A majority of patients with intermediate or high-grade non-Hodgkin's lymphoma (NHL) who are treated with high-dose chemotherapy (HDT) and hematopoietic stem cell transplantation subsequently relapse. Until recently, transplantation was associated with high morbidity and mortality and the focus was on improving the safety of this procedure. However, the use of growth factors and other supportive measures has successfully reduced treatment mortality to less than 5%. Therefore, new strategies need to be developed to eliminate the growth of any occult tumor cells reinfused with the stem cell products and the tumor cells remaining in the patient. One approach is to improve the immune function of the patients by a more rapid immune reconstitution and augmentation of effector cell function. We report studies comparing immune recovery following HDT and autologous peripheral stem cell transplantation (PSCT) as compared to autologous bone marrow transplantation (ABMT). These studies examined patients with intermediate and high-grade non-Hodgkin's lymphoma (NHL) who were treated with HDT and PSCT (n = 56) or ABMT (n = 60). The PSCT patients had a significantly faster recovery of circulating monocytes (CD14+ cells), natural killer ((NK) CD56+) cells, T helper (CD4+) cells, TCR gamma/delta cells, and naive T lymphocytes (CD45RA+). Following ABMT there was a significantly more rapid increase in the frequency of T suppressor/effector (CD8+) cells, B (CD19+) cells, CD34+ cells, polymorphonuclear leukocytes (PMN) and memory T lymphocytes (CD45RO+). The CD4:CD8 and CD45RA:CD45RO ratios were consistently higher in the PSCT group as compared to ABMT suggesting an improved ratio of T helper to T effector/suppressor cells and naive T cells. The differences in cellular phenotype translated into improved T cell function (PHA mitogenesis) and T cell help (pokeweed mitogenesis). In addition, there as an accelerated reconstitution of NK cell activity following PSCT as compared to ABMT. The more rapid reconstitution of NK and T cells in patients rescued with PSCT as compared to ABMT may contribute to an improved clinical outcome. Further, patients receiving a PSCT may be more responsive to adjuvant immunotherapy following transplantation.

Hematologic effects of granulocyte colony-stimulating factor (G-CSF) and erythropoietin (EPO) combination after printing intensive chemotherapy in the treatment of female breast carcinoma are presented. In a previous group treated with G-CSF alone, 36% of patients became anemic and had to be transfused for correction of their anemia. To the present study 11 consecutive patients with different stages of breast carcinoma were admitted. All were given priming intensive chemotherapy (epirubicin 150 mg/m2 and cyclophosphamide 1300 mg/m2 followed by subcutaneous application of G-CSF at a dose of 5 micrograms/kg/day and EPO 250 IU/kg/day. In cases where leucocyte counts dropped below 1 x 10(9)/l and hemoglobin levels fell to 85 g/l administration of growth factors was started. The therapy stopped when normal leucocyte count reached 4 x 10(9)/l for G-CSF and hemoglobin level rose to 115 g/l for EPO. Our results show significant difference between MNC/T1 (min.), CD34+ cells/microliters (min.), CFU-GM/ml (min.), BFU-E/ml (min.) and MNC/microliters (max.), CD34+ cells/microliters (max.), CFU-GM/ml (max.), BFU-E/ml (max.) p < 0.01, with mean peak values of 16.9-fold for circulating MNC/microliters, 7.8-fold for CD34+ cells/microliters 23.4-fold for CFU-GM/ml and 28.7-fold increase for BFU-E/ml. Side effects were minimal, no infectious complications occurred, body temperature did not rise over 38 degrees C and no corrections of anemia were needed. It is concluded that the administration of G-CSF plus EPO combination following intensive chemotherapy reduces hematologic toxicity and induces large amount of hemopoietic progenitors suitable for autologous transplantation in women with breast carcinoma.

Reconstitution of hematopoiesis by means of peripheral blood stem cells is a valid alternative to autologous bone marrow transplantation. The aim of this investigation was to increase the efficiency of collection of circulating blood progenitor cells and to obtain a purer product for transplant.

Patients receiving high-dose chemotherapy (HD-CT) are at risk of severe mucositis. Most prevention studies evaluate the degree of mucositis on clinical, and therefore subjective, measurements. The aim of this study was to develop an objective in vitro assay of chemotherapy-induced mucositis. Twelve patients with locally advanced breast carcinoma received HD-CT followed by peripheral stem cell reinfusion. Before and twice weekly after HD-CT, the mucosa was evaluated by an oral washing, a buccal smear and the World Health Organization (WHO) toxicity grading; furthermore, blood leucocyte levels were determined. For the oral washings, the percentage of viable epithelial cells was determined by trypan blue dye exclusion and leucocytes were counted by fluorescence microscopy after incubation with acridine orange. Maturity of buccal cells was assessed by staining buccal smears for morphology according to Papanicolaou (Whitacker D and Williams V, 1994). Eight healthy volunteers served as controls. The mean percentage (+/- s.e.m.) of viable oral epithelial cells was stable in controls (44 +/- 2%). In patients, they increased after HD-CT, which was significant after day 7 compared with pretreatment (P < or = 0.05). In addition, a shift from mature to immature epithelial cells in buccal smears was observed. Oral leucocyte levels were closely correlated with the blood leucocyte counts. The WHO score followed the results of these other evaluations with some delay. The viability of buccal cells obtained by oral washings increases after HD-CT. This is possibly because of desquamation of the upper oral mucosa layer, with a shift from mature to more immature cells. These data can be quantitated, and this assay may therefore be useful in studies aimed at prevention of mucositis.

Herein we report on the feasibility of mobilizing peripheral blood progenitor cells (PBPC) in a prospective study of the HOVON-SAKK Groups in 96 cases with newly diagnosed acute myeloid leukemia (AML). Among 96 patients, 76 patients (79%) entered complete remission. Mobilization was undertaken with variable dosages of G-CSF in 63 patients, and 54 patients (87%) were leukapheresed. The comparative yields of pheresis following the G-CSF schedules and hematopoietic recovery data are presented and discussed. PBPC transplantation results in faster hematopoietic regeneration compared to autologous marrow grafting in the prior AML HOVON study.

The combination of cyclophosphamide (CY) and etoposide is synergistic, spares bone marrow stem cells and can be given repeatedly in high doses without stem cell support. Thirteen patients with non-Hodgkin's lymphoma (n = 8) or Hodgkin's disease (n = 5), received high-dose chemotherapy (HDC). Median age was 32 years (24-52). Male to female ratio was 10:3. All the patients were in advanced-stage. Karnofsky score prior to HDC was 60% (range 40-90). Six patients showed primary refractoriness and 7 had resistant relapse. HDC consisted of CY 1,500 mg/m2/day and etoposide 300 mg/m2/day, both for 4 days. rhG-CSF was started 24 h after the last dose of chemotherapy as a continuous intravenous infusion at a dose of 0.01 mg/kg/day and stopped when the leukocyte count reached 1 x 10(9)/1 on 3 consecutive days. Overall, 69% (9/13) of patients responded to HDC. Four achieved CR and 5 achieved PR. Two of the patients showed disease progression. The other 2 died during the early period of HDC. Neutrophil and platelet recovery after HDC were 8 (6-16) and 10 (4-14) days, respectively. The major nonhematological toxicities were nausea-vomiting (100%) and diarrhea (61%). The median follow-up was 204 (7-600) days. Two patients relapsed 48 and 185 days after HDC. Eight patients are still alive, 7 progression free. The progression-free survival is 220 (40-285) days. In conclusion, HDC + granulocyte colony-stimulating factor (G-CSF), without stem cell support seems to be promising in refractory or resistant relapse lymphoma patients bringing the need for randomized studies to show the cost effectiveness of HDC + G-CSF compared to HDC + autologous stem cell support.

In vitro and animal studies suggest that high concentrations of recombinant human erythropoietin (rHuEPO) might divert multipotent progenitors into erythroid maturation at the expense of granulocyte production. We determined whether changes of number and lineage commitment of peripheral blood progenitor cells occur in premature infants during therapy with rHuEPO. Thirty preterm infants were randomly assigned either to receive 300 IU of eopoetin alpha s.c. per kilogram body weight three times a week for four weeks or to a control group. At study entry and after two weeks of treatment the numbers of circulating BFU-E, granulocyte-macrophage colony-forming units (CFU-GM) and granulocyte-erythrocyte-macrophage-megakaryocyte CFU (CFU-GEMM) were analyzed by semisolid culture technique, CD34+ cells and early myeloid CD34+CD45RA- progenitors by flow cytometry. As compared with the control group, rHuEPO treatment did not exert any significant modulatory effect on numbers of CFU-GM, nor was there a significant change in numbers of BFU-E, CFU-GEMM, total-CFU, percentage of CD34+ or CD34+CD45RA- cells. Mean neutrophil count was not significantly reduced at any period during the study. Compared with the control group, the infants receiving rHuEPO had higher hematocrit values (p = 0.003) and absolute reticulocyte counts (p < 0.001). The median cumulative volume of blood transfused per kilogram per day was 0.86 ml (first quartile 0.5 ml; third quartile 1.1 ml) in the control group and 0 ml (first quartile 0 ml; third quartile 0.47 ml) in the rHuEPO group (p = 0.038). We conclude using a relatively high dose of rHuEPO in premature infants, no significant in vivo effect on circulating peripheral blood progenitor or neutrophil count could be detected.

The optimal use of mitoxantrone (NOV) in the high-dose range requires elucidation of its maximum tolerated dose with peripheral blood progenitor cell (PBPC) support and the time interval needed between drug administration and PBPC reinfusion in order to avoid graft toxicity. The aims of this study were: (1) to verify the feasibility and haematological toxicity of escalating NOV up to 90 mg m(-2) with PBPC support; and (2) to verify the safeness of a short (96 h) interval between NOV administration and PBPC reinfusion. Three cohorts of ten patients with breast cancer (BC) or non-Hodgkin's lymphoma (NHL) received escalating doses of NOV, 60, 75 and 90 mg m(-2) plus melphalan (L-PAM), 140-180 mg m(-2), with PBPC rescue 96 h after NOV. Haematological toxicity was evaluated daily (WHO criteria). NOV plasma pharmacokinetics was also evaluated, as well as NOV cytotoxicity against PBPCs. Haematological recovery was rapid and complete at each NOV dose level without statistically significant differences, and there were no major toxicities. NOV plasma concentrations at the time of PBPC reinfusion were below the toxicity threshold against haemopoietic progenitors. It is concluded that, when adequately supported with PBPCs, NOV can be escalated up to 90 mg m(-2) with acceptable haematological toxicity. PBPCs can be safely reinfused as early as 96 h after NOV administration.

A multicenter phase I/II clinical trial was conducted to evaluate the safety of a device (Isolex System; Baxter Health Corporation, Irvine, Calif., USA) using the immunomagnetic bead method to purify CD34+ stem cells from peripheral blood and to assess the efficacy and toxicity of high-dose chemoradiotherapy with peripheral blood stem-cell transplantation (PBSCT) using purified CD34+ stem cells in patients with refractory hematological malignancies. Patients eligible for the study included those who had T-cell acute lymphoblastic leukemia (T-ALL), lymphoblastic lymphoma (LBL), mantle-cell lymphoma (MCL), high-risk aggressive non-Hodgkin's lymphoma (NHL), and adult T-cell leukemia/lymphoma (ATLL) in first complete remission (CR) and those who had standard-risk aggressive NHL, indolent lymphoma, Hodgkin's disease, or acute promyelocytic leukemia (APL) in second CR or first partial remission (PR) after the completion of first-line chemotherapy and were chemosensitive to salvage chemotherapy, in whom tumor contamination of harvested peripheral blood stem cells (PBSCs) was possible due to bone marrow or peripheral blood involvement. Lack of CD34 expression by tumor cells was an important selection factor. Eight patients with hematological malignancies (six NHL patients, one ATLL patients, and one APL patient) were enrolled; their median age was 41 years (range 26-49 years). After consolidation and mobilization chemotherapy, two or three courses of apheresis were performed in each patient. After high-dose chemo(radio)therapy, in each patient a median of 1.8 x 10(6) cells/kg (range 8.2 x 10(5)-5.1 x 10(6) cells/kg) purified CD34+ PBSCs were infused; granulocyte colony-stimulating factor was given from day 1. Median times to hematopoietic recovery were as follows: WBC of > or = 1,000/microliter, day 11; platelet count of > or = 50,000/microliter, day 19; and reticulocyte count of > or = 10/1000, day 15. Two NHL patients relapsed at 23 and 9 months after PBSCT, respectively; the remaining six patients are alive and in CR. No severe toxicity was observed in any patient. Tumor contamination as measured using a polymerase chain reaction-mediated RNase protection assay at the 10-4 level was detected in the CD34(+)-purified fractions of 2 of the 5 samples analyzed; however, a reduction in contaminating lymphoma cells from the autograft of at least 1,000 to 10,000 orders of magnitude was achieved by CD34+ selection using the immunomagnetic bead method. High-dose chemoradiotherapy with transplantation of CD34+ PBSCs purified by the immunomagnetic bead method was thus shown to be an active and safe therapy for refractory hematological malignancies with bone marrow or peripheral blood involvement. However, it is too early for evaluation of the long-term survival benefit.

Therapy for aggressive non-Hodgkin's lymphomas has undergone significant evolution in the past 25 years. First-generation combination chemotherapy studies produced complete response (CR) rates of 45-53% together with 30-37% rates of long-term survival. New treatment programs aimed at increasing CR rates were then developed on the assumption that the additional patients who achieved a CR would become long-term disease-free survivors. Initial reports of single-institution pilot studies with third-generation regimens suggested CR and survival rates of 68-86% and 58-69%, respectively; however, after longer follow-up-periods, survival rates decreased. Furthermore, confirmatory national phase II trials using these newer regimens produced CR rates of only 49-65% and survival rates of 50-61%. Thus, ultimate conclusions concerning the efficacy of these new regimens awaited the results of prospective randomized trials. The Southwest Oncology Group (SWOG) conducted a randomized trial comparing standard therapy. CHOP, to the third-generation chemotherapy regimens m-BACOD, ProMACE-CytaBOM, and MACOP-B. After 6 years, on difference in the response rate, progression-free survival, or overall survival has been found between CHOP and third-generation regimens. For example, the 6-year estimates of progression-free survival are CHOP 33%, m-BACOD 36%, ProMACE-CytaBOM 34%, and MACOP-B 32% (P = 0.41). The 6-year overall survival estimates are CHOP 42%, m-BACOD 40%, ProMACE-CytaBOM 46%, and MACOP-B 41% (P = 0.89). Furthermore, we have not identified any subset of patients who survive longer on treatment with the third-generation regimens, and the cost and toxicity of the new regimens are higher. On the basis that < 50% of these patients are cured, the best approach for any patient is an experimental one designed to improve our ability to cure the disease. Examples of this include (1) increasing the dose intensity of drugs used in standard regimens and (2) autologous bone marrow transplantation and/or peripheral stem-cell support as rescue from marrow-ablative chemotherapy. If a patient is not eligible or does not wish to participate in a clinical trial, CHOP, as inadequate as it is, remains the gold standard.

This study was undertaken to evaluate the need for erythropoietin (Epo) therapy to augment autologous blood collection in adolescents undergoing spinal corrective surgery.

Platelet interaction with leukocytes can occur to a significant degree during hemodialysis, but it remains to be determined what pathophysiological consequences stem from the intradialytic formation of platelet-leukocyte coaggregates. By the use of flow cytometry techniques, this study was set out to analyze intradialytic platelet-neutrophil coaggregate formation and neutrophil hydrogen peroxide production from 10 end-stage renal disease patients each dialyzed with cuprophane and polyacrylonitrile membranes. Platelet-neutrophil coaggregates increased during dialysis with cuprophane, whereas no changes occurred with polyacrylonitrile membranes. Dialysis with cuprophane, unlike that with polyacrylonitrile, also resulted in a significant increase in neutrophil hydrogen peroxide production 10 min after dialysis initiation which persisted at significantly higher levels than predialysis values through the first 20 min. We found that the increased hydrogen peroxide production by neutrophils essentially occurred in concomitance with neutrophil-platelet coaggregation. Intracellular fluorescence representing hydrogen peroxide formation significantly increased through the first 20 min of cuprophane dialysis in neutrophils aggregated to platelets. By contrast, no change occurred in neutrophils not aggregated to platelets. Neutrophils which had formed aggregates with platelets produced higher hydrogen peroxide levels, as assessed by significantly higher fluorescence values, than non-aggregate-forming neutrophils at all time points tested. The phenomenon was duplicated in vitro when ADP-activated normal platelets were incubated with neutrophil cells but was largely inhibited when ADP-activated platelets were treated with anti-P-selectin antibody before incubation with neutrophils. These results strongly suggest that platelet-neutrophil aggregates occurring during hemodialysis, representing cell-cell interactions with pathophysiological effects, may serve as a new parameter to assess biocompatibility.

The generation of megakaryocytes (MK) from cultured peripheral blood progenitor cells (PBSC), harvested via apheresis, from 18 female breast cancer patients treated with either PIXY321 or GM-CSF was compared. Nonadherent mononuclear cells (MNC) were cultured in liquid suspension with 50 U/ml thrombopoietin (TPO) and 2.5% autologous heparinized plasma for 12 days. Flow cytometric analysis was used to measure the percentage of CD34+ on day 1 and CD41+ cells on day 12. The frequency of CD34+ cells was greater in GM-CSF-mobilized samples than in PIXY321-mobilized samples, and MK/MNC yields correlated directly with the number of CD34+ cells seeded, PIXY321-mobilized samples produced more MKs per CD34+ cell than GM-CSF-mobilized samples. Overall, there was no significant difference in the MK/MNC yield between PIXY321- and GM-CSF-mobilized samples. Cyclophosphamide (CY) increased the frequency of CD34+ cells and the corresponding MK/MNC yield for both cytokines, but had no effect on the MK/CD34+ yield. Compared to GM-CSF, PIXY321 mobilization resulted in increased CD34+ cell commitment to the MK lineage.

To formally test the hypothesis that the granulocyte/macrophage colony-forming unit (GM-CFU) cells can contribute to early hematopoietic reconstitution immediately after transplant, the frequency of genetically modified GM-CFU after retroviral vector transduction was measured by a quantitative in situ polymerase chain reaction (PCR), which is specific for the multidrug resistance-1 (MDR-1) vector, and by a quantitative GM-CFU methylcellulose plating assay. The results of this analysis showed no difference between the transduction frequency in the products of two different transduction protocols: "suspension transduction" and "stromal growth factor transduction." However, when an analysis of the frequency of cells positive for the retroviral MDR-1 vector posttransplantation was carried out, 0 of 10 patients transplanted with cells transduced by the suspension method were positive for the vector MDR-1 posttransplant, whereas 5 of 8 patients transplanted with the cells transduced by the stromal growth factor method were positive for the MDR-1 vector transcription unit by in situ or in solution PCR assay (a difference that is significant at the P = 0.0065 level by the Fisher exact test). These data suggest that only very small subsets of the GM-CFU fraction of myeloid cells, if any, contribute to the repopulation of the hematopoietic tissues that occurs following intensive systemic therapy and transplantation of autologous hematopoietic cells.

The clinical application of gene transfer is hindered by the availability of the multipotential stem cells and the difficulty in obtaining efficient retroviral transduction. To assess potential means by which gene transfer into human hemopoietic stem cells might be enhanced, the retroviral transduction efficiency of human bone marrow cells (BM) or peripheral blood progenitor cells (PBPC) was compared at multiple time points after in vivo administration of granulocyte colony-stimulating factor (G-CSF). This was further compared with the transduction efficiency of cells mobilized with G-CSF plus stem cell factor (SCF) in a cohort of patients randomized to receive either one or two growth factors and with normal BM function. Using the LNL6 retrovirus, retroviral transduction efficiencies of up to 19% were observed for both PBPC and BM (n = 26 patients). There was at least a 100-fold increase in PBPC with G-CSF alone and a further 30-fold increase in the total number of progenitor cells available for retroviral transduction using the combination of SCF plus G-CSF. However, pretreatment of patients with G-CSF with or without SCF did not enhance the retroviral infectability of growth factor-mobilized progenitor cells. The effect of the growth factor, Flk-2/Flt3 ligand (FL), was also examined with respect to retroviral transduction efficiency of human progenitor cells. FL plus IL-3 in vitro increased the retroviral transduction efficiency up to eightfold compared with results observed using other combinations of cytokines tested (P < .001). These findings have clinical implications both for increasing the number of target cells for in vivo gene-marking/gene-therapy studies and improving the efficiency of gene transfer.

The objective of this study was to determine the optimal conditions for blood progenitor cell harvest for transplantation, with main emphasis on the mobilisation kinetics of primitive, marrow repopulating cells.

It has been reported that hypophysectomized rats exhibit normochromic, normocytic anaemia. Pancytopenia with impaired DNA synthesis in the bone marrow can be restored in these hypophysectomized rats by syngeneic pituitary grafts placed under the kidney capsule or treatment with growth hormone (GH). Until now, adults with hypopituitarism have received adequate replacement therapy with thyroxine, cortisol and sex steroids, but not with GH. We therefore investigated the effects of GH replacement therapy on the proliferation and differentiation of erythroid and myeloid progenitor and peripheral blood cells in 11 adult patients with growth hormone deficiency in a double-blind, placebo-controlled study for the first 6 months of therapy. The placebo group showed no changes during the first 6 months without therapy in either insulin-like growth factor I (IGF-I) levels, erythroid and myeloid progenitor precursor cells or peripheral blood cells. After commencement of GH therapy, IGF-I levels rose significantly during 24 months of therapy from 75.3 +/- 13.5 to 225 +/- 34.7 ng mL-1 (P < 0.001). Erythroid and myeloid progenitor precursor cells showed a steep and significant increase after 18 and 24 months of therapy (erythroid: from 10.7 +/- 3.5 to 261.4 +/- 79.8, P < 0.02, after 18 months and to 276.8 +/- 149.8 x 10(5) mononuclear cell colonies, P < 0.03, after 24 months; granulocyte-macrophage colony-forming units: from 39.7 +/- 9.8 to 316.9 +/- 124.6, P < 0.002, after 18 months and to 366 +/- 188.7 x 10(5) mononuclear cell colonies, P < 0.03, after 24 months), whereas the peripheral red and white blood cells exhibited only minimal non-significant changes. The principal regulators of erythropoiesis, such as erythropoietin, and parameters reflecting erythropoiesis in the peripheral blood, such as reticulocytes, remained almost unchanged throughout the whole study period. We therefore conclude that patients with GH deficiency do not have anaemia, but have haematopoietic precursor cells in the lower normal range, and that GH substitution therapy over a period of 24 months has a marked effect on erythroid and myeloid progenitor precursor cells but only negligible effects on peripheral blood cells in GH-deficient adults.

Current treatments for metastatic breast cancer are not associated with significant survival benefits despite response rates of over 50%. High-dose therapy with autologous bone marrow transplantation (ABMT) has been investigated, particularly in North America, and prolonged survival in up to 25% of women has been reported, but with a significant treatment-related mortality. However, in patients with haematological malignancies undergoing autologous transplantation, haematopoietic reconstruction is significantly quicker and mortality lower than with ABMT, when peripheral blood progenitor cells (PBPCs) are used. In 32 women with metastatic breast cancer, we investigated the feasibility of PBPC mobilisation with high-dose cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) after 12 weeks' infusional induction chemotherapy and the subsequent efficacy of the haematopoietic reconstitution after conditioning with melphalan and either etoposide or thiotepa. PBPC mobilisation was successful in 28/32 (88%) patients, and there was a rapid post-transplantation haematopoietic recovery: median time to neutrophils > 0.5 x 10(9) l-1 was 14 days and to platelets > 20 x 10(9) l-1 was 10 days. There was no procedure-related mortality, and the major morbidity was mucositis (WHO grade 3-4) in 18/32 patients (56%). In a patient group of which the majority had very poor prognostic features, the median survival from start of induction chemotherapy was 15 months. Thus, PBPC mobilisation and support of high-dose chemotherapy is feasible after infusional induction chemotherapy for patients with metastatic breast cancer, although the optimum drug combination has not yet been determined.

Hematopoietic progenitor and stem cells are contained within the CD34+ cellular compartment of the bone marrow. Positively selected cytokine primed peripheral blood derived CD34+ cells have been shown to support autologous hematopoiesis after myeloablative therapy. We investigated hematologic reconstitution and incidence of graft-versus-host disease (GVHD) after transplantation of allogeneic peripheral blood CD34+ cells. CD34+ cells were selected from the peripheral blood of 10 matched related donors after treatment with rG-CSF followed by one to four apheresis procedures and biotin-avidin immune affinity purification. Ten patients with advanced hematologic malignancies were subsequently transplanted with cryopreserved allogeneic CD34+ cells after myeloablative chemotherapy. Immune affinity purification of CD34+ cells resulted in a 370-fold T cell reduction. Patients were grafted with a median number of 4.1 x 10(6) kg (1.6-6.4) CD34+ cells and 0.42 x 10(6)/kg (0.29-2.2) CD3+ cells. All patients received rG-CSF 5 micrograms/kg post-transplant and completely engrafted with neutrophils > 500/microliter after a median time of 10 days (9-15) and platelets > 20,000/microliter after 16 days (10-74). Complete donor chimerism was demonstrated by cytogenetic and molecular methods up to day +385 post-transplant. Cyclosporin A only was used for GVHD prophylaxis. Four of 10 patients developed acute GVHD with grade I (one) and II (three) which completely resolved with treatment. Two patients died from infectious complications. Three patients died from relapse or progressive disease. Five patients are alive in remission without GVHD with a median follow-up time of 254 (93-457) days and three of five are without immunosuppression. Allogeneic transplantation of positively selected peripheral blood-derived CD34+ cells is feasible and safe and leads to long-term engraftment without severe GVHD suggesting that peripheral blood-derived CD34+ cells contain pluripotent hematopoietic stem cells. The reduced number of T cells transplanted appears to be sufficient for engraftment.

Patients with non-myeloid hematologic malignancies (including Hodgkin's and non-Hodgkin's lymphomas, myeloma and acute lymphoid leukemia) or solid tumors underwent cytoreductive conditioning regimens followed by either autologous bone marrow transplantation (ABMT) (n = 343) or transplantation of peripheral blood stem cells (PBSC) with (n = 44) or without bone marrow (BM) (n = 16). In a randomized double-blind phase III multi-center trial, patients received either granulocyte-macrophage colony-stimulating factor (GM-CSF, 10 micrograms/kg/day) or placebo by daily i.v. infusion beginning 24 h after bone marrow infusion and continuing until the absolute neutrophil count (ANC) had recovered to > or = 1000/mm3, or for a maximum of 30 days. Median time to neutrophil recovery was significantly shorter in the GM-CSF group (18 vs 27 days, P < 0.001), and more GM-CSF patients had neutrophil recovery by day 30 (70 vs 48%). Median duration of hospitalization was significantly shorter in the GM-CSF group (29 vs 32 days, P = 0.02). GM-CSF significantly reduced the median time to neutrophil recovery in patients receiving bone marrow only (19 vs 27 days, P < 0.001) or PBSC with or without bone marrow (14 vs 21 days, P < 0.001). The overall incidence of adverse events was comparable in the two groups, although more patients in the GM-CSF group discontinued treatment due to adverse events (17 vs 9%, P < 0.001). No difference was noted in infection incidence or time to platelet independence. GM-CSF had no negative impact on time to relapse or long-term survival. These data indicate the positive influence of GM-CSF on neutrophil recovery and hospital stay in patients receiving ABMT for a variety of clinical indications.