Immunological features of acute cytomegalovirus infection in immunocompetent patients

Abstract

Objective. To identify and evaluate immunological features in immunocompetent patients with acute cytomegalovirus infection (CMVI).Materials and methods. Thirty-three immunocompetent adult patients with acute cytomegalovirus infection were included in the study; 4 of them had thrombotic complications. The control group consisted of 10 healthy donors. All 33 blood samples were tested by flow cytometry. The content of antigen-specific cells was checked in all patients. Results. All patients had positive cytomegalovirus DNA PCR tests. The content of activated T cells in patients with acute CMV infection and thrombotic complications is 7.7 times higher (p < 0.001) than in conditionally healthy patients (median values: 36.02% (31.01; 47.92) and 4.68% (3.39; 5.25), respectively). The content of granulocytic myeloid suppressor cells (G-MLSC) in patients with acute CMV infection and thrombosis exceeds the same indicator in the group of healthy volunteers by 8.3 times (p < 0.001) (median values were 0.38% (0.24; 0.54) and 0.05% (0.03; 0.07) respectively). The number of regulatory T cells in patients with acute CMV infection and thrombosis was reduced by 3.1 times (p < 0.001) compared to the same indicator in the group of healthy volunteers (median indicators: 0.79% (0.57; 1.09) and 2.45% (2.01; 3.86), respectively). Immunophenotyping of CD3+ cells showed a tendency to increase the proportion of more mature cells, namely effector memory cells (TEM) and terminally differentiated memory cells (TEM RA) with a decrease in the percentage of “naive” cells.Conclusion. A high level of antigen-specific T-cell response and a low content of T-regulatory cells may indicate insufficient control of the proliferation of T-cytotoxic lymphocytes, which may contribute to the long-term persistence of the virus and the development of chronic inflammation of the vessel wall, which requires further study. Thus, in patients with acute CMV infection, an additional risk factor for thrombosis appears, which must be taken into account when carrying out therapeutic and diagnostic measures.