INDIUM-LABELED WHITE BLOOD-CELLS APHERESED FROM DONORS RECEIVING G-CSF LOCALIZE TO SITES OF INFLAMMATION WHEN INFUSED INTO ALLOGENEIC BONE-MARROW TRANSPLANT RECIPIENTS

G-CSF administration to normal donors results in granulocyte apheresis yields generally greater than those observed with other neutrophil mo bilizing agents, In vitro, neutrophils cultured with G-CSF exhibit pro longed survival; however, the random migration of neutrophils exposed to this agent is inhibited, Although transfused neutrophils mobilized with agents other than G-CSF migrate to sites of inflammation or infec tion in vivo, this has yet to be demonstrated with infusion of G-CSF-m obilized neutrophils into neutropenic human subjects, Five neutropenic allogeneic bone marrow transplant (BMT) patients each received a fres h infusion of G-CSF-mobilized indium-labeled irradiated white blood ce lls (WBC) apheresed from HLA-matched normal donors on day +5 post-tran splant. Localization of activity on delayed scintigraphic images of in dium-labeled WBC scans to sites of tissue damage (oral/nasopharynx in two patients with mucositis and terminal ileum/cecum in one with diarr hea) occurred, and supports the hypothesis that G-CSF-mobilized HLA-ma tched donor neutrophils which have been irradiated are functional afte r infusion into neutropenic recipients.