Cadmium is very toxic substances due to its wide range of organ toxicity and long elimination half-life of 10-30 years. EDTA is the agent most widely accepted for clinical treatment of cadmium toxicity. Nanoparticulate drug delivery systems are used to achieve a more effective treatment and minimizing side effects. This study was concerned with the study of the immunotoxic effects of cadmium on adult female rats as well as the ameliorating effects of CaNa2EDTA nanoparticles against such toxicity. The predictive protective effect was compared with CaNa2EDTA macroparticles. At the start of the experiment, animals were divided into two groups; one acted as control (contains15 rats) and the other one (contains15
rats) received drinking water contains 30 ppm cadmium for 10 weeks. At the end of the 6th week of the experiment, the cadmium-intoxicated group was subdivided equally into three groups. The second and third groups respectively were injected intraperitoneally with 50 mg/kg/day macroparticles or nanoparticles CaNa2EDTA for 4 courses (4 days each) with an interval of 3 days between the courses. Results showed that cellular immune response (as determined by assessment of total and differential leucocytic count and phagocytic activity of neutrophils) was significantly reduced by cadmium. Lymphocytes percentage was also decreased while neutrophils and monocytes percentages were increased. Humoral immune response as estimated by the measurement of electrophoresis pattern of serum proteins (albumin, alpha, beta and gamma globulins) reported a significant inhibition in cadmium intoxicated rats except levels of beta globulins, which showed a significant increase. The alterations that associated with cadmium toxicity were markedly alleviated by CaNa2EDTA nanoparticles treatment,while CaNa2EDTA macroparticles treatment induced a mild protective effect against cadmium toxicity when compared to the nanoparticles form. These findings suggested that CaNa2EDTA nanoparticles could be used as an effective chelating agent for cadmium because they have a more powerful chelating capacity and thus could modulate the development of severe immunotoxic effects of cadmium in rats.