STRONG INCREASE IN THE PERCENTAGE OF THE CD8(BRIGHT-) T-CELLS AND DELAYED ENGRAFTMENT ASSOCIATED WITH CYCLOSPORINE-INDUCED AUTOLOGOUS GVHD() CD28()

Four children with acute lymphoblastic leukaemia had autologous bone m arrow (BM) or peripheral stem cell (PSC) transplantation with low dose of cyclosporine (CsA, 1 mg/kg/d i.v. during the first 28 d) to induce an autologous GVHD (auto-GVHD). Two children did not have clinical au to-GVHD and they relapsed 3 and 4 months after treatment. The 2 other children had clinical signs of auto-GVHD (grade I and grade II): they both are in complete remission but after a first normal haematological recovery they had a prolonged period of aplasia until month 9 for 1 p atient and still persistent at month 7 in the other case. We studied l ymphocyte subsets reconstitution after transplantation in these patien ts. All patients had an important decrease in the CD4/CD8 ratio relate d both to a strong decrease in the CD4(+) cells and a strong increase in the CD8(+) cells. Most of the CD8(+) cells were of the CD8(bright+) CD28(-) phenotype. These CD8(bright+) CD28(-) T-cells represented fro m 33% to 68% of the total lymphocytes. We discuss the role of these ce lls after autologous transplantation with CsA, and wonder if these cel ls could mediate cytotoxicity. In conclusion, among 4 children who rec eived autologous BM or PBC transplantation with low dose of CsA, we ob served a complete remission after an auto-GVHD and a prolonged period of aplasia in 2 patients and a relapse of leukaemia in 2 other patient s. All these 4 patients had an increase in the CD8(bright+) CD28(-) ly mphocytes.