Trial of Outpatient Immunotherapy With Rituximab and Aldesleukin (IL-2) vs. Rituximab Alone for Non-Hodgkin's Lymphoma

INCLUSION CRITERIA: A patient will be eligible for inclusion in this study if s/he meets all of the following criteria: * Has previously undergone BEAC or BEAM autologus SCT with PBSC rescue for any stage aggressive B-cell NHL, including transformed indolent NHL or mantle cell lymphoma according to REAL classification - only B-cell lymphomas are permitted. * ECOG performance status 0-1. * Previously histological documented CD20 +NHL. * Is greater than 18 years of age. * Is 30-100 days from autologous peripheral blood stem cell transplant. * Must meet laboratory values (see protocol for values): Absolute neutrophils, hemoglobin and platelets. * Has a negative serum pregnancy test within 7 days prior to trial registration (only for female patients of childbearing potential). * If fertile, patient (male or female) has agreed to use physician-approved method of birth control to avoid pregnancy for the duration of the study and for a period of 3 months thereafter. * Has signed a Patient Informed Consent Form. * Has signed a Patient Authorization Form (HIPAA). EXCLUSION CRITERIA: Patients will be taken off treatment if any of the following occur: * ECOG PS \>2. * A history of hypersensitivity to study drugs, or any component thereof, or anaphylactic history to murine protein. * Manifested cardiac complications during transplant, including arrthymias, congestive heart failure, angina, or myocardial infarct, or had a decreased LVEF to \<45% prior to transplant * On systemic corticosteroids. * Diffusion capacity \<60% (corrected) and has decreased 30% or more following transplant * Documented disease progression (See Section 10.1.6 for definition). * Active infection, and/or is known to be seropositive for hepatitis B, hepatitis C, or HIV * Pericardial effusion, pleural effusions, or ascites. * A history of very aggressive NHL, such as Burkitt's or atypical Burkitt's lymphoma * Receiving concurrent immunotherapy or rituximab therapy. * Previously received a solid organ transplant. * History of CNS involvement. * A serious uncontrolled intercurrent medical or psychiatric illness, including serious infection * A history of other malignancy within the last 5 years (except cured basal cell carcinoma of skin and carcinoma in situ of uterine cervix), which could affect the diagnosis or assessment of any of the study drugs. * A pregnant or nursing woman. * Unable to comply with requirements of study.