Survival after PBSC Transplantation and Comparison of Engraftment Speed with Autologous and Allogeneic Marrow Transplantation: Results of a Multicenter Study

We have analyzed the results of a multicenter study on peripheral blood stem cell transplantation (PBSCT) performed on 55 patients suffering from various neoplastic diseases. After myeloablative therapy, they received a mediam of 6.8x108/kg MNC and 11.4x104/kg CFU-GM harvested by a median of 9 apheresis after mobilization with chemotherapy alone. As of date, 34 of the 55 patients are alive and 28 of them are in continuous complete remission after a follow-up of 30 months. The probability of survival was related to the disease status at transplant, CR/PR vs. PD (p= 0.0001) and the bone marrow involvement, BM-vs. BM+ (P=0.009). Furthermore, a comparative study on speed of engraftment and clinical management was conducted on the 55 PBSCT patients as well as on 41 autoBMT and 52 alloBMT patients. Days to reach WBC> 1.0x109/L, PMN> 0.5x109/L and PLT> 50x109/L was 12/14/33 for PBSCT, 17/20/23 for ABMT and 15/16.5/18 for BMT, respectively. Days with fever >38° C, systemic antibiotic therapy and length of hospitalization was 3/12/36 for PBSCT, 5/18.5/42 for ABMT and 9/25/46 for BMT respectively.

Five-year Experience in PBSC Collection: Results of the Catholic University of Rome

Several authors have reported a faster immunological and hemopoietic post- transplant reconstitution using autologous peripheral blood stem cell (PBSC) than using autologous bone marrow stem cells. A large number of PBSC can be collected by leukapheresis during the hematological recovery after induction or salvage chemotherapy. In our experience we demonstrated that several separators, even if they have different results in mononuclear cell (MNC) yields, red blood cell and platelet contaminations, are able to collect PBSC for autotransplantation in patients with several malignant diseases and different status of disease. Eighty three patients were submitted to 590 leukapheresis procedures using 4 different blood cell separators: the results showed that all employed protocols are efficient in the collection of peripheral MNC even if after the widespread use of granulocytecolony stimulating factor (G-CSF) in the harvesting phase, the blood cell separator efficiency in terms of MNC is reduced. The use of GCSF in combination with other growth factors, during chemotherapy mobilization could simplify, in the future, this therapeutical program even if improvements in the efficiency of PBSC collection protocols are required.

A new blood donation strategy: Automated blood collection (ABC)

Background

The aim of this study was to find out if Cobe Trima, a blood cell separator that automatically collects RBC, PLT and plasma, is adequate for routine multiple blood donation by apheresis.

Materials and Methods

Eighty donors underwent multiple blood component donations by Cobe Trima. Blood counts were determined on the apheresis products to analyze their quality.

Results

Eighty procedures were performed collecting 193 products. The average platelet yield was 3.5×1011 (± 0.46) in the 54 single product (SP) procedures and 7×1011 (± 0.88) in the 26 double product (DP) procedures. WBC contamination of the PLT products was 1.7 × 105 (1.2–4.2). The mean platelet efficiency was 60 ± 8.35% for SP and 66 ± 9.59% for DP. The hemoglobin (Hb) content per unit was 46.21 g (± 7.84) in 8 DP and 40.82 g (± 6.41) in 34 SP procedures.

Conclusion

The production of standardized blood components with good PLT yield and low WBC contamination plus high efficiency makes Trima one of the best blood cell separators of the new generation.

Large Volume Leukapheresis for Collecting Hemopoietic Progenitors: Role of CD 34+ Precount in Predicting Successful Collection

In this work we evaluated the efficacy of stem cell collection with Large Volume Procedures. (LVP), and analysed the importance of the CD34+ cell precount in promoting the collection of a sufficient number of CD34+ cells for transplantation, using the Univariate Logistic Regression analysis. Eighty-nine leukapheresis were performed in 49 patients with hematological malignancies and solid tumors, mobilized with chemotherapy plus Granulocyte Colony Stimulating Factor (G-CSF). For each procedure 15.8 liters of blood were processed. The median value of Nucleated Cells (NC) and CD34+ cells precount was respectively 8.29 × 109/ml (range 1.13÷45.4) and 43.08 × 103/ml (range 1.06÷795.2). Results show the capability of LVP to collect large quantities of hemopoietic progenitors with a median CD34+ cell total yield of 215.02 × 106 (range 5.03÷2210). The yields per patients’ body weight were: CD34+ cells 3.23 × 106/kg (range 0.081÷41.58). The regression analysis between blood cell precounts and collection yields gave the following correlations: the CD34+ cell precount correlates with CD34+ yield (r = 0.78 p < 0.00) and with CD34+ cell yield/kg (r = 0.76 p < 0.00). The number of CD34+ cells processed correlated with the number of CD34+ cells collected/kg (r = 0.83 p < 0.000). To investigate the importance of CD 34+ cell precount in promoting CD34+ cell yields ≥2.5 × 106/kg we performed a Univariate Logistic Regression analysis that showed in our patients a probability of collecting ≥2.5 × 106 CD34+/kg that rose from 0.6 to 0.95 for CD 34+ precounts that oscillated from 30 to 40 × 103 CD34+ cells/ml, respectively. The Univariate Logistic Regression gave a probability of collecting ≥2.5 × 106 CD34+ cells/kg that oscillated between 0.64÷0.98 for values of CD34+ cells processed from 6 × 106/kg to 8 × 106/kg, p <0.000. Sixty-three percent of patients reached the target dose of 2.5 × 106 CD34+ cells/kg with only one LVP. Until now 12 patients have been transplanted and all have had a prompt and complete lasting recovery. These results confirm the efficacy of LVP in harvesting hemopoietic progenitors and their ability in reconstituting hemopoiesis of transplanted patients, enabling the estimation of CD34+ precounts and CD34+ cells processed values, highly predictive for the collection of ≥2.5 × 106 CD34+ cells/kg. Furthermore, the Logistic Model suggests that the best strategy to plan a successful CD34+ cell collection procedure is to identify for each patient the amount of CD34+ cells/kg to be processed rather than the fixed processing of 3÷5 blood volumes in all patients.

The Application of Two Different Blood Cell Separators to Harvest CD34+ Cells in Patients Suffering from Non Hodgkin's Lymphoma

From January 1996 until now, thirty-eight PBSC procedures were carried out on 20 patients suffering from NHL, mobilized by polichemotherapy regimens plus recombinant human Granulocyte-Growth Factor (rhG-CSF). Patients were enrolled in PBSC procedures using Dideco Excel (group A) and Cobe Spectra v.4.7 (group B) blood cell separators. Twelve patients were enrolled in group A (6 males and 6 females, median age 33) and 9 patients in group B (5 males and 4 females, median age 55). The mean White Blood Cell (WBC) and Mononuclear Cells Fraction (MNC) peripheral blood counts were not statistically different in either group and neither were blood CD34+ cell peripheral counts. CD34+ cell peripheral value was predictive of the CD34+ yield while mean values of harvested CD34+ cells were not significantly different. CD34+ cell efficiences were statistically the same. The CD34+ cell purity of the apheresis harvest was statistically different between the two groups (group A = 3.0 ± 2.2%; group B = 1 ± 0.9%) p = 0.001. High CD34+ cell yields were observed in both groups which confirms that both blood cell separators are able to harvest hematopoietic progenitor cells from peripheral blood.

A prospective, active haemovigilance study with combined cohort analysis of 19,175 transfusions of platelet components prepared with amotosalen-UVA photochemical treatment

BACKGROUND AND OBJECTIVES

A photochemical treatment process (PCT) utilizing amotosalen and UVA light (INTERCEPT(™) Blood System) has been developed for inactivation of viruses, bacteria, parasites and leucocytes that can contaminate blood components intended for transfusion. The objective of this study was to further characterize the safety profile of INTERCEPT-treated platelet components (PCT-PLT) administered across a broad patient population.

MATERIALS AND METHODS

This open-label, observational haemovigilance programme of PCT-PLT transfusions was conducted in 21 centres in 11 countries. All transfusions were monitored for adverse events within 24 h post-transfusion and for serious adverse events (SAEs) up to 7 days post-transfusion. All adverse events were assessed for severity (Grade 0-4), and causal relationship to PCT-PLT transfusion.

RESULTS

Over the course of 7 years in the study centres, 4067 patients received 19,175 PCT-PLT transfusions. Adverse events were infrequent, and most were of Grade 1 severity. On a per-transfusion basis, 123 (0.6%) were classified an acute transfusion reaction (ATR) defined as an adverse event related to the transfusion. Among these ATRs, the most common were chills (77, 0.4%) and urticaria (41, 0.2%). Fourteen SAEs were reported, of which 2 were attributed to platelet transfusion (<0.1%). No case of transfusion-related acute lung injury, transfusion-associated graft-versus-host disease, transfusion-transmitted infection or death was attributed to the transfusion of PCT-PLT.

CONCLUSION

This longitudinal haemovigilance safety programme to monitor PCT-PLT transfusions demonstrated a low rate of ATRs, and a safety profile consistent with that previously reported for conventional platelet components.

Red blood cell alloimmunization in sickle cell disease and in thalassaemia: current status, future perspectives and potential role of molecular typing

Red blood cell (RBC) transfusions are a milestone in the treatment for sickle cell anaemia (SSA) and for thalassaemia. RBC alloimmunization remains a major challenge of chronic transfusion therapy, and it can lead to adverse life-threatening events. The alloimmunization risk could depend on multiple factors such as the number of transfusions and, most of all, the genetic background. Different ethnic groups are predisposed to immunization because of a significant degree of RBC antigenic mismatch between donor and recipient. There is no universal agreement and standards for the most appropriate selection of RBC units in chronically transfused subjects. Current practice only deals with compatibility of ABO, Rh and K antigens. Molecular RBC antigenic matching extended to other blood group systems is an innovative strategy to ensure a better quality and effectiveness of transfusion therapy.

The application of multiparameter reference intervals for pre-donation capillary blood counts: the experience of a single institution

OBJECTIVES

To evaluate a set of reference counts applied to multiparameter pre-counts in blood donors.

AIM

Analyse the impact of pre-donation counts and specific reference intervals on donors' management.

BACKGROUND

Multiparameter blood counts allow an improved enrollment process of blood donors due to a prompt identification of abnormalities involving haemoglobin (Hb), white blood cells (WBC) and platelets (PLT).

METHODS/MATERIALS

Multiple pre-donation capillary counts were applied in the enrollment process of 13,347 consecutive donors. The rate of specific alterations of permanent exclusion and donor readmittance to donations for temporary exclusion had been evaluated, applying a set of multiparameter reference intervals.

RESULTS

Alterations involved Hb in 72.55% of cases, mean corpuscular volume (MCV) in 20.99%, total WBC in 9.39%, lymphocytes in 7.55% and PLT in 6.07%. Among donors with initial alterations (543; 4.06%), 12.70% were readmitted to donations within 15 days, 14.36% had permanent exclusion, 36.83% underwent prompt supplementation treatment and 36.09% were lost at follow-up or refused treatments.

DISCUSSION

The systematic use of blood count reference intervals and pre-donation multiparameter blood counts allowed prompt identification of WBC, PLT and MCV alterations, readmittance within 15 days of 12.70% of initially excluded donors and contributed to prompt management of supplement deficiency.

Autologous Blood Stem Cell Transplantation in Malignant Lymphomas: An Italian Cooperative Study

Twenty-three patients with malignant lymphoma, (7 Hodgkin's, and 16 non-Hodgkin's) in different phases of disease were autografted in 4 Italian Haematology institutions using only chemotherapy-mobilized blood stem cells (BSC) collected by apheresis. Clinical and laboratory data were analysed centrally and showed mean collection yields of 8.1 x 10(8) kg mononuclear cells (MNC) (SE 0.5; range 2.6-13.8) and 24.1 x 10(4) kg CFU-GM (SE 7.4; range 1.4-162.9). The mean times required to attain 0.5 x 10(9)/l neutrophils and 50 x 10(9)/l platelets after marrow-ablative high-dose chemo+radiotherapy and BSC reinfusion were 14.9 days (SE 1.5; range 7-38) and 18.6 days (SE 2.6; range 6-49) respectively. The incidence of early deaths was < 5% and the requirement for support with blood product transfusion was moderate. The progression free survival (PFS) is > 50% at 3 years with a median follow-up of 17.3 months. Results were significantly better for patients autografted in remission. These results suggest that autologous blood stem cell transplantation (ABSCT) may be proposed for the primary treatment of poor prognosis malignant lymphomas. However, ABSCT needs to be compared with autologous bone marrow transplantation (ABMT) followed by infusion of growth factors to accelerate recovery.

Expression of CD133-1 and CD133-2 in ovarian cancer

Cancer stem cells have been isolated from several solid tumors including prostate, colon, liver, breast, and ovarian cancer. Stem cells isolated from nervous system and prostate express CD133 antigen, which is widely used to isolate hematopoietic stem and progenitor cells. The aims of this study were to investigate the expression of the CD133-1 and CD133-2 epitopes in primary ovarian tumors and to biologically characterize CD133(+) ovarian cancer cells, also according to clinicopathologic parameters. Tissue specimens were obtained at primary surgery from 41 ovarian carcinomas; eight normal ovaries and five benign ovarian tumors were also collected. Flow cytometry with monoclonal antibodies against CD133-1 and CD133-2 epitopes was employed. FACS (fluorescence activated cell sorting) analysis enabled the selection of CD133(+) cells, whose epithelial origin was confirmed by immunofluorescence analysis with monoclonal anti-cytokeratin 7. CD133(+) cells gave rise to a 4.7 +/- 0.9-fold larger number of colonies than that documented in CD133(-) population (P < 0.001). Moreover, CD133(+) cells showed an enhanced proliferative potential compared to CD133(-) cells. The percentages of CD133-1- and CD133-2-expressing cells were significantly lower in normal ovaries/benign tumors with respect to those in ovarian carcinoma. Both the percentages of CD133-1- and CD133-2-expressing cells were significantly lower in omental metastases than in primary ovarian cancer (P = 0.009 and 0.007 for CD133-1- and CD133-2-expressing cells, respectively). There seems not to be any difference in the distribution of the percentage of CD133-1- and CD133-2-expressing cells according to clinicopathologic parameters and response to primary chemotherapy. CD133-1 and CD133-2 may be useful in order to select and enrich the population of CD133(+) ovarian tumor cells, which are characterized by a higher clonogenic efficiency and proliferative potential.

Accurate prediction of autologous stem cell apheresis yields using a double variable-dependent method assures systematic efficiency control of continuous flow collection procedures

BACKGROUND AND OBJECTIVES

Stem cell collection is a standard procedure for the procurement of autologous grafts to rescue myelosuppression induced by high-dose treatments. Accurate prediction of collection yields may contribute to optimize planning and quality control of collection.

MATERIALS AND METHODS

Data of 313 autologous haematopoietic stem cell (AHSC) evaluable collections performed in 208 patients with haematologic and non-haematologic neoplasms from seven centres were prospectively analysed to test the accuracy of yield predictions generated by a formula that required the input of peripheral blood (PB) CD34+ cell precount and desired PB volume to be processed. Data were matched in a standard linear regression, in a zero-point regression analysis and tested for prediction accuracy. Further 165 AHSC collections were analysed on a single-centre basis, using yield predictions as reference standards.

RESULTS

Analysis showed high levels of correlation between measured collection yields (my) and predictions (py) (R = 0.85; P = 0.000000) as well as high degree of prediction accuracy (my vs. py at paired t-test: P = 0.114781; median my/py ratio = 1.23). Analysis of additional 165 AHSC collections on a single-centre basis showed that the analysed centres had 70% or more measured yields comprising the 0.6-1.8 interval of the my/py ratio. The observance of the 'efficiency' my/py interval assured collection quality control in these centres confirming the reliability of the method.

CONCLUSIONS

This prediction method generates accurate and immediate yield predictions allowing collection planning and rapid efficiency control. As a consequence of our study, four centres out of seven use the described method to plan both leukapheresis number and single-procedure blood processing volume while the remaining three centres plan leukapheresis number on the basis of our predictions, maintaining a fixed single-procedure 200 ml/kg blood volume processing, according to their centre AHSC collection policy.

Stem cell-based treatments for gynecological solid tumors

BACKGROUND AND OBJECTIVE

We have recently assisted to an increasing scientific interest and a new research effort in the field of stem cell-based therapy. Since the late 1980s hematopoietic stem cells (HSC) have been used to set up therapeutic strategies for the treatment of solid tumors such as gynecological cancers. In this context, different approaches have been suggested and clinically investigated.

STATE OF THE ART

In the autologous setting we can describe the well-known use of HSC as hematologic support to high-dose chemotherapy regimens, and the use of HSC as a source of dendritic cells for cancer vaccination protocols. In our institution a long-term experience has been developed in high-dose chemotherapy with autologous HSC transplantation as first-line treatment of advanced ovarian cancer, and in the use of cytokines both for HSC collection and for post-transplantation hematopoietic recovery and immune reconstitution. An alternative approach consists of allogenic HSC transplantation following either myeloablative/standard or non-myeloablative/reduced conditioning regimens, which have been proposed as new adoptive immunotherapeutic treatments for different non-hematologic malignancies.

PERSPECTIVES

Future strategies in the use of HSC in oncology comprise the possibility of HSC ex-vivo expansion, the use of umbilical cord blood HSC, and the development of HSC-based gene-therapy programs. Further investigations are expected in the new field of cancer stem cells.

A human umbilical cord stem cell rescue therapy in a murine model of toxic liver injury

BACKGROUND

Several studies have demonstrated that bone marrow contains a subpopulation of stem cells capable of participating in the hepatic regenerative process, even if some reports indicate quite a low level of liver repopulation by human stem cells in the normal and transiently injured liver.

AIMS

In order to overcome the low engraftment levels seen in previous models, we tried the direct intraperitoneal administration of human cord blood stem cells, using a model of hepatic damage induced by allyl alcohol in NOD/SCID mice.

METHODS

We designed a protocol based on stem cell infusion following liver damage in the absence of irradiation. Flow cytometry, histology, immunohistochemistry and RT-PCR for human hepatic markers were performed to monitor human cell engraftment.

RESULTS

Human stem cells were able to transdifferentiate into hepatocytes, to improve liver regeneration after damage and to reduce the mortality rate both in both protocols, even if with qualitative and quantitative differences in the transdifferentiation process.

CONCLUSIONS

We demonstrated for the first time that the intraperitoneal administration of stem cells can guarantee a rapid liver engraftment. Moreover, the new protocol based on stem cell infusion following liver damage in the absence of irradiation may represent a step forward for the clinical application of stem cell transplantation.

Stem cells in gynecology and obstetrics

Over the past 10 years, we have become involved in a new research effort and an increasing scientific interest in the field of stem cell-based therapy. We are therefore able to describe different areas in which stem cell research can be applied and developed in gynecology and obstetrics. I) Hematopoietic stem cells have been used to set up therapeutic strategies for the treatment of gynecological solid tumors such as ovarian cancer. In this context different autologous or allogeneic transplantation approaches have been proposed and clinically investigated. II) Umbilical cord blood, which was often considered a waste material of the delivery, actually represents a precious source of stem cells that can be used for cell-based treatments of malignancies and inherited diseases. III) A feto-maternal cell traffic has recently been demonstrated through the placental barrier during pregnancy. This cellular exchange also includes stem cells from the fetus, which can generate microchimerisms in the mother and contribute to tissue repair mechanisms in different maternal organs. IV) Stem cells can be used for prenatal transplantation to treat different severe congenital diseases of the fetus. Nevertheless, several problems need to be solved to achieve an efficient in utero stem cell transplantation. Recent reports have pointed out the importance of timing in prenatal stem cell transplantation procedures and have shown the advantage of an early stem cell injection. An ultrasound-guided intracelomic approach could allow this possibility.

Efficacy of granulocyte transfusions for neutropenia-related infections: retrospective analysis of predictive factors

BACKGROUND

The transfusion of G-CSf-primed granulocytes (GTX) might represent an important treatment option for neutropenia-related infections unresponsive to conventional antimicrobial therapies and to recombinant hematopoietic growth factors. However, few studies to date have identified the factors that can predict clinical outcome and the patient populations who are likely to benefit most from GTX. The primary endpoint of the present retrospective study was to evaluate the efficacy of GTX in 22 patients with hematological malignancies who developed neutropenia-related bacterial and fungal infections that were unresponsive to appropriate antimicrobial therapies.

METHODS

Peripheral blood granulocytes were collected by continuous-flow leukapheresis from HLA-identical siblings after priming with G-CSF. The response to GTX was classified as 'favorable' if clinical symptoms and signs of infection resolved or 'unfavorable' if clinical symptoms and signs of infection were unchanged or worsened. Control of infection at Day 30 after the enrollment in the GTX program was considered as the outcome variable in multiple regression analysis.

RESULTS

Two patients died of infection before receiving the granulocyte concentrates. Bacterial infections (monomicrobial or mixed bacteremias) were documented in 11 patients, whereas fungal infections (fungemia or focal fungal infections) were diagnosed in seven patients. In two patients, no infecting agent could be isolated (clinical infection). Control of infection at Day 30 after the first GTX was achieved in 10 of 20 assemble patients. Overall, 54% of patients with bacterial infections had a favorable response, compared with 57% of patients with fungal infections. No differences in terms of survival were found when comparing patients with bacterial and those with fungal infections at a median follow-up 90 days from the first GTX. In univariate analysis, disease status before GTX, e.g., complete or partial remission, and spontaneous recovery of the neutrophil count were significantly associated with control of infection. when multivariate regression models were formed, the recovery 0.5 x 10 (9)/L PMN was the only parameter that significantly and independently correlated with a favorable response to GTX.

DISCUSSION

GTX can be used to successfully treat bacterial as well as fungal infections in severely neutropenic patients when administered early after the onset of febrile neutropenia in patients with remission of the underlying disease and who are likely to recover marrow function.

Administration of low-dose interleukin-2 plus G-CSF/EPO early after autologous PBSC transplantation: effects on immune recovery and NK activity in a prospective study in women with breast and ovarian cancer

This study evaluated the effects of low-dose IL-2 plus G-CSF/EPO on post-PBSC transplantation (PBSCT) immune-hematopoietic reconstitution and NK activity in patients with breast (BrCa) and ovarian cancer (OvCa). To this end, two consecutive series of patients were prospectively assigned to distinct post-PBSCT cytokine regimens (from day +1 to day +12) which consisted of G-CSF (5 microg/kg/day) plus EPO (150 IU/kg/every other day) in 17 patients (13 BrCa and 4 OvCa) or G-CSF/EPO plus IL-2 (2 x 10(5) IU/m(2)/day) in 15 patients (10 BrCa and 5 OvCa). Hematopoietic recovery and post-transplantation clinical courses were comparable in G-CSF/EPO- and in G-CSF/EPO plus IL-2-treated patients, without significant side-effects attributable to IL-2 administration. In the early and late post-transplant period a significantly higher PMN count was observed in G-CSF/EPO plus IL-2-treated patients (P = 0.034 and P = 0.040 on day +20 and +100, respectively). No significant differences were found between the two groups of patients in the kinetics of most lymphocyte subsets except naive CD45RA(+) T cells which had a delayed recovery in G-CSF/EPO plus IL-2 patients (P = 0.021 on day +100). No significant difference was observed between NK activity in the two different groups, albeit a significantly higher NK count was observed in G-CSF/EPO plus IL-2 series on day +20 (P = 0.020). These results demonstrate that low-dose IL-2 can be safely administered in combination with G-CSF/EPO early after PBSCT and that it exerts favorable effects on post-PBSCT myeloid reconstitution, but not on immune recovery.

The role of hematopoietic stem cells in the treatment of ovarian cancer

In recent years hematopoietic stem cells (HSC) have been the object of new research efforts and scientific advances. Therapeutic strategies have been set up using HSC for the treatment of solid tumors such as ovarian cancer. In this context different approaches have been proposed and clinically investigated. The "autologous" approach refers to the use of HSC as hematologic support to high-dose chemotherapy regimens, and to the use of HSC as an abundant source of dendritic cells for cancer vaccination protocols. Our institution has developed a long-term experience in high-dose chemotherapy with autologous HSC transplantation as first-line treatment of advanced ovarian cancer, and in the use of cytokines both for the HSC collection and for the post-transplantation hematopoietic recovery. Moreover, the "allogeneic" approach with HSC consists of the allogeneic transplantation with both myeloablative/standard or nonmyeloablative/reduced conditioning regimens, which has been proposed as a new adoptive immunotherapeutic treatment for different nonhematologic malignancies. Perspectives in the use of HSC in oncology comprise the possibility of an HSC ex vivo expansion, the use of umbilical cord blood HSC, and the development of future HSC-based gene-therapy programs.

Transforming growth factor-beta1 transcriptionally activates CD34 and prevents induced differentiation of TF-1 cells in the absence of any cell-cycle effects

A number of cytokines modulate self-renewal and differentiation of hematopoietic elements. Among these is transforming growth factor beta1 (TGF-beta1), which regulates cell cycle and differentiation of hematopoietic cells, but has pleiotropic activities depending on the state of responsiveness of the target cells. It has been previously shown by us and other authors that TGF-beta1 maintains human CD34(+) hematopoietic progenitors in an undifferentiated state, independently of any cell cycle effects, and that depletion of TGF-beta1 triggers differentiation accompanied by a decrease in CD34 antigen expression. In the present work, we show that exogenous TGF-beta1 upregulates the human CD34 antigen in the CD34(+) cell lines TF-1 and KG-1a, but not in the more differentiated CD34(-) cell lines HL-60 and K-562. We further studied this effect in the pluripotent erythroleukemia cell line TF-1. Here, TGF-beta1 did not effect cell growth, but induced transcriptional activation of full-length CD34 and prevented differentiation induced by differentiating agents. This effect was associated with nuclear translocation of Smad-2, activation of TAK-1, and with a dramatic decrease in p38 phosphorylation. In other systems TGF-beta1 has been shown to activate a TGF-beta-activated kinase 1 (TAK1), which in turn, activates p38. The specific inhibitor of p38 phosphorylation, SB202190, also increased CD34 RNA expression, indicating the existence of a link between p-38 inhibition by TGF-beta1 and CD34 overexpression. Our data demonstrate that TGF-beta1 transcriptionally activates CD34 and prevents differentiation of TF-1 cells by acting independently through the Smad, TAK1 and p38 pathways, and thus provide important clues for the understanding of hematopoietic development and a potential tool to modify response of hematopoietic cells to mitogens or differentiating agents.

Immune reconstitution after autologous peripheral blood progenitor cell transplantation: effect of interleukin-15 on T-cell survival and effector functions

OBJECTIVE

The aim of this study was to evaluate the occurrence of T-cell spontaneous apoptosis (A(spont)) and its modulation in vitro by the interleukin-2 receptor (IL-2R) gamma-chain (gammac)-signaling cytokine IL-15 in patients transplanted with autologous peripheral blood progenitor cells (PBPC) for hematologic malignancies.

MATERIALS AND METHODS

Patients were examined on days 30-60, 60-90, and 90-120 after PBPC infusion. Dissipation of mitochondrial transmembrane potential, a hallmark of T-cell apoptosis, has been detected using the fluorescent probe 3,3'-dihexyloxacarbocyanine iodide, after short-term T-cell culture in the absence or presence of exogenous cytokines. Expression of Bcl-2 family members has been studied by flow cytometry and reverse transcriptase polymerase chain reaction. T-cell proliferative responses to recall antigens have been estimated in autologous mixed leukocyte cultures.

RESULTS

A(spont) was seen in 45% +/- 6% of CD4(+) and 55% +/- 6% of CD8(+) T cells cultured in the absence of cytokines. Of interest, IL-15 and, to a lesser extent, its structural cousin IL-2 counteracted T-cell A(spont) by inhibiting the processing of caspase-3 and up-regulating Bcl-2 mRNA and protein levels. Cell division tracking confirmed that IL-15 did not rescue T cells from A(spont) by promoting proliferation but rather acted as a genuine survival factor. Addition of a gammac-blocking antibody to cytokine-conditioned cultures abrogated both apoptosis inhibition and Bcl-2 induction by IL-15, suggesting involvement of the IL-2Rgammac signal transduction pathway. Whereas cytokine-unprimed posttransplant T cells mounted inadequate responses to recall antigens, T cells conditioned with IL-15 expanded vigorously, indicating restoration of antigen-specific proliferation.

CONCLUSIONS

T cells recovering after autologous PBPC transplantation are highly susceptible to spontaneous apoptosis in vitro. This phenomenon can be counteracted by the gammac-signaling cytokine IL-15. These findings suggest that IL-15 might be a promising immunomodulating agent to improve postgrafting T-cell function.

The role of growth factor administration and T-cell recovery after peripheral blood progenitor cell transplantation in the treatment of solid tumors: results from a randomized comparison of G-CSF and GM-CSF

BACKGROUND

Peripheral blood progenitor cell (PBPC) transplantation (PBPCT) combined with post-PBPCT administration of myelopoietic growth factors is a valid therapeutic intervention to rapidly restore hematopoiesis after the delivery of intensive, myeloablative cancer chemotherapy. On the other hand, the best growth factor regimen to potentiate PBPC-mediated immunohematopoietic recovery has yet to be determined.

STUDY DESIGN AND METHODS

In a randomized evaluation, the effects produced by post-PBPCT G-CSF and GM-CSF on myeloid/lymphoid recovery and transplant outcome in women with chemosensitive cancer were compared. Thirty-seven ovarian cancer patients and 34 breast cancer patients ranging in age from 24 to 60 years were treated with carboplatin, etoposide, and melphalan (CEM) high-dose chemotherapy and then randomly assigned to receive G-CSF (5 microg/kg subcutaneously) or GM-CSF (5 microg/kg subcutaneously) until Day 13 after PBPCT. Patients were compared in regard to hematopoietic recovery, posttransplant clinical management, and immune recovery. Finally, clinical outcome was estimated as time to progression and overall survival.

RESULTS

Hematopoietic recovery and posttransplant clinical management were comparable in both the G-CSF and GM-CSF series. Conversely, significantly higher T-cell counts were observed in G-CSF-treated patients during the early and late posttransplant follow-up. Patients who received G-CSF showed a significantly longer median time to progression. A parallel analysis revealed that patients in whom a higher CD3+ count was recovered had a significantly longer overall survival and time to progression.

CONCLUSION

The enhancement of post-PBPCT T-cell recovery observed in G-CSF-treated patients encourages the use of G-CSF to ameliorate immune recovery, which seems to play a role in post-PBPCT control of disease in cancer patients. GM-CSF might be administered to prolong immunosuppression after autologous PBPCT for autoimmune diseases or allogeneic PBPCT.

Transplantation of autologous peripheral blood progenitor cells: impact of CD34-cell selection on immunological reconstitution

Peripheral blood progenitor cells (PBPC) represent an ideal source of stem cells for autologous transplantation because of technical advantages and more favourable engraftment kinetics. The reconstituion of a functional immune system occurs earlier in patients transplanted with cytokine-mobilized autologous PBPC compared with bone marrow; because of the greater T-cell content in PBPC products, donor-derived antigen-specific T-cells transferred with the graft might contribute to short-term immunity in transplant recipients. Despite a prompt reconstitution of B- and T-cell numbers, both B- and T-cell function are profoundly impaired for a prolonged period of time after PBPC infusion. The positive selection of CD34+ cells might provide effective tumor cell purging without compromising hematopoietic recovery in patients with acute leukemia, multiple myeloma, breast cancer and non-Hodgkin's lymphoma, whose autografts have been reported to contain malignant cells which might promote disease relapse. However, the incidence of viral infections in the early posttransplant period might be increased after CD34-selected compared with unmanipulated PBPC transplants, as a result of the lack of accessory and immune cells in the graft. The purpose of this review is to provide an update on immunological reconstitution after transplantation of autologous PBPC; in particular, emphasis will be placed on the mechanisms of immune dysfunction after the infusion of unmanipulated and CD34-selected autografts.

A new method to evaluate in vitro myelotoxicity of antitumour agents in the first steps of drug development

Research focused on the development of new anticancer agents has been based mainly on the assessment of the antitumour activity. This yields a large number of newly developed drugs endowed with good antitumour properties, but heavy side-effects on myelopoiesis. In this work, we validate a new method potentially useful to assess myelotoxic effect of newly developed agents. The proposed technique uses peripheral blood CD34+ cells as source of haematopoietic progenitors. These cells are grown in liquid culture in the presence of cytokines able to induce differentiation versus the three main lineages. Doxorubicin, carboplatin and topotecan served as reference drugs to investigate the accuracy of the technique. The three drugs mimick the effects reported in vivo. Doxorubicin and carboplatin produce a specific effect toward erythropoietic and thrombopoietic lineages, respectively, and topotecan a three-lineage toxicity. An advantage of the technique is the possibility to further investigate myelotoxicity. Here, we assessed differentiation markers in CD34+ cells to evaluate if the three drug treatments can affect the process of differentiation. Data show that the drug treatments were unable to modulate the expression of the selected differentiation markers in the surviving population. We propose this method as an innovative tool to score the myelotoxic effect of compounds in the first steps of drug development to further develop those compounds with the best ratio between activity and myelotoxic effects. Moreover, the fact that the method is performed in liquid phase allows its optimisation in a conventional "high throughput system".

CD105 (endoglin) expression on hematopoietic stem/progenitor cells

Endoglin (CD105) is a component of the transforming growth factor-beta (TGF-beta) receptor (TGF-betaR) complex. Together with betaglycan, CD105 is considered as a TGF-betaR accessory molecule (also called TGF-betaRIII), but its functions in the receptor-ligand interactions are still poorly understood. A small subset of human CD34+ hematopoietic stem/progenitor cells that has phenotypic and functional features suggestive of very primitive hematopoietic cells expresses the CD105 antigen. CD34+/CD105+ cells recirculate in the peripheral blood of mobilized subjects and can be purified by immunomagnetic isolation strategies. The hematopoietic potential of these CD34+/CD105+ cells appears to be sustained by a combination of hematopoietic and non-hematopoietic cytokines, which comprises Flt3 ligand, erythropoietin, interleukin-15 and vascular endothelial growth factor. Endogenous TGF-beta1 is a crucial factor for the maintenance of CD34+/CD105+ immaturity acting through positive modulation of both CD105 and CD34 molecules in the absence of relevant effects on the cell cycle profile. CD105 is absent on very primitive CD34-/lineage-/CD45+ (CD34-Lin-) human hematopoietic cells isolated from cord blood. However, in vitro exposure of CD34-Lin- cells to exogenous TGF-beta1 causes the appearance of a discrete population of CD34+/CD105+ cells. Collectively, available data on CD105 expression and function in primitive hematopoiesis indicate that this molecule could cooperate with the dissociation of TGF-beta1 cell cycle effects from its other effects on cell survival and differentiation.

Role of DNA-dependent protein kinase in recognition of radiation-induced DNA damage in human peripheral blood mononuclear cells

The DNA-dependent protein kinase (DNA-PK) complex plays a crucial role in radiation-induced DNA damage recognition. The complex includes the ku heterodimer, which comprises ku 70 and ku 80 subunits, that binds DNA termini of breaks without sequence specificity, and the catalytic subunit DNA-PKCS: The activation of the DNA-PK complex was studied in X-irradiated peripheral blood mononuclear cells (PBMC) from subjects of different ages. Radiation-induced changes in the DNA-binding activity of the ku heterodimer, and in the concentrations of ku 70, ku 80, DNA-PKcs and phosphorylated ku 80 were determined in nuclear and cytoplasmic extracts. DNA-binding activity was increased by irradiation only in the nuclear extract of PBMC from young, but not from elderly subjects, whereas it was found unchanged in cytoplasmic extracts regardless of age. The radiation-induced activation of the DNA-PK complex may result from the increased concentrations of ku 80 and DNA-PKcs in the cytoplasm of PBMC from young, but not from elderly subjects, leading to a higher concentration of phosphorylated ku 80 which readily migrates to the nucleus where, after dimerization with ku 70, binds to DNA breaks. These findings suggest major steps involved in DNA-PK activation, and the intracellular and molecular changes that may account for the age-dependent impairment of DNA repair capacity in irradiated mammalian cells.

High-dose chemotherapy as a consolidation approach in advanced ovarian cancer: long-term results

The aim of this study was to assess the long-term impact of high-dose chemotherapy (HDC) as consolidation in a large series (n = 55) of advanced chemosensitive ovarian cancer patients who were optimally cytoreduced at time of first surgery or at interval debulking surgery (IDS). HDC consisted of carboplatin (600 mg/m(2) days 1 and 2), etoposide (450 mg/m(2) days 1 and 2) and melphalan (50 mg/m(2), days 3 and 4). The primary endpoint of the study was the assessment of time to progression (TTP) and overall survival (OS). In September 2000 the overall population had a median follow-up of 55 months (range 17--137) and a TTP of 35 months with a 5-year TTP rate of 35% (CI 95%: 21--49) whereas OS averaged 75 months with a 5-year OS of 59% (CI 95%: 45--73). In patients achieving optimal primary cytoreduction the median TTP was 44 months with a 5-year rate of 43% (CI 95%: 26--60). In the same series the 5-year OS rate was 62% (CI 95%: 45--79) (median OS = 75 months). In patients who were optimally cytoreduced at the time of IDS the median TTP was 25 months and the 5-year TTP rate was 22% (CI 95%: 3--41) and median OS was 46 months with a 5-year OS rate of 50% (CI 95%: 27--73). HDC with hematopoietic support could represent an effective approach for the treatment of advanced optimally cytoreduced ovarian cancer patients with chemosensitive disease. Patients who underwent IDS because of unresectable tumors at the time of first surgery had the greater survival benefit from HDC.