ECP 2023 Abstracts

S303 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 were studied and their tissue samples were taken for histological exami- nations. Microscopy of H&E stained slides performed at x10, x20, x40. Autopsy protocols were recorded. Demographic data and clinical peculiarities were noted. Results: Present investigation revealed that majority of deaths were recorded in 43-54 group (70%).The second age group with frequent fatal outcomes ranged 28- 38 years (30%).The respiratory system was the most frequent one involved by SARS-CoV-2 and HIV co-infection diseases leading to death. Interstitial pneumonia, tracheitis with epi- glottitis features revealed in all cases and were complicated by acute respiratory distress syndrome in 60 % of patients. Autopsy investigation also discovered HIV-induced pathological changes, including pneu- mocystis infection, candidiasis, chronic meningitis, chronic hepatitis, chronic pancreatitis, chronic nephritis and malignant lymphoma. The main histological peculiarities were in lungs as alveolar damage, vas- cular involvement accompanied with local and systemic tissue damages in the internal organs. Conclusion: A pandemic of SARS-CoV-2 is still an urgent problem of modern medicine. Accession of HIV infection is an additional risk factor for severe disease course with a high probability of the patient’s death. Autopsy studies make it possible to find out in detail the entire spectrum of pathological changes observed in a combination of two infections, as well as taking into account damage caused by concomi- tant diseases. Investigation of these lesions will have a positive impact on the health care system. E-PS-14-011 Retrospective histopathological classification of 348 skin biopsies from patients with suspected leprosy from Fortaleza, Northeast Brazil 2018-2023 D. Nunes Oliveira*, G. Ferreira Morgantetti, G. Alencar Medeiros, J. Carneiro Melo, V. Queirós Calheiros Campelo Maia, H. Neves Feitosa Filho, M.C. Rocha Muniz, A. de Carvalho Assunção, M. Macêdo Mil- itão Mendonça, A.V. Pinto de Lima, F. Figueiredo *University of Fortaleza, Brazil Background & objectives: Leprosy is a chronic disease caused by Mycobacterium leprae that affects the skin, peripheral nerves and mucous membranes. Our objective was to analyse the histopathologi- cal findings in biopsy reports obtained from patients with suspected leprosy. Methods: This was a retrospective, descriptive study of biopsy reports from patients with suspected leprosy, carried out in a pathol- ogy laboratory, in northeastern Brazil, from January 2018 to March 2023. The variables age, sex, and histopathological subtype were analysed. Also, a correlation with the WHO classification of the cases was established. Results: A total of 361 cases were obtained, in 175 (48.4%) the his- tology showed chronic dermatitis, but in the other 186 (51.5%) cases the histopathological diagnosis of leprosy was made, with a mean age of 40.3 years with 99 (53.2%) men. 127 (68.2%) used Ziehl, 44 (34.6%) positive and 83 (65.4%) negative; 83 (44.6%) Fite, with 57 (68.7% of these 83 reports) negative and 26 (31.3% of these 83 reports) positive; 103 (55.3%) .140 (75.2%) were paucibacillary, 18 (9.6%) undetermined, 97 (52.1%) tuberculoid and 25 (13.4%) bor- derline tuberculoid. In addition, 46 (24.8%) were multibacillary, 6 (3.2%) borderline borderline, 8 (4.3%) borderline lepromatous and 32 (17.2%) lepromatous. Conclusion: Histopathological reports of biopsies from patients with sus- pected leprosy found that, in just under half of the patients, histology failed to confirm the presence of the leprosy bacillus. However, in the other cases, the histopathological diagnosis of leprosy could be confirmed, with the majority of patients having paucibacillary leprosy. Accurate histopatho- logical diagnosis is crucial for the proper management of leprosy. E-PS-14-012 Histological and immunohistochemical characteristics of lung tis- sue from deceased patients in early convalescent phase of viral pneumonia caused by a SARS-CoV-2 V. Pechnikova*, L. Mikhaleva, A. Kontorshchikov, D. Atiakshin, G. Kudryavtsev, Y. Kudryavtseva, R. Vandysheva, Z. Gioeva, L. Kakturskiy *Avtsyn Research Institute of Human Morphology of Federal State Budgetary Scientific Institution "Petrovsky National Research Centre of Surgery", Russia Background & objectives: The aim of the study was to analyse clini- cal and pathological data of the deceased patients, who had previously had viral pneumonia caused by SARS-CoV-2 during early convalescent phase. Methods: The clinical, laboratory and pathological data of 9 deceased patients were analysed. Clinical diagnosis was established in period of 12-46 days, period from clinical recovery to death aver- aged from 2 up to 30 days. Histological slides were stained with H&E, Martius Scarlet Blue and Van Gieson’s stain. Immunohisto- chemical (IHC) staining was performed with antibodies to SARS- CoV-2 S-protein and CK5. Results: H&E staining revealed hyaline membranes in the alveoli, bronchial and alveolar epithelial desquamation. We observed granu- locytes, erythrocytes, siderophages, giant cells and fibrin filaments in the lumen of the alveoli and bronchioles. Foci of bone tissue were found in the cartilaginous plates. Martius Scarlet Blue stain confirmed the presence of hyaline membranes, mixed and hyaline thrombi in the lumen of the branches of the pulmonary arteries. Van Gieson’s stain revealed foci of collagen fibre growth, fibro- sis of the alveolar septa. Metaplasia of the bronchial and alveolar epithelium was confirmed by IHC reaction (CK5). No intracellular viral particles were detected during the IHC reaction to the SARS- CoV-2 S-protein. Conclusion: Despite the absence of a clinical features of viral pneumonia in patients and a negative PCR test result, we found diffuse alveolar damage (DAD) features microscopically in the lungs. In all cases microscopic changes correspond to the exuda- tive-proliferative phase of DAD. Sanogenesis was complete, which was confirmed by a negative IHC reaction with a SARS-CoV-2 S protein. There was no confirmation of "Long Covid" develop- ment, since the microscopic picture corresponded to the exudative- proliferative phase of DAD. E-PS-14-013 The role of cell death in the pathogenesis of rabies virus-infected mice isolated from insectivorous bats I.S. Santos Katz*, G. Hering Motta, L.P. Guimarães, E. Raniero Fernandes, S. Dos Ramos Silva, F. Guedes, O. Garcia Ribeiro *Pasteur Institute, Brazil Background & objectives: Rabies is a viral zoonotic infectious dis- ease that affects mammals. Rabies virus (RABV) from insectivorous bats activates the inflammatory response and cell death by distinct mechanisms. Here we characterized the molecules related to cell death in RABV-infected mice. Methods: Brain tissues from mice infected with CVS-31, Myotis nigricans and Eptesicus furinalis were subjected to an H&E histo- pathology study and immunohistochemistry assay. Double-stained with anti-NeuN or anti-GFAP, and molecules related to cell death (Anti-Caspase-3 or Anti-iNOS or Anti-TNF-α) were evaluated. Differences in the distribution of astrocytes or neurons express- ing cell death molecules between groups were analysed using the Kruskal-Wallis test.