Almanac of Clinical MedicineAlmanac of Clinical Medicine2072-05052587-9294Moscow Regional Research and Clinical Institute (MONIKI)133810.18786/2072-0505-2020-48-034Morphological and immunohistochemical characteristics of changes in the bronchopulmonary lymph nodes in patients with a new COVID-19 coronavirus infection (based on autopsy results)FedorovD. N.<p>Dmitry N. Fedorov - MD, PhD, Associate Professor, Head of Department of Pathology.</p><p>61/2-13 Shchepkina ul., Moscow, 129110, Tel.: +7 (903) 662 09 10</p><p> </p>mmapath_dnf@mail.ruhttps://orcid.org/0000-0001-6697-122XKorostelevaP. A.<p>Polina A. Korosteleva - Pathologist, Department of Pathology.</p><p>61/2 Shchepkina ul., Moscow, 129110</p>fake@neicon.ruhttps://orcid.org/0000-0001-7867-5241ZybinD. I.<p>Dmitry I. Zybin - MD, PhD, Head of Department of Cardiovascular Surgery.</p><p>61/2 Shchepkina ul., Moscow, 129110</p>fake@neicon.ruhttps://orcid.org/0000-0001-7087-5441PopovM. A.<p>Mikhail A. Popov - Cardiovascular Surgeon, Research Fellow, Department of Cardiovascular Surgery.</p><p>61/2 Shchepkina ul., Moscow, 129110</p><p> </p>fake@neicon.ruhttps://orcid.org/0000-0002-0316-8410TyurinaV. M.<p>Vlada M. Tyurina - Clinical Resident, Department of Pathology.</p><p>61/2 Shchepkina ul., Moscow, 129110</p><p> </p>fake@neicon.ruhttps://orcid.org/0000-0002-1426-0917VarlamovA. V.<p>Andrey V. Varlamov - Pathologist, Department of Pathology.</p><p>61/2 Shchepkina ul., Moscow, 129110</p><p><br /><br /><br /></p>fake@neicon.ruhttps://orcid.org/0000-0002-9866-9567Moscow Regional Research and Clinical Institute (MONIKI)190920204837420609202006092020Copyright © 2020, Fedorov D.N., Korosteleva P.A., Zybin D.I., Popov M.A., Tyurina V.M., Varlamov A.V.2020<p><strong><span class="fontstyle0">Background: </span></strong><span class="fontstyle2">Research into the pathogenesis and morphogenesis of new coronavirus infection (COVID-19) is currently a hot topic that requires the accumulation, management and analysis of the data. Understanding the mechanisms of the disease and their characteristics would help to improve diagnostic quality, treatment efficacy and reduce mortality. </span></p><p><span class="fontstyle0"><strong>Aim:</strong> </span><span class="fontstyle2">To identify morphological and immunohistochemical characteristics of the bronchopulmonary lymph node tissues in autopsied patients with COVID-19. </span></p><p><strong><span class="fontstyle0">Materials and methods: </span></strong><span class="fontstyle2">The study was carried out on 44 autopsy samples from patients who were hospitalized and died from the new coronavirus infection COVID-19 in the Moscow Regional Research and Clinical Institute. Macroscopic, histological, and immunohistochemical assessment methods were used.<br /></span></p><p><strong><span class="fontstyle0">Results: </span></strong><span class="fontstyle2">We found stereotypical abnormalities in the morphology and cellular composition of the lymphoid tissue depending on the duration of the disease. These included signs of B-cell-mediated immunity suppression manifested by a decrease in the number and size of lymphoid follicles and occurs at latest after 7 days from the onset of the disease. In the patients with the disease duration of up to 14 days, the T-cell pool of the lymph nodes is represented mainly by CD4</span><span class="fontstyle2">+ </span><span class="fontstyle2">T-lymphocytes. With longer duration of the disease, there is a gradual increase in the number of lymphoid follicles and their sizes, with changes of the CD4</span><span class="fontstyle2">+ </span><span class="fontstyle2">to CD8</span><span class="fontstyle2">+ </span><span class="fontstyle2">T-cell ratio towards higher CD8</span><span class="fontstyle2">+ </span><span class="fontstyle2">counts. After 21 days of the disease, the CD4</span><span class="fontstyle2">+ </span><span class="fontstyle2">to CD8</span><span class="fontstyle2">+ </span><span class="fontstyle2">ratio levels off.<br /></span><strong></strong></p><p><strong><span class="fontstyle0">Conclusion: </span></strong><span class="fontstyle2">The results obtained indicate a direct damaging effect of SARS-CoV-2 on the lymph node tissues of the bronchopulmonary group. The possibility of secondary transient immune deficiency and infectious complications in patients with a new coronavirus infection is discussed.</span></p>COVID-19 infectionpathogenesispathological anatomylymphoid tissueинфекция COVID-19патогенезпатологическая анатомиялимфоидная ткань[1. Министерство здравоохранения Российской Федерации. Временные методические рекомендации: профилактика, диагностика и лечение новой коронавирусной инфекции (COVID-19) [Интернет]. Версия 7 (03.06.2020). М.; 2020. 166 с. Доступно на: https://static-0.rosminzdrav.ru/system/attachments/attaches/000/050/584/origi-nal/03062020_%D0%9CR_C0VID-19_v7.pdf.][2. Park WB, Kwon NJ, Choi SJ, Kang CK, Choe PG, Kim JY, Yun J, Lee GW, Seong MW, Kim NJ, Seo JS, Oh MD. Virus Isolation from the First Patient with SARS-CoV-2 in Korea. J Korean Med Sci. 2020;35(7):e84. doi: 10.3346/jkms.2020.35.e84.][3. Hoffmann M, Kleine-Weber H, Schroeder S, Kruger N, Herrler T, Erichsen S, Schiergens TS, Herrler G, Wu NH, Nitsche A, Muller MA, Dro-sten C, Pohlmann S. SARS-CoV-2 Cell Entry Depends on ACE2 and TMPRSS2 and Is Blocked by a Clinically Proven Protease Inhibitor. Cell. 2020;181 (2):271 -80.e8. doi: 10.1016/j.cell.2020.02.052.][4. Wang K, Chen W, Zhou YS, Lian JQ, Zhang Z, Du P, Gong L, Zhang Y, Cui HY, Geng JJ, Wang B, Sun XX, Wang CF, Yang X, Lin P, Deng YQ, Wei D, Yang XM, Zhu YM, Zhang K, Zheng ZH, Miao JL, Guo T, Shi Y, Zhang J, Fu L, Wang QY, Bian H, Zhu P, Chen ZN. SARS-CoV-2 invades host cells via a novel route: CD147-spike protein [Internet]. bioRxiv. 2020 Mar 14. doi: 10.1101/2020.03.14.988345.][5. Walls AC, Park YJ, Tortorici MA, Wall A, McGuire AT, Veesler D. Structure, Function, and Antigenicity of the SARS-CoV-2 Spike Glycoprotein. Cell. 2020;181(2):281-92.e6. doi: 10.1016/j.cell.2020.02.058.][6. Perrella A, Trama U, Bernardi FF, Russo G, Monastra L, Fragranza F, Orlando V, Coscioni E. Editorial - COVID-19, more than a viral pneumonia. Eur Rev Med Pharmacol Sci. 2020;24(9):5183-5. doi: 10.26355/eur-rev_202005_21216.][7. Lin L, Lu L, Cao W, Li T. Hypothesis for potential pathogenesis of SARS-CoV-2 infection - a review of immune changes in patients with viral pneumonia. Emerg Microbes Infect. 2020;9(1):727-32. doi: 10.1080/22221751.2020.1746199.][8. Mason WH. Measles (Chapter 246). In: Klieg-man RM, Stanton BMD, St. Geme J, Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Elsevier; 2016. p. 1542-8.e1.][9. Gershon AA. Measles Virus (Chapter 160). In: Mandell G, Bennett J, Dolin R. Mandell, Douglas and Bennett's Principles and Practice of Infectious Diseases. 7th ed. Churchill Livingstone; 2009. p. 2229-36.e2.]