CLINICAL AND PATHOGENETIC ASPECTS OF INFECTIOUS MONONUCLEOSIS

Аннотация

Epstein – Barr virus and infectious mononucleosis are synonymous for many physicians. Epstein – Barr virus causes approximately 90% of cases of Выпуск журнала №-23 Часть–3_ Апрель –2025 268 MODERN EDUCATION AND DEVELOPMENT infectious mononucleosis, while the rest of the cases are associated mainly with cytomegalovirus, human herpesvirus type 6, toxoplasmosis, HIV infection and adenovirus. Aim. Pathogenetic, clinical and epidemiological features of Epstein – Barr virus infectious mononucleosis have been analyzed as well as the problems of its diagnosis and treatment. Materials and methods. The article presents an overview of Russian and foreign literature data on Epstein – Barr virus infectious mononucleosis. Results and discussion. In connection with a significant increase in the incidence of infectious mononucleosis caused by Epstein – Barr virus in recent years, improvement of specific diagnostic methods and antiviral therapy will successfully solve the problem of arresting pathological process at the early stages of the disease. However, the problem of chronic forms of the disease requires in-depth study. Conclusion. The key to success in treatment of patients with infectious mononucleosis is timely diagnosis, correct individual approach to etiotropic and pathogenetic therapy, as well as timely hospitalization of patients with severe forms of infectious mononucleosis. Key words: infectious mononucleosis; Epstein – Barr virus; hepatitis. The relevance of studying infectious mononucleosis (IMN) is due to the high circulation of the pathogen among the population, the specific tropism of the herpes virus to immunocompetent cells, lifelong persistence of the virus in the body and often a latent course [1]. More than 95% of people worldwide are infected with the Epstein- Barr virus, mainly in the higher socio-economic groups of industrialized countries, primarily becoming infected at the age of 1 to 5 years [2]. In the last 10 years, the incidence of IMN caused by the Epstein-Barr virus has increased 5-fold not only in adults but also in infants. This is due to both a true increase in the incidence due to the impact of various exogenous and endogenous factors, and the improvement of laboratory diagnostic methods for this infection [3]. Infectious mononucleosis was first described as a generalized inflammation of the lymph nodes by the famous Russian pediatrician N.F. Filatov in 1885. Later, descriptions of outbreaks of glandular fever appeared, presented by K.L. Pfeiffer (1888) and N.S. Korsikov Выпуск журнала №-23 Часть–3_ Апрель –2025 269 MODERN EDUCATION AND DEVELOPMENT (1901). The first report on the characteristic hematological changes in this disease was made by G. Turk in the Vienna Medical Society in 1907. Later, in 1909, D. Berne noticed changes in the "white blood" in glandular fever. In the blood of these patients, he saw an increase in the number of "small mononuclears ". In 1920, scientists from the USA F. Evans and T. Sprunt proposed to introduce the term "infectious mononucleosis". In 1964, M.A. Epstein and J. Barr isolated a virus from the herpes group, which was found with great consistency in patients with infectious mononucleosis and had a tropism for lymphoid tissue, causing blast transformation of lymphocytes [4]. The first representative of the human γ-herpesvirus family was the Epstein-Barr virus (EBV). It was discovered through the study of B-cell lines obtained from patients with African Burkitt lymphoma . EBV is a representative of oncogenic DNA-containing viruses, the capsid diameter is 120-150 nm , surrounded by a membrane, contains lipids. During virus replication, over 70 different virus- specific proteins are expressed. However, to date, groups of immunogenic proteins have been identified, the determination of antibodies to which makes it possible to differentiate the stage of infection (EA - early antigen, EBNA-1 - nuclear antigen, VCA - capsid antigen, LMP - latent membrane protein). As soon as the virus enters the epithelium of the mucous membrane of the oropharynx and upper respiratory tract, infection of lymphocytes occurs. There are a number of differences in the infection of epithelial cells and lymphocytes. In epithelial cells , complete replication of the virus occurs with the formation of a large number of virions, epithelial cell lysosomes , which subsequently infect neighboring cells. At the time of infection of B- lymphocytes, virus replication occurs only in a small percentage of cells, and in the remaining cells the virus is in a latent state. The mechanism of interaction of EBV with B-lymphocytes has been studied most thoroughly. The supercapsid of the virus contains glycoprotein complexes - gp350, 85, 25 and 42. The gp350 complex plays a leading role in interaction with B-lymphocytes. Its structure is similar to the component of the C3 dg complex , and also interacts with the CD21 molecule on the surface of the B-lymphocyte, being a receptor for it. Interacting,