Immunohistochemical Characteristic of Intratesticular SARS-CoV-2 Invasion

Abstract

Based on studies on the effect of SARS-CoV-2 on tissues, not only pulmonary invasion but an impaired testicular function also were revealed. In single studies on small samples of patients, an increase in the number  of  apoptotic  cells,  CD138+  plasma  cells,  CD3+  T-lymphocytes,  CD20+  B-lymphocytes,  CD68+  macrophages in the interstitial tissue was found. However, a comprehensive morphological and immunohistochemical study has not been performed on a significant cohort of patients. Thus, the study of the mechanisms of influence of SARS-CoV-2 on spermatogenesis remains relevant.The aim of the study was to carry out an immunohistochemical evaluation of spermatogenesis disorders in SARS-CoV-2 invasion.Material and methods. For the first time, a cohort of COVID-19-positive patients was collected (n=69). The autopsy material was prepared for morphological, morphometric, and immunohistochemical analysis, and the index of spermatogenesis was calculated  to  assess  the degree of   hypospermatogenesis.  The invasion of SARS-CoV-2 was studied by immunohisto-chemical method with antibodies to the spike protein, the nucleocapsid protein of the SARS-CoV-2 virus, and angiotensin-converting enzyme type 2 (ACE2).Results. In the morphometric study of the testicles of patients with  COVID-19,  a  decrease  in  the  degree  of  spermatogenesis  was  observed.  Based  on  the  morphological  and morphometric analysis, as well as the decrease in the spermatogenesis index, it is highly likely that in patients with confirmed coronavirus infection over 45 years of age, the identified pathomorphological changes were more pronounced than in young people. An immunohistochemical study revealed S-protein- and nucleocapsid-positive germ cells, as well as an increase in the number of ACE2-positive germ cells, which indicates the invasion of SARS-CoV-2 into them. Conclusion. The immunophenotypic characteristics of the testicles of patients with a new coronavirus infection indicates the viral load of SARS-CoV-2, estimated by the amount of S-protein-, nucleocapsid-  and  ACE2-positive  germ  cells.  The  revealed  morphological  and  immunohistochemical  patterns  most likely indicates the development of COVID-19-associated orchitis.