OBJECTIVES: I. Evaluate the efficacy of rituximab in patients with B-cell lymphoproliferative disorders while under pharmacologic immune suppression for control of either allograft rejection or autoimmune disease. II. Evaluate the safety and direct toxicity of rituximab in this patient population, including the potential for opportunistic infections. III. Evaluate the secondary consequences of rituximab therapy in this population, including changes in the requirement for immunosuppressive drugs, effects on graft rejection, graft survival, and severity of autoimmune disease.
OUTLINE: Patients receive rituximab IV over several hours. Treatment repeats every week for 4 courses. Patients are followed every month for 6 months, and then every 3 months until relapse or 2 years.
PROJECTED ACCRUAL: A total of 15 patients will be accrued for this study within 1 year.