Peripheral Blood Stem Cell Autografts in Children with Acute Lymphoblastic Leukemia and Lymphoma: Updated Experience

Immune reconstitution after haematopoietic cell transplantation in children: immunophenotype analysis with regard to factors affecting the speed of recovery

Immune reconstitution was studied prospectively in 66 children who underwent 77 haematopoietic cell transplantations (HCT): 46 autologous HCTs in 39 patients and 31 allogeneic HCTs in 27 patients. We studied the dynamic analysis of immune recovery with regard to potential factors affecting its speed, including age, type of HCT, diagnosis, graft-versus-host disease (GvHD) and cytomegalovirus (CMV) infection reactivation. Absolute counts of different lymphocyte subsets and immunoglobulin serum levels were determined in peripheral blood of patients on d -7 and +16, and then at various intervals up to 24 months post transplant. Common patterns of immune recovery after both allogeneic and autologous HCT were identified: (i) CD4+CD45RO+ peripheral T-cell expansion on d +16; (ii) inverted CD4+:CD8+ ratio from d +30 onwards; (iii) rapid natural killer (NK) cell (CD16+/-CD56+) count normalization. We observed prolonged T-cell lymphopenia (CD3+, CD3+CD4+, CD4+CD45RA+) until 24 months after autologous HCT, whereas in the allogeneic setting CD3+CD4+ cells, including naive CD45RA+ cells, returned to normal values at 9 months post transplant. Age > 10 years and coexistence of GvHD and CMV reactivation were associated with a substantial delay in T- (CD4+, including CD45RA+) and B-cell recovery after allogeneic HCT. Multidrug GvHD prophylaxis resulted in impaired T- (CD4+, CD4+CD45RA+) and B-cell reconstitution only in the early phase after allogeneic HCT (up to 4 months). Our results demonstrated that T-cell recovery was severely impaired in children after autologous HCT. It should be emphasized that specific approaches to enhance immune reconstitution are necessary to control minimal residual disease and avoid the risk of infectious complications in the autologous setting. Thymic involution after allogeneic HCT seems to be associated with age and coexistence of GvHD and CMV reactivation.

Nutritional assessment of peripheral blood stem cell transplantation in children

Peripheral blood stem cell transplantation (PBSCT) has many advantages for patients because hematopoiesis and general condition return to normal more rapidly than they do following bone marrow transplantation. Thus, the authors hypothesize that the nutritional condition of patients also returns to normal more rapidly after PBSCT. The duration of insufficient nutrition was investigated in children undergoing PBSCT. The subjects of this study were 8 patients with malignant diseases. The factors measured were body weight, body fat, cholesterol, albumin, pre-albumin, and retinol-binding protein. These parameters were measured a day before transplantation, and then once a week for 4 weeks after transplantation. All parameters were recovered until day 28 from the lowest level in transplantation. In this study, all parameters returned to normal comparatively early. PBSCT causes little damage to patients' nutrition.

The relation between the number of PBSC and number of leukaphereses in children

Although PBSC transplantation has an advantage over BM transplantation in that fewer burdens are placed on the patient at the time of stem cell collection, the number of collected cells decreases when leukapheresis is done repeatedly. We examined the relation between the number of times leukapheresis is performed and the number of mononuclear cells (MNC), CD34+ cells, and colony-forming unit-granulocyte-macrophages (CFU-GM) collected. The percentage of CD34+ cells was measured by flow cytometry and the number of CFU-GM was measured by a progenitor assay. The number of cells collected was significantly decreased by the third collection. Therefore, to secure enough cells for transplantation, leukapheresis ideally should be performed no more than twice if PBSC collection is to be efficient.

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.

Characterization of hematopoietic stem cells

On the basis of density-separated mononuclear cells isolated from bone marrow, peripheral blood, and cord blood, we have repeatedly shown good correlation between two-color flow cytometric (FACS) CD34 analysis and colony formation in the clonogenic assay. We have analyzed the distributions of CD34 subpopulations in these three stem cell sources using patients' and donors' bone marrow biopsies (n = 196), cord blood samples from full-term deliveries (n = 14), and peripheral blood from patients mobilized by chemotherapy and/or cytokine treatment (n = 258). Irrespective of absolute cell counts, the mean (+/- SD) proportions of CD34+ cells were clearly higher in bone marrow (5.6 +/- 4.6% of mononuclear cells) than in peripheral blood (1.9 +/- 2.6) and cord blood (1.7 +/- 2.6). However, two-color FACS analyses revealed significant differences among these cell sources with regard to their distribution of CD34 subpopulations: B-cell progenitors coexpressing CD34 and CD19, at considerable concentrations of > 0.5%, were only found in bone marrow (mean 30 +/- 24.3% of CD34+ mononuclear cells, median 28.7%, minimum 0%, maximum 83.3%). In addition, CD34+ cells in S/G2M phase were never detected in peripheral blood or cord blood, but only in bone marrow at a concentration of 10-15% of CD34+ mononuclear cells. On the other hand, the proportions of relatively immature myeloid progenitors, as characterized by not expressing CD45RA and by higher clonogenic capacity, were significantly higher in cord blood (76.7 +/- 17.2) and peripheral blood (58.2 +/- 17.5) than in bone marrow (26.4 +/- 16.7). These data were confirmed by analysis of apheresis products and of progenitors positively selected from different cell sources, and they may explain why, in autologous transplantations of analogous amounts of CD34+ cells, peripheral blood is superior to bone marrow. We conclude from our results that if successful transplantation and timely recovery depend on the number of CD34+ cells transplanted, the mean amount of stem cells required is 1.4- (for myeloid cells) or 2.2-fold (for early myeloid cells) higher for bone marrow than for peripheral blood.

Quantitative and qualitative comparative analysis of gradient-separated hematopoietic cells from cord blood and chemotherapy-mobilized peripheral blood

Some of the uncertainty regarding the use of cord blood (CB) in transplant settings includes the suspected relative rarity of hematopoietic stem cells (SC) in CB and the feasibility of incorporating a cell separation protocol to remove red blood cells, which may result in an unacceptable loss of SC. To address this uncertainty, we isolated a SC fraction by Percoll or Ficoll gradients from CB and peripheral blood (PB), which had been mobilized by chemotherapy. The frequencies of mononuclear cells (MNC), CD34+ cells, colony-forming units granulocyte-macrophage (CFU-GM), and the output of colony-forming cells (CFC) after five weeks in long-term culture (LTC) assay were then evaluated. The mean numbers of these cells per ml of CB sample before gradient separation were, respectively, 4.9 x 10(6), 13.8 x 10(4), 3.0 x 10(3) and 681 (n = 37). In the recovery phase of PB, these numbers were, respectively, 2.0 x 10(6), 14.9 x 10(4), 3.5 x 10(3) and 270 per ml of processed blood at apheresis (n = 35). After Percoll separation, the recovery rates of these cells were, respectively, 29%, 92%, 97% and 95% in CB, and 65%, 87%, 123% and 102% in PB. After Ficoll separation of CB, the rates were, respectively, 55%, 107%, 92% and 105%. These results suggest that CB contains an adequate number of more immature progenitors which can be retained after cell separation with Percoll or Ficoll, thereby making it feasible to incorporate a cell processing procedure into a CB transplant protocol. Percoll separation provided a greater enrichment of cells than Ficoll.

Combination chemotherapy (RCM protocol: response-oriented cyclic multidrug protocol) for the acute or lymphoma type adult T-cell leukemia

43 patients with the acute or lymphoma type ATL were treated with the new combination chemotherapy (RCM protocol: response-oriented cyclic multidrug protocol) between January 1989 and December 1991. Complete response (CR) and partial response (PR) were achieved in 20.9% and 65.1% of all treated patients respectively. The median duration of survival was 6.0 months. The survival duration of patients with a high serum lactate dehydrogenase (LDH) value (> or = 1,000 unit) and/or a poor performance status (PS) (PS 3 or 4) were also improved but not in patients with a severe leukocytosis (> or = 35,000/microliters). Toxicity was mild (grade 1 or 2) except hematologic toxicity in 4 patients (9.3%) and alopecia in one patient (2.3%). In spite of many patients with a poor PS (PS 3 or 4), our chemotherapeutic results are equal or superior to other previous reports. It seems that response-oriented chemotherapy is suitable for the ATL patients with poor prognostic factors. These results indicate that the RCM protocol is very useful as the first choice chemotherapy for the acute or lymphoma type ATL.

Optimal growth of human blood hematopoietic progenitor cells collected by apheresis for autografts

For safe autografts with peripheral blood hematopoietic cells (PBSCT), better methods for determining the kinetics of stem cell populations and predicting engraftment speed after PBSCT need to be established. Current methods include culture in semi-solid medium and measurement of CD34 cell surface antigen. In this study with only partially purified blood cells obtained from children with cancer in remission, we compared the effects of phytohemagglutinin-stimulated lymphocyte-conditioned medium (PHA-LCM) and recombinant human cytokines on the growth of progenitor cells in a methylcellulose culture system. Interleukin-3 (IL-3) alone supported more progenitor growth than standard PHA-LCM by a factor of 1.54 for colony-forming unit granulocyte/macrophages (CFU-GM) and by a factor of 1.84 for burst-forming unit/erythroids (BFU-E). No significant change, in terms of the number of growing colonies, was observed by adding granulocyte/macrophage colony-stimulating factor (GM-CSF), granulocyte-CSF (G-CSF), or IL-1 to IL-3. However, the addition of G-CSF resulted in increased colony size. A further increase in CFU-GM growth was observed by the addition of IFN-gamma to the combination of cytokines. No significant effect was observed when stem cell factor (SCF) was added to the combination of cytokines containing IL-3, G-CSF, and IFN-gamma. This analysis suggests that the combination of IL-3, G-CSF, and IFN-gamma may provide sufficient stimulation for the growth of human blood cells. The effects of different oxygen tensions on progenitor growth in the presence of IL-3, G-CSF, and IFN-gamma were also evaluated.(ABSTRACT TRUNCATED AT 250 WORDS)

Transplantation of allogeneic peripheral blood stem cells after myeloablative treatment of a patient in blastic crisis of chronic myelocytic leukemia

A 48-year-old man in blastic crisis of chronic myelocytic leukemia received a transplant of allogeneic peripheral blood stem cells. The donor was his HLA-identical sister, who refused to donate bone marrow cells, but agreed to donate peripheral blood stem cells. The patient received standard transplant conditioning with cyclophosphamide (120 mg/kg) and busulfan (16 mg/kg). Peripheral blood stem cells were mobilized with granulocyte colony stimulating factor and collected by apheresis. After transplantation, the white blood cell count and the result of microscopic analysis of the bone marrow became normal, and the leukocyte karyotype became 46XX. DNA fingerprinting showed complete chimerism. Graft-versus-host disease was suppressed with cyclosporine and methyl-prednisolone. The patient died of recurrence of leukemia on day 102+.

Peripheral blood stem cells used to augment autologous bone marrow transplantation

Peripheral blood stem cells (PBSC) were used to augment autologous bone marrow transplantation (ABMT), aiming to hasten engraftment after high dose treatment in a group of heavily pretreated patients. PBSC were obtained by leukapheresis during the rebound after standard chemotherapy. In 11 patients aged 7-17 years, high dose chemotherapy consisted of busulphan 16 mg/kg orally with melphalan 160 mg/m2 intravenously for seven patients, and melphalan 200 mg/m2 intravenously alone for four. The median number of granulocyte-macrophage colony forming units in the reinfused PBSC was 3.42 x 10(4)/kg (3.03-18.01) and bone marrow 12.4 x 10(4)/kg (4.16-28.6). Neutrophil recovery to > or = 0.5 x 10(9)/l and platelet transfusion independence occurred at a median of 14 days (11-18) and 22 days (9-84) respectively. In five patients the early engraftment was transient with neutrophils again dropping below 0.5 x 10(9)/l then slowly recovering. There was one toxic death due to sepsis. PBSC harvesting in these children was undertaken without interrupting routine chemotherapy and without the use of bone marrow growth factors. In some patients PBSC failed to influence engraftment and the use of combined chemotherapy and growth factor priming for PBSC collection may give improved results.

Recombinant human interleukin-3 hastens trilineage hematopoietic recovery following high-dose (7 g/m2) cyclophosphamide cancer therapy

BACKGROUND

Interleukin-3, a recombinant cytokine with multilineage stimulatory effect on hematopoietic cells, was administered to 22 previously untreated breast cancer patients following high-dose therapy with cyclophosphamide (7 g/m2).

PATIENTS AND METHODS

The growth factor, administered through continuous intravenous infusion at 1 (3 patients), 2.5 (3 patients), 5 (10 patients) and 10 micrograms/kg/day (6 patients), was well tolerated up to 5 micrograms/kg/day.

RESULTS

Nausea, vomiting, fever and headache prevented administration of the intended dose to all 6 patients in the 10 micrograms/kg/day cohort. At the maximal tolerable dose (5 micrograms/kg/day) the growth factor significantly accelerated granulocyte, platelet and reticulocyte recovery as compared to matched historical controls who received high-dose cyclophosphamide without cytokine infusion. Moreover, no platelet transfusions and fewer erythrocyte transfusions were required in interleukin 3-treated patients. In contrast to GM-CSF and G-CSF, interleukin 3 showed no effect on the mobilization of hematopoietic progenitor cells in the peripheral blood.

CONCLUSIONS

Interleukin-3 represents a well-tolerated cytokine, clinically useful for accelerating trilineage hematopoietic recovery following severely myelotoxic treatments such as high-dose cyclophosphamide.

Peripheral blood stem cell autografts for the treatment of childhood cancer: a review of the Japanese experience. Japanese Cooperative Study Group of PBSCT (JCSG/PBSCT)

Harvesting peripheral blood stem cells (PBSC) for autografts (PBSCT) in children with active cancers is a safe and reliable procedure with a low incidence of serious morbidity. A significant correlation between the number of infused CFU-GM and the time to both granulocyte and platelet engraftment was found. Cells induced by G-CSF could speed the recovery of granulocyte or platelet counts after PBSCT. In terms of preserving engraftment potential, cryopreservation of PBSC by a simplified uncontrolled-rate method is at least as effective as the traditional controlled-rate freezing procedure with a programmed freezer. As the serum G-CSF level increases immediately following infusion of PBSC graft, therapy with G-CSF may have only a limited ability to further enhance hematopoietic recovery after PBSCT. Preliminary results of high-dose chemotherapy without TBI and PBSCT for the treatment of children with relapsed ALL are encouraging.