Autologous Progenitor Cell Transplantation Research Articles

Factors influencing haemopoietic recovery following chemotherapy-mobilised autologous peripheral blood progenitor cell transplantation for haematological malignancies: a retrospective analysis of a 10-year single institution experience.

We retrospectively analysed the factors that influenced rate of haemopoietic recovery (HR) in 243 patients after transplantation with chemotherapy-mobilised autologous peripheral blood progenitor cells (PBPC). Approximately half the patients also received haemopoietic growth factors (HGF) for mobilisation. Conditioning for transplantation was with either chemotherapy alone or chemotherapy plus total body irradiation (TBI). Median time to recovery of granulocytes > or = 0.5 x 10(9)/l was 13 days (range 7-93 days) and of platelets > or = 50 x 10(9)/l 14 days (7-440). Speed of HR was greater, both for neutrophils and platelets for patients who received more rather than less CFU-GM than our median value of 18.9 x 10(4)/kg (P < 0.0001 in both instances) and more rather than less CD34-positive cells than our median value of 8.8 x 10(6)/kg (P < 0.0001 and P < 0.0005, respectively). For granulocyte recovery, in the multivariate analysis the dose of infused CFU-GM (P = 0.05) and the use of HGF for both mobilisation and post-transplantation (P < 0.0014) were significant positive factors. For platelet recovery in the multivariate analysis the dose of infused CFU-GM (P < 0.0016) was a positive factor. The use of busulphan and of TBI were significant adverse factors for rate of platelet recovery (P = 0.005 and 0.0004, respectively). When compared with non-HGF-mobilised PBPC, HGF-mobilised PBPC reduced the number of days of hospitalisation (28 vs 24, P = 0.0001) and of treatment with intravenous antibiotics (15 vs 11, P = 0.0004). These findings emphasise the importance of cell dose in accelerating haemopoietic recovery after autologous blood stem cell transplantation.

Autologous peripheral blood stem and progenitor (CD34+) cell transplantation for systemic lupus erythematosus complicated by Evans syndrome.

Immunoablation followed by allogeneic stem cell (SC) transplantation has been shown to be capable of curing a large spectrum of experimental autoimmune disorders, hereditary and/or induced. Superimposable results, albeit with some exceptions, have been obtained in human patients affected by coincidental autoimmune and blood diseases. However, both because of encouragine experimental results and of the procedure's greater safety, autologous SC are being increasingly utilized worldwide. Case reports are being collected in the registry of the European Group for Blood and Marrow Transplantation (EBMT)/European League against Rheumatism (EULAR) Autoimmune Disease Stem Cell Project. Among the severe autoimmune diseases (SADs), which are the target of autologous transplantation, severe refractory systemic lupus erythematosus (SLE) is a condition which may benefit from this procedure. We report here the case of a 19 year old female patient with a six year history of SLE with secondary antiphospholipid syndrome (APS), who later developed refractory Evans syndrome. She was transplanted with autologous mobilized CD34+ SC and progenitor cells after conditioning with cyclosphosphamide, anti-T lymphocyte globulin and prednisone. Eight months after transplant, the patient is alive and well, with normal blood counts and persistent low-titre direct antiglobulin (DAT, Coombs) and anti-nuclear antibody (ANA) tests. Anti-double stranded DNA antibody (Anti-dsDNA), lupus anticoagulant tests and anti-cardiolipin antibody (ACA) test are negative.

Factors affecting both peripheral blood progenitor cell mobilization and hematopoietic recovery following autologous blood progenitor cell transplantation in multiple myeloma patients: a monocentric study.

The aim of the study was to analyze the factors influencing peripheral blood progenitor cell (PBPC) collection after high-dose cyclophosphamide (HDCYC) (7 g/m2) and hematopoietic recovery after autologous transplantation of HDCYC-mobilized PBPC (ABPCT) in 116 patients with aggressive multiple myeloma (MM). Following HDCYC 74 patients received hematopoietic growth factors (HGF), either G-CSF (n = 19) or GM-CSF (n = 55). All the patients were subsequently planned to undergo ABPCT. PBPC collection was possible for 106 patients. The most important prognostic factor for collection of more than 25 x 10(4) CFU-GM cells/kg and 2 x 10(6) CD34+ cells/kg was the use of HGF (P = 0.002 and 0.009, respectively). Previous use of an alkylating agent, response to treatment before HDCYC, and interval between diagnosis and HDCYC were also significant factors (P = 0.004, 0.025 and 0.001, respectively). The number of CFU-GM cells infused was the most important parameter for rapid and complete hematological recovery after ABPCT (P < 0.0001). Thus the use of HGF post-HDCYC is the major factor which, associated with reduced time between diagnosis and HDCYC and the use of an alkylating agent, could increase the numbers of hematopoietic progenitors collected, and subsequently improve hematopoietic recovery following ABPCT in MM patients.

Variables associated with the platelet count 6 weeks after autologous peripheral blood progenitor cell transplantation.

While abundant data exist documenting variables associated with early platelet engraftment after autologous PBPC transplantation, data concerning later sustained platelet engraftment is sparse. We retrospectively examined a series of 80 patients undergoing autologous PBPC transplantation with respect to their platelet count 6 weeks after transplant. Underlying diagnoses included breast cancer (n = 33), non-Hodgkin's lymphoma (n = 32), Hodgkin's disease (n = 9), and other hematologic malignancies (n = 6). Patients received G-CSF for PBPC mobilization and collected a target threshold number of 2.0 x 10(6) CD34+ cells per kilogram. A univariate analysis revealed that a diagnosis of breast cancer, fewer courses of prior chemotherapy, younger age and complete remission were associated with a higher 6-week platelet count. Additionally, the ability to collect the threshold number of CD34+ with fewer sessions of leukapheresis was also associated with a higher 6-week platelet count. The platelet count and the white blood cell count at the initiation of PBPC collection was also associated with a higher 6-week platelet count. A multivariate analysis revealed a higher platelet count on the first day of pheresis, fewer phereses required to collect 2 x 10(6) CD34+ cells per kilogram, and a diagnosis of breast cancer were all associated with a higher 6-week post-transplant platelet count. Seven patients failed to reach a 6-week platelet count of 30 x 10(9)/l and an additional five patients had a platelet count of 30-50 x 10(9)/l. We conclude that underlying clinical characteristics, as well as hematologic variables at the time of PBPC collection, influence later, sustained platelet engraftment. A percentage of patients have poor sustained platelet engraftment and may be candidates for new cytokines that specifically target megakaryocyte growth and development.

Assessment of pulmonary and cardiac function after high dose chemotherapy with BEAM and peripheral blood progenitor cell transplantation.

Limited information is available regarding the cardiac and pulmonary effects of high dose chemotherapy (HDCT) and autologous peripheral blood progenitor cell (PBPC) transplantation. The authors evaluated cardiac and pulmonary function after BEAM (BCNU 300 mg/m2, etoposide 400 mg/m2/day x 3 days, cytosine arabinoside 200 mg/m2/day x 4 days, and melphalan 140 mg/m2), HDCT, and PBPC transplantation in 26 patients with non-Hodgkin's lymphoma or Hodgkin's disease. Therapy prior to BEAM included doxorubicin (25 patients), bleomycin (6 patients), and mediastinal irradiation (4 patients). All patients had pulmonary function tests (PFTs) and equilibrium radionuclide angiography before and at a median of 57 weeks after transplantation. Prior to high dose therapy, 8 patients had abnormal PFTs, including 6 with a diffusing capacity of the lung for carbon monoxide (DLCO) <70% of predicted value. At the time of reevaluation after HDCT, all patients included in the study were in complete remission, and none had received additional therapy after transplantation. At a median of 77 weeks after transplantation, none of the patients had cardiac or pulmonary symptoms. Moreover, there were no significant changes in total lung capacity, forced vital capacity, forced expiratory volume in 1 second/forced vital capacity, DLCO, or left ventricular ejection fraction values when compared with baseline studies. The authors concluded that HDCT with BEAM and PBPC transplantation did not result in significant cardiac or pulmonary toxicity, even in patients with borderline pretransplantation PFT values. Further studies of patients undergoing HDCT and PBPC transplantation are needed.

Cytomegalovirus Monitoring by Culture of Urine and Throat Swabs from Japanese Children Undergoing Autologous Bone Marrow or Peripheral Blood Progenitor Cell or Allogeneic Bone Marrow Transplantation

Cytomegalovirus Monitoring by Culture of Urine and Throat Swabs from Japanese Children Undergoing Autologous Bone Marrow or Peripheral Blood Progenitor Cell or Allogeneic Bone Marrow Transplantation

Autologous peripheral blood progenitor cell transplantation mobilized with high-dose cytarabine in acute myeloid leukemia in first complete remission

The aim of this study was to increase disease-free survival (DFS) in AML in CR1 using a high-dose cytarabine consolidation plus G-CSF as in vivo purging and mobilization of CD34+ cells before ablative therapy and peripheral blood autograft. Fifty-six consecutive AML patients (pts) (including 11 children < 15 years), with a median age of 32 years, were analyzed. After achievement of CR with cytarabine-mitoxantrone (7 + 3) in adults and a BFM-like protocol in children, pts were intensified with cytarabine 2 g/m2 x six doses plus mitoxantrone for adults, or, 3 g/m2 x six doses plus etoposide for children, followed by G-CSF 5 micrograms/kg SC daily. The ablative regimens used were busulfan and cyclophosphamide (Bu/Cy) in standard-risk pts plus etoposide (2400 mg/m2) for high-risk pts. For the 54 pts who underwent autologous transplant, the median time to reach > 1.0 x 10(9)/l neutrophils was 13 days (8-48), and to reach platelets > 25 x 10(9)/l 32 days (8-364), and the median numbers of red blood cell and platelet units transfused were 3 and 5, respectively. Six pts had treatment-related deaths (11%). The disease-free survival and overall survival at 30 months (mos) for the 56 eligible pts were 61% and 62%, respectively. Only two relapses were observed after 21 mos, while there were 12 relapses within 12 mos. The above treatment results in a similar DFS rate as does rescue with bone marrow cells, with faster neutrophil and platelet recovery.

Incidence of Sepsis After Peripheral Blood Progenitor Cells Transplantation: Analysis of 86 Consecutive Hemato Oncological Patients

The incidence of documented infections after autologous peripheral blood progenitor cells transplantation (PBPCT) was retrospectively evaluated in 86 consecutive patients (47 males 39 females; median age 36 years, range, 18–63) treated in our institution; 83 patients had refractory hematological malignancies (40 non-Hodgkin's lymphoma, 19 Hodgkin's disease, 17 multiple myeloma, 7 acute myeloblastic leukemia) and 3 had solid tumors (1 rab-domyosarcoma, 1 neuroblastoma, 1 osteosarcoma). All patients developed fever after transplantation lasting a median of 2 days (range 1–17); 20 instances of documented sepsis developed in 17 patients (19.7%). Gram positive microorganisms were implicated in all but 4 cases. There were no fatalities directly due to infections and no correlation was found between the risk of infection and reaching PMN > 0, 1 × 109/L, PMN > 0.5 × 109/L. In addition no specific risk factors related to age, disease, conditioning regimen, use of central venous catheter (CVC), type of transplant, and isolation measures were identified.

BEAM chemotherapy and autologous haemopoietic progenitor cell transplantation as front-line therapy for high-risk patients with diffuse large cell lymphoma.

In two consecutive and unselected cohorts of diffuse large cell lymphoma (DLCL) patients with advanced stage disease (IIB or bulk or more) and aged < 60 years, we compared a standard (MACOP-B for 12 weeks, 60 patients) versus a high-dose chemotherapy programme (8 weeks of MACOP-B plus one or two cycles of intensification with mitoxanthrone, dexamethasone, high-dose Ara-C, and finally BEAM chemotherapy with autologous haemopoietic progenitor cell transplantation, 61 patients). 41 patients (68%) in the standard group and 51 (84%) in the high-dose chemotherapy group, achieved a complete remission (CR) or an uncertain complete remission (CRu) (P = 0.0491). With a median follow-up time of 28 months for the high-dose group and 63.5 months for the standard group, the actuarial estimate of event-free survival (EFS) at 2 years demonstrates a significant benefit (70% v 50%, P = 0.03) for patients treated with the intensive regimen. The analysis of subgroups of patients showed that only high-risk patients (two or three risk factors) benefitted from the high-dose chemotherapy programme. Nevertheless, the overall survival does not show a significant difference between the two treatment modalities. The treatment-related morbidity was similar and the mortality rate was 8% in the standard (MACOP-B) group and 3% in the high-dose chemotherapy programme. In conclusion, our results show that high-dose chemotherapy and autologous stem cell transplantation is a safe procedure which should be considered for the front-line treatment of non-Hodgkin lymphoma patients with poor prognostic features.

Platelet transfusion requirements during autologous peripheral blood progenitor cell transplantation correlate with the pretransplant platelet count.

The use of primed peripheral blood progenitor cells (PBPC) has improved platelet engraftment following autologous bone marrow/PBPC transplantation (ABMT). The thrombocytopenia associated with ABMT generally lasts 14-18 days, and is associated with variable platelet transfusion requirements. Little, if any, data exist examining prognostic parameters for platelet transfusion requirements during autologous transplantation. We retrospectively examined 286 consecutive patients undergoing autologous transplantation from 1 January 1994 to 1 June 1996 with respect to platelet engraftment and platelet transfusion requirements. One hundred and fifty four patients were transplanted for breast cancer (54%), 72 for non-Hodgkin's lymphoma (25%), 35 for Hodgkin's disease (12%), 13 for acute leukemia (5%), eight for myeloma (3%), and four for other malignancy (1%). The median age was 44. All patients received cytokine priming, usually with G-CSF, for the procurement of PBPC. The median number of CD34+ cells collected was 4.3 x 10(6)/kg. All patients received a chemotherapeutic preparative regimen and all received an autologous transplant using PBPC alone. The median time to a platelet count of 20 x 10(9)/l was 13 days. Patients beginning the transplant with a less than normal platelet count (less than 150 x 10(9)/l) engrafted in 17 days, and received a median number of seven platelet transfusions, as compared with platelet engraftment of 12 days, and four platelet transfusions, for patients beginning the transplant with a normal platelet count (P = 0.001). Both groups of patients received an equivalent dose of CD34+ cells. We conclude that thrombocytopenia at the initiation of autologous transplantation is associated with increased platelet transfusion requirements, independent of the dose of CD34+ cells infused.

Index of pretreatment intensity predicts outcome of high-dose chemotherapy and autologous progenitor cell transplantation in chemosensitive relapse of Hodgkin's disease

To identify prognostic factors in patients with chemosensitive relapsed Hodgkin's disease treated by high-dose chemotherapy with autologous progenitor cell transplantation (HDC) and to compare the duration of treatment-free remission prior to HDC with the progression-free survival after HDC in individual patients. Forty-five consecutive patients were analyzed retrospectively. We devised an index of pretreatment intensity (IPTI) based number of different chemo- and radiotherapy regimens given between diagnosis and HDC and on the duration of disease. With a median follow-up of 47 months the post-transplant event-free survival (EFS) was 44% and the overall survival (OAS) was 62% at four years. The IPTI allowed to discriminate between a low and a high-risk group with a four-year post-transplant EFS of 66% and 11% and a OAS of 87% and 28%, respectively (P = 0.0001). Of the 39 patients with sufficient follow-up after HDC, post-transplant EFS lasted on average > or = 18.5 months longer than the pretransplant treatment-free remission. HDC with the CBV regimen confers significant benefit to patients with chemosensitive relapsed Hodgkin's disease. The IPTI may help to select patients with a good response to HDC and to identify poor prognosis patients suitable for experimental protocols or palliative care only.

Cytomegalovirus monitoring by polymerase chain reaction of whole blood samples from patients undergoing autologous bone marrow or peripheral blood progenitor cell transplantation.

Sensitive screening for cytomegalovirus (CMV) by polymerase chain reaction (PCR) following autologous bone marrow or peripheral blood progenitor cell transplantation has not been evaluated. In a three-center study, 98 autograft transplant recipients were prospectively screened for CMV infection by PCR and culture techniques. At a median of 20 days (range, 3-28) after transplantation, 21 (39.6%) of 53 CMV-seronegative patients were PCR positive for CMV, and at a median of 17 days (range, 7-84) after transplantation, 19 (42.2%) of 45 CMV-seropositive patients were PCR positive for CMV. Low-level DNAemia (1-10 fg CMV DNA/mL blood) occurred for 1 week in 31 patients but was never associated with CMV disease. Of 9 patients who presented with at least two consecutive positive PCR results, 1 developed CMV pneumonia. No patients died because of CMV disease. Screening for CMV infection by PCR had a negative predictive value of 100% (as also observed after allogeneic transplantation), but its positive predictive value was significantly lower.

Megakaryocytic Progenitors Can Be Generated Ex Vivo and Safely Administered to Autologous Peripheral Blood Progenitor Cell Transplant Recipients

AbstractWe evaluated different culture conditions to obtain a lineage-selected proliferation of clonogenic megakaryocytic progenitors (MP). In low-density (LD) or CD34+ cell cultures, the best results were obtained in serum-free medium in the presence of megakaryocyte growth and development factor, stem cell factor, interleukin-3 (IL-3), IL-6, IL-11, FLT-ligand, and macrophage inflammatory protein-1α. In paired studies, expansion of LD cells was less effective than expansion of CD34+ cells, and pre-enrichment of CD34+ cells using negative depletion of lineage-positive cells produced significantly larger quantities of MP than pre-enrichment using positive selection. MP proliferation peaked on day 7 in culture, and an 8- ± 5-fold expansion of CD34+/CD61+ cells, a 17- ± 5-fold expansion of colony-forming units-megakaryocytes, and a 58- ± 14-fold expansion of the total number of CD61+ cells was obtained. In a feasibility clinical study, 10 cancer patients (8 with breast cancer and 2 with non-Hodgkin's lymphoma) undergoing autologous peripheral blood progenitor cell (PBPC) transplant received MP generated ex vivo (range, 1 to 21 × 105/kg CD61+ cells) together with unmanipulated PBPC. Eight patients received a single allogeneic platelet transfusion, whereas platelet transfusion support was not needed in 2 of the 4 patients receiving the highest doses of cultured MP. This result compares favorably with a retrospective control group of 14 patients, all requiring platelet transfusion support. Adverse reactions or bacterial contamination of cell cultures have not been observed. In conclusion, MP can be expanded ex vivo and safely administered to autologous transplant recipients. Further clinical trials will indicate the reinfusion schedule able to consistently abrogate the need for allogeneic platelet transfusion support in autologous transplantation.

Endocrine function and bone metabolism 5 years after autologous bone marrow/blood-derived progenitor cell transplantation.

High dose chemotherapy with or without total body irradiation supported by autologous transplantation of hematopoietic progenitor cells is increasingly being used for hematologic and solid tumors. However, there is only limited information available on late toxicity. The authors investigated endocrine function and bone metabolism in 29 patients with a median interval of 5 years after autografting. In accordance with an earlier report on this patient cohort, ovarian failure was observed to be unchanged, except for one woman with recovered ovarian function who gave birth to two healthy children. In two-thirds of the men, follicle-stimulating hormone levels were elevated, suggesting germinal aplasia. Determination of bone mineral density did not reveal osteopenia, despite several risk factors: prolonged immobilization, high dose corticosteroid treatment, and, in women, transient estrogen insufficiency. Frequent impairment of thyroid function has been reported in patients receiving single dose total body irradiation. Overt or subclinical hypothyroidism was not detected, most likely because the total body irradiation was hyperfractionated. With the exception of gonadal failure, no significant late effects on endocrine function or bone metabolism were observed in this patient cohort.

Purging of peripheral blood progenitor cell autografts and treatment of minimal residual disease.

Clinical success of autologous peripheral blood progenitor cell (PBPC) transplantation is challenged by relapse of malignant disease which might at least in part be mediated by graft-contaminating tumor cells. Although the clinical efficacy of tumor cell depletion still remains to be demonstrated, multiple purging strategies are currently pursued in the context of autologous stem cell transplantation. This report discusses ex vivo manipulations of PBPC transplants with respect to purging of tumor cells, including positive selection of CD34+ cells with or without negative depletion of tumor cells as well as ex vivo expansion techniques. Moreover, strategies with an adoptive immunotherapy using ex vivo-generated autologous dendritic cells for the treatment of minimal residual disease after stem cell transplantation will be discussed here.

Peripheral blood stem cell harvesting and CD34-positive cell selection.

High-dose chemotherapy is effective treatment for patients with a variety of high-risk malignancies who have little chance of long-term survival with standard-dose regimens [1–3]. Such therapy produces profound myelosuppression that may be ameliorated by transplantation of allogeneic or autologous hematopoietic progenitor cells (AHPCs). The most conventional source of cells for repopulating the hematopoietic compartment has been bone marrow that is aspirated from the patient’s iliac crests while under general anesthesia. Recently, peripheral blood progenitor cells (PBPCs) have replaced marrow as the major source of hematopoietic support. This shift from marrow to PBPCs occurred because many of the PBPC-supported studies have shown significantly faster engraftment rates, particularly for platelets, when compared to similar studies of conventional bone marrow transplants [1–5]. Additionally, the leukapheresis procedure is considered to be less morbid than a marrow harvest by most patients. Several studies with multiyear follow-up have now confirmed the durability of hematopoietic reconstitution produced with PBPCs as sole hematopoietic support, leading to the increased use of this technology [1,6–8].

Peripheral Blood Progenitor Cell Collection during Hematopoietic Recovery following Autologous Blood Progenitor Cell Transplantation

Peripheral Blood Progenitor Cell Collection during Hematopoietic Recovery following Autologous Blood Progenitor Cell Transplantation

Growth Factor Administration Following Autologous Peripheral Blood Progenitor Cell Transplantation

Hematopoietic growth factor (HGF) administration following autologous peripheral blood progenitor cell transplantation (APBPCT) is a current approach for shortening the duration of high-dose chemotherapy-induced transient peripheral pancytopenia. Several published clinical experiences and a retrospective study reported here show that recombinant human granu-locyte colony stimulating factor (rhG-CSF) or recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) administration potentiates polymorphonuclear leukocyte (PMN) and white blood cell (WBC) recovery with some clinical benefits mainly related to the reduction of infectious complications during the shortened period of neutropenia. However, this therapeutic strategy does not produce any enhancement of platelet (PLT) recovery or potentiation of red cell production.Conversely, a recent phase I/II study carried out in our institution showed that the combined administration of rhG-CSF and recombinant human erythropoietin (rhEPO) is able to potentiate trilineage hematopoietic recovery with a reduction of PLT transfusions and to considerably simplify the clinical management of patients as compared to patients treated with APBPCT alone. The post-APBPCT administration of rhEPO with rhGM-CSF decreased the number of days with WBC < 1× 109/L but failed to produce any appreciable effect on PLT recovery. Both combined treatments significantly reduced the patients' hospital stay and allowed the abrogation of systemic antibiotic administration following APBPCT. A further group of patients were treated with the combined administration of rhEPO, rhG-CSF and rhGM-CSF; they did not show a faster hematopoietic recovery than rhG-CSF plus EPO treated patients and a consistent hyperthermia was observed in most patients as a prominent side effect.Future prospective randomized studies will clarify the efficacy of HGF administration following APBPCT. Moreover, further improvements in the hematopoietic support of transplanted patients may be obtained when stem cell factor, flt3/flk2 tyrosine kinase ligands or megakaryocyte growth and development factor will become clinically available.

Early Recurrence or Persistence of Autoimmune Diseases After Unmanipulated Autologous Stem Cell Transplantation

Autologous stem cell transplantation with or without in vitro lymphocyte depletion has been suggested as a new treatment option for severe autoimmune diseases. We describe five patients with autoimmune diseases (CREST syndrome, myasthenia gravis and Hashimoto's thyroiditis, systemic lupus erythematosus, atopic dermatitis, and rheumatoid arthritis) who underwent autologous bone marrow (n = 1) or peripheral blood progenitor cell (n = 4) transplantation with unmanipulated grafts as treatment for the autoimmune disease in one case or as treatment for a malignant disorder with a concomitant autoimmune disorder in four cases. In all patients serological and clinical signs of the autoimmune disease recurred early or persisted. These observations should be regarded as a cautionary note concerning the efficacy of high-dose therapy followed by transplantation of unmanipulated autologous stem cells for treatment of severe autoimmune diseases.

High-dose melphalan followed by autograft employing non-cryopreserved peripheral blood progenitor cells in children.

High-dose chemotherapy followed by autologous bone marrow transplantation (ABMT) enables dose escalation in the treatment of childhood malignancies. Here we report our experience of using peripheral blood progenitor cells (PBPC) to restore haematopoiesis in five children using a simple cell mobilising regime and non-cryopreservation of the harvests. Cells were mobilised using cyclophosphamide and granulocyte colony stimulating factor. Each patient underwent only two leukaphereses, the product being stored before use at 4 degrees C. Successful autologous PBPC transplantation was achieved with melphalan conditioning chemotherapy and re-infusion of the total progenitor cell product. No colony stimulating factors were administered after transplantation. The median numbers of mononuclear cells collected per patient was 10.0 x 10(8)/kg (range 8.13-19.44) and CFU-GM 57.6 x 10(4)/kg (range 10.4-178.85). All patients subsequently engrafted with the median number of days to a neutrophil count > 0.5 x 10(9)/l being 11 (range 10-16), and to a platelet count > 50 x 10(9)/l being 14 (range 12-31). The median number of in-patient days was only 20 (range 19-30). The median demand for blood was 2 units (range 1-2), and platelets 4 units (range 2-28). Usage of systemic antimicrobials and intravenous feeding was also low. Using this simple strategy, collection and transplantation of autologous progenitor cells can be a straightforward procedure in children. It is possible that this could enable dose escalation in some poor prognosis paediatric tumours.