ADOPTIVE IMMUNOTHERAPY FOR RECURRENT CML AFTER BMT

Three patients with CML who relapsed after transplantation with T-depl eted BM from their HLA-identical siblings were treated with transfusio ns of donor peripheral blood mononuclear cells, in combination with (s hort) IFN alpha2 therapy. CML was successfully controlled as shown by the complete disappearance of Philadelphia-positive metaphases within 90 days of treatment. This treatment appears to be very effective as n either bcr-abl transcripts nor markers specific for hematological cell s of recipient origin could be detected by very sensitive PCR techniqu es. Two patients treated in chronic phase are without evidence of dise ase 300 and 360 days after treatment. The third patient, treated in ac celerated phase, died with BM aplasia, 39 days following PBMC infusion s. Failure to detect residual donor-derived granulocytes, as was the c ase in this patient prior to initiating adoptive immunotherapy, may in dicate toss of donor-derived BM activity. This may help predict and po ssibly prevent the occurrence of life-threatening aplasia after succes sful clearance of malignant hematopoiesis.