Biology

Sokolenko V.L., Ph.D., Sokolenko S.V., Ph.D., Donets N.V.

Cherkasy State University of Bohdan Khmelnytsky

DYNAMICS IN INDICATORS OF PHAGOCYTIC IMMUNITY

IN POPULATION OF 4-TH RADIATION ZONE

For the population of Ukraine the most pressing factor for immune system is a chronic effect of low doses of radiation exposure caused by Chernobyl accident [1]. In literature there is rather contradictory information concerning the level of phagocytic sensitivity of natural resistance to the effects of ionizing radiation [7; 9]. This conditioned the actuality of our research and determined the purpose: to study the indicators of phagocytic immunity in patients aged 18-24 in the period of time 1995-2014.

Studying the leukogram indicators was performed in a group of male and female students, who arrived from Kaniv, Zvenygorod and Lysyanka regions (fourth radiation zone of enhanced radiation monitoring area). We have analyzed the data for 1995, 2000, 2005 and 2010 and 2014. The control group consisted of students who arrived from relatively environmentally friendly areas. Leukocyte level was calculated in Hemocytometer, phagocytic population level was determined on a blood smear. Phagocytic index (PhI) and phagocytic number (PhN) of neutrophils and monocytes was counted in their ability to absorb bacteria S.aureus, followed by dyeing smears on Romanowsky-Giemsa [3; 5]. Collecting the capillary blood was performed in the morning, before eating.

We found that the analyzed indicators in the control group were within normal limits recommended in the literature [6].

We compared leukogram indicators of the examined people from contaminated areas received over the years, with the data in the control group. We found that in the analyzed years the level of leukocytes, relative and total number of band and segmented neutrophils was significantly higher than in the control group. In 1995 the relative number of monocytes significantly increased.

Thus, even 28 years after the Chernobyl accident in persons aged 18-24, who lived from birth in areas contaminated with radionuclides, there can be observed a redistribution of immune parameters in favor of certain leukocyte populations that implement the functions of nonspecific cellular immunity, including polymorphonuclear cells. This trend is fairly typical for stress-induced changes in natural resistance [2].

Throughout the analyzed period of time, indicators of phagocytic populations did not show statistically significant dynamics, in average we observed the tendency for increase of segmented neutrophils percentage and reduction of monocytes percentage. Analysis of the phagocytic number and phagocytic index of examined people showed the tendency for decrease in neutrophils with acquisition of a reliable significance in 2010 and 2014, and a significant decrease in the population of monocytes.

The literature gives rather contradictory information as for the impact of ionizing radiation on the contents of neutrophils. In acute radiation exposure, abrupt decrease in the content of this population is observed, which is associated with damage of immature antecedents and short lifespan of mature granulocytes. However, in chronic low-dose radiation exposure, the level of neutrophils often increases [7; 9] on the background of attenuation of monocytes and lymphatic reactions [4].

However, the growth of level of granulocytic phagocytes occurs on a background of a certain reduction in their phagocytic activity. The correlation analysis confirms it, showing growth of negative correlation between neutrophils and their phagocytic index. Perhaps the effect is conditioned by forming neutrophils with certain pathologies, as experiments show that the radiation-induced stimulation of proliferative activity of granulocyte hematopoiesis is accompanied by a significant number of errors in mitosis [7].

Reducing the phagocytic activity of monocytes may indicate another potential danger: inhibition of phagocytic number and especially of phagocytic index signal about deterioration of macrophage receptor characteristics and, consequently, decrease of antigen-presenting characteristics and ability of co-operation with T-helpers. Especially under conditions of chronic low-dose radiation exposure, level of T-helpers can be reduced, which was marked in our previous publications [8].

Literature:

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2. Haitov R.M. Ecological immunology / R.М. Haitov, B.V. Pinegin, H.I. Islamov. – М.: Russian Research Institution of Fishery and Oceanography, 1995. – 219 p.

3. Immunology: Workshop / [ E.U. Paster, V.V. Ovod, V.K. Pozur and others] – K .: High school. – 1989. – 280 p.

4. Klimenko M. O. Effects of low intensive г-radiation on bone marrow in chronic inflammation / M. O. Klimenko, V.V. Zolotukhin // Ukrainian radiologic journal – 2006. – V.41, №1. – P. 42-46.

5. Olyferuk I.S. Estimation of phagocytic and bactericidal activity of neutrophils, macrophages and immanure dendritic cells. / I.S. Olyferuk, A.I. Illynskaya, B.V. Pinegin // Immunology. – 2005. – № 1. – P. 10-12.

6. Paul W. Fundamental immunology / W. Paul, 7th ed. – Philadelphia: Wolters Kluwer Health / Lippincott Williams & Wilkins, 2013. – 1283 p.

7. Pinchuk L.B. Changes in the system of bone marrow hematopoiesis in animals, permanently kept in the Chernobyl zone // Chernobyl Zone: collected articles in science / L.B. Pinchuk, N.K. Rodionova // edited by V.G. Baryakhtar. – K .: Scientific opinion, 2001. – P. 429-435.

8. Sokolenko V.L. Indicators of T-cell immunity in people who lived a long time in contaminated areas / V.L.Sokolenko, S.V. Sokolenko // Herald of Luhansk State University, Biomedical Sciences. – 2012. – №9. – P.128-133.

9. Zahumennova O. N. Evaluation of cellular immunity in people living in radionuclide contaminated territories / O. N. Zahumennova, E.V. Malysheva, A.V. Gulin // Herald of TSU, 2011. – V.16, №1. – P. 313-315.