Low-dose recombinant interleukin-2 therapy: rationale and potential clinical applications.

Interleukin-2 is a lymphocytotrophic hormone that plays a critical role in the host's normal immune response. Deficiencies in the production of IL-2 are likely to be important in the pathogenesis of certain infectious and malignant diseases. A better understanding of IL-2 and its potential applications in the treatment of human disease will come about with continued efforts in at least two areas. First, we must continue to characterize IL-2 receptor expression on the cells that normally use IL-2, in an attempt to fully elucidate their functional responsiveness to this hormone in vitro and their physiologic role in vivo. Second, we should proceed with clinical trials that use rIL-2 in an effort to assess cellular and humoral responses in vivo, and to learn more about the ability of rIL-2 to provide additional defense against persistent infection or malignancy in both immunocompromised and cancer patients.