In the interval from December 1987 to November 1990, 196 consecutive patients with chronic myelogenous leukemia (CML) received unrelated donor marrow transplantation using marrow procured by the National Marrow Donor Program (NMDP) at 21 NMDP-affiliated marrow transplant centers. Baseline donor and recipient data as well as follow-up data were obtained systematically in all cases by the NMDP. The median interval from the initiation of a search for an unrelated donor to bone marrow transplantation was 8.4 months (range, 1.7 to 34.6 months). Median age of the recipients was 33.3 years (4.5 to 54.5 years). Seventy-five recipients were female and 121 were male. At time of transplant, 115 patients were in chronic phase, 51 in accelerated phase, 14 in blast crisis, and 16 in a second or subsequent chronic phase. In 133 cases, donors and recipients were identical at the HLA A, B, and DR loci using standard serologic typing, and in 63 cases, there was nonidentity at one HLA locus. Patients were prepared for transplantation with a combination of high-dose chemotherapy and total body irradiation (N = 169) or with high-dose chemotherapy only (N = 27). Thirty-five patients received marrow depleted ex vivo of T lymphocytes, whereas 161 patients received non-T-depleted marrow. One hundred seventy-four of 196 patients engrafted (absolute neutrophil count > or = 500/mm3 for 3 consecutive days). The median time to engraftment was 22 days (6 to 69 days). Twenty-two patients failed to engraft, and an additional 10 patients experienced late graft failure. The incidence of grades III or IV acute graft-versus-host disease (GVHD) was 0.54 +/- 0.10, and that of extensive chronic GVHD was 0.52 +/- 0.12. A lower incidence of both grades III and IV acute GVHD (P = .0003) and of extensive chronic GVHD (P = .01) were independently associated with use of T-depleted marrow. The actuarial incidence of hematologic relapse at 2 years is 0.11 +/- 0.06. The 2-year actuarial incidence of disease-free survival for patients transplanted in first chronic phase within 1 year of diagnosis is 0.45 +/- 0.21, in chronic phase more than 1 year from diagnosis is 0.36 +/- 0.11, in accelerated phase is 0.27 +/- 0.12, in second or subsequent chronic phase is 0.22 +/- 0.21, and in blast crisis is 0. Fifteen of 55 patients transplanted at 40 to 50 years of age survive.(ABSTRACT TRUNCATED AT 400 WORDS)

An in vitro clonal assay for a class of human hemopoietic progenitors (CFU-GEMM) with several characteristics of pluripotential stem cells has been previously described. In the presence of medium conditioned by leukocytes stimulated with phytohemagglutinin (PHA-LCM) and erythropoietin (Ep), CFU-GEMM give rise to mixed hemopoietic colonies containing granulocytic, erythroid, monocyte-macrophage, and megakaryocytic elements. In initial studies we found that CFU-GEMM were present in equal but low frequencies in blood (B) and bone marrow (M) mononuclear cell populations. However, when the culture system was modified by the substitution of Iscove's modified Dulbecco's medium for alpha-MEM and the addition of mercaptoethanol, a significant enhancement of mixed colony formation occurred, and an approximately 3- 4-fold difference in the frequency of CFU-GEMM between B and M emerged. Replating studies showed the formation of secondary differentiated hemopoietic colonies and at least a limited capacity for self-renewal of CFU-GEMM. The in vitro growth of normal CFU-GEMM was highly dependent on hemopoietin(s) present in PHA-LCM. In vitro detection of CFU-GEMM, however, requires only relatively low permissive concentrations of Ep, in contrast to the high Ep requirement for optimal BFU-E growth in vitro. These and other data described demonstrate CFU-GEMM to be a distinct multipotential stem cell class whose assay may prove useful in the study of human blood dyscrasias.

From April, 1985, to February, 1989, 102 consecutive patients received unrelated donor bone marrow transplantation therapy for chronic myelogenous leukemia (CML) at four centers. Median age of the group was 31 years (range, 4.5 to 51 years). Fifty-four patients were in first chronic phase (CP) at time of transplantation, and 48 had evidence of more advanced disease (AD) (accelerated phase, 32; blast crisis, 9; second CP, 7). In 44 cases, the donor and recipient were identical at the HLA A, B, and DR loci and were nonreactive in bidirectional mixed leukocyte culture (MLC) (“matched”). In 58 cases, nonidentity between donor and recipient could be determined at at least one HLA locus or in bidirectional MLC (“mismatche”). Fifty-eight patients were prepared for transplantation with a combination of cyclophosphamide and fractionated total body irradiation (FTBI) and received acute graft- versus-host disease (GVHD) prophylaxis consisting of methotrexate alone or in combination with cyclosporine, prednisone, or antithymocyte globulin (ATG). In 44 cases, patients received preparative agents in addition to cyclophosphamide and FTBI, and marrow depleted of mature T lymphocytes by ex vivo incubation with either anti-CD3 antibody plus complement (n = 24) or Campath-1 (n = 20). Engraftment defined by a peripheral blood neutrophil count greater than 0.5 X 10(9)/L was demonstrated in 92 cases and occurred at a median of 22 days (range, 11 to 46 days). In 10 cases, peripheral blood evidence of engraftment did not occur, and in one case, engraftment was followed by aplasia. Hematologic relapse was seen in four cases. Recurrence or persistence of the Ph1 chromosome without evidence of hematologic relapse occurred in four additional cases. The incidence of grade II to IV acute GVHD is 65% (95% confidence interval [CI], +/- 10%). After adjustment for recipient age and donor matching status, recipients of T lymphocyte- depleted donor marrow had a significantly lower incidence of grade II to IV acute GVHD (P less than .01); however, T depletion was not significantly associated with improved survival (P = .34), disease-free survival (P = .51), or increased incidence of relapse (P = .39). Of 102 patients, 46 are alive, with a median survival of 12 months (range, 3 to 46 months), and the Kaplan-Meier estimate of disease-free survival is 29% (95% CI, +/- 9%) for the entire group at 2 1/2 years.(ABSTRACT TRUNCATED AT 400 WORDS)

A black patient with severe aplastic anemia is described who underwent successful bone marrow transplantation from a sibling with chronic neutropenia. During an evaluation to identify a suitable donor, it was found that the majority of family members tested had neutropenia, with no familial history of significant infections or related hospitalizations. In vitro hemopoietic culture studies of marrow from the patient's HLA-MLC-matched siblings showed normal numbers of pluripotential and committed hemopoietic progenitors; in vitro hemopoietic colony formation from the patient was markedly subnormal, consistent with the clinical picture of severe aplastic anemia. Following appropriate conditioning therapy, marrow transplanted from one of these neutropenic sibs produced full hematopoietic reconstitution. Posttransplant marrow culture studies of the patient showed restoration of a normal pattern of in vitro hemopoiesis. The in vitro culture studies and clinical experience in this patient support the concept that chronic neutropenia of blacks is not primarily a marrow progenitor cell disorder but, more likely, a manifestation of a genetically determined alteration in granulocyte kinetics.

Analysis of surface antigenic determinants of hematopoietic progenitor cells has relevance both to basic biologic study of cell differentiation and to potential clinical application in the diagnosis and treatment of hematologic neoplasia. The production and characterization of monoclonal antibody BA-2 by immunization with a pre- B-ALL cell line has been reported previously. In this study we utilized complement-dependent cytotoxicity and rosette-separation with antibody indirectly coupled to ox RBC to determine if the antigen (p24) recognized by the antibody BA-2 is represented on human pluripotential (CFU-GEMM) or committed hematopoietic progenitors (CFU-GM, BFU-E, CFU- E). BA-2 showed no reactivity with normal hematopoietic progenitors by either method. In contrast, BA-2 exhibited potent complement-mediated cytotoxicity for selected ALL-derived cell lines. These results show that normal human hematopoietic progenitors do no express antigenic sites represented on ALL cells that are recognized by BA-2 and suggest that this monoclonal antibody may serve as a potent and specific agent for treatment of lymphocytic leukemia, perhaps most useful in ex vivo marrow conditioning for autologous bone marrow transplantation.