Occupational exposure to ionizing radiation has no effect on T‐ and B‐cell total counts or percentages of helper, cytotoxic and activated T‐cell subsets in the peripheral circulation of male radiation workers

Rees, Gwen S.; Daniel, Christoph; Morris, Sheila; Whitehouse, Caroline; Binks, K.; MacGregor, D. H.; Tawn, E. Janet

doi:10.1080/09553000410001725099

Cited by 15 publications

(12 citation statements)

References 18 publications

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“…No significant differences were found between the exposed groups and the control in terms of the main lymphocyte populations - B and T lymphocytes, NK cells with phenotypes CD3-CD16+ CD56+ and CD57+ CD8-. Similar observations have been reported by other authors who did not find changes of the total T cell, B cell and NK cell counts in occupationally exposed persons ( Godekmerdan et al 2004 , Rees et al 2004 , Zakeri et al 2010 ). The weak inverse correlation of B lymphocyte counts with age in our study is in good correspondence with some investigations for an age-related decline of this cell population in peripheral blood ( Hakim et al .…”

Section: Discussionsupporting

confidence: 92%

“…(1999) also found reduced CD4+ T lymphocyte counts and CD4+/CD8+ ratios and moderately increased CD8+ T cell counts in residents in a building with radioactive source. Other authors ( Rees et al 2004 , Torkabadi et al . 2007 , and Zakeri et al .…”

Section: Discussionmentioning

confidence: 93%

“…The reports specifically concerning the immune status of occupationally exposed persons ( Godekmerdan et al 2004 , Korraa et al . 2010 , Rees et al .2004 , Torkabadi et al 2007 , Tuschl et al . 1990 , 1995 , Zakeri et al 2010 ) are quite limited and not uniform.…”

Section: Introductionmentioning

confidence: 99%

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Assessment of Some Immune Parameters in Occupationally Exposed Nuclear Power Plants Workers: Flowcytometry Measurements of T, B, NK and NKT Cells

Gyuleva¹,

Panova²,

Djounova³

et al. 2014

Dose-Response

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The purpose of this article is to analyze the results of a 10-year survey of the radiation effects of some immune parameters of occupationally exposed personnel from the Nuclear Power Plant “Kozloduy”, Bulgaria. 438 persons working in NPP with cumulative doses between 0.06 mSv and 766.36mSv and a control group with 65 persons were studied. Flow cytometry measurements of T, B, natural killer (NK) and natural killer T (NKT) cell lymphocyte populations were performed. Data were interpreted with regard to cumulative doses, length of service and age. The average values of the studied parameters of cellular immunity were in the reference range relative to age and for most of the workers were not significantly different from the control values. Low doses of ionizing radiation showed some trends of change in the number of CD3+CD4+ helper-inducer lymphocytes, CD3+ CD8+ and NKT cell counts. The observed changes in some of the studied parameters could be interpreted in terms of adaptation processes at low doses. At doses above 100–200 mSv, compensatory mechanisms might be involved to balance deviations in lymphocyte subsets. The observed variations in some cases could not be attributed only to the radiation exposure because of the impact of a number of other exogenous and endogenous factors on the immune system.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 93%

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Assessment of Some Immune Parameters in Occupationally Exposed Nuclear Power Plants Workers: Flowcytometry Measurements of T, B, NK and NKT Cells

Gyuleva¹,

Panova²,

Djounova³

et al. 2014

Dose-Response

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“…However, in occupationally exposed radiation workers, no change was seen in the number of circulating B cells (Rees et al, 2004). Moreover, there was a decrease in the level of immunoglobulins (IgA, IgG, IgM) (Godekmerdan et al, 2004).…”

Section: Acquired Immunitymentioning

confidence: 96%

ICRP PUBLICATION 118: ICRP Statement on Tissue Reactions and Early and Late Effects of Radiation in Normal Tissues and Organs — Threshold Doses for Tissue Reactions in a Radiation Protection Context

Stewart¹,

Akleyev²,

et al. 2012

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This report provides a review of early and late effects of radiation in normal tissues and organs with respect to radiation protection. It was instigated following a recommendation in Publication 103 (ICRP, 2007), and it provides updated estimates of 'practical' threshold doses for tissue injury defined at the level of 1% incidence. Estimates are given for morbidity and mortality endpoints in all organ systems following acute, fractionated, or chronic exposure. The organ systems comprise the haematopoietic, immune, reproductive, circulatory, respiratory, musculoskeletal, endocrine, and nervous systems; the digestive and urinary tracts; the skin; and the eye. Particular attention is paid to circulatory disease and cataracts because of recent evidence of higher incidences of injury than expected after lower doses; hence, threshold doses appear to be lower than previously considered. This is largely because of the increasing incidences with increasing times after exposure. In the context of protection, it is the threshold doses for very long follow-up times that are the most relevant for workers and the public; for example, the atomic bomb survivors with 40-50years of follow-up. Radiotherapy data generally apply for shorter follow-up times because of competing causes of death in cancer patients, and hence the risks of radiation-induced circulatory disease at those earlier times are lower. A variety of biological response modifiers have been used to help reduce late reactions in many tissues. These include antioxidants, radical scavengers, inhibitors of apoptosis, anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, growth factors, and cytokines. In many cases, these give dose modification factors of 1.1-1.2, and in a few cases 1.5-2, indicating the potential for increasing threshold doses in known exposure cases. In contrast, there are agents that enhance radiation responses, notably other cytotoxic agents such as antimetabolites, alkylating agents, anti-angiogenic drugs, and antibiotics, as well as genetic and comorbidity factors. Most tissues show a sparing effect of dose fractionation, so that total doses for a given endpoint are higher if the dose is fractionated rather than when given as a single dose. However, for reactions manifesting very late after low total doses, particularly for cataracts and circulatory disease, it appears that the rate of dose delivery does not modify the low incidence. This implies that the injury in these cases and at these low dose levels is caused by single-hit irreparable-type events. For these two tissues, a threshold dose of 0.5Gy is proposed herein for practical purposes, irrespective of the rate of dose delivery, and future studies may elucidate this judgement further.

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“…Thus the killing of one or a few cells in a system which is continually undergoing regeneration is unlikely to be significant and may well not induce the types of response discussed above, although in more isolated cell populations (e.g., some in the arterial wall) this may not apply. Of relevance here is a study of workers employed at the Sellafield nuclear facility which examined a group with cumulative exposures >0.2 Sv (mean 0.33 Sv) and an otherwise similar group with exposure <0.028 Sv (mean 0.014 Sv) and found no differences in levels of CD4 + , CD8 + and CD3 + /HLA-DR + cells or in the CD4 + :CD8 + ratio, indicating that such fractionated exposures were not affecting these markers of immune response [144]. …”

Section: Non-malignant Diseasementioning

confidence: 99%

Do non-targeted effects increase or decrease low dose risk in relation to the linear-non-threshold (LNT) model?

Little

2010

Mutation Research/Fundamental and Molecular Mechanisms of Mutag

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In this paper we review the evidence for departure from linearity for malignant and non-malignant disease and in the light of this assess likely mechanisms, and in particular the potential role for non-targeted effects. Excess cancer risks observed in the Japanese atomic bomb survivors and in many medically and occupationally exposed groups exposed at low or moderate doses are generally statistically compatible. For most cancer sites the dose–response in these groups is compatible with linearity over the range observed. The available data on biological mechanisms do not provide general support for the idea of a low dose threshold or hormesis. This large body of evidence does not suggest, indeed is not statistically compatible with, any very large threshold in dose for cancer, or with possible hormetic effects, and there is little evidence of the sorts of non-linearity in response implied by non-DNA-targeted effects. There are also excess risks of various types of non-malignant disease in the Japanese atomic bomb survivors and in other groups. In particular, elevated risks of cardiovascular disease, respiratory disease and digestive disease are observed in the A-bomb data. In contrast with cancer, there is much less consistency in the patterns of risk between the various exposed groups; for example, radiation-associated respiratory and digestive diseases have not been seen in these other (non-A-bomb) groups. Cardiovascular risks have been seen in many exposed populations, particularly in medically exposed groups, but in contrast with cancer there is much less consistency in risk between studies: risks per unit dose in epidemiological studies vary over at least two orders of magnitude, possibly a result of confounding and effect modification by well known (but unobserved) risk factors. In the absence of a convincing mechanistic explanation of epidemiological evidence that is, at present, less than persuasive, a cause-and-effect interpretation of the reported statistical associations for cardiovascular disease is unreliable but cannot be excluded. Inflammatory processes are the most likely mechanism by which radiation could modify the atherosclerotic disease process. If there is to be modification by low doses of ionizing radiation of cardiovascular disease through this mechanism, a role for non-DNA-targeted effects cannot be excluded.

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Occupational exposure to ionizing radiation has no effect on T‐ and B‐cell total counts or percentages of helper, cytotoxic and activated T‐cell subsets in the peripheral circulation of male radiation workers

Cited by 15 publications

References 18 publications

Assessment of Some Immune Parameters in Occupationally Exposed Nuclear Power Plants Workers: Flowcytometry Measurements of T, B, NK and NKT Cells

Assessment of Some Immune Parameters in Occupationally Exposed Nuclear Power Plants Workers: Flowcytometry Measurements of T, B, NK and NKT Cells

ICRP PUBLICATION 118: ICRP Statement on Tissue Reactions and Early and Late Effects of Radiation in Normal Tissues and Organs — Threshold Doses for Tissue Reactions in a Radiation Protection Context

Do non-targeted effects increase or decrease low dose risk in relation to the linear-non-threshold (LNT) model?

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