Impact of Low-Dose Occupational Exposure to Ionizing Radiation on T-Cell Populations and Subpopulations and Humoral Factors Included in the Immune Response

Abstract

The aim of the present study is to assess the effects of low-dose occupational exposure on T helper response. One Hundred five employees working in Nuclear Power Plant, Kozloduy, Bulgaria and control group of 32 persons are included in this investigation. Flow cytometry measurements of T-cell populations and subpopulations and natural killer T cells are performed and levels of G, A, and M immunoglobulins and interleukin 2 (IL-2), IL-4, and interferon γ were determined. The data interpreted with regard to cumulative doses, length of service, and age. The results of the present study are not enough to outline a clear impact of occupational radiation exposure on T helper populations. Nevertheless, the observed even slight trends in some lymphocyte’s populations and in cytokines profile give us the reason to assume a possibility of a gradual polarization of T helper 1 to T helper 2 immune response at dose range 100 to 200 mSv. The results of the present study indicate the need to perform a more detailed epidemiological survey including potential confounding and misclassifying factors and possible selection bias that could influence the results.

Immunomodulatory Low-Dose Whole-Lung Radiation for Patients with Coronavirus Disease 2019-Related Pneumonia

“…Although these outcomes appear promising, and although potential efficacy mechanisms are well delineated for COVID-19, these findings remain preliminary and require confirmation through randomized trials. 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 Additional immunologic analyses of these and other cytokines and immune markers was performed and will be forthcoming.…”

“… 6 , 7 , 8 Numerous prior articles have described the mechanistic pathways whereby low-dose radiation therapy (LD-RT) could provide a therapeutic advantage. 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 The first exploration into this intervention, a 7-day interim safety analysis of 5 initial patients treated on a phase 1 trial, investigated safety of LD-RT using a dose of 1.5 Gy with no detected acute toxicity or reflex exacerbation of the cytokine storm. 17 Preprint publication of this safety data was first released on June 8, 2020.…”

Low-Dose Whole-Lung Radiation for COVID-19 Pneumonia

“…Anti-Inflammatory effects of LD-RT can result in apoptosis and decrease adhesion of the leukocytes to endothelial cells, 10 mitigate proinflammatory effects of macrophages by reducing secretion of nitric oxide and reactivation oxygen species, 11 and induce polarization of M1inflammatory macrophages to M2-anti-inflammatory subtype. 12 LD-RT may also reduce TNF-α, IL-1β, IL-2, IL-6, IL-8, and INF-γ, [13][14][15][16][17] which are thought to be increased in COVID-19 cytokine storm. While these findings require further investigation, whole-lung LD-RT did not induce post-treatment pancytopenia or immunosuppression and therefore is unlikely to slow viral clearance.…”

“…[7][8][9] Anti-Inflammatory effects of low-dose radiation therapy (LD-RT) can result in apoptosis and decrease adhesion of the leukocytes to endothelial cells, 10 mitigate proinflammatory effects of macrophages by reducing secretion of nitric oxide and reactivation oxygen species, 11 and induce polarization of M1-inflammatory macrophages to M2-anti-inflammatory subtype. 12 Furthermore, LD-RT may also reduce TNF-α, IL-1β, IL-2, IL-6, IL-8, and INF-γ, [13][14][15][16][17] which are thought to be increased in the COVID-19 cytokine storm. Thus, it was hypothesized that LD-RT directed at the lungs may dampen the cytokine hyperactivation and improve the outcome of COVID-19 hospitalized and oxygen-dependent patients.…”

Low dose ionizing radiation effects on the immune system

“…The main added value of this study compared to the previous ones was that a) it took into account confounding factors such as smoking and alcohol consumption and b) it discussed the influence of aging as another confounding factor on immune parameters, which can overlap with certain changes seen following radiation. Though, they also showed that most of the changes in the measured parameters remained within the normal reference values illustrating the discrete effects of low doses ( Gyuleva et al, 2018 ; Gyuleva et al, 2015a ; Gyuleva et al, 2015b ). Other occupational data are from interventional cardiologists, radiologists and radiation workers.…”