BACKGROUND:Cord blood (CB) has been used as an alternative source of transplantable allogeneic stem cells for a variety of malignant and non-malignant diseases. However, we have demonstrated delayed recovery of T- and B-cell function, and T-cell subsets post unrelated CB transplantation (UCBT), and deficiencies of CB mononuclear cells (MNC) in producing cytokines, including G-CSF, GM-CSF, M-CSF, IL-12, and IL-15. In this study we have investigated the ex vivo generation of DC from CB versus mobilized adult peripheral blood (APB) for later use as adoptive cellular immunotherapy.METHODS:CB and APB-adherent MNC were cultured in serum-free media with GM-CSF IL-4, FLT-3 ligand, tumor growth factor-beta (TGF-beta), and tumor necrosis factor-alpha (TNF-alpha) for 7 days. Morphology, phenotype, immunohistochemistry, clonogenic activity, and alloreactivity in MLR were evaluated.RESULTS:CB and APB monocyte-derived ex vivo expanded DC expressed similar DC markers CD83 (31.27+ 11.7% versus 34.0+ 5.2%, CB versus APB), CD1a (23.4+ 4.2% versus 27.6+ 6.3%), and CD80 (21.97+ 12.01% versus 27.7+ 5.95). Immunohistochemistry showed that cells with DC morphology expressed CDla but not CD14. Neither FLT-3 ligand nor TGF-fl enhanced DC expansion. Addition of 10% autologous plasma to CB cultures promoted greater cell survival and a 150% increase in CDla + /CD80+ cell recovery. CB DC were 62% as effective stimulators of adult allogeneic T-cels as APB DC (p < .05) in allogeneic MLR.DISCUSSION:While phenotypically similar, CB and APB DC have differential potency in allogeneic MLR, which may account for the difference in GvHD and infection incidence and severity between UCBT and allogeneic stem cell transplantation, and may require a different approach for adoptive cellular immunotherapy. The mechanism(s) associated with these differences require further elucidation.

Purpose: Pediatric patients with solid tumors treated with prolonged dose-intensive chemoradiotherapy are poor mobilizers of peripheral blood stem cells (PBSC). We have conducted a pilot study to mobilize PBSC in eight pediatric patients with relapsed solid tumors using ifosfamide, carboplatin, and etoposide (ICE) followed-up by IL-11 plus granulocyte colony-stimulating factor (G-CSF).Patients and Methods: Patients received ifosfamide 1.8 g/m(2) per day for 5 days, carboplatin 400 mg/m(2) per day for 2 days, and etoposide 100 mg/m(2) per day for 5 days. After completion of ICE chemotherapy, patients received daily subcutaneous injections of G-CSF (5 mug/kg per day) and IL-11 (50-100 mug/kg per day) until peripheral stem cell apheresis.Results: The median age was 11 years. Diagnosis included three relapsed Hodgkin disease, three relapsed central nervous system tumors, one relapsed Wilms tumor, and one relapsed rhabdomyosarcoma. The median number of apheresis procedures required to obtain 5 x 10(6) CD34(+) cells/kg was one. The mean +/- standard error of mean (SEM) total CD34(+) cells collected was 14.0 +/- 2.7 x 10(6)/kg. The mean +/- SEM total CD34(+)/CD41(+) cells collected was 4.6 +/- 1.9 x 10(6)/kg. Seven of the eight patients have subsequently undergone myeloablative chemotherapy with autologous PBSC transplantation and have reconstituted hematopoiesis with a median time to neutrophil recovery of 10 days and platelet recovery of 15.5 days.Conclusions: We conclude that the regimen of ICE/IL-11 plus G-CSF is successful in mobilizing large numbers of CD34(+) PBSC cells with a limited number (one) of apheresis collections in patients that have previously been heavily pretreated with chemotherapy/radiotherapy.

In an attempt to reduce the high relapse rate associated with ABMT, five children with high-risk first CR and 19 in second or subsequent CR lacking matched family allogeneic donors underwent ABMT with chemopurged bone marrow utilizing verapamil (VPL), vincristine, and VP-16. Patients were conditioned with TBI, VPL bolus and infusion with VP-16 and cyclophosphamide. The first cohort of patients (n = 4) received only cyclosporin A (CsA). The second cohort (n = 7) received CsA and alpha interferon (total = 11 with post-transplant immunotherapy alone.) The third cohort (n = 13) received CsA and six alternating cycles of alphaIFN and chemotherapy and six additional cycles of chemotherapy (vincristine, VP-16, Ara-C, prednisone) followed by G-CSF (post-transplant immune chemotherapy (PTIC)). The 2-year DFS is 42+/-10% (90% confidence interval (CI) is 26.5-58.5%) and 2-year overall survival is 54+/-10% (90% CI is 37.5-70.5%). Furthermore, patients receiving PTIC (n = 13) vs immunotherapy alone (CsA+/-aIFN) (n = 11) had a substantially better 2 year DFS and OS: 69+/-13% vs 13+/-12% and 85+/-10% vs 25+/-15% (P = 0.008 and P = 0.06, respectively). These results suggest that the use of ABMT with chemopurging, combined with PTIC is well tolerated and may be an alternative new approach in the treatment of a subset of children with high-risk first CR or > or = second CR ALL who lack closely matched family-related allogeneic donors.

A Phase I trial was conducted to determine the safety, biological activity, and hematopoietic recovery by the combination of interleukin 6 (IL-6) and granulocyte-colony stimulating factor (G-CSF) after myelosuppressive chemotherapy in children. Patients <22 years of age at diagnosis with either recurrent or refractory solid tumors received ifosfamide 1,800 mg/m2/day x 5 days, carboplatin 400 mg/m2/ day x 2 days, and etoposide 100 mg/m2/day x 5 days, followed by daily s.c. G-CSF (5 microg/kg/day) and IL-6 (2.5, 3.75, or 5.0 microg/kg/day). Pharmacokinetic, proinflammatory mediator levels, hematopoietic colony assays, and cytokine receptor expression studies were performed during course one. Nineteen patients were evaluable for toxicity and received IL-6 at doses of 2.5 (n = 8), 3.75 (n = 5), or 5.0 (n = 6) microg/kg/day. Dose-limiting constitutional toxicity occurred in two of six patients at 5.0 microg/kg/day, two of five patients at 3.75 microg/kg/day, and two of eight patients at 2.5 microg/kg/day. The maximum tolerated dose (MTD) exceeded the lowest dose tested. Because of lack of drug availability, an MTD was not established. The maximum concentration of IL-6 (2.5 microg/kg/day) was 0.799 +/- 1.055 ng/ml (mean +/- SD). During the first course, the median time to absolute neutrophil count > or = 1,000/mm3 and platelets > or = 100,000 mm3 was estimated at 19 and 23 days, respectively. Peripheral blood progenitor cells expressing receptors to IL-3, IL-6, and G-CSF increased significantly over baseline (P < 0.05). After the first dose of IL-6, IFN-gamma levels were abnormal in 13 patients, and IL-1beta levels were abnormal in 10 patients. IL-6 has a high incidence of constitutional toxicity and a lower MTD in children compared with adults. In vivo use of IL-6 in children after chemotherapy remains limited. However, IL-6 may be more optimally investigated in children under ex vivo conditions.

Ex Vivo Expansion and Activation of Cord Blood Antigen Presenting and Immune Effector Cells

Anderson, B.; Krailo, M.; Davenport, V.; Martorella, A.; Bracho, F.; Reaman, G.; Cairo, M. Author Information

Bracho, F.; Davenport, V.; Goldman, S.; Shen, W. P.; Reaman, G.; Laver, J.; Blazar, B. R.; Rimm, I.; Cairo, M. Author Information

Houtenbos, I.; Bracho, F.; Davenport, V.; Slack, R.; de Ven, C. Van; Killen, R.; Shen, W. P.; Cairo, M.Author Information

The immaturity of neonatal phagocytic immunity contributes to increased mortality during neonatal sepsis. Neonates have both quantitative and qualitative neutrophil defects with decreased bone marrow neutrophil storage pool (NSP) reserves, an inability to increase neutrophil production, and defective neutrophil functional activity. Neonates respond to overwhelming sepsis with depletion of the NSP and the development of peripheral neutropenia. The myelopoietic cytokines granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) have been documented to induce neutrophilia in neonatal animals and human infants, increase the NSP, and upregulate neutrophils for improved functional activity. Preclinical studies in neonatal rats demonstrate increased survival with prophylactic G-CSF during experimental group B streptococcal sepsis. In pilot phase l/ll human trials, G-CSF and GM-CSF were demonstrated to be both safe and well tolerated and to induce significant increases in absolute neutrophil count and NSP. Prophylactic GM-CSF in the very low birth weight neonate may reduce the incidence of nosocomial infections. Phase III trials are needed to further delineate the clinical usefulness of these myelopoietic cytokines in neonates with a high predisposition to sepsis.