Expansion of granulocyte colony-stimulating factor/chemotherapy-mobilized CD34+ hematopoietic progenitors: role of granulocyte-macrophage colony-stimulating factor/erythropoietin hybrid protein (MEN11303) and interleukin-15

Ex vivo stroma-free static liquid cultures of granulocyte colony-stimulating factor (G-CSF)/chemotherapy-mobilized CD34+ cells were established from patients with epithelial solid tumors. Different culture conditions were generated by adding G-CSF, granulocyte-macrophage colony-stimulating factor (GM-CSF), Flt3 ligand (Flt3), megakaryocyte growth and development factor (Peg-rHuMGDF), GM-CSF/erythropoietin (EPO) hybrid protein (MEN11303), and interleukin-15 (IL-15) to the basic stem cell factor (SCF) + interleukin-3 (IL-3) + EPO combination. This study showed that, among the nine different combinations tested in our 5% autologous plasma-containing cultures, only those containing IL-3/SCF/Flt3/MEN11303 and IL-3/SCF/Flt3/MEN11303/IL-15 significantly expanded colony-forming unit granulocyte-macrophage (CFU-GM), burst-forming unit erythroid (BFU-E), long-term culture-initiating cells (LTC-IC), CD34+, and CD34+/CD38- cells after 14 days of culture. Particularly, the addition of IL-15 to IL-3/SCF/Flt3/MEN11303 combination produced a significant increase of LTC-IC, with an average 26-fold amplification as compared to input cells, without any detrimental effect on CFU-GM and BFU-E expansion. This combination also produced a statistically significant 3.6-fold expansion of primitive CD34+/CD38- cells. Moreover, this study confirms the previously described erythropoietic effect of MEN11303, which, in our experience, was the only factor capable of expanding BFU-E. Compared to equimolar concentrations of GM-CSF and EPO, MEN11303 hybrid protein showed a significantly higher capacity of expanding CFU-GM, BFU-E, LTC-IC, CD34+, and CD34+/CD38- cells when these cytokines were tested in combination with IL-3/SCF/Flt3. These cultures indicated that Peg-rHuMGDF addition to IL-3/SCF/EPO/Flt3 does not affect CFU-GM and BFU-E expansion but, unlike G-CSF or GM-CSF, it does not decrease the ability of Flt3 to expand primitive LTC-IC. These studies indicate that, starting from G-CSF/chemotherapy-mobilized CD34+ cells, concomitant expansion of primitive LTC-IC, CFU-GM, BFU-E, CD34+, and CD34+/CD38- cells is feasible in simple stroma-free static liquid cultures, provided IL-3/SCF/Flt3/MEN11303/IL-15 combination is used as expanding cocktail in the presence of 5% autologous plasma.

In vitro effect of amifostine on haematopoietic progenitors exposed to carboplatin and non-alkylating antineoplastic drugs: haematoprotection acts as a drug-specific progenitor rescue

We evaluated the protective ability of amifostine on peripheral blood mononuclear cell (PBMC)-derived colony-forming unit (CFU) and PB CD34+ cells which were previously exposed in vitro to etoposide, carboplatin, doxorubicin and taxotere. Amifostine pretreatment protected PBMC-derived CFU from the toxic effect of etoposide, carboplatin and taxotere. A significant detrimental effect was exerted by amifostine on the growth of doxorubicin-treated PBMC-derived CFU. Liquid cultures of PB CD34+ cells reproduced faithfully the effects observed on growth of PBMC-derived CFU and confirmed amifostine chemoprotection against etoposide and carboplatin with its detrimental effect on doxorubicin-treated progenitors. Combining the data of viable cell count, cytometric estimation of apoptosis, cell cycle and viable cell replication rate, we found that amifostine protects from etoposide and carboplatin toxicity mainly through a mechanism of cell rescue. Conversely, the detrimental effect of amifostine on the growth of doxorubicin-treated PB CD34+ cells is apparently due to an increased G2/M arrest. In conclusion, amifostine protects haematopoietic progenitors from etoposide, carboplatin and taxotere. Progenitor rescue is the mechanism through which amifostine reduced etoposide and carboplatin toxicity.

Functional, phenotypic and molecular characterization of cytokine low-responding circulating CD34+ haemopoietic progenitors

Circulating CD34+ cell populations characterized by a low rate (up to five) or high rate (more than five) of cell divisions were isolated from 8 d cultures in the presence of stem cell factor (SCF), interleukin-3 (IL-3), granulocyte-macrophage colony stimulating factor (GM-CSF), granulocyte colony stimulating factor (G-CSF), erythropoietin (EPO), Flt3 ligand and Peg-rHu megakaryocyte growth and development factor (Peg-rHuMGDF) using the fluorescent dye 5,6-carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) and flow cytometric cell sorting. Phenotypic characterization of cells which had experienced up to five divisions (CFDA-SEbright) showed a similar surface antigen expression to starting, freshly isolated CD34+ cells. Conversely, cells which experienced more than five divisions (CFDA-SEdim) showed a differentiating behaviour, down-regulating CD34 antigen and acquiring differentiation markers. CFDA-SEbright cells were significantly enriched in CD105 (endoglin) positive precursors as compared to both freshly isolated CD34+ and CFDA-SEdim cells. Functional analysis indicated that CFDA-SEbright had a 3-fold and 10-fold greater cumulative cloning efficiency as compared to freshly isolated CD34+ cells and CFDA-SEdim cells, respectively. CFDA-SEbright cells retained the vast majority of LTC-IC and showed a LTC-IC frequency 2.8-fold higher than that found in freshly isolated CD34+ cells. RT-PCR and Western blot analyses showed significantly higher bcl-2 RNA and protein levels in CFDA-SEbright cells as compared to freshly isolated CD34+ and CFDA-SEdim cells. This study indicates that cytokine low-responding circulating CD34+ cells (CFDA-SEbright cells) represent a functionally, phenotypically and molecularly distinct multipotent progenitor population with biological properties associated with primitive precursors.

Erythroplateletapheresis: A New Strategy in the Global Apheresis Program

Blood donation allowed by cell separators can offer higher performance and higher yield to guarantee better quality and pureness of collected products. New systems for the collection of platelet concentrate (PC) and packed red blood cells (PRBC) are currently available. The aim of our work was to test the possibility of preparing PC routinely from normal apheresis donors in a minimum amount of time while providing a second product. Over a 3-month period we performed 40 procedures using the Hemonetics MCS3P blood cell separator and the Dideco Excel. The mean values of platelet yield were 2.8 x 1011 (range 1.4-4.1) with the MCS3P and 3.49 x 1011 (range 2.9-3.9) with the Excel, in a plasma volume of 240 ml and 215 ml respectively; the PRBC units were added with SAG-Mannitol allowing a storage time of 42 days. Collection times were 71’ and 48’ respectively. Donor tolerance was analogous to phateletapheresis or plasmapheresis.

Evaluation of two different protocols for peripheral blood stem cell collection with the Fresenius AS 104 blood cell separator

OBJECTIVES

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.

METHODS

We carried out leukapheresis procedures with the Fresenius AS 104 blood cell separator, using two different protocols, the previously used PBSC-LYM and a new mononuclear cell collection program.

RESULTS

Both programs were highly effective in collecting mononuclear cells (MNC) and CD34+ cells. Some differences were found, especially regarding MNC yield and efficiencies. There are remarkable differences in the efficiency of collection of CD34+ cells (62.38% with the new program as opposed to 31.69% with the older one). Linear regression analysis showed a negative correlation between blood volume processed and MNC efficiency only for the PBSC-LYM program. Differences were also observed in the degree of inverse correlation existing in both programs between patients' white blood cell precount and MNC collection efficiency. The inverse correlation was stronger for the PBSC-LYM program. Seven patients with solid tumors and hematologic malignancies received high dose chemotherapy and were subsequently transplanted with peripheral blood stem cells collected using the new protocol. All patients obtained a complete and stable engraftment with the reinfusion product collected with one or two leukapheresis procedures.

CONCLUSIONS

High efficiencies and yields were observed in the new protocol for MNC and CD34+ cells. These were able to effect rapid and complete bone marrow recovery after myeloablative chemotherapy.

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 granulocyte 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 x 10(9)/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.

Autologous stem cell transplantation: evaluation of erythropoietic reconstitution by highly fluorescent reticulocyte counts, erythropoietin, soluble transferrin receptors, ferritin, TIBC and iron dosages

The plasma concentrations of erythropoietin (Ep), soluble transferrin receptors (sTfRs), iron, total iron binding capacity (TIBC) and ferritin were monitored in five leukaemia patients undergoing autologous bone marrow stem cell transplantation (BMSCT) and in 10 lymphoma and 21 ovarian cancer patients undergoing autologous peripheral blood SCT (PBSCT); 9/21 ovarian cancer patients received recombinant human G-CSF and Ep and six recombinant human GM-CSF and Ep following SCT. All parameters were evaluated in relation to the kinetics of erythroid reconstitution as evaluated by haemoglobin (Hb) and reticulocyte levels [including the fraction of immature reticulocytes, also called highly fluorescent reticulocytes (HFR)]. Leukaemia patients undergoing BMSCT showed only a delayed (occurring at days 35-50 after SCT) and partial RBC, neutrophil and platelet recovery, whereas all patients undergoing PBSCT exhibited a rapid (occurring at days 10-15 after SCT) and sustained haemopoietic recovery. The various levels of erythroid rescue observed among these patients markedly influenced the kinetics of the different parameters investigated: (i) in leukaemia BMSCT patients sTfRs declined following SCT and remained at low levels thereafter, whereas Ep, iron. TIBC and ferritin showed a progressive and significant increase; (ii) in the different groups of patients undergoing PBSCT: (a) sTfR levels first declined following SCT and then returned to pre-therapy values at days 12-16, this response preceded erythropoietic recovery; (b) Ep, total iron, TIBC and ferritin showed an initial increase in the first days following SCT and then returned to pre-therapy values. Altogether, these observations indicate that: (i) both sTfR levels and reticulocyte counts are predictive parameters of erythropoietic recovery; (ii) coordinated changes of biochemical parameters underlying iron metabolism (iron, TIBC and ferritin) accompany erythroid rescue following SCT.

High-dose carboplatin, etoposide and melphalan (CEM) with peripheral blood progenitor cell support as late intensification for high-risk cancer: non-haematological, haematological toxicities and role of growth factor administration

The present report describes the non-haematological toxicity and the influence of growth factor administration on haematological toxicity and haematopoietic recovery observed after high-dose carboplatin (1200 mg m(-2)), etoposide (900 mg m(-2)) and melphalan (100 mg m(-2)) (CEM) followed by peripheral blood progenitor cell transplantation (PBPCT) in 40 patients with high-risk cancer during their first-line treatment. PBPCs were collected during the previous outpatient induction chemotherapy programme by leukaphereses. CEM administration with PBPCT was associated with low non-haematological toxicity and the only significant toxicity consisted of a reversible grade III/IV increase in liver enzymes in 32% of the patients. Haematopoietic recovery was very fast in all patients and the administration of granulocyte colony-stimulating factor (G-CSF) plus erythropoietin (EPO) or granulocyte-macrophage colony-stimulating factor (GM-CSF) plus EPO after PBPCT significantly reduced haematological toxicity, abrogated antibiotic administration during neutropenia and significantly reduced hospital stay and patient's hospital charge compared with patients treated with PBPCT only. None of the patients died early of CEM plus PBPCT-related complications. Low non-haematological toxicity and accelerated haematopoietic recovery renders CEM with PBPC/growth factor support an acceptable therapeutic approach in an adjuvant or neoadjuvant setting.

Generation of multinuclear tartrate-resistant acid phosphatase positive osteoclasts in liquid culture of purified human peripheral blood CD34+ progenitors

Circulating CD34+ cells were isolated from leukapheresis products collected from patients with ovarian cancer. CD34 contaminating cells, identified immediately after immunoselection, ranged from 5% to 25% in five different experiments and were predominantly CD3+ T-lymphocytes (range 2-12%), CD3+/CD16+/CD56+ natural killer cells (range 2-11%) and rare mature CD15+/ CD11b+ granulocytes (range 1-2%). CD34+ cells were cultured in liquid medium in the presence of interleukin-3, granulocyte-macrophage colony stimulating factor. stem cell factor, granulocyte colony stimulating factor and a powerful proliferation with prevalent differentiation along the granulocytic/monocytic lineage was obtained. After 10 d of culture a small but consistent number of early multinucleated osteoclasts were identified with a frequency of one cell per 700 granulocytic/monocytic cells, as revealed by cytologic examination. This observation was confirmed by staining for tartrate-resistant acid phosphatase activity which revealed red multinucleated elements with a frequency comparable to that reported above. Conversely, no osteoclasts were observed in those cultures in which macrophage overgrowth was obtained by culturing CD34+ cells until day 35. These observations suggest that circulating progenitors have a multilineage potential in vitro and contribute to the clarification of osteoclast development in humans: additionally, they provide the basis for the future development of optimized osteoclast culture techniques in liquid medium and the basic culture system, to test the distinct activity of 1,25(OH)2D3. parathyroid hormone interleukin-11 and of other cytokines on osteoclast development in humans.

Purified unfractionated G-CSF/chemotherapy mobilized CD34+ peripheral blood progenitors and not bone marrow CD34+ progenitors undergo selective erythroid differentiation in liquid culture in the presence of erythropoietin and stem cell factor

A combination of erythropoietin (EPO) plus stem cell factor (SCF) drove purified unfractionated granulocyte colony stimulating factor (G-CSF)/chemotherapy mobilized peripheral blood CD34+ cells to selective erythroid differentiation in liquid culture with an average 28-fold increase in the total cell number after 21 d. From day 6 of culture cytologic and cytofluorimetric characterization revealed that cultured cells belonged to the erythroid lineage with a gradual wave of maturation along the erythroid pathway to terminal cells. A similar pattern of erythroid differentiation was observed when the same peripheral blood CD34+ cells were culture with EPO plus SCF in serum-free medium. This cytokine combination produced selective erythroid differentiation with the complete exhaustion of the clonogenic potential on day 21. In parallel experiments the same circulating CD34+ cells underwent granulocytic/ monocytic differentiation in liquid culture in response to granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin-3 (IL-3) and SCF, demonstrating that these CD34+ progenitors had intact pluripotent differentiating potential. Conversely, bone marrow CD34+ cells isolated from bone marrow allografts were unable to selectively differentiate along the erythroid pathway when they were exposed to EPO plus SCF combination. However, these cells maintained a greater number of colony forming cells on day 21 of culture compared to mobilized peripheral blood CD34+ cells. This model is a simple and reliable way to obtain selective erythroid differentiation of peripheral blood G-CSF/ chemotherapy mobilized CD34+ progenitor cells in liquid culture. The absence of cytokines such as GM-CSF and IL-3 in the culture medium permits studies on in vitro erythropoiesis without disturbance of prevalent myelopoiesis.

Separation of chemotherapy plus G-CSF-mobilized peripheral blood mononuclear cells by counterflow centrifugal elutriation: in vitro characterization of two different CD34+ cell populations

Counterflow centrifugal elutriation (CCE) has been extensively employed in T cell depletion of bone marrow cells for allografting. Nevertheless very little is known about CCE properties of mobilized hematopoietic progenitors. In this study five leukapheresis products collected after chemotherapy and G-CSF from patients with non-Hodgkin's lymphoma were elutriated. Two mononuclear cell fractions were obtained containing smaller and less dense cells (lymphocyte fraction) and larger and denser cells (monocyte fraction), respectively. The presence of immature CD34+ progenitor cells, not co-expressing CD33, CD38 and HLA-DR antigens, was demonstrated in both cell fractions. CD34+ cells were isolated from each fraction and grown in various culture conditions (CFU-GM and BFU-E assay, blast cell colony assay, cytokine supplemented liquid culture). CD34+ cells isolated from the monocyte fraction showed a longer lasting expansion in liquid culture and a higher number of blast cell colonies than CD34+ cells selected from the lymphocyte fraction. Moreover a significant reduction of T cell number was obtained in the monocyte fraction. These data suggest that chemotherapy plus G-CSF-mobilized progenitor cells show a characteristic behavior when subjected to CCE, allowing an efficient T cell depletion without losing more immature progenitors.

The combination of erythropoietin and granulocyte colony-stimulating factor increases the rate of haemopoietic recovery with clinical benefit after peripheral blood progenitor cell transplantation

In order to investigate the effects of erythropoietin (EPO) plus granulocyte colony-stimulating factor (G-CSF) administration after peripheral blood progenitor cell transplantation (PBPCT) we performed a phase I/II study in patients with high-risk cancer. 15 consecutive patients were treated wit recombinant human G-CSF (rhG-CSF) at the dose of 5 micrograms/kg subcutaneously (s.c.) every 24 h until day + 12 and with recombinant human EPO (rhEPO) at the dose of 150 IU/kg s.c. every 48 h until day + 11 following PBPCT. Their haemopoietic recovery was compared to that obtained in eight historic and control patients who did not receive any cytokines after PBPCT. No side-effects were observed during EPO plus G-CSF treatment and the treatment was not discontinued in any of the patients before completion of the treatment plan. The administration of EPO plus G-CSF after PBPCT produced a significant increase in the rate of white blood cell (WBC) (P = 0.0005), polymorphonuclear leucocyte (PMN) (P = 0.0005) and platelet (PLT) (P = 0.0105) recovery compared to the control group. The acceleration in haemopoietic recovery observed in the EPO plus G-CSF-treated patients produced a significant reduction of the days with WBC < 1 x 10(9)/l (P = 0.0009), PMN < 0.2 x 10(9)/l (P = 0.0030) and PMN < 0.5 x 10(9)/l (P = 0.0006). EPO plus G-CSF-treated patients required a significantly lower number of single donor PLT transfusions (P = 0.0142) and did not experience neutropenic fever, but historic control patients experienced fever > 38 degrees C for a median period of 4 d (0-12) with a medial period of parenteral antibiotic administration of 7.5 d (0-17). The length of the hospital stay was significantly shorter in the study group than in the historic control group (P = 0.0264). In conclusion, we can confirm that EPO plus G-CSF treatment is feasible and potentiates the haemopoietic recovery after PBPCT, thus simplifying the clinical management of cancer patients who undergo high-dose chemotherapy.

Very high-dose chemotherapy with autologous peripheral stem cell support in advanced ovarian cancer

20 patients with stage III-IV ovarian cancer were submitted to induction chemotherapy (ICT) (40 mg/m2 cisplatin, days 1-4; 1.5 g/m2 cyclophosphamide, day 4; every 4 weeks for 2 cycles) followed by intensified CT (100 mg/m2 cisplatin, day 1; 650 mg/m2 etoposide, day 2; 1.8 g/m2 carboplatin by 24 h infusion, day 3). Haematological support consisted of autologous peripheral stem cells (APSC) and bone marrow (ABM) transplant (T) in 16 and 4 patients, respectively. All patients were evaluable for toxicity and 19 for pathological response (PR), one patient dying of systemic mycosis after ABMT. Severe (grade 3-4) non-haematological toxic effects were gastrointestinal (100%), neurological (10%) and hepatic (10%). PR was observed in 84% of patients (complete response 37%, partial response with microscopic residual disease 26%, partial response with macroscopic residual disease 21%). Five year overall survival was 60% and progression-free survival was 51% with 9 patients still disease-free (DFS). APSCT significantly reduced the duration of aplasia compared with ABMT, and toxicity was acceptable in those patients undergoing APSCT. The prolonged DFS in patients showing PCR suggests that this new approach may have a therapeutic impact.

Patterns of recovery phase infection after autologous blood progenitor cell transplantation in patients with malignancies. The Gruppo Italiano di Studio per la Manipolazione Cellulare in Ematologia

Recovery phase infection patterns in 55 patients who had undergone autologous blood progenitor cell transplantation (ABPCT) were evaluated retrospectively. The results were compared to those obtained in a group of 41 patients who received autologous bone marrow transplantation (ABMT). Fever related to documented or suspected infection developed in 38 of 55 patients in the ABPCT group and in 37 of 41 in the ABMT group (p < 0.05). The percentages of patients with positive blood cultures did not differ significantly (ABPCT, 8/55 vs. ABMT, 8/41, p > 0.05). However, fewer acquired systemic fungal infections (1/55 vs. 5/41, p < 0.05) as well as fewer days of antibiotic usage were observed in the ABPCT group.

Bisdioxopiperazine, (+)-1,2-bis(3,5-dioxopiperazinyl-1-yl)propane (ICRF 187), enhances the antiproliferative effect of cisplatin on human ovarian cancer cells

The bisdioxopiperazine ICRF 187 is a potent intracellular chelating agent which effectively diminishes Adriamycin cardiotoxicity without compromising its antitumor activity. Our study aimed at verifying whether ICRF 187 can modulate the cytotoxic action of cisplatin (CDDP) on ovarian cancer cells. We used the A2780 ovarian cancer cell line and a subline resistant to CDDP (A2780-CDDP) obtained in our laboratory by continuous exposure of the parenatal cells to progressively increasing CDDP doses. In both cell lines ICRF 187 (0.1-0.5 microgram/ml) used in combination with CDDP (0.01-1 microgram/ml) produced a dose-dependent reduction of CDDP IC50 (the concentration inhibiting 50% of cell growth). Moreover, when ICRF 187 was used in combination with CDDP, analysis of the data by the isobole method showed that the combination of the two drugs produced a synergistic antiproliferative activity in both cell lines, with a CDDP potentiation up to fivefold. Our in vitro data show that ICRF 187 can synergize with CDDP. Prospective clinical trials are now needed to verify whether the addition of ICRF 187 to CDDP-containing regimens will result in an improved clinical response in ovarian cancer.

High-dose chemotherapy with autologous peripheral stem cell support in advanced ovarian cancer

Twenty patients with advanced (stage III-IV), previously untreated ovarian carcinoma were treated by: (a) induction chemotherapy (40 mg/m2 cisplatin, days 1-4; 1.5 g/m2 cyclophosphamide, day 4; every 4 weeks for two cycles) followed by (b) intensification chemotherapy (100 mg/m2 cisplatin, day 1; 650 mg/m2 etoposide, day 2; 1.8 g/m2 carboplatin, day 3). Eligibility criteria further included: age less than 55 years, moderately good to poor tumour grade, macroscopic (> 0.5 cm) residual tumour. Autologous peripheral stem cells were recruited after the induction cycles and, to ensure haematological support, autologous bone marrow harvesting was routinely performed in the first 14 cases. Haematological support consisted of autologous peripheral stem cells and autologous bone marrow transplant in 16 and four patients, respectively. All patients are evaluable for toxicity and 19 for pathological response, one being dead of systemic mycosis 35 days after the autologous bone marrow transplant. Severe extra-haematological toxicities were the following: gastrointestinal (100%), neurological (10%), hepatic (10%). Pathological response was detected in 84% of cases (CR 37%, microscopic PR 26%, macroscopic PR 21%). Median follow-up times of 48 and 41 months have been reached respectively from enrolment and second-look. Four-year 62% overall and 57% progression-free survivals have been reached. Ten patients are still alive with NED (six of seven with CR, three of five with microscopic PR, and one of four with macroscopic PR). Autologous peripheral stem cell transplant significantly reduced the duration of aplasia compared with autologous bone marrow transplant, and toxicity was proved to be manageable in those patients undergoing autologous peripheral stem cell transplant. The prolonged disease-free survival in patients showing CR and microscopic PR suggests that further investigation on this new approach is worthwhile.

Low-dose cyclophosphamide in combination with cisplatin or epirubicin plus rhG-CSF allows adequate collection of PBSC for autotransplantation during adjuvant therapy for high-risk cancer

Six patients with advanced ovarian carcinoma (OvCa), and six patients with stage II or III resectable breast cancer (BrCa) were treated with low-dose CY (LD-CY, 1500 mg/m2) and cisplatin (CDDP) 100 mg/m2 (OvCa) or epirubicin (EPR) 120 mg/m2 (BrCa) plus recombinant human G-CSF (rhG-CSF). Twelve days after chemotherapy, all patients underwent PBSC collection on an outpatient basis. Following the completion of the induction programme, all patients underwent high-dose chemotherapy (HDC) with carboplatin 1200 mg/m2, etoposide 900 mg/m2 and melphalan 100 mg/m2 with the reinfusion of PBSC. LD-CY plus rhG-CSF in combination with CDDP or EPR mobilised a very large number of PBSC. After a median of 13 days from chemotherapy, the concentration of PBSC in the peripheral blood was 40-fold higher than the same patient's baseline value. Each collection yielded a median of 10.8 x 10(4)/kg colony-forming unit granulocyte-macrophage. Severe myelosuppression occurred in all patients following HDC, but the infusion of PBSC produced a rapid and sustained haemopoietic recovery. After a median of 11 days from reinfusion, haemopoietic engraftment was complete and 80% of the patients had platelets > 100 x 10(9)/l and PMN > 1 x 10(9)/l within 14 days after reinfusion. We can conclude that the present therapeutic approach is an excellent option for mobilisation, collection and transplantation of PBSC during intensive dose adjuvant polychemotherapy of high-risk cancer.

Autologous stem cell transplantation: release of early and late acting growth factors relates with hematopoietic ablation and recovery

We have monitored the serum concentrations of hematopoietic growth factors (HGFs; ie, stem cell factor [SCF], leukemia inhibitory factor [LIF], interleukin-3 [IL-3], IL-6, IL-8, and granulocyte colony-stimulating factor [G-CSF]) in 15 lymphoma/leukemia and 6 ovarian cancer patients undergoing autologous bone marrow (BM) or peripheral blood (PB) stem cell transplantation (SCT). Thus, the analysis was performed during and after high-dose chemotherapy (from day -6 to day -1), at the time of SCT (day 0), and thereafter (through day +17). Despite the heterogeneity of these patients and their conditioning regimens, a consistent kinetic pattern was observed for all analyzed cytokines. Particularly, (1) SCF serum concentration did not significantly fluctuate. (2) High levels of LIF (approximately 250 to 450 pg/mL) before chemotherapy rapidly declined to markedly lower concentrations (approximately 10 ng/mL) starting from day -1 through day +17; (3) conversely, IL-3 level was low before treatment, sharply increased during chemotherapy, and rapidly returned to base-line level after SCT. Hypothetically, the sharp LIF decrease and IL-3 increase during chemotherapy may underlie the induction of stem cell cycling and differentiation caused by hematopoietic ablation. Furthermore, (4) IL-6 concentration was low before and immediately after chemotherapy, but increased starting from day +5, peaked at day +6 through 9 and then declined to baseline level from day +10 onward; (5) a strictly similar pattern was consistently observed for both G-CSF and IL-8 levels, in agreement with our previous studies. It is relevant that peak IL-6, G-CSF, and IL-8 concentrations were directly correlated to peak neutrophil numbers in the recovery phase, thus suggesting an important role for these cytokines in granulocyte rescue; in line with this interpretation, hematologic patients undergoing PBSCT (10 of 15) exhibited higher peaks of IL-6, G-CSF, and IL-8 and a more pronounced increase of neutrophil/platelet number than did hematologic cases undergoing BMSCT (5 of 15). Altogether, these studies indicate a coordinate pattern of cytokine release during hematopoietic ablation/recovery after chemotherapy and autologous SCT, the fluctuations of LIF and IL-3 levels during chemotherapy are seemingly related to stem cell recruitment, whereas the post-SCT increase of IL-6, G-CSF, and IL-8 may underlie the neutrophil recovery.

Characterization of peripheral blood CD34+ progenitor cells mobilized with chemotherapy and granulocyte colony-stimulating factor

Peripheral blood (PB) mononuclear cells mobilized with chemotherapy and granulocyte colony-stimulating factor (G-CSF) were enriched in CD34+ cells; aliquots were seeded in long-term cultures (LTC) on bone marrow (BM)-derived stromal layers and in liquid cultures containing various growth factors. The final recovery of PB CD34+ cells was similar to normal BM controls, and no difference was found in the expression of CD33 and CD13 antigens; a lower number of CD34+/HLA-DR- cells was found in PB with respect to BM samples (p < 0.001). PB cells sustained hematopoiesis in LTC at least as long as BM cells. At week 3 and 4, PB total mononuclear cell (MC) and CD34(+)-selected cell cultures showed a higher nonadherent cell recovery compared to the respective BM controls (p = 0.05 and p < 0.01). The liquid culture of PB CD34+ cells in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and stem cell factor (SCF) resulted in a marked and long-lasting increase of colony-forming units-granulocyte/macrophage (CFU-GM). Taken together, our data suggest that chemotherapy and G-CSF-primed cells contain a considerable number of both committed and early precursors, accounting for the rapid hematopoietic recovery observed after their reinfusion following myeloablative chemotherapy.

In vitro and in vivo effects of recombinant human erythropoietin plus recombinant human G-CSF on human haemopoietic progenitor cells

We tested in vitro the effect of recombinant human erythropoietin (rhEPO) plus recombinant human G-CSF (rhG-CSF) on purified human CD34+ haemopoietic progenitors (HP) and in vivo in patients who had undergone anti-cancer chemotherapy for advanced ovarian cancer. In this preliminary experience we found that, in vitro, rhEPO potentiates the effect of rhG-CSF on HP growth and differentiation toward the granulocyte-macrophage lineage. rhEPO plus rhG-CSF produced in vitro a proliferative stimulus of HP which represents 26% of the maximum stimulation obtained using IL-1, IL-3, IL-6, G-CSF, GM-CSF and stem cell factor in combination. In the patients treated with rhEPO plus rhG-CSF after chemotherapy, we observed a favourable trend for platelet and neutrophil recoveries compared with a control group treated with rhG-CSF alone and a significantly higher haematocrit nadir was observed in the rhEPO plus rhG-CSF series. In the patients treated with rhEPO plus rhG-CSF we observed a significant increase of circulating colony-forming unit granulocyte-macrophage (CFU-GM) and burst forming unit-erythroid (BFU-e) compared with the rhG-CSF series. Our results, in vitro and in vivo, encourage the in vivo use of rhEPO plus rhG-CSF to improve blood cell recoveries of patients who have undergone conventional or high-dose chemotherapy. Moreover, rhEPO plus rhG-CSF was demonstrated to be a good HP mobilising treatment for blood stem cell collection after chemotherapy.

Sequential peripheral blood progenitor cell transplantation after mobilization with salvage chemotherapy and G-CSF in patients with resistant lymphoma

We enrolled 18 patients affected by refractory or relapsed lymphoma (HD, NHL) in a two-step protocol that included salvage chemotherapy with mitoxantrone, carboplatinum, methylprednisolone, and cytosine arabinoside (MiCMA) plus G-CSF (5 micrograms/kg/day), peripheral blood progenitor cell (PBPC) collection, and subsequent transplantation after BUCY2 regimen. After MiCMA chemotherapy, four patients (22%) achieved complete response, eight patients (44%) obtained a partial response, and six showed progression of disease (PD). Fourteen out of 18 patients (78%) were considered eligible for PBPC transplantation. Three patients with complete response refused PBPCT; they are currently in continuous complete remission (CCR) at 15, 13, and 15 months, respectively. One patient has been recently transplanted but is too early to be evaluated. Ten patients so far completed the study, eight of whom are currently alive in CR, with a median follow-up of 7.5 months (range 2-13). Hematologic reconstitution was very rapid with a median time to achieve WBC > 1 x 10(9)/L, PMN > 0.5 x 10(9)/L, platelets > 50 x 10(9)/L and > 100 x 10(9)/L of 13 (range 9-15), 12 (range 9-14), 10 (range 0-22), and 14 (range 5-49) days, respectively. Our protocol is highly effective as a salvage treatment, while permitting PBPC collection after G-CSF administration. Hemopoietic reconstitution after transplantation of PBPCs collected with this procedure is complete, rapid, and sustained.

Fetal tissue collection from spontaneous abortions: a report from a single centre

Due to immunological immaturity, the fetus is the ideal recipient as well as donor of haemopoietic stem cells (HSCs); thus intrauterine therapy may prove to be effective in all major haemopoietic disorders when early prenatal diagnosis is available. In man, "fetus-to-fetus" transplantation has demonstrated the possibility of grafting donor HSCs and reconstituting immunodeficient fetuses. The limitations of fetal tissue use for transplantation derive from the origin of tissues from elective abortions. Early and late live spontaneous abortions may constitute an alternative to elective abortions, but are widely considered as unsuitable for fetal tissue collection because of rapid loss of viability and/or infections. The aim of this retrospective study was to assess the number of live abortions in a population of women who underwent spontaneous abortion in a single centre. In a 19-month period, 9 spontaneous abortions alive at the moment of delivery and 8 with a heart beat at the last ultrasound scan before abortion were recorded. In 1 case, fetal liver (FL) harvesting was easily performed and the tissue was cryopreserved, subsequently thawed and injected into a monkey fetus. This case shows the feasibility of this approach. The majority of cases reviewed consisted of late abortions. These findings clearly show that fetal tissue collection from spontaneous abortions is feasible for research purposes, for postnatal FL transplantation and for intrauterine transplantation, postnatal FL transplantation and for intrauterine transplantation, provided that depletion of more mature cells is performed when FL of later gestational age are used.(ABSTRACT TRUNCATED AT 250 WORDS)