TREATMENT OF RELAPSE AFTER ALLOGENEIC BONE-MARROW TRANSPLANTATION WITH UNMANIPULATED G-CSF-MOBILIZED PERIPHERAL-BLOOD STEM-CELL PREPARATION

Donor lymphocyte infusions (DLI) are an effective treatment of leukemi a relapse after allogeneic bone marrow transplantation. Undesired side -effects are the development of graft-versus-host disease (GVHD) and t he occurrence of pancytopenia in some patients. In a pilot study, we i nvestigated if unmanipulated G-CSF-mobilized peripheral blood stem cel ls which naturally contain large numbers of T lymphocytes (D-PBSC/LI) would be equally effective or even superior than DLI in generating a g raft-versus-leukemia reaction (GVL) but could mitigate or prevent the development of pancytopenia. We treated 12 patients with CML chronic p hase (n = 5), CML blast crisis (n = 2), AML (n = 2), ALL (n = 1), CLL (n = 1) and multiple myeloma (n = 1), In five patients with acute leuk emia or CML blast crisis D-PBSC/LI followed intensive chemotherapy (gr oup A), in seven patients D-PBSC/LI were given without any prior chemo therapy (group B). In group A two patients were evaluable for hematolo gic toxicity, Leukopenia <1000/mu l lasted for 10 and 19 days, and thr ombocytopenia <20 000/mu l for 11 and 13 days, respectively. In group B leukopenia <1000/mu l and thrombocytopenia <20 000/mu l was observed in only one patient. Moderate cytopenia developed in four of five eva luable patients. A complete remission could be achieved in all seven p atients with CML who all developed acute and/or chronic GVHD. None of the remaining five patients achieved a complete remission despite acut e and/or chronic GVHD in two of them. Four patients died from disease progression, one patient from a secondary lymphoma, and one patient as a result of uncontrolled GVHD, In conclusion, D-PBSC/LI is effective in inducing GVL reaction but it does not prevent pancytopenia in each case. It remains unclear if it mitigates the incidence and severity of pancytopenia.