1.
Monitoring of human populations for early markers of cadmium toxicity: a review.
Fowler, BA
Toxicology and applied pharmacology. 2009;(3):294-300
Abstract
Exposure of human populations to cadmium (Cd) from air, food and water may produce effects in organs such as the kidneys, liver, lungs, cardiovascular, immune and reproductive systems. Since Cd has been identified as a human carcinogen, biomarkers for early detection of susceptibility to cancer are of an importance to public health. The ability to document Cd exposure and uptake of this element through biological monitoring is a first step towards understanding its health effects. Interpretation and application of biological monitoring data for predicting human health outcomes require correlation with biological measures of organ system responses to the documented exposure. Essential to this understanding is the detection and linkage of early biological responses toxic effects in target cell populations. Fortunately, advances in cell biology have resulted in the development of pre-clinical biological markers (biomarkers) that demonstrate measurable and characteristic molecular changes in organ systems following chemical exposures that occur prior to the onset of overt clinical disease or development of cancer. Technical advances have rendered a number of these biomarkers practical for monitoring Cd-exposed human populations. Biomarkers will be increasingly important in relation to monitoring effects from the exposure to new Cd-based high technology materials. For example, cadmium-selenium (CdSe), nano-materials made from combinations of these elements have greatly altered cellular uptake characteristics due to particle size. These differences may greatly alter effects at the target cell level and hence risks for organ toxicities from such exposures. The value of validated biomarkers for early detection of systemic Cd-induced effects in humans cannot be underestimated due to the rapid expansion of nano-material technologies. This review will attempt to briefly summarize the applications, to date, of biomarker endpoints for assessing target organ system effects in humans and experimental systems from Cd exposure. Further, it will attempt to provide a prospective look at the possible future of biomarkers. The emphasis will be on the detection of early toxic effects from exposure to Cd in new products such as nano-materials and identification of populations at special risk for Cd toxicity.
2.
The influence of metals on the expression of surface antigens on human lymphocytes in vitro.
Petanová, J, Fucíková, T, Bencko, V, Sterzl, I
Neuro endocrinology letters. 2006;:46-8
Abstract
OBJECTIVES Metals have different effects on the immune functions. Through the experimental in vitro model, we studied the changes in the activation and co-stimulatory surface markers in human lymphocytes cultivated with selected metal salts. METHODS Whole human blood was cultivated with cadmium (Cd) or zinc (Zn) sulfate for 18 hours. The number of lymphocytes positive for activation and co-stimulatory markers was evaluated by flow cytometry. RESULTS Elevation of the CD69 and CD23 markers as well as higher expression of CD28 was found in cultures of lymphocytes incubated with Cd. In cultures incubated with Zn, minor elevation of the HLA-DR antigen expression was observed in comparison to Cd-treated cell cultures. Decrease of CD3 expression was observed after cultivation with both Cd and Zn salts. CONCLUSION Cd and Zn exhibit different effects on the expression of human surface activation antigens and co-stimulatory molecules. Cd in non-toxic concentrations stimulated expression of early activation molecules and therefore could change the early phase of immune response. This was not the case for Zn, where the results were similar to untreated cell cultures.
3.
[The impact of lead and cadmium on the immune system].
Skoczyńska, A, Poreba, R, Sieradzki, A, Andrzejak, R, Sieradzka, U
Medycyna pracy. 2002;(3):259-64
Abstract
A long-lasting exposure to lead and cadmium may cause changes in the immune response. Until now only a few reports have addressed this problem. At present, the direct immunotoxicity of heavy metals is the subject of extensive studies, especially on in vitro models. Heavy metals may regulate the immune response of the body at its different stages, modifying early and late inflammatory reactions, among others through changing the number of circulating B and T lymphocytes, NK cells and immunological memory cells. Some authors show that lead and cadmium stimulate the production of cytokines and IgE antibodies, which can be the reason for the increased number of atopic diseases in populations exposed to these two metals. Clinical tests in patients occupationally exposed to lead revealed the diminished number of B and T lymphocytes, and a considerable decrease in the number of NK cells. Other authors noted the increased number of CD8+ lymphocytes, which play a pivotal role in cytotoxic response, and the decreased number of B lymphocytes together with the increased IgA levels in policemen of road services. In copper smelters some changes in humoral response can be detected, e.g. a lower production of IgA and IgG, predisposing them to infections and cancers. To elucidate the exact impact of heavy metals on the immunological response further investigations are required. The growing pollution of the environment by heavy metals probably contributes to the enhanced incidence of allergic diseases and cancers in urban populations. Our goal should be to identify the mechanisms responsible for the changes in the immunological response induced by lead and cadmium, so that it could be possible to reduce or minimize serious pathologies resulting from the exposure to these metals.