High-Dose Aluminum Exposure Further Alerts Immune Phenotype in Aplastic Anemia Patients

This study explored the relationship between immunological status and clinical characteristics of aplastic anemia (AA) patients to plasma aluminum levels, which were increased after constant exposure to high levels of this metal. Sixty-two AA patients (33 cases with high and 29 cases with low or no exposure to aluminum) and 30 healthy controls were selected for this study. Aluminum in human albumin solution was measured by inductivity coupled plasma mass spectrometry. IL-10, IL-12, IL-17, and INF-γ levels were measured by enzyme-linked immunosorbent assay. The distribution of lymphocyte subsets were determined by flow cytometry. The expression levels of immunoglobulins and complement C3 and C4 were also measured. Exposure to high aluminum raised the levels of serum aluminum in AA patients (P < 0.01). The levels of hemoglobin and complement C4 were lower in AA patients with high aluminum exposure (P < 0.05 and < 0.01, respectively). The percentage of CD4⁺ T cells and the ratio of CD4⁺/ CD8⁺T cells in peripheral blood in AA patients with high aluminum exposure were higher compared with control AA patients (P < 0.05 in both cases), while the percentage of CD8⁺ T cells was significantly lower than that in non-aluminum-exposed AA patients (P < 0.05). Compared with non-aluminum-exposed AA patients, the level of IL-10 in the high aluminum-exposed AA group was significantly higher (P < 0.05 in both cases). The immunological and clinical characteristics of AA patients from regions of high aluminum exposure are different to those in from non-aluminum areas. These results suggest that high aluminum exposure alters the immune system in patients suffering from AA.