If viral and CD4 levels do not return to pre-study levels promptly, patients will continue to be monitored and will be advised about possible treatment changes. Alternatively, patients whose viral and CD4 levels are similar to or better than pre-study values may be offered laboratory testing every 3 months for at least 1 year if there is a scientific reason to continue studying the patient s immune system. Patients may be asked to undergo additional leukapheresis in the future, or another interruption of therapy in the future if it is felt safe to do so.