Effects of metal ions on white blood cells of patients with failed total joint arthroplasties

In this study twenty-two patients who had revision surgery for aseptic loos ening of joint prostheses were examined. The concentration in serum of solu ble products of corrosion from the implant, that is, chromium (Cr), cobalt (Co), and nickel (Ni) ions, and the number of white blood cells (leucocytes , myeloid cells, lymphocyte subpopulations) were measured. Twenty patients with no implants were used as controls. The patients who had revision surge ry showed normal Ni concentration whereas by statistical analysis that same patient group was shown to have serum Cr and Co levels significantly highe r than those of the control. By flow cytometry, a significant decrease of l eucocytes, myeloid cells, lymphocytes, and CD16 populations as found in pat ients versus controls whereas CD3, CD4, CD8, and CD20 positive cells were d ecreased, but not significantly. In the arthroplasty patients the Cr concen trations were inversely correlated with some of the immunologic parameters while no significant correlation was found between Co levels and decreased lymphocyte subpopulations. Only in revision surgery patients with high Cr c oncentrations did we find a significant decrease of lymphocytes, namely of CD4 and CD16 positive cells; revision surgery patients with normal Cr conce ntrations did not show a significant decrease of lymphocyte subpopulations. These data suggest that the presence of metal ions, especially chromium, r eleased from prosthesis components could be associated with changes of lymp hocyte subpopulations in patients with loosening of joint prostheses. (C) 1 999 John Wiley & Sons, Inc.