Changes in the proportions of peripheral blood lymphocytes in patients with worn implants

We compared the peripheral blood and periprosthetic tissues of 53 patients at revision arthroplasty with those of 30 patients at primary arthroplasty to determine whether there is a systemic difference in lymphocytes in patie nts with worn hip implants, The absolute number and relative proportion of lymphocytes bearing CD2, CD3, CD4, CD8, CD16, CD19, HLA-DR, kappa and lambd a antigens were compared with the levels of IL-1 beta, IL-6 and PGE(2) in t he pseudosynovial membrane as well as with a semiquantitative estimate of m etal and polyethylene particles, necrosis and chronic inflammation and the total concentration of metals within the periprosthetic tissues, There was a significant increase in the relative proportion of CD2-positive T-cells and CD16-positive natural killer cells in the peripheral blood at revision arthroplasty compared,vith primary arthroplasty and an increased p roportion of CDS-positive T-cells and a decreased ratio of CD4 to CD8 (help er inducer/suppressor cytotoxic cells). Three control patients, who went on to have revision surgery, had values at primary arthroplasty which were si milar to those of patients at the time of revision surgery. These differenc es did not correlate with the local concentration of metal, plastic or ceme nt or inflammatory response or the type of prosthesis, An inverse correlati on was noted between the necrosis in the periprosthetic tissue and both the local production of IL-6 and the absolute numbers of T-cells in peripheral blood. We conclude that there may be several cell-mediated systemic immune respons es to aseptic loosening, at least one of which may be directly related to e vents in the periprosthetic tissues. We cannot exclude the possibility that the changes in the proportion of CD8-positive cells reflected a predisposi tion, rather than a reaction, to loosening of the implant.