IMPACT OF EMOTIONAL STRESS ON THE IMMUNE SYSTEM INDICES AMONG RESIDENTS OF RADIATION CONTAMINATED AREAS.

Abstract

The aim of this research is to study special characteristics of immune system functioning among residents of the areas contaminated with radionuclides, under conditions of additional emotional load. We examined 350 people, including a group of radiation free areas residents (control group, 150 people) and a group of residents living in the areas of enhanced radiation monitoring (IV radiation zone, the density of soil contamination with isotopes (137)Cs 1-5 Ki/km(2), 200 people). All examined are the students of Cherkassy State University, aged 18-24 years, at the time of research didn't have any acute diseases. The role of additional stress factor (additional emotional load) was fulfilled by winter examination session. The first analysis of immune system indices was carried out in the interval between examination sessions, the second 2 after the first exam, the third - after the last exam, the fourth - after two weeks recovery period. Indicators of cellular immunity were determined by immunophenotyping and dyeing on Romanowsky-Giemsa. The level of immunoglbulins in blood serum was determined by radial immunodiffusion on Mancini. The level of cortisol in blood serum was determined-by immunoenzyme method. We determined that leukogram redistribution in favor of granulocyte fractions can be observed in the analyzed group in the intersession period, and also the reduction of the relative and absolute number of lymphocytes expressing antigens CD3, CD5, CD4 and CD 16. Also, all examined had reduced immunoregulatory index CD4(+)/CD8(+) and increased concentration of serum immunoglobulin G. Emotional stress increased earlier revealed tendencies. As a result the relative(23.41±1.01%) and absolute (0.28±0.02x10(9)/) number of T cells with the phenotype CD4(+), and immunoregulatory index (1.04±0.03) reached values lower than homeostatic norm. These indicators also show the longest period of recovery. Dynamics of the analyzed indices in session and recovery periods gives a reason to believe that mechanisms of adaptation and deadaptation are better displayed for thymus-dependent cells. Additional short-term stress factor intensifies immuno-suppression caused by living in radiation contaminated areas, and creates the basis for regular monitoring of health status of the population that suffered from the combined stress and for implementing preventive measures during the recovery period.