MIXED HEMATOPOIETIC CHIMERISM FOLLOWING BONE-MARROW TRANSPLANTATION FOR HEMATOLOGIC MALIGNANCIES

  • 1 November 1987
    • journal article
    • research article
    • Vol. 70  (5) , 1331-1337
Abstract
Twenty-nine of 172 patients (17%) who received an allogenetic bone marrow transplant (BMT) from histocompatible sibling donors for hematologic malignancies were mixed hematopoietic chimeras; ie, they had a mixture of donor and host hematopoietic or lymphohematopoietic cells at .gtoreq. 14 days after transplantation. Twenty-four of the 29 mixed chimeras (83%) have remained in continuous complete remission up to 116 months (>9 years) following BMT. Four of the 29 patients (14%) have had recurrent leukemia, and 7 of the 29 (24%) have had moderate or severe graft-v-host disease (GVHD). Twelve of these 29 patients have persisted as stable mixed chimeras for .gtoreq.2 years after BMT, whereas other patients converted to all donor-type hematopoiesis. The incidence of mixed chimerism was independent of the pretransplant regimen, the donor or recipient age (20 years), remission status (first complete remission of acute leukemia and first chronic phase of chronic myelocytic leukemia v later stages of disease), and type of leukemia. Our data indicate that mixed hematopoietic chimerism is not rare after BMT for hematologic malignancies and that its presence is compatible with long-term disease-free survival. Prospective studies of mixed chimerism after BMT are warranted to achieve better understanding of its biologic importance.