reported to have specific effect on megakaryocytopoiesis and enhance platelet recovery post chemotherapy. A mixture of growth factors are being evaluated for the ex vivo of periphera! progenitor cells to further reduce the period of marrow aplasia post therapy.
Recombinant proteins are also helpful to enhance immune functions of compromised patients. Interferon gamma (IFN--),), a T-cell derived lymphokine, possesses broad macrophage-monocyte activating effects. It has been used in combination of conventional antimicrobials in the treatment of refractory, opportunistic non-viral infections (such as atypical mycobacterium, fungal and parasitic infections) in patients with AIDS and cancer. IFN-3, may be combined with other cytokines (e.g., G-CSF) to treat children with resistant fungal infection. The use of G-CSF with antifungal agents was also suggested. Vaccines may be produced by recombinant technology to provide active immunization for selective groups of immunocompromised children. The immune system can also be promoted to express antitumor effects, IFN-a was given after BMT for hematologic malignancies and was shown to prolong the duration of tumor response. IL 2 was similarly tested in children with Ewing's sarcoma, neuroblastoma and acute myeloid leukemia. Combined cytokine therapy may be active in the treatment of some chemoresistant maligancies.