GM-CSF and Rituximab After Autologous Stem Cell Transplant in Treating Patients With Relapsed or Refractory Follicular Non-Hodgkin Lymphoma

RATIONALE: Giving high-dose chemotherapy before an autologous stem cell transplant helps stop the growth of cancer cells by stopping them from dividing or by killing them. An autologous stem cell transplant may be able to replace the blood-forming cells that were destroyed by chemotherapy. GM-CSF may increase the number of immune cells found in bone marrow or peripheral blood. Giving a monoclonal antibody, such as rituximab, after the transplant may find any remaining cancer cells and either kill them or deliver cancer-killing substances to them without harming normal cells. Giving GM-CSF together with rituximab after autologous stem cell transplant may be an effective treatment for follicular non-Hodgkin lymphoma. PURPOSE: This phase II trial is studying how well giving GM-CSF together with rituximab after autologous stem cell transplant works in treating patients with relapsed or primary refractory follicular non-Hodgkin lymphoma.