Patients enrolled in NIH protocol 95-I-0133 at the Clinical Center may participate in an extension phase of this study in which the drug prednisone will be eliminated from the treatment regimen. Prednisone is associated with avascular necrosis, a condition that has been found in a number of patients in this study. Also, certain patients in this protocol may receive future interleukin-2 treatment cycles at home. Home administration of IL-2 injections involves less frequent data and safety monitoring and no medical evaluations at the Clinical Center except at the beginning of each cycle.

To be eligible for home administration of IL-2, patients must:

• Be enrolled in a current NIAID protocol for IL-2 therapy and have received at least 1 year of treatment on the protocol, with at least two well-tolerated outpatient cycles at a stable dose.
• Have a history of tolerable side effects while receiving IL-2 without frequent medical interventions, intravenous fluid replacement or dose reductions.
• Not have had any significant clinical or laboratory abnormalities during days 0 to 5 of the last two outpatient cycles.
• Have a strong relationship with a private physician or health-care provider who has been involved in the patient's care and is willing to help supervise the patient's care during each home IL-2 cycle.
• Live in a home with easy telephone access and have proved reliable in responding to telephone calls from clinic staff.
• Give the clinic staff contact information for a close friend or relative who will agree to serve as a caregiver during each home cycle, providing the patient non-medical assistance and checking on his or her condition daily.
• Have reasonable access to emergency medical services and a nearby medical facility.
• Have proved reliable and consistent in using sterile technique, reconstituting IL-2 vials and administering subcutaneous IL-2 injections.
• Be receiving outpatient IL-2 injections cycles at least once every 6 months as part of their normal protocol participation.
• Have access to a home weight scale and be able to weigh themselves each day for safety monitoring.

Participants will receive IL-2 cycles on the same schedule they followed in their original protocol participation. They will be seen at the Clinical Center at regularly scheduled follow-up visits between cycles and for a medical evaluation and blood drawing before the start of each cycle to determine the safety of administering the cycle. During the home cycle, the patient's case manager or other team member will place monitoring telephone calls on days 2 and 4 of the cycle and again a week later. The timing and number of these calls may change depending on the findings of ongoing assessments of their usefulness. Patients will be required to notify the study team promptly of any complications or other problems that develop with therapy.