Cytokine profile in the subjects after long-term <i>in utero</i> and postnatal exposure to chronic irradiation

Abstract

Persons exposed to ionizing radiation in utero and in early childhood constitute a risk group for the development of long-term stochastic consequences of irradiation. The imbalance of cytokines at the long terms after irradiation could be considered a carcinogenic triggering factor in subjects previously irradiated in utero and in early childhood, thus determining relevance of the study. The aim of the present study was to assess the levels of serum cytokines in native residents of coastal villages at the Techa River, whose chronic irradiation had been begun antenatally and to study probable interrelatirons between the detected changes, radiation and non-radiation factors at long terms after the exposure was begun. The main group included 61 persons from the Techa River Cohort who were born in 1950-1960, whose irradiation was begun in utero, being continued over the early postnatal period. For patients from the main group, the mean dose of antenatal radiation was calculated 74.7 mGy for red bone marrow as of, the mean dose of postnatal irradiation was calculated for red bone marrow as 537.5 mGy, and the median age of patients was 64.0 years. The comparison group (90 nonirradiated persons) was comparable to the main group in terms of age, gender, ethnicity and socio-economic status. The median levels for IL-2 in the main group were 1.37 pg/ml; in the comparison group, 2.70 pg/ml, p = 0.020; for IL-10, 4.53 pg/ml versus 7.58 pg/ml, p = 0.030 respectively; for GM-CSF, 0.39 pg/ml in the subjects who were irradiated in utero and in the early postnatal period versus 0.86 pg/ml in non-irradiated persons, p = 0.040. The median serum concentrations of IL-1β, IL-1α, IL-1(ra), IL-4, IL-6, IL-8, G-CSF, TNFα, IFNα, IFNγ in the study group did not show differences from the values in a group of non-irradiated persons. The decrease of the serum IL-2, IL-10 and GM-CSF levels in the persons of the main group did not depend on the dose of antenatal irradiation to red bone marrow, and on the radiation dose to red bone marrow received during the postnatal period of ontogenesis. In the main group, there was a moderate inverse relationship between the serum IL-10 level and age at the time of examination (SR = -0.53, p 0.001). Serum concentrations of IL-2 and IL-10 in the people from comparison group showed a moderate positive correlation with their present age (SR = 0.47, p 0.001 and SR = 0.42, p 0.001 respectively).