Poor mobilization of peripheral blood stem cells is a risk factor for worse outcome in lymphoma patients undergoing autologous stem cell transplantation

The effect of poor blood stem cells mobilization on the outcome of autologous stem cell transplantation (ASCT) has not been well studied. Our aim is to evaluate poor mobilization as a prognostic factor in lymphoma patients undergoing ASCT. We analyzed 90 consecutive patients with Hodgkin's (HD) and non-Hodgkin's lymphoma (NHL) who underwent ASCT. Poor mobilization was defined as the inability to obtain > or = 1 x 10(6) CD34+ cells/kg ideal body weight with two large volume aphereses. Patients were divided into 2 groups: group 1 = poor mobilizers, and group 2 = good mobilizers. The poor mobilizers received lower median transplant CD34+ cell dose (2 x 10(6) vs. 4.5 x 10(6)/kg for good mobilizers, P = 0.001), were more heavily pretreated (P = 0.01), and required higher number of aphereses for PBSC collection (P = 0.0006). The median progression-free survival (PFS) in groups 1 and 2 was 10 and 41 months (P = 0.04), while the median overall survival (OS) was 38 months and not reached (P = 0.02), respectively. Univariate analysis showed that > or = 3 pre-transplant treatments, CD34+ cell dose < or = 2 x 10(6), elevated LDH before transplant, and poor mobilization were significant prognostic factors for poor PFS, while only the first three were significant for worse OS. Multivariate analysis using these same four factors revealed that number of pre-transplant treatments (HR = 6.03, P = 0.001), CD34+ cell dose (HR = 0.1, P = 0.0007) were the only independent predictive factors for worse overall outcome. In conclusion, our data show that poor mobilization could indicate poor outcome in lymphoma patients undergoing ASCT, however, it is more likely to be a reflection of the heavy pre-transplant therapy and lower CD34+ cell dose re-infused in this group of patients.     

Age has no influence on mobilization of peripheral blood stem cells in acute myeloid leukemia

The upper age limit for autologous stem cell transplantation (ASCT) in acute myeloid leukemia (AML) is increasing and peripheral blood (PB) represents the standard source of stem cell (SC). However, no data are available on the impact of age on SC mobilization in AML. We analyzed a cohort of 150 consecutive AML patients in first complete remission in order to make a comparison between patients up to 60 years and above 60 years, by evaluating CD34+ cells mobilization into PB and the number of leukapheresis needed to collect at least one single SC graft. The successful mobilization rate (>2 x 10(6) CD34+ cells/kg) was comparable between the two groups (87% vs. 80%, p = 0.29). In addition, no statistically significant difference was found in terms of either median number of CD34+ cells collected (p = 0.54) or CD34+ cells peak in PB (p = 0.70). Both groups of patients needed a median of two apheresis and no difference was found in the median number of CD34+ cells collected per single apheresis (p = 0.67). Finally, no correlation was found between age and total number of CD34+ cells collected (r = 0.003, p = 0.58). We conclude that age has no impact on mobilization of PBSCs in AML.     

An antecedent diagnosis of refractory anemia with excess blasts has no prognostic relevance in acute myeloid leukemia of older adult patients.

BACKGROUND: Conflicting results have been reported about the prognostic relevance of antecedent myelodysplastic syndrome (MDS) in acute myeloid leukemia (AML) of older adults. PATIENTS AND METHODS: Data from 87 intensively treated AML patients (median age 69 years) were analyzed, with the aim of comparing therapeutic results and toxicity between de novo and AML secondary to a previous MDS (s-AML). Rate of CD34+ cells mobilization and feasibility of autologous stem cell transplantation (ASCT) were also compared. RESULTS: Complete remission rate, death in induction and primary resistance were not statistically different between the two groups. Median time for neutrophil recovery was similar, while s-AML patients required a longer time for platelet recovery (P = 0.04). There was no difference as to eligibility for consolidation as well as for mobilization and feasibility of ASCT. S-AML had negligible impact on overall survival (OS) and disease-free survival (DFS). In the multivariate analysis the only parameter significantly related to either OS or DFS duration was adverse karyotype (P = 0.02 and 0.04, respectively). CONCLUSIONS: A diagnosis of s-AML does not represent a clinically relevant prognostic factor in elderly AML patients treated with aggressive therapy. Furthermore, s-AML patients can be mobilized and autografted with comparable results as opposed to de novo cases.     

Continuous sequential infusion of fludarabine and cytarabine for elderly patients with acute myeloid leukaemia secondary to a previously diagnosed myelodysplastic syndrome

Acute myeloid leukaemia (AML) secondary to myelodysplastic syndrome (MDS) is characterized by poor prognosis, namely in older patients. The combination of fludarabine (F) with cytarabine (ARA‐C) ± G‐CSF was proven as effective in patients with poor risk AML. The efficacy and toxicity of a regimen including F + ARA‐C as sequential continuous infusion (CI‐FLA) in 64 untreated patients aged >60 years, in which AML arose after a previous MDS, was investigated. Median age was 67 years (61–81). In patients achieving CR, an additional course, followed by G‐CSF to mobilize CD34+ cells and subsequent autologous stem cell transplantation (ASCT) were programmed. Overall, 43 patients (67%) achieved complete remission (CR). There were 10 induction deaths (16%), while 11 patients (17%) were refractory to induction treatment. Thirty‐four patients (79% of remitters) were eligible for the consolidation and 30 were monitorized for the mobilization of CD34+ cells, collection being successful in 20 of them (67%). Median number of CD34+ cells/kg collected was 6.8 × 10E6. Thirteen patients (20% of the whole population) received ASCT. Median disease free survival (DFS) and overall survival (OS) were 10 and 9 months, respectively. Survival at 5 years is projected to 15%. The only parameter significantly related to either DFS duration or OS duration was unfavourable cytogenetics, which did significantly influence also CR achievement. CI‐FLA is effective in elderly patients with AML secondary to previously diagnosed MDS. Best results are achievable in the subgroup of patients with diploid karyotype. Copyright © 2010 John Wiley & Sons, Ltd.     

Prognostic relevance of immunophenotyping in 379 patients with acute myeloid leukemia

We investigated the prognostic relevance of immunophenotype and other clinical pathological features in 379 adult patients with de novo (acute myeloid leukemia) AML diagnosed and treated at our institution during an 8-year period. Acute promyelocytic leukemia (APL) cases were excluded because they received different treatment. The overall complete remission (CR) rate post-induction therapy with Ara-C and daunorubicin (DNR) was 60% with a median disease free survival (DFS) of 72 weeks, and a median overall survival (OS) of 54 weeks. At diagnosis, CD34, deoxynucleotidyl transferase (TdT), CD7, CD56, HLADR and CD19 were expressed in 65, 19, 32, 15, 87 and 5%, respectively, of 379 evaluable cases. CD34 positive patients had a significantly lower CR rate (P=0.0003) than CD34 negative patients and there was a trend to a lower remission rate in HLADR positive patients (P=0.067). In multi-variate analysis, co-expression of CD34 and HLADR was an independent adverse factor for achieving CR (P=0.0364). CD56 expression was associated with a significantly shorter overall survival (P=0.0262), but did not affect remission rate or disease free survival. Neither TdT nor CD7 expression was associated with treatment outcome. Age (60 years or older) and cytogenetic features (classified by favorable, intermediate and unfavorable groups) were associated with a lower CR rate, shorter disease free survival and shorter OS. Patients with higher white cell counts (WBC) also had a significantly lower remission rate (P=0.0064) and OS (P=0.0127). We propose a prognostic score for achieving CR in AML patients based on age, WBC, cytogenetics and CD34/HLADR status as four independent factors. Defined by number of factors, this score system may help to stratify AML patients to alternative treatment for better outcome.     

CD34+ cells from acute myeloid leukemia, myelodysplastic syndromes, and normal bone marrow display different apoptosis and drug resistance-associated phenotypes.

Myelodysplastic syndromes and acute myeloid leukemia (AML) are heterogeneous disorders in which conflicting results in apoptosis and multidrug resistance (MDR) have been reported. We have evaluated by multiparameter flow cytometry the expression of apoptosis- (APO2.7, bcl-2, and bax) and MDR-related proteins [P-glycoprotein (P-gp), multidrug resistance protein (MRP), and lung resistance protein (LRP)] specifically on bone marrow (BM) CD34+ cells, and their major CD32-/dim and CD32+ subsets, in de novo AML (n=90), high-risk myelodysplastic syndrome (n=9), and low-risk myelodysplastic syndrome (n=21) patients at diagnosis, and compared with normal BM CD34+ cells (n=6). CD34+ myeloid cells from AML and high-risk myelodysplastic syndrome patients displayed higher expression of bcl-2 (P <0.0001) and lower reactivity for APO2.7 (P=0.002) compared with low-risk myelodysplastic syndrome and normal controls. Similar results applied to the two predefined CD34+ myeloid cell subsets. No significant differences were found in the expression of P-gp, MRP, and LRP between low-risk myelodysplastic syndrome patients and normal BM, but decreased expression of MRP (P <0.03) in AML and high-risk myelodysplastic syndromes and P-gp (P=0.008) in high-risk myelodysplastic syndromes were detected. Hierarchical clustering analysis showed that low-risk myelodysplastic syndrome patients were clustered next to normal BM samples, whereas high-risk myelodysplastic syndromes were clustered together and mixed with the de novo AML patients. In summary, increased resistance to chemotherapy of CD34+ cells from both AML and high-risk myelodysplastic syndromes would be explained more appropriately in terms of an increased antiapoptotic phenotype rather than a MDR phenotype. In low-risk myelodysplastic syndromes abnormally high apoptotic rates would be restricted to the CD34- cell compartments.     

Efficacy of up-front treatment with a double stem cell transplantation in multiple myeloma

BACKGROUND: We report the outcome of 53 patients with multiple myeloma (MM), who received autologous stem cell transplantation (ASCT) from April 1996 to September 2004 at our institution and who survived for more than 3 months after the transplant. METHODS: Following the first ASCT, 36 patients underwent an up-front second SCT, which consisted of either an ASCT (n = 24) or a reduced-intensity conditioning allogeneic stem cell transplant (RIST) (n = 12). Seventeen patients were given maintenance treatment. RESULTS: Seventy-seven percent of the patients (n = 41) showed an objective response to the initial therapy prior to the first ASCT. Overall, 60.4% (32 out of 53) and 32.1% (17 out of 53) of the patients had a complete response (CR) and partial response (PR) after the first ASCT, respectively. At the time of analysis, 34 patients (64.2%) were still alive. With a median follow-up of 32 months (range 9-98), the estimated progression-free survival (PFS) and overall survival (OS) at 5 years were 17.0 and 34.9%, respectively. Multivariate analysis revealed that the second SCT, normal hemoglobin and <50% marrow plasma cells were associated with an improved PFS. A second SCT, CR to the first SCT, female gender and an absence of advanced bone lesions were associated with a better OS. CONCLUSIONS: A second SCT is the most significant factor for an improved PFS and OS after the first ASCT (P < 0.001, respectively). Up-front double SCT is needed to improve the OS and PFS in patients with MM.     

High percentage of CD34-positive cells in autologous AML peripheral blood stem cell products reflects inadequate in vivo purging and low chemotherapeutic toxicity in a subgroup of patients with poor clinical outcome.

In this study, a high CD34% in autologous peripheral blood stem cell (PBSC) products from 71 AML patients was associated directly with a high relapse rate (P = 0.006) and inversely with disease-free survival (P = 0.003), irrespective whether patients were transplanted or not. The relapse rate at 12 months was 67% in a group with >0.8% CD34+ cells and 34% in a group with < or = 0.8% CD34+ cells. Although the percentage of malignant CD34+ cells in the CD34+ compartment in the relapses of the first group was not high (median 8%), the total number of malignant cells as a percentage of WBC was about 13 times higher than for the patients remaining >12 months in remission. When all patients evaluable were taken together, this frequency of malignant cells correlated strongly with disease-free survival (P < 0.001). Both this massive mobilization of normal CD34+ cells and high frequency of malignant cells in the subgroup of patients with CD34 >0.8% and relapse within 12 months indicate an insufficient in vivo purging, as well as low chemotherapeutic bone marrow toxicity. This was confirmed by an inverse correlation between hypoplasia period after the induction therapy and CD34% in PBSC products (P < 0.002). It is concluded that a subgroup of patients has been identified that might benefit from a more intensive chemotherapeutic treatment.     

Immunologic purging of autologous peripheral blood stem cell products based on CD34 and CD133 expression can be effectively and safely applied in half of the acute myeloid leukemia patients.

PURPOSE: Several studies have shown survival benefit by autologous stem cell transplantation in acute myeloid leukemia (AML) after purging of grafts. This has, however, not been confirmed in randomized studies due to high toxicity of purging modalities for normal progenitor/stem cells. In this study, we investigated whether positive selection for CD34+ and/or CD133+ cells, which results in high recovery of normal progenitor/stem cells, is applicable for purging AML grafts. EXPERIMENTAL DESIGN: Positive selections of normal stem cells using CD34 and/or CD133 can be done if one or both markers are absent or have dim expression and remain so during the course of the disease. Marker expressions in newly diagnosed AML were measured with flow cytometry using a cutoff value for positivity of 1%. Stability of marker expression was studied by pairwise comparison of material at diagnosis and relapse. Leukemia associated phenotype expression was used to measure the efficacy of tumor cell reduction. RESULTS: In newly diagnosed AML (n = 165), we found no CD34 and/or CD133 expression in 32% of the cases and dim expression in 20% of the cases. No increase in the percentage of CD34+ cells (n = 44) and CD133+ cells (n = 29) was found in corresponding relapses. Positive selection using grafts contaminated with AML blasts, showing either no or dim expression of CD34 or CD133, resulted in a 3 to 4 log tumor cell reduction (n = 11) with median 50% recovery of normal stem cells.CONCLUSIONS: Purging by positive selection of CD34+ and/or CD133+ cells can safely, effectively, and reproducibly be applied in about 50% of AML cases.     

Senescence Effects of Angelica sinensis Polysaccharides on Human Acute Myelogenous Leukemia Stem and Progenitor Cells

Leukemia stem cells (LSCs) play important roles in leukemia initiation, progression and relapse, and thusrepresent a critical target for therapeutic intervention. Hence, it is extremely urgent to explore new therapeuticstrategies directly targeting LSCs for acute myelogenous leukemia (AML) therapy. We show here that Angelicasinensis polysaccharide (ASP), a major active component in Dong quai (Chinese Angelica sinensis), effectivelyinhibited human AML CD34+CD38− cell proliferation in vitro culture in a dose-dependent manner while sparingnormal hematopoietic stem and progenitor cells at physiologically achievable concentrations. Furthermore, ASPexerted cytotoxic effects on AML K562 cells, especially LSC-enriched CD34+CD38− cells. Colony formation assaysfurther showed that ASP significantly suppressed the formation of colonies derived from AML CD34+CD38−cells but not those from normal CD34+CD38− cells. Examination of the underlying mechanisms revealed thatASP induced CD34+CD38− cell senescence, which was strongly associated with a series of characteristic events,including up-regulation of p53, p16, p21, and Rb genes and changes of related cell cycle regulation proteins P16,P21, cyclin E and CDK4, telomere end attrition as well as repression of telomerase activity. On the basis of thesefindings, we propose that ASP represents a potentially important agent for leukemia stem cell-targeted therapy.     

Factors influencing the collection of peripheral blood stem cells in patients with acute myeloblastic leukemia and non-myeloid malignancies

Factors influencing the collection of autologous peripheral blood stem cells (PBSCs) were studied in 182 mobilization procedures performed on 145 consecutive patients with acute myeloblastic leukemia (AML; n=67) and with various non-myeloid malignancies (NMM; n=78). PBSC were collected following mobilization with chemotherapy, treatment with granulocyte colony-stimulating factor (G-CSF) or chemotherapy plus G-CSF. Fewer colony-forming unit granulocyte-macrophages (CFU-GMs) were collected from patients with AML than from patients with NMM (P<0.0001), although there were no differences in the numbers of CD34+ cells collected between both groups. Multiple regression analysis showed that chemotherapy alone was predictive of a low CD34+ yield in patients with NMM (regression coefficient (RC)=-2.1; P=0.003). In addition, the interactions "diagnosis mutliple myeloma (MM)xmobilization with chemotherapy" (RC=2.9; P=0.004) and "diagnosis MMxmobilization with chemotherapy plus G-CSF" (RC=2.1; P=0.04) also remained in the model, both showing a favorable influence. In AML, mobilization with chemotherapy plus G-CSF was associated with higher CD34+ yields (P=0.003). In this subgroup of patients, multiple regression analysis identified the number of cycles of previous chemotherapy (< or =2 cycles; RC=1.3; P=0.03) and peripheral blood counts (WBC > or =1.5 x 10(9)/l and monocytes >20%; RC=0.8; P=0.02) as the factors most predictive of CD34+ cell yield. These findings emphasize the need to optimize harvesting technique to enhance safety and minimize morbidity and costs of this valuable procedure.     

CD7 expression predicts poor disease free survival and post-remission survival in patients with acute myeloid leukemia and normal karyotype

AML patients with normal karyotype comprise the largest subgroup ( approximately 50%) but have a highly heterogeneous clinical course. By multi-parameter flow cytometry we analyzed CD7 expression along with other phenotypic markers in 185 patients with normal-karyotype AML. CD7 was expressed in 68 (37%) patients. CD7 expression was associated with younger age (P=0.024) but not with sex, WBC count, or extramedullary disease. Patients expressing CD7 had significant shorter disease free (DFS) and post-remission survivals (PRS) than patients without CD7 (DFS of 12 months versus 42 months, P=0.005; PRS of 15 months versus 33 months, P=0.013). We also found that expression of CD34 or HLA-DR was associated with lower CR rate (P=0.0007 and P=0.019, respectively) but did not affect DFS or OS. Furthermore, as for all AML patients, we demonstrated that in the normal karyotypic subgroup, patients with higher WBC counts (>50) and older age (>60 years) had lower CR rate (P=0.003 and P=0.0157, respectively) and shorter OS (P相似文献   

TWIST-1 promotes cell growth,drug resistance and progenitor clonogenic capacities in myeloid leukemia and is a novel poor prognostic factor in acute myeloid leukemia

Alterations of TWIST-1 expression are often seen in solid tumors and contribute to tumorigenesis and cancer progression. However, studies concerning its pathogenic role in leukemia are scarce. Our study shows that TWIST-1 is overexpressed in bone marrow mononuclear cells of patients with acute myeloid leukemia (AML) and chronic myeloid leukemia (CML). Gain-of-function and loss-of-function analyses demonstrate that TWIST-1 promotes cell growth, colony formation and drug resistance of AML and CML cell lines. Furthermore, TWIST-1 is aberrantly highly expressed in CD34⁺CD38⁻ leukemia stem cell candidates and its expression declines with differentiation. Down-modulation of TWIST-1 in myeloid leukemia CD34⁺ cells impairs their colony-forming capacity. Mechanistically, c-MPL, which is highly expressed in myeloid leukemia cells and associated with poor prognosis, is identified as a TWIST-1 coexpressed gene in myeloid leukemia patients and partially contributes to TWIST-1-mediated leukemogenic effects. Moreover, patients with higher TWIST-1 expression have shorter overall and event-free survival (OS and EFS) in AML. Multivariate analysis further demonstrates that TWIST-1 overexpression is a novel independent unfavourable predictor for both OS and EFS in AML. These data highlight TWIST-1 as a new candidate gene contributing to leukemogenesis of myeloid leukemia, and propose possible new avenues for improving risk and treatment stratification in AML.     

TGF beta-induced SMAD2 phosphorylation predicts inhibition of thymidine incorporation in CD34+ cells from healthy donors, but not from patients with AML after MDS.

Cells from patients with MDS-derived AML display heterogeneous proliferative responses to transforming growth factor beta (TGF beta). We analyzed growth inhibition and SMAD2 phosphorylation by TGF beta in CD34+ cells from nine patients, as compared to normal controls. While TGF beta consistently inhibited thymidine incorporation of normal cells (41% of control, P < 0.05), cells from patients with AML were growth-inhibited in only four of seven cases (40%), whereas TGF beta stimulated thymidine incorporation in the three other samples (166%). Remarkably, TPO reverted the stimulatory effect of TGF beta to profound growth inhibition. Upon exposure to TGF beta, SMAD2 protein was phosphorylated in normal CD34+ cells (n = 3), CD34+ leukemic blasts from all examined patients with AML (n = 4), and in the myeloid leukemic cell lines M-07e and HEL. TGF beta inhibited TPO-mediated thymidine incorporation, cell proliferation and survival in all samples analyzed. In M-07e cells and CD34+ cells from healthy donors, this inhibition was enhanced by an antagonist of JAK2 (AG490), but not a MEK-1 antagonist (PD098059). Conversely, in CD34+ cells from a patient with AML, both AG490 and PD098059 significantly enhanced TGF beta-mediated suppression of TPO-induced thymidine incorporation. Thus, in MDS-derived AML, altered responses to TGF beta may be due to defects downstream of SMAD2 and may involve MAPK activation.     

Initial chemotherapy with mitoxantrone, chlorambucil, prednisone impairs the collection of stem cells in patients with indolent lymphomas--results of a randomized comparison by the German Low-Grade Lymphoma Study Group.

Myeloablative radio-chemotherapy with subsequent autologous stem cell transplantation (ASCT) significantly prolongs progression free and probably overall survival in follicular lymphoma (FL) in first remission. The current trial explored prospectively the rate of successful stem cell mobilization in patients with advanced stage FL after initial therapy with either Mitoxantrone, Chlorambucil, Prednisone (MCP) or Cyclophosphamide, Doxorubicin, Vincristine, Prednisone (CHOP) as part of a prospective randomized comparison of both regimens. ASCT patients received Dexa-BEAM (Dexamethasone, BCNU, Melphalan, Etoposide, Cytarabine) for mobilization of stem cells. Stem cells were collected and a minimum of 2x2.0x106/kg bw CD34+ was required for ASCT. Of 79 evaluable patients, 58 (73%) had follicular lymphoma, 13 (16%) mantle cell lymphoma and 8 (10%) lymphoplasmacytic lymphoma. In the 45 patients assigned to CHOP, stem cell collection was successful in 42 cases (93%, 95% CI 82% to 99%). This high mobilization rate after CHOP could be confirmed in 61 subsequent patients (87%). In contrast, after MCP therapy stem cell collection was successful in only 15 of 34 patients (44%, 95% CI 27% to 62%; P=0.0003). In conclusion, initial therapy with MCP significantly impairs the ability to collect stem cells and should be avoided for first line therapy of younger patients potentially qualifying for high dose consolidation and ASCT in first remission.     

Expression of HOX genes, HOX cofactors, and MLL in phenotypically and functionally defined subpopulations of leukemic and normal human hematopoietic cells.

To explore the possibility that deregulated HOX gene expression might commonly occur during leukemic hematopoiesis, we compared the relative levels of expression of these and related genes in phenotypically and functionally defined subpopulations of AML blasts and normal hematopoietic cells. Initially, a semi-quantitative RT-PCR technique was used to amplify total cDNA from total leukemic blast cell populations from 20 AML patients and light density cells from four normal bone marrows. Expression of HOX genes (A9, A10, B3 and B4), MEIS1 and MLL was easily detected in the majority of AML samples with the exception of two samples from patients with AML subtype M3 (which expressed only MLL). Low levels of HOXA9 and A10 but not B3 or B4 were seen in normal marrow while MLL was easily detected. PBX1a was difficult to detect in any AML sample but was seen in three of four normal marrows. Cells from nine AML patients and five normal bone marrows were FACS-sorted into CD34+CD38-, CD34+CD38+ and CD34-subpopulations, analyzed for their functional properties in long-term culture (LTC) and colony assays, and for gene expression using RT-PCR. 93 +/- 14% of AML LTC-initiating cells, 92 +/- 14% AML colony-forming cells, and >99% of normal LTC-IC and CFC were CD34+. The relative level of expression of the four HOX genes in amplified cDNA from CD34- as compared to CD34+CD38- normal cells was reduced >10-fold. However, in AML samples this down-regulation in HOX expression in CD34- as compared to CD34+CD38- cells was not seen (P < 0.05 for comparison between AML and normal). A similar difference between normal and AML subpopulations was seen when the relative levels of expression of MEIS1, and to a lesser extent MLL, were compared in CD34+ and CD34- cells (P < 0.05). In contrast, while some evidence of down-regulation of PBX1a was found in comparing CD34- to CD34+ normal cells it was difficult to detect expression of this gene in any subpopulation from most AML samples. Thus, the down-regulation of HOX, MEIS1 and to some extent MLL which occurs with normal hematopoietic differentiation is not seen in AML cells with similar functional and phenotypic properties.     

Endothelial cells (EC) and endothelial precursor cells (EPC) kinetics in hematological patients undergoing chemotherapy or autologous stem cell transplantation (ASCT)

Our objective was to study the kinetics of circulating endothelial cells (EC) and endothelial precursor cells (EPC) in hematological patients during chemotherapy and autologous stem cell transplantion (ASCT). Eighteen newly diagnosed patients and 17 patients undergoing ASCT were studied and compared to healthy controls. ECs were evaluated as CD146+CD31+Lin- cells, while EPCs were evaluated as CD34+CD133+Lin-, or CD34+VEGFR2+Lin- cells, or CFU-En colony forming units. Numbers of these cells were evaluated before and after treatment, and, in patients treated with ASCT, during mobilization of hematopoietic progenitors. Both newly diagnosed patients and patients before ASCT had significantly higher number of CD146+CD31+Lin- cells and significantly lower number of CFU-En colonies than healthy controls. These parameters did not return to normal for at least 3 months after chemotherapy or ASCT. Numbers of CFU-En did not correlate either with numbers of CD34+CD133+Lin- cells or with numbers of CD34+VEGFR2+Lin- cells but they did correlate with numbers of CD4+ lymphocytes and NK cells. In conclusion, we have found that hematological patients have higher number of EC and lower numbers of CFU-En than healthy controls and that these parameters do not return to normal after short-term follow-up. Furthermore, our observations support emerging data that CFU-En represent cell population different from flowcytometrically defined EC and endothelial precursors and that their development requires cooperation of monocytes and CD4+ lymphocytes. However, cells forming CFU-En express endothelial surface markers and can contribute to proper endothelial function by NO production.     

Human stem cell factor-antibody [anti-SCF] enhances chemotherapy cytotoxicity in human CD34+ resistant myeloid leukaemia cells

Acute myeloid leukaemia (AML) is a heterogenous malignant disease with diverse biological features in which disease progression at the level of CD34+ cells has a major impact on the resistance to chemotherapy and relapse. The AML blast cells in these elderly patients are often characterised by several unfavourable covariates that predict the poor treatment outcome, including high stem cell marker CD34 expression, minimally or undifferentiated features, high P-glycoprotein expression, high bcl-2/bax ratio, unfavourable karyotype and more frequent internal tandem duplications (ITDs) and mutations of class III receptor-type tyrosine kinase for key haematopoietic cytokines: Flt-3 (receptor for Flt-ligand), c-kit (receptor for stem cell factor) and fms (receptor for M-CSF). Testing the new and more specific molecular-targeted therapeutic approaches in CD34+ AML cells can provide the basis for a more effective combined molecular/chemotherapy regimen and may consequently improve the treatment outcome in elderly AML patients. Therefore, the present study was performed to evaluate whether stem cell factor-antibody (anti-SCF) can enhance the efficacy of the two main chemotherapeutic drugs used in AML therapy: cytarabine and daunorubicin at low doses in human-resistant CD34+ AML cells, in an attempt to identify a novel effective regimen with tolerable side-effects for elderly AML patients. The effect of anti-SCF on each of the two chemotherapeutic drugs-induced apoptosis and necrosis was investigated in KG1a human-resistant CD34+ AML cells expressing P-glycoprotein to determine its enhancing activity. Anti-SCF has significantly enhanced the low dose cytarabine- and daunorubicin-induced apoptosis+necrosis in KG1a CD34+ AML cells from 12.0+/-1.7 to 40.9+/-5.9% and from 16.3+/-0.9 to 48.9+/-1.0%, respectively, p<0.01. It has also exerted its significant enhancement activity on the low dose cytarabine- and daunorubicin-induced apoptosis+necrosis in KG1a CD34+ AML cells in the presence of SCF, p<0.05. Anti-SCF has significantly enhanced the low dose cytarabine- and daunorubicin-induced bcl-2 reduction in KG1a CD34+ AML cells from 26.7+/-0.6 to 64.6+/-1.0% and from 59.8+/-3.1 to 80.1+/-7.9%, respectively, p<0.01. The addition of SCF has not altered the low dose cytarabine- and daunorubicin-induced bcl-2 reduction in KG1a CD34+ AML cells (Table 4). Anti-SCF has also significantly enhanced the low dose cytarabine- and daunorubicin-induced bcl-2 reduction in KG1a CD34+ AML cells in the presence of SCF, p<0.05. The unique potent enhancing activity of anti-SCF on low dose chemotherapy-induced apoptosis and necrosis in extremely resistant AML cells suggest a novel promising role for the treatment of elderly AML patients. Further studies are warranted to evaluate a similar enhancing effect for anti-SCF in blast cells from elderly AML patients in primary cultures before its introduction in a pilot clinical study. In conclusion, the combination of anti-SCF and the low dose cytarabine provides a promising solution for the dilemma of therapy in elderly AML patients.     

Lymphocyte recovery in advanced ovarian cancer patients after high-dose chemotherapy and peripheral blood stem cell plus growth factor support: clinical implications.

PURPOSE: The purpose of this study was to investigate the clinical role of immunological recovery together with selected biological parameters on long-term survival in a series of ovarian cancer administered high-dose chemotherapy with peripheral blood stem cell and growth factor support. EXPERIMENTAL DESIGN: Thirty-eight patients with stages IIIB-IV epithelial ovarian cancer were studied. Lymphocyte immunophenotyping for the identification of CD3(+), CD4(+), CD8(+), and CD3(-)/CD16(+)CD56(+) natural killer T cells and CD19 B cells was performed. RESULTS: Twenty-three patients (60%) had a CD3(+) cell count <850 cells/ microl. Multivariate logistic regression showed that tumor grading (chi(2) = 6.6, P = 0.010) and type of growth factor (chi(2) = 4.1, P = 0.042) retained an independent role in predicting T-cell recovery above the value of 850 cells/ microl. The 3-year time to progression (TTP) rate was 86% (95% confidence intervals, 70, 102) in cases with high CD3(+) cell count with respect to a 3-year TTP of 23% (95% confidence intervals, 8, 38) in cases with low CD3(+) cell count (P = 0.0026). The absolute number of CD3(+) cells was shown to be inversely associated with risk of progression (chi(2) = 4.8; P = 0.028), as assessed by Cox univariate analysis using CD3(+) cell count as continuous covariate. In multivariate analysis only residual tumor and status of CD3(+) cell counts retained an independent association with shorter TTP. Similar results were obtained for overall survival. CONCLUSIONS: Long-term immune reconstitution and particularly the recovery of adequate counts of CD3(+), CD4(+), and CD8(+) T cells are independent markers of longer TTP and overall survival in ovarian cancer patients receiving high-dose chemotherapy with peripheral blood stem cell and growth factor support.     

Autologous stem cell transplantation for patients with chronic myeloid leukemia. The Argentine Group of Bone Marrow Transplantation (GATMO) experience

BACKGROUND: The objective of this analysis was to evaluate the role of autologous stem cell transplantation (ASCT) in prolonging disease free survival (DFS) and overall survival (OS) in patients with chronic myeloid leukemia (CML) who received autografts of Philadelphia chromosome (Ph) positive or Ph negative cell harvests. METHODS: Over a 4-year period (1994-1999), 53 patients who underwent ASCT for CML were reported to the Argentine Group of Bone Marrow Transplantation (GATMO) Registry. RESULTS: Ph negative cell products were harvested in only 18 patients (34%). Comparison of disease status at the time of autograft, duration of neutropenia, thrombocytopenia, days of antibiotics, and transfusional requirements of red blood cells and platelets did not reveal statistical significant differences between the Ph positive group and the Ph negative group. Only days of hospitalization were increased significantly in patients who received Ph positive autografts. Although DFS at 36 months was significantly longer after infusion of Ph negative cell products (54% vs. 14%; P 相似文献