Peripheral Blood Stem/progenitor Cells Research Articles

The early secreted antigenic target of 6 kD of Mycobacterium tuberculosis inhibits the proliferation and differentiation of human peripheral blood CD34+ cells

Abnormalities in hematopoiesis are common in tuberculosis patients and highly prevalent in AIDS patients with tuberculosis coinfection. To explore the potential role of the early secreted antigenic target of 6-kD (ESAT-6) of Mycobacterium tuberculosis (Mtb) in abnormal hematopoiesis in tuberculosis, we studied the effect of ESAT-6 on proliferation and differentiation of invitro-expanded CD34+cells isolated from the peripheral blood of the healthy donors. ESAT-6 but not control protein antigen 85A (Ag85A) of Mtb inhibited the proliferation of CD34+cell derived peripheral blood stem/progenitor cells (PBSPC) in a dose dependent manner when determined by MTT-assay. ESAT-6 but not Ag85A reduced the number of colony forming cells (CFC) of PBSPC by 60-90% as determined by CFC assay by incubation of CD34+cells in a semi-solid cellulose media in the presence of cytokine cocktail for two weeks. ESAT-6 but not Ag85A increased the percentages of the Annexin-V positive cells and enhanced the cleavage of caspase-3 in PBSPC in a time and dose dependent manner as determined by flow cytometry and Western blot analysis, respectively. ESAT-6 also inhibited murine bone marrow derived non-adherent cell proliferation in response to granulocyte-macrophage colony stimulating factor treatment. We conclude that ESAT-6, an essential virulence factor of Mtb, may contribute to the abnormal hematopoiesis of tuberculosis patients by inhibiting the proliferation and differentiation of hematopoietic cells via apoptosis.

Clinical Study on Efficacy of Docetaxel Combined with G-CSF for Mobilization of Peripheral Blood Stem Cell in Metastatic Breast Cancer Patients

Objective To study the efficacy and factors that affect the efficacy of Doctaxel Combined rhG-CSF for peripheral blood stem cell(PBSC)mobilization for patients with breast cancer.Methods Fifty five patients with breast cancer were included in our study.TXT at the dose of 120 mg/m2 was given continuously for 3 hours.When the number of white blood cell was less than 1.0×109/L,rhG-CSF was given until the end of leukopheresis.CD34+ cells collected by a continuous flow cell separator from peripheral blood were analyzed with FACS.Various elements might affecting the yield of CD34+,including age,the lowest number of leucocyte after chemotherapy,the blood cell count before leukopheresis,visceral or bone metastases,prior chemotherapy and radiotherapy,were analyazed.Results The leukopheresis was started on the median 10th day after mobilization chemotherapy.The mean number of MNC and CD34+ cells were(5.51±1.24)×108/kg and(2.90±1.38)×106/kg respectively.The age and the lowest number of leucocyte were related with CD34+ cells number.The CD34+ cells number was higher in patients with the cycles of chemotherapy less than or equal to 6 than that in the matched group(P0.05).No serious adverse side effect was observed.Conclusion TXT plus rhG-CSF was an effective and safe mobilization regimen for autologous peripheral blood stem progenitor cells in patients with breast cancer.The age and prior chemotherapy cycles affected the number of CD34+ cells collected.The lowest number of leucocyte may be a good predictor of CD34+ cells collected.

Efficacy and Factors Involved in Mobilization of Peripheral Blood Stem Cell in Metastatic Breast Cancer Patients after Paclitaxel Plus G-CSF Treatment

Objective To study the efficacy and factors that affect peripheral blood stem cell(PBSC)mobilization of patients with breast cancer treated by paclitaxel plus recombinant human G-CSF(rhG-CSF).Methods Twenty-six patients with breast cancer were included in our study.PTX at the dose of 175 mg/m2 was continuously given for 24 hours.When the number of white blood cell reached 1.0×109/L,rhG-CSF was given until the end of leukopheresis.The mononuclear cells(MNC)and CD34+ cells collected by a continuous flow cell separator from peripheral blood were analyzed with FACS.Various factors affecting the yield of CD34+,including age,the lowest leucocyte counts after chemotherapy,the blood cell counts before leukopheresis,pathological stage,prior chemotherapy were analyzed.Results The leukopheresis was started on the median 10th day following mobilization chemotherapy.The mean values of MNC and CD34+ cells were(7.89±1.45)×108/kg and(4.88±1.54)×106/kg,respectively.The age was related with CD34+ cells counts.The other factors didn't significantly affect the CD34+ cells counts(P0.05).No serious side effect was observed.Conclusion PTX combined with rhG-CSF was an effective and safe mobilization regimen for autologous peripheral blood stem progenitor cells of patients with breast cancer.The age affected the collected number of CD34+ cells.

New Mobilization Strategies for Collection of Peripheral Blood Progenitor Cells for Lymphoma and Myeloma Patients

Autologus stem cell transplantation (SCT) is a common treatment modality for lymphoma and myeloma patients. The success of SCT depends on the collection of adequate number of CD34 positive cells. Standard mobilization therapy consits of granulocyte-colony-stimulating factor G-CSF and Sargramostine (GM-CSF). Some patients that are mobilized with G-CSF alone fail to collect the target cell dose while others are able to collect target dose after numerous apheresis procedures. In Autologus progenitor cell moblizaton, the addition of chemotherapy in conjunction with G-CSF/GM-CSF can substantially increase the yield of CD34 peripheral blood progenitor stem cells (PBSC), it is not without significant toxicities, additional cost and quality of life issues.

Whole body radiotherapy: A TBI-guideline.

Total Body Irradiation (TBI) is one main component in the interdisciplinary treatment of widely disseminated malignancies predominantly of haematopoietic diseases. Combined with intensive chemotherapy, TBI enables myeloablative high dose therapy and immuno-ablative conditioning treatment prior to subsequent transplantation of haematopoietic stem cells: bone marrow stem cells or peripheral blood progenitor stem cells. Jointly prepared by DEGRO and DGMP, the German Society of Radio-Oncology, and the German Association of Medical Physicists, this DEGRO/DGMP-Leitlinie Ganzkoerper-Strahlenbehandlung - DEGRO/DGMP Guideline Whole Body Radiotherapy, summarises the concepts, principles, facts and common methods of Total Body Irradiation and poses a set of recommendations for reliable and successful application of high dose large-field radiotherapy as essential part of this interdisciplinary, multi-modality treatment concept. The guideline is geared towards radio-oncologists, medical physicists, haematooncolo-gists, and all contributing to Whole Body Radiotherapy. To guide centres intending to start or actualise TBI criteria are included. The relevant treatment parameters are defined and a sample of a form is given for reporting TBI to international registries.

Autologous stem cell transplantation using modified TAM or combination of triple-alkylating agents conditioning regimens as one of the post-remission treatments in patients with adult acute myeloid leukemia in first complete remission.

A total of 174 newly diagnosed adult acute myeloid leukaemia (AML) patients were treated in first complete remission (CR1) using modified TAM or a combination of triple-alkylating agents followed by autologous transplantation (AT). Cytogenetic risk groups were classified and most patients received mobilized peripheral blood stem/progenitor cells (PBSCs). The infused cell dose consisted of a median of 4.1+/-2 (range, 1.2-17.1)x 10(6)/kg CD34+ cells. With a median follow-up of 51 months (range, 5-131 months) after CR1, the estimated 5-year disease-free survival (DFS) rate was 68 (95% confidence interval (CI), 63-73%) and the event-free survival rate at 5 years was 59 (95% CI, 54-64%). AML patients other than M3 subtype, the long-term DFS rate was 76, 33% for favourable and unfavourable risk groups, respectively. In all, 40 patients had relapses (40/174, 23%) at the median 15 months after CR1 (range, 8-66 months). Overall, seven patients (4%) died in connection with AT. The infused CD34+ cell dose (P=0.0389) was associated with survival by multivariate analysis. In conclusion, two novel conditioning regimens in AT are feasible for adults with variable risk AML followed for over a 10-year period.

Increased peripheral stem cell pool in MDS: an indication of disease progression?

The colony-forming capacity of the peripheral blood stem/progenitor cells (PBSC) in different forms of myelodysplastic syndrome (MDS) was investigated. In most cases of refractory anemia (RA) the colony growth of PBSC was definitely reduced as compared to the controls. However, in RA with unfavorable chromosomal aberrations, in refractory anemia with ringed sideroblasts (RARS) and in advanced stages of MDS such as refractory anemia with excess blasts (RAEB) and refractory anemia in transformation (RAEB-t), the number of myeloid progenitor cells increased up to 100-fold. In chronic myelomonocytic leukemia (CMML), the increase was even more marked, up to 350-fold. Although the number of PBSC was strongly elevated, these cells were not able to restore hematopoiesis in vivo. In conclusion, the increase of circulating colony-forming cells (CFC) seems to be associated with disease progression, and thus, the evaluation of PBSC could be an important parameter in the diagnosis of MDS.

Cytokine-mobilized peripheral blood progenitor cells for allogeneic reconstitution of miniature swine.

Because of the relative ease of acquisition, increased yield, and improved engraftment characteristics, mobilized peripheral blood progenitor (stem) cells (PBSCs) have recently become the preferred source for hematopoietic stem cell transplantation. In our laboratory, procurement of a megadose of PBSCs is necessary for on-going studies evaluating non-myelosuppressive transplant regimens for the induction of mixed chimerism and allograft tolerance. To exploit hematopoietic growth factor synergy, we have sought to combine growth factors with proven utility to improve PBSC mobilization and maximize our PBSC procurement through an automated collection procedure. Mobilization characteristics of PBSCs were determined in 2-5-month-old miniature swine. Animals received either swine recombinant stem cell factor (pSCF, 100 microg/kg) and swine recombinant interleukin 3 (pIL-3, 100 microg/kg), administered intramuscularly for 8 days, or pSCF, pIL-3, and human recombinant granulocyte-colony stimulating factor (hG-CSF), at 10 microg/kg. Leukapheresis was performed beginning on day 5 of cytokine treatment and continued daily for 3 days. Collection of PBSCs from cytokine-mobilized animals via an automated leukapheresis procedure demonstrated a 10-fold increase in the number of total nucleated cells (TNC) (20-30 x 10(10) TNC) compared to bone marrow harvesting (2-3 x 10(10) total TNC). A more rapid rise in white blood cells (WBCs) was seen after administration of all three cytokines compared to pSCF and pIL-3 alone. An increase in colony-forming unit granulocyte-macrophage frequency measured daily from peripheral blood during cytokine treatment, was seen with the addition of hG-CSF to pSCF/pIL-3 correlating well with the rise in WBCs. Similarly, the addition of hG-CSF demonstrated a notable increase in the median progenitor cell yield from the 3-day leukapheresis procedure. Cytokine-mobilized PBSCs were capable of hematopoietic reconstitution. PBSCs mobilized with pSCF/pIL-3 were infused into an SLA-matched recipient conditioned with cyclophosphamide (50 mg/kg) and total body irradiation 1150 cGy. Neutrophil and platelet engraftment occurred on days 5 and 7, respectively, with minimal evidence of graft-versus-host disease. Complete donor chimerism has been demonstrated 331 days after transplant. Our preliminary results show that in this well-defined miniature swine model, recombinant swine cytokine combinations (pSCF, pIL-3 with or without hG-CSF) successfully mobilize a high yield of progenitor cells for allogeneic transplantation. Furthermore, these cytokine-mobilized PBSCs demonstrate the potential to reconstitute hematopoiesis and provide long-term engraftment in miniature swine.

Retroviral marking and transplantation of rhesus hematopoietic cells by nonmyeloablative conditioning.

The ability to engraft significant numbers of genetically modified hematopoietic stem and progenitor cells without the requirement for fully myeloablative conditioning therapy is a highly desirable goal for the treatment of many nonmalignant hematologic disorders. The aims of this study were to examine, in nonhuman primates (rhesus), (1) the effects of pretreatment of host animals with cytokines (G-CSF and SCF), i.e., before nonmyeloablative irradiation, on the degree and duration of neo gene marking of circulating leukocytes after autologous cell reinfusion and (2) to compare transduction of primitive hematopoietic target cells in the presence of our standard transduction cytokine combination of IL-3, IL-6, and stem cell factor (SCF) and in the presence of an alternative combination containing SCF, G-CSF, and the thrombopoietin analog MGDF. Cytokine-mobilized rhesus peripheral blood progenitor/stem cells (PBSCs) were enriched for CD34+ cells and transduced with neo vectors (either G1Na or LNL6) for 96 hr in cultures containing rhIL-3, rhIL-6, and rhSCF or MGDF, rhSCF, and rhG-CSF and cryopreserved. Four animals underwent minimal myeloablative conditioning with 500 cGy irradiation with or without pretreatment with SCF and G-CSF, followed by reinfusion of the cryopreserved cells on the subsequent day. Neutrophil nadirs (< or =500/mm3) were 0-3 days in duration; there were no significant periods of severe thrombocytopenia. Marking of circulating granulocytes and mononuclear cells was extensive and durable in all animals (exceeding 12% in the mononuclear cells of one animal) and persisted beyond the final sampling time in all animals (up to 33 weeks). No difference in extent or duration of marking was attributable to either cytokine presensitization of recipients prior to irradiation, or to the substitution of MDGF and G-CSF for IL-3 and IL-6 during transduction.

Clinical use of rHuEPO in bone marrow transplantation.

Recipients of bone marrow (BMT) or peripheral blood progenitor stem cells (PBSCT) transplant have in the period following transplantation a frequent need for red blood cell transfusions and therefore an increased risk of blood-transmitted infections. The anaemia is caused mainly by myelosuppression after high-dose chemotherapy, but an impaired erythropoietin (EPO) production and an inappropriate EPO response may also contribute. Since recombinant human erythropoietin (rHuEPO) has been established as a treatment for renal anaemia it has been of interest whether treatment may be of benefit in the transplant setting. This paper gives an overview of the studies conducted to date with rHuEPO treatment in patients receiving bone marrow transplants. Current data do not support any transfusional benefits when rHuEPO is used in patients receiving autologous transplants. However, in patients receiving allogeneic transplants several studies clearly indicate a therapeutic role for rHuEPO with patients showing accelerated erythroid engraftment, increased haemoglobin levels, a reduced requirement for red blood cell transfusions, and a shortened time to transfusion independence. Especially patients with immune haemolysis after transplantation seems to benefit from the treatment. In addition, rHuEPO treatment has been used for late-onset anaemia after BMT and to prevent the need for homologous red blood cell transfusions to the BMT donor. To reduce costs, it is important in future studies to identify not only the optimal dose and route of administration of rHuEPO but also the most effective combination with other haematopoietic growth factors and cytokines that are used before and after transplantation.

Quantity and quality of engrafting cells in cord blood and autologous mobilized peripheral blood.

Cord blood (CB) and autologous mobilized peripheral blood stem/progenitor cells (PBSC) are now used widely for clinical transplantation. We characterized the short-term (<8 weeks) and long-term (>8 weeks) engraftment in NOD/SCID mice resulting from transplanted CD34+ cells from these two sources. We also quantified the frequency of long-term engrafting cells, and the average proliferative capacity of individual engrafting cells by a competitive repopulation assay with binomial variance-covariance modeling. We found that 0.5 million CD34+ CB cells were able to generate sustained, high-level, multilineage human hematopoiesis, whereas a sixfold higher number of CD34+ PBSC (3 million) from cancer patients undergoing chemotherapy generated comparable short-term, but much lower sustained multilineage human hematopoiesis after transplantation. In comparison to CD34+ cells from PBSC from cancer patients, long-term engrafting cells were approximately eightfold enriched in CB CD34+ cells, and each CB long-term engrafting cell had an approximately 15-fold higher multilineage proliferative capacity. Thus, the number and function of transplantable hematopoietic cells were remarkably different between these two sources of stem/progenitor cells.

Efficient serum-free retroviral gene transfer into primitive human hematopoietic progenitor cells by a defined, high-titer, nonconcentrated vector-containing medium.

Defined serum-free conditions have great conceptual advantages for the biological safety and standardization of clinical gene transfer into hematopoietic stem cells. In the only study reported to date, Sekhar et al. achieved low serum conditions by a complex concentration procedure of a retroviral supernatant initially containing 10% fetal bovine serum. The high cost, small volume, possible coenrichment of serum-derived pathogens, limited recovery of vector particles, and low titer of the final diluted medium restrict the clinical application of this procedure. Transduction of primitive hematopoietic progenitor cells was not demonstrated. In the present study, a defined serum-free medium containing high titers of the pseudotyped retroviral vector PG13/LN was generated from PG13/LN producer cells without requiring a physical enrichment procedure. The transduction of committed hematopoietic progenitor cells in the serum-free vector-containing medium was efficient, and similar to that occurring under serum-containing control conditions. The number of primitive human hematopoietic long-term culture-initiating cell-derived colonies (LTC-IC-derived colonies) generated from CD34+ and CD34+/HLA-DRlo peripheral blood progenitor "stem" cells (PBSCs) increased during 7 days of treatment in this vector-containing medium in the presence of IL-3, SCF, and flt-3 ligand. The described procedure allowed efficient transduction of LTC-IC-derived colonies generated from CD34+, CD34+/HLA-DRlo, and CD34+/CD38lo PBSCs. This is the first report to demonstrate an increase in primitive peripheral blood LTC-IC-derived colonies in vitro as well as their efficient transduction in a high-titer, serum-free vector-containing medium that can be produced exclusively from defined pharmaceutical-grade components, making it ideally suited for applications in clinical gene therapy.

68 Diagnostic and prognostic significance of elevated percent of fetal hemoglobin containing erythrocytes in patients with myelodysplastic syndromes

The colony-forming capacity of the peripheral blood stem/progenitor cells (PBSC) in different forms of myelodysplastic syndrome (MDS) was investigated. In most cases of refractory anemia (RA) the colony growth of PBSC was definitely reduced as compared to the controls. However, in RA with unfavorable chromosomal aberrations, in refractory anemia with ringed sideroblasts (RARS) and in advanced stages of MDS such as refractory anemia with excess blasts (RAEB) and refractory anemia in transformation (RAEB-t), the number of myeloid progenitor cells increased up to 100-fold. In chronic myelomonocytic leukemia (CMML), the increase was even more marked, up to 350-fold. Although the number of PBSC was strongly elevated, these cells were not able to restore hematopoiesis in vivo. In conclusion, the increase of circulating colony-forming cells (CFC) seems to be associated with disease progression, and thus, the evaluation of PBSC could be an important parameter in the diagnosis of MDS.

Comparison of the content and subpopulations of CD3 and CD34 positive cells in bone marrow harvests and G-CSF-mobilized peripheral blood leukapheresis products from healthy adult donors

Recombinant human granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem/progenitor cells (PBPC) have replaced bone marrow (BM) harvests for autologous transplantation after myeloablative therapy in cancer patients. G-CSF-mobilized PBPC from healthy donors contain one log excess of T lymphocytes representing a potential risk for graft-versus-host disease (GVHD). However, recent pilot clinical studies of G-CSF-mobilized allogeneic PBPC transplantation have shown rapid haematological recovery and no severe acute GVHD except in a very few cases. Therefore, the risk of inducing severe acute GVHD is not as high as was expected during the pioneering period of allogeneic PBPC transplantation. The present study was performed to address the possible reasons for the rapid haematological recovery and the absence of severe acute GVHD observed after allogeneic PBPC transplantation by comparing the contents and subsets of CD3 + and CD34 + G-CSF-mobilized PBPC ( n = 31) with those of BM ( n = 26) allografts from healthy adult donors. The present results revealed that the phenotypic profiles of CD3 + and CD34 + cells differ between PBPC and BM allografts. The single PBPC leukapheresis product contained 10 times more mononuclear cells, 1.5 times more CD34 + cells, 5.5 times more CD3 + T lymphocytes, 3 times more CD19 + B lymphocytes and 3.8 times more CD14 + monocytes than the single BM harvest. Both CD34 +CD33 + myeloid progenitor cells and CD34 +HLA-DR- long-term reconstituting haemopoietic stem cells were significantly increased in the CD34 + G-CSF-mobilized PBPC compared with the CD34 + BM cells; median 73.1% and 30.4% vs 60.6% and 5.0%, respectively, P < 0.01. The percentage of CD3 + cells coexpressing CD4 (T helper/inducer) was similar in both PBPC and BM allografts, 47.2% and 45.6%, respectively, whereas the percentage of CD3 + cells coexpressing CD8 (T suppressor/cytotoxic) was significantly decreased in PBPC compared with BM; 37.0% vs 55.9%, p < 0.01.

B-cell non-Hodgkin's lymphoma: evidence for the t (14;18) translocation in all hematopoietic cell lineages.

B cells of patients with non-Hodgkin's lymphoma (B-NHL) harbor specific chromosomal translocations, including t(14;18), the most common aberration found in this disease. The translocation involves the immunoglobulin (Ig) heavy-chain joining (JH) region gene on chromosome 14 and the BCL2 gene on chromosome 18, resulting in dysregulated expression of the BCL2 gene. The t(14;18) translocation has been thought to occur in the pre-B-cell stage, during the first event of Ig gene rearrangement. This study was conducted to investigate the potential involvement of nonlymphoid lineages in B-NHL. We studied the t(14;18) translocation and other frequently occurring translocations in total bone marrow aspirates of 10 patients with B-NHL, with the use of the fluorescence in situ hybridization (FISH) technique. We also performed cytogenetic analyses on representative bone marrow aspirates from the patients. Moreover, to define which of the major cell lineages present in the bone marrow carry the t(14;18) translocation, we used a series of monoclonal antibodies together with fluorescence-activated cell sorter (FACS) analyses to purify cells positive for CD3 (T cells), CD19 (B cells), CD10 (CALLA-positive cells), CD41a (megakaryocytic cells), CD13 (myeloid cells), and glycophorin A (erythroid cells). The cells of each subgroup underwent FISH analysis with the use of JH and BCL2 probes to detect the t(14;18) translocation. Bone marrow samples obtained from five healthy donors served as controls. Bone marrow cells from eight of the 10 patients studied carried the t(14;18) translocation. When present, the translocation was observed in many or even all of the cell lineages (lymphoid, myeloid, megakaryocytic, and erythroid) present in the bone marrow, including peripheral blood progenitor stem cells; for seven of the eight patients carrying the translocation, it was found in 96%-100% of the unfractionated bone marrow cells as well as in all of the FACS-purified cell fractions in which it could be detected or studied. Conventional cytogenetic analyses performed on representative bone marrow aspirates confirmed the results obtained by FISH analysis. Cells in control bone marrow samples obtained from the five healthy donors were negative for the t(14;18) translocation by FISH analysis. Our findings indicate that the t(14;18) translocation most probably occurs in a very early multilineage progenitor stem cell. Given that the t(14;18) chromosomal translocation was found in all types of bone marrow cells when only the B cells were malignant, our results suggest that this translocation is not sufficient to induce neoplastic transformation. This finding underscores the need for the development of new approaches for the detection and surveillance of B-NHL.

Characterization and transfusion of in vitro cultivated hematopoietic progenitor cells

Our study is to show the safety of transfusion and the number, phenotype, and proliferative potential of in vitro cultivated autologous hematopoietic peripheral blood progenitor/stem cells (PBPCs). An in vitro long-term liquid culture using PBPC suspension from consenting patients with metastatic breast cancer was established. The medium was supplemented with a variety of hematopoietic growth factors. The mononuclear cells (MNCs), their viability, CD34+ subsets, clonogenic cells, and neutrophil function were measured prior to, during, and after liquid culture for 14 days. The total cell number increased during incubation in vitro from 2.5 × 10 8 to 5 × 10 9. The clonogenic and CD34+ cells increased during the first week 6- and 3.5-fold, respectively, and were almost undetectable after 2 weeks. Maturation into the myeloid cell series was demonstrated by standard cytology and increase of CD33+ and CD38+ cell numbers. On average, 1.5 × 10 9 cells were transfused to consenting patients with metastatic breast cancer after high-dose chemotherapy and PBPC transplantation at nadir of WBC ⩽0.1/nL. One hour later, the mean WBC was measurable at 0.3/nL. Subsequently, WBC counts dropped to 0.2/nL and 0.1/ nL at 6 and 24 h post transfusion. No side effects and complications were observed. In summary, an in vitro expansion can produce a ⩾20-fold increase of maturing PBPCs for an effective and safe autologous transfusion. This unique approach, when refined, could lead to a safer post-transplant period and a decrease of complications due to neutropenic fever.

Relapse of neuroblastoma 38 months after high-dose chemotherapy and peripheral blood stem-cell autografts

A 5-year-old girl with stage IV neuroblastoma with diesseminated marrow involvement was treated with high-dose chemotherapy and autografts with peripheral blood stem/progenitor cells (PBSC), without local or total-body irradiation. After PBSC autograft, hematologic recovery was complete. Without further anticancer therapy, she remained tumor-free for 38 months until a local recurrence was identified. This case illustrates that late relapse can occur in advanced-stage neuroblastoma after long-term remission following high-dose chemotherapy without irradiation.