Effects of interleukin 2 on engraftment following autologous bone marrow transplantation (ABMT) in dogs.

Beagle dogs were treated with recombinant human interleukin 2 (IL-2) 6 x 10(6) International Units (IU)/day for 7 consecutive days following conditioning with sublethal (200 cGy) or lethal (400 cGy) doses of high-dose rate whole body irradiation (WBI) and reconstitution with 2 x 10(8)/kg autologous bone marrow cells, in order to assess the effect of IL-2 on engraftment. Engraftment of dogs conditioned by lethal doses of WBI was not impaired following treatment with IL-2 6 x 10(6) IU/day. At an RIL-2 dose of 6 x 10(6) and 9 x 10(4) IU/day, enhanced engraftment of autologous bone marrow cells was observed in dogs irradiated with a sublethal WBI dose in comparison with controls not treated by IL-2(p < 0.05). We conclude that therapeutic doses of IL-2 may be safely utilized during hematopoietic reconstitution. Under certain conditions IL-2 may even enhance hematopoietic reconstitution following ABMT.