy, Masson’s trichrome stain and immunohistochemistry (Spike glycopro- tein, Nucleocapsid protein). Results: All autopsy cases have shown similar morphological changes in the brain tissue microcirculation: impaired capillary permeability due to severe oedema of endotheliocytes, signs of blood stasis, sludge phenomenon, and the formation of micro- thrombi. A significant number of capillaries contained only plasma without blood cells. Pronounced perivascular oedema and small perivascular haemorrhages were detected. In two autopsy cases, high expression of SARS-CoV-2 spike glycoprotein and nucleocap- sid protein was detected in the brain vessels. Such changes were accompanied by the presence of microthrombi in the microcir- culatory vessels (1-2 in 10HPF). The frequency of the detection of microthrombi in cases of low SARS-CoV-2 marker expression was low. Conclusion: In this clinical case series, we have shown the high expression of SARS-CoV-2 spike glycoprotein and nucleocapsid pro- teins in cerebral vessels of patients with the severe brain microcircula- tion disorders and the formation of microthrombi. Funding: Funded by NIH (R21AG73919) E-PS-14-008 Pneumocystis jiroveci pneumonia in COVID-19 & HIV co-infected patients A. Malysheva*, O. Reshetnikova, A. Ermakov, T. Shapovalova *Immanuel Kant Baltic Federal University, Russia Background & objectives: Pneumocystis jiroveci pneumonia (PJP) is the opportunistic infection, which is commonly associated with human immunodeficiency virus (HIV) infection. The aim of present study was to evaluate morphological features of PJP in COVID-19-related deaths of HIV infected individuals. Methods: Post-mortem examinations were performed on five cadav- ers with PJP in HIV& COVID-19 co-infected individuals (one female and four male bodies 30-47 y.o.). Medical histories, laboratory data and clinical peculiarities of these patients were studied. Macroscopic pictures of lungs and other organs, as well as histological features of their tissue samples at the magnifications x10, x20, x40 were recorded at the autopsy protocols. Results: Autopsies revealed that the lung was the most frequent organ involved by HIV& COVID-19 co-infection-associated patholo- gies leading to death. All cases were represented with gross pic- ture of diffuse bilateral pneumonias. Histological examination has shown alveolar spaces in lungs were filled with amorphous, foamy, eosinophilic, mostly acellular fibrinous exudate. Inflammatory reac- tion with fibrin exudate, hyaline membranes formation was a com- mon histological pattern in our material. In some areas, there were signs of organization of exudate in the alveoli and the development of fibrosis. The interstitial inflammation was accompanied with the sclerotic features in the lungs septas’ interstitium. Widespread microangiopathy, with focal thrombosis of the vessels discovered in all lung parenchyma samples. Conclusion: Studying an autopsy material using a collection of lung and other internal organs tissues is essential to increase knowledge of a COVID-19 clinical manifestations worsened by compromised immune function. Pathological examination is an important instrument to better understanding of the PJP’s role in thanatogenesis, particularly when the knowledge of disorders in COVID-19 & HIV co-infected individuals is restricted and the influence on the healthcare system is significant. Future studies is needed to understand the pathogenesis of combined infection’s severe course. E-PS-14-009 Coagulopathy as a contributor to the lethal outcome to COVID-19 & HIV infection comorbidities A. Malysheva*, O. Reshetnikova, A. Ermakov, L. Rudiuk *Immanuel Kant Baltic Federal University, Russia Background & objectives: Thrombotic complications are the common cause of increased morbidity and mortality in patients with COVID-19. The aim of present study was to evaluate the role of the coagulopathy in lethal cases’ thanatogenesis in SARS-CoV-2 & HIV co-infected individuals. Methods: Medical records, blood tests information and autopsy find- ings were studied in ten lethal cases the COVID-19 & HIV infec- tion comorbidities. Naked eye examinations of the internal organs of five male and five female corpses were followed with the histological studies their tissue samples collection. Microscopy of H&E stained slides performed at x10, x20, x40. Clinical-morphological analysis carried out. Results: Haematological changes noted in most lethal cases of COVID-19 & HIV infection comorbidities. Thrombocytopenia was recorded in half of the individuals, and in 20% of cases it was severe. Elevated plasma D-dimer levels and decreased prothrombin Index were common findings. Post-mortem examinations revealed multiple haemorrhages, severe damages to various internal organs, especially to the respiratory system. The alveoli were filled with oedematous fluid; hyaline membranes were found in 80% of lung histological slides. The development of acute respiratory distress syndrome against this back- ground caused the death of many patients. The presence of chronic hepatitis was noted in 40% of patients with an outcome in cirrhosis in a third of individuals. Conclusion: An analysis of the data obtained showed that the respira- tory pathology characteristic of COVID-19 is exacerbated by the pres- ence of liver damage, usually noticeable in patients with HIV infection. A decreased level of blood platelets in combination with coagulopathy contributes to the development of a widespread haemorrhagic syn- drome. The data obtained are discussed in the aspect of thanatogenesis of the COVID-19 & HIV infection lethal cases. E-PS-14-010 Clinical and morphological comparisons in lethal cases of co-infec- tion with SARS-CoV-2 and HIV A. Malysheva*, O. Reshetnikova, A. Ermakov, T. Shapovalova *Immanuel Kant Baltic Federal University, Russia Background & objectives: In recent years SARS-CoV-2 pandemic resulted in a global public health emergency. High morbidity and mor- tality is one of the major concerns. Clinical-pathological features of the SARS-CoV-2 infection’ fatal cases in patients co-infected with HIV evaluated in the study. Methods: Full pathological post-mortem examinations were performed in ten fatal cases of SARS-CoV-2 and HIV co-infection, including five males and five female’s bodies. Gross pictures of the internal organs