Systemic lupus erythematosus (SLE) is an autoreactive Tcell mediated autoimmune disease. Immunization with inactivated autoreactive Tcells may induce idiotype anti-idiotypic reaction to deplete specific subsets of autoreactive Tcells involved in SLE. Six SLE patients unsuitable or refused to use immunosuppressants were treated with Tcell vaccination. Their clinical manifestations and laboratory parameters including mixed lymphocyte reactions were evaluated. Autoreactive Tcell clones were derived from peripheral blood mononuclear cells of the patients and 1 107 irradiated Tcells were inoculated subcutaneously at 0, two, six and eight weeks, respectively. The enrolled patients were followed up for 32-40 months at an interval of three to six months. The clinical characteristics and laboratory abnormalities improved after inoculation without increasing the dose of corticosteroids and immunosuppressants in most patients. SLE disease activity index (SLEDAI) scores decreased. Proliferative responses against the Tcell vaccine were observed in four of six patients. At the time of this report, the six patients remain in clinical remission. No significant side effect from the vaccination was noticed during the follow-up period. The results of this pilot study indicate that T cell vaccination is a safe and effective treatment in SLE.