Современная онкология (Mar 2018)
Epstein-Barr virus in children with classical Hodgkin’s lymphoma
Abstract
Classical Hodgkin's lymphoma (cHL) is one of the many malignant tumors associated with the Epstein-Barr virus (EBV). It is shown that EBV-positive cases of cHL are distributed with different frequencies among all cases of the disease. The frequency of EBV-positive cases of cHL is influenced by the demographic characteristics of the studied population and other factors. Russia belongs to geographical regions with a low incidence of this form of tumor. The aim of the study was to estimate the humoral response to EBV and the level of viral DNA in the blood plasma of children with cHL and to evaluate the significance of both EBV markers for clinical manifestations of the disease. The data obtained have shown that the level of EBV persistence in children with cHL practically does not differ from that in healthy children, however, the activity of the humoral response to EBV was significantly lower. The study of the composition of the elements of the leukocyte germ, responsible for cellular and humoral immunity, did not make it possible to explain the observed phenomenon. In particular, the number of circulating leukocytes in the patients' blood before the treatment corresponded to normal values, but it turned out to be below the normal values after the treatment. Conversely, the percentage of lymphocytes in patients before treatment turned out to be lower than normal values, but it reached normal values after the treatment. The percentage of neutrophils and monocytes in patients before and after the treatment was almost the same as in healthy individuals. The data obtained suggest that the reduced humoral response in patients with cHL is not associated with the altered composition of the leukocyte germ cells, but due to their reduced functional activity. The search for copies of virus DNA in plasma and oral cavity swabs made it possible to detect them only in some patients before the therapy and to state their complete absence after the treatment. Dynamic observation of the EBV DNA concentration in blood plasma and humoral response to EBV in 3 patients showed increased values viral DNA copies before treatment, and their decrease to zero after successful therapy, while antibody titers remained at the same level and did not reflected the clinical state of patients. It can be assumed that the increased concentration of plasma viral DNA detected in cHD patients can become a marker that allows indirectly estimating the degree of minimal residual disease and the probability of recurrence of the disease.
