Characteristics of immunocompetent cells in the testicles of different age group patients with COVID-19

BACKGROUND: There is an opinion that the new coronavirus infection COVID-19 can initiate the development of a local inflammatory reaction in the testicles, which leads to damage to spermatogenic epithelial cells and a decrease in the fertility of patients in the long term. AIM: Morphofunctional assessment of immunocompetent cells in the testicles of patients with COVID-19 depending on age. MATERIAL AND METHODS: Based on anamnestic, clinical and morphological data, groups of patients were formed, each of which included subgroups according to the age periodization of the World Health Organization: the first group of patients who died as a result of COVID-19 (n=109; average age 58±2.8 years) — young subgroup (n=19, age 18–44 years), middle-aged subgroup (n=37, age 45–59 years), elderly subgroup (n=53, age 60–74 years); second group (n=30, average age 49±2.3 years; autopsy material from the testicles of patients who died from causes unrelated to COVID-19, obtained outside the pandemic) — a subgroup of young people (n=10, age 18–44 years), middle-aged subgroup (n=10, age 45–59 years), elderly subgroup (n=10, age 60–74 years). Histological and immunohistochemical studies were carried out using primary antibodies to CD3, CD4, CD68, CD163, CD138 and statistical methods: Kolmogorov–Smirnov test, Student's t-test, Mann–Whitney U test and Fisher test. RESULTS: All testicular samples from patients with COVID-19 revealed signs of viral orchitis and a significant decrease in the spermatogenesis index (in young people — 5.9±0.2% with p=0.02; in middle age — 5.1±0.2% with p=0.008; in the elderly — 3.6±0.1% at p=0.006) compared to the control group (6.8±0.3%), and in immunohistochemical studies — an increase in the number of T-lymphocytes (CD3+, CD4+), macrophages (CD68+, CD163+) and plasma cells (CD138+) in interstitial tissue. In addition, a significant decrease in the spermatogenesis index (3.6±0.1% in the elderly versus 5.9±0.2% in the young, p=0.007) and a decrease in the number of T-lymphocytes (CD3+, CD4+) and macrophages (CD68+, CD163+) was found in older versus younger patients with COVID-19. CONCLUSION: In patients with COVID-19, an increase in the number of immunocompetent cells (CD3+, CD4+, CD68+, CD138+, CD163+) in the interstitial tissue of the testicles was found, especially pronounced in the elderly group.