Allogeneic hematopoietic cell transplantation without myeloablative conditioning for patients with advanced hematologic malignancies

BACKGROUND

The effect of allogeneic hematopoietic cell transplantation (alloHCT) on hematologic malignancies is based on the graft-versus-malignancy effect. Obtaining this effect with reduced toxicity has been possible by non-myeloablative (NMA) alloHCT. Once mixed chimeric status, and host versus graft with graft versus host tolerance are achieved, further strengthening of chimerism and graft-versus-malignancy effect can be obtained by donor lymphocyte infusions (DLIs) when needed.

METHODS

The patient group consisted of 13 patients with advanced hematological malignancies: seven had CML, four of them in blastic-, two in chronic- and the remainder in accelerated-phase; four patients with AML, refractory or in second remission state; one patient with primary refractory secondary AML; and one patient with ALL relapsed after alloHCT. Conditioning regimen consisted of fludarabine 30 mg/m(2)/day for 6 days and anti-T-lymphocyte globulin (ATG) 10 mg/kg/day for 4 days as immunosuppressive. Ara-C or Bu or melphalan were used as the cytoreductive component. All transplants were performed using HLA-identical sibling donors' peripheral blood hematopoietic cells, after priming with filgrastim. Post-transplant GvHD prophylaxis was achieved with CsA alone in 10 patients, and with CsA plus mycophenolate mofetil in the last three patients.

RESULTS

Median follow-up is 3 months (range, 0-20) for all the patients and 6 months (range, 2-15) for the live patients. Donor chimerism was shown in 10 patients, not regarding any pretransplant feature. DLIs were performed in seven patients after transplantation and two of them achieved complete chimeric status and molecular remission. Two CML patients in blastic phase (CML-BP), and the primary refractory secondary AML patient did not respond to procedure. In four patients, drug therapy in conventional doses was added to post-transplant DLIs for their relapsed or refractory diseases. Two patients with AML in second CR, and another CML-BP patient, relapsed or progressed after transplantation. A patient with CML-BP achieved CR and full donor chimerism after transplantation, but developed refractory post-transplant lymphoproliferative disease in the 19th month. Two patients with refractory AML, one patient with relapsed ALL and two patients with CML in chronic phase were in complete chimeric status and free of disease signs. Acute GvHD, Grade II-III, was observed in five patients, and two of them developed secondary progressive chronic GvHD subsequently. We observed one early death in a platelet transfusion refractory blastic phase CML patient due to intracranial hemorrhage. Procedure-related severe toxicity was not observed, either in standard-risk patients or stem-cell donors.

DISCUSSION

Establishing engraftment with donor chimerism was the first successful step in this approach. The second step, which was the result of the graft-versus-malignancy effect, could be seen in most of the patients, but was not sustained in all of them because of the aggressiveness of their malignancy. It can be suggested that the immunotherapeutic efficacy of this approach could be more successful, and with acceptable toxicity, when performed in patients with minimal residual disease. The role of NMA conditioning, and of the treatment in standard disease indications, remains to be determined in further studies.

Clinical significance of dual color-dual fusion translocation fluorescence in situ hybridization in the detection of bcr/abl fusion gene

OBJECTIVE

To study the expression of bcr/abl hybridized gene in chronic myeloid leukemia (CML), acute lymphatic leukemia (ALL) and polycythemia vera (PV), and its clinical significance.

METHODS

The bcr/abl hybridized gene of interphase metaphase cells of bone marrow in 67 such patients were investigated with a probe of dual color-dual fusion translocation fluorescence in situ hybridization (D-FISH).

RESULTS

In 38 CML patients, 34 (89.5%) were positive, with one having a typical t (9; 22) at first, which changed into negative after having been treated with interferon for 38 months. In another patient, 60 days after post-allogeneic peripheral blood stem cell transplantation (PBSCT), the cytomorphology and cytogenetics were in completely remission. But 3% cells were bcr/abl positive as detected by D-FISH. Six (25%) of 24 ALL patients were positive for Bcr/abl fusion gene, which was negative in 2 PV patients. Three patients suspected of having CML were also negative and one of these three was finally diagnosed as suffering from primary thrombocythemia and one, acute myeloid leukemia (M(2a)) as detected by ETO/AML(1) gene, though the other one was still not confirmed. Two (67%) of the 3 bcr/abl negative CML patients and 5 (87%) of the 6 bcr/abl positive ALL patients had refractory leukemia.

CONCLUSION

bcr/abl hybridized gene is accurately detected by a probe of dual color-dual fusion translocation fluorescence in situ hybridization, which can serve as an effective index for clinical diagnosis, estimation of prognosis and monitor of minimal residual disease in some hematopathies.

Effect of the hemoregulatory peptide (pEEDCK)2 (pyroGlu-Glu-Asp-Cys-Lys)2 and MIP-1alpha is reduced in bone marrow cultures from patients with chronic myeloid leukemia (CML)

The granulocyte-derived hemoregulatory peptide pyroGlu-Glu-Asp-Cys-Lys = pEEDCK is known to keep hematopoietic cells quiescent. When oxidized to its dimeric form (pEEDCK)2, it activates growth of hematopoietic progenitors in association with stroma-derived cytokines. (pEEDCK)2 has a Cys-Cys motif which is also a typical feature of the macrophage inflammatory protein (MIP-1alpha). The present study was designed to analyze differences between the response of normal and leukemic progenitor cells to (pEEDCK)2 or MIP-1alpha. When long-term bone marrow cultures (LTBMCs) were incubated with (pEEDCK)2 or MIP-1alpha and/or cytokines, the stimulatory effect on colony-forming units-granulocyte/erythroid/macrophage/megakaryocyte of LTBMC from chronic myeloid leukemia (CML) patients was less than 50% compared to LTBMC from healthy humans. No difference in oncogene expression could be observed in LTBMC from CML patients regarding reduction of Philadelphia chromosome-associated transcription of the BCR-ABL gene. With respect to the expression of growth and differentiation-associated genes (Galpha16, 5-lipoxygenase, phospholipaseA2, c-kit, and CD34), which were analyzed from LTBMC by semiquantitative reverse transcriptase-polymerase chain reaction, the same transcription rate was observed in CML patients and healthy donors. However, two isoforms of a key enzyme of oxidative metabolism, carnitine palmitoyltransferase (CPT1A and CPT1B), showed 50-fold higher expression rates in LTBMC cells of healthy donors compared to CML patients. It is known that a decrease in oxidative metabolism is associated with an increase in redox equivalents in malignancy. This might result in a reduction of disulphide bonds in (pEEDCK)2 or MIP-1alpha, thus inducing a downregulation of these factors in bone marrow from CML patients.

Modeling Philadelphia chromosome positive leukemias

The Ph chromosome has been genetically linked to CML and ALL. Its chimeric fusion gene product, BCR-ABL, can generate leukemia in mice. This review will discuss selected model systems developed to study BCR-ABL induced leukemia and focuses on what we have learned about the human disease from these models. Five main experimental approaches will be discussed including: (i) Reconstitution of mice with bone marrow cells retrovirally transduced with BCR-ABL; (ii) Transgenic mice expressing BCR-ABL; (iii) Knock-in mice with BCR-ABL expression driven from the endogenous bcr locus; (iv) Development of CML-like disease in mice with loss of function mutations in heterologous genes; and (v) ES in vitro hematopoietic differentiation coupled with regulated BCR-ABL expression.

Confidence bands for the difference of two survival curves under proportional hazards model

A common approach to testing for differences between the survival rates of two therapies is to use a proportional hazards regression model which allows for an adjustment of the two survival functions for any imbalance in prognostic factors in the comparison. When the relative risk of one treatment to the other is not constant over time the question of which therapy has a survival advantage is difficult to determine from the Cox model. An alternative approach to this problem is to plot the difference between the two predicted survival functions with a confidence band that provides information about when these two treatments differ. Such a band will depend on the covariate values of a given patient. In this paper we show how to construct a confidence band for the difference of two survival functions based on the proportional hazards model. A simulation approach is used to generate the bands. This approach is used to compare the survival probabilities of chemotherapy and allogeneic bone marrow transplants for chronic leukemia.

[Endogenous intoxication, immunological reactivity and erythrocyte membrane permeability in patients with chronic myelogenous leukemia]

Patients with chronic myeloid leukemia (CML) have been shown to present with apparent metabolic abnormalities, such as enhanced endogenous intoxication against the background of deterioration of the functional condition of the liver and decline in immune reactivity of the organism; the erythrocytic membrane permeability changes considerably. The data secured are discussed from the standpoint of using them as prognostic criteria of the course of CML.

Expression of apoptosis proteins in chronic myelogenous leukemia: associations and significance

BACKGROUND

The mechanisms favoring the growth advantage of Philadelphia chromosome positive cells over normal cells in chronic myelogenous leukemia (CML) are not fully elucidated but could be due partly to altered apoptosis and longer survival of CML clones. Also, little is known about the biologic characteristics of disease progression in CML. Bcl-2 expression has been demonstrated to exert an antiapoptotic effect resulting in increased cell survival. Other proteins such as Bax and Bad are proapoptotic proteins. Fas, a cell surface protein, can be triggered by an appropriate death-promoting ligand (FasL) to activate downstream caspases pivotal in initiation of programmed cell death. Although the mechanisms underlying cellular proliferative and apoptotic pathways are complex, with involvement of multiple interlocking proteins, the relative expression of pro- and antiapoptotic proteins may have an influence on disease progression. This study aimed to determine whether the changes in the cellular expression of Bcl-2, Bax, and Fas correlate with caspase-3 activity and disease progression in CML, or with response to interferon (IFN)-alpha therapy and prognosis in early chronic phase CML.

METHODS

Bcl-2, Bax, and Fas expression were measured on whole cell lysates from bone marrow mononuclear cell fractions by Western blot analysis and quantitative radioimmunoassay. Caspase-3 activity was determined using the DEVD system. Specimens from 203 patients with CML were examined. These included 130 patients in early chronic phase disease (ECP; diagnosis to therapy, < or =12 months), 33 patients in late chronic phase (diagnosis to therapy, > 12 months), 27 patients in accelerated phase, and 13 patients in blastic phase. Correlations between apoptosis proteins and CML phases, risk groups in ECP, and response to IFN-alpha therapy and survival in ECP were investigated by standard statistical methods, and positive findings were assessed by multivariate analysis.

RESULTS

Levels of Bcl-2, Fas, Bax, and caspase-3 activity did not correlate with disease progression. Among patients in ECP, higher Fas levels correlated with poorer risk groups (P = 0.05) and higher caspase-3 activity correlated with better risk groups (P = 0.048). With IFN-alpha therapy, major cytogenetic responses were noted in 30% of patients with high Fas and 53% with low Fas (P = 0.016) and failure to achieve a complete hematologic response (CHR) in 25% versus 2% (P = 0.0001). Survival was shorter with high Fas levels (5-year rates, 71% vs. 52%; P = 0.002), and the independent poor prognostic significance of high Fas levels was confirmed by multivariate analysis (P = 0.014). Response to IFN-alpha therapy and survival were not significantly different by different levels of Bcl-2, Bax, or caspase-3 activity.

CONCLUSIONS

High Fas levels were associated with intrinsically worse disease at diagnosis, whereas high caspase-3 activity was associated with good risk disease. In ECP CML, high Fas levels were associated with significantly worse response to IFN-alpha therapy and with significantly worse survival. The influence of these cellular proteins and caspase-3 activity on apoptosis in CML is complex and merits further investigation.

Chronic myeloid leukemia with increased granulocyte progenitors in mice lacking junB expression in the myeloid lineage

The functions of JunB during myelopoiesis were studied in vivo. Transgenic mice specifically lacking JunB expression in the myeloid lineage (junB(-/-)Ubi-junB mice) develop a transplantable myeloproliferative disease eventually progressing to blast crisis, which resembles human chronic myeloid leukemia. Similarly, mice reconstituted with ES cell-derived junB-/- fetal liver cells also develop a myeloproliferative disease. In both cases, the absence of JunB expression results in increased numbers of granulocyte progenitors, which display enhanced GM-CSF-mediated proliferation and extended survival, associated with changes in the expression levels of the GM-CSFalpha receptor, the anti-apoptotic proteins Bcl2 and Bclx, and the cell cycle regulators p16(INK4a) and c-Jun. Importantly, ectopic expression of JunB fully reverts the immature and hyperproliferative phenotype of JunB-deficient myeloid cells. These results identify JunB as a key transcriptional regulator of myelopoiesis and a potential tumor suppressor gene.

Interferon-alpha and the pathogenesis of myeloproliferative disorders

Interferon-alpha (IFN-alpha), a molecule with multiple biological actions, is widely used in the treatment of chronic myelogenous leukemia (CML) and the other myeloproliferative disorders. This glycoprotein belonging to the type I subfamily of interferons has been recombinantly manufactured and has been approved for the biotherapy of CML, now becoming the first line of treatment for CML patients in chronic phase who are not candidates for allogeneic hematopoietic stem cell or bone marrowtransplantation. Interferon-alpha action involves binding to its cell membrane receptor and initiation of an intracellular signal transduction cascade. Two major pathways mediate the biologic actions of IFN-alpha. The JAK-STAT pathway leads to phosphorylation and activation of STAT 1 and STAT 2 molecules and transcription of genes like p21 and caspase-1 resulting in cycle arrest and apoptosis. The PKR (protein kinase dsRNA-induced) kinase phosphorylates and inhibits the eukaryotic initiator of translation eIF-2alpha leading again to apoptosis. The PKR kinase cascade also leads to activation of the transcription factor NF-kappaB. The relevance of this activation is unclearand it is possiblethat NF-kappaB has not had the opportunity to transcribe its target genes as it is a substrate of effector caspases and is maybe cleaved by them before exerting any transcription activity. Through the JAK-STAT and the PKR kinase pathways IFN-alpha is able to modify the proliferative and antiapoptotic actions of the constitutively activated kinase bcr-abl, the product of the t(9;22) translocation present in CML, and has therapeutic effects in this disease.

Bcr-Abl and inhibition of apoptosis in chronic myelogenous leukemia cells

Chronic myelogenous leukemia (CML) cells are highly resistant to apoptosis induced by chemotherapeutic drugs. The observation that production of Bcr-Abl is the initiating event in CML has focussed attention on the survival signals triggered by this oncogene. A number of signal transducers and transcription factors have been associated with the antiapoptotic phenotype of CML cells, some of which lead to the expression and/or activation of members of the Bcl-2 family of apoptosis modulators, such as Bcl-xL and Bad. In this article, recent advances in understanding the antiapoptotic pathways triggered by Bcr-Abl in CML cells, are discussed.

Natural killer cell dysfunction and apoptosis induced by chronic myelogenous leukemia cells: role of reactive oxygen species and regulation by histamine

Natural killer (NK) cells are deficient in patients with chronic myelogenous leukemia (CML), but the mechanisms responsible for the dysfunction are not completely understood. This study reports that CML cells effectively inhibit the baseline and interleukin-2 (IL-2)-induced NK cell cytotoxicity against a CML cell-derived line (K562). A sizable fraction of NK cells subsequently acquired features characteristic of programmed cell death/apoptosis. The CML cell-mediated inhibition of NK cells required triggering of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-mediated formation of reactive oxygen species (ROS) and was prevented by catalase, a scavenger of ROS, and by histamine, acting via H(2)-receptor-mediated inhibition of ROS production in CML cells. In contrast, nonmalignant neutrophilic granulocytes inhibited NK cells via ROS production without the requirement of exogenous NADPH oxidase-triggering stimuli. We propose that paracrine production of ROS may contribute to the dysfunction of NK cells in CML and that histamine may serve as an autocrine inhibitor of ROS formation in leukemic granulocytes. (Blood. 2000;96:1961-1968)

Tyrosine kinase inhibitors: a cure for chronic myeloid leukemia?

Chronic myeloid leukemia (CML), a malignant transformation of hematopoietic cells, accounts for one-fifth of all leukemias and will be diagnosed in 4,400 individuals in the United States this year. CML has three phases: chronic, accelerated, and blastic. Interferon, hydroxyurea, busulfan, and bone marrow and stem cell transplantation are used to treat CML, but individuals who are in the accelerated phases or blast crisis usually respond poorly to treatment. A new tyrosine kinase inhibitor, STI 571, is being evaluated in clinical trials. STI 571 is highly bioavailable in oral form and produced minimal toxicities in phase I studies. Further research is needed to determine the rate of response and survival data, but STI 571 holds great promise in the treatment of CML.

Atypical chronic myeloid leukaemia with trisomy 21 mosaicism as a sole chromosomal abnormality

We present a 46-year-old patient with Ph-chromosome negative, bcr-negative chronic myeloid leukaemia (CML) in accelerated phase with a clonal trisomy 21 in the leukaemic blast cells. A rapid progress of disease with appearance of monocytosis is described, showing similar features to chronic myelomonocytic leukaemia (CMML). Heterogeneous characteristics and possible distinction of these two entities are discussed.

Transforming growth factor beta3 inhibits chronic myelogenous leukemia hematopoiesis by inducing Fas-independent apoptosis

OBJECTIVE

Transforming growth factor beta3 (TGF-beta3) is a potent suppressor of human hematopoietic progenitor cells. In this article, we compare the activity of TGF-beta3 on highly purified CD34+ cells and more immature CD34-DR(-) cells from chronic myelogenous leukemia (CML) patients in chronic phase and normal donors.

MATERIALS AND METHODS

Primitive hematopoietic progenitors were stimulated in liquid cultures and clonogenic assays by early-acting growth factors such as stem cell factor (SCF) and interleukin 11 (IL-11) and the intermediate-late-acting stimulating factors IL-3, granulocyte-macrophage colony-stimulating factor, and erythropoietin. Molecular analysis of bcr/abl mRNA was performed on single CML colonies by nested reverse transcriptase polymerase chain reaction. Moreover, cell cycle analysis and assessment of apoptosis of normal and leukemic CD34+ cells were performed by propidium iodide (PI) alone and simultaneous staining with annexin V and PI, respectively.

RESULTS

The colony-forming efficiency of CML CD34+ cells was generally inhibited by more than 90% regardless of whether the colony-stimulating factors were used alone or combined. When compared to normal CD34+ cells, leukemic cells were significantly more suppressed in 6 of 8 culture conditions. The inhibitory effect of TGF-beta3 on CD34+ cells was exerted within the first 24 hours of incubation as demonstrated by short-term preincubation followed by IL-3-and SCF-stimulated colony assays. Evaluation of bcr/abl transcript on residual CML colonies incubated with TGF-beta3 demonstrated a small subset of neoplastic CD34+ cells unresponsive to the inhibitory effect of the study cytokine. TGF-beta3 demonstrated a greater inhibitory activity on primitive CD34+DR cells than on more mature CD34+ cells. Again, CML CD34+DR(-) cells were significantly more inhibited by TGF-beta3 than their normal counterparts in 3 of 8 culture conditions. Kinetic analysis performed on CD34+ cells showed that TGF-beta induces cell cycle arrest in G(1) phase. However, this mechanism of action is shared by normal and leukemic cells. Conversely, TGF-beta3 preferentially triggered the programmed cell death of CML CD34-cells without increasing the proportion of leukemic cells coexpressing CD95 (Fas receptor), and this effect was not reversed by functional blockade of Fas receptor. Conclusion. We demonstrate that TGF-beta3 exerts a potent suppressive effect on CML cells that is partly mediated by Fas-independent apoptosis.

Risk assessment in patients with Ph+ chronic myelogenous leukemia at first relapse after allogeneic stem cell transplant: an EBMT retrospective analysis. The Chronic Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Patients with Ph+ chronic myelogenous leukemia who relapse after a first allogeneic stem cell transplant still have a possibility of long-term survival. To assess the value of the individual therapeutic options, the factors predicting outcome should be identified. We investigated data from 500 patients who relapsed before July 1996; follow-up was updated during 1998. The actuarial survival from relapse was 34.2% (95% confidence interval [CI]: 29. 9%-38.5%) at 5 years and 23.4% (95% CI: 18.9%-27.9%) at 10 years. Survival after relapse was significantly related to 5 factors: time from diagnosis to transplant (< 2 years vs >/= 2 years), disease phase at transplant (first chronic phase vs other), disease stage at relapse (cytogenetic or chronic phase vs advanced phase), time from transplant to relapse (< 1 year vs >/= 1 year), and donor type (HLA-identical sibling vs volunteer unrelated donor). The effects of individual adverse risk factors were cumulative: The probability of survival at 10 years decreased stepwise from 42% (0 factors), 32% (1 factor), 14% (2 factors), 3% (3 factors), to 0% (4 or 5 factors). Novel strategies for high-risk patients are warranted. We conclude that these 5 factors should be taken into account when comparing results of salvage therapies in patients with Ph+ chronic myeloid leukemia relapsing after allogeneic stem cell transplant.

[The genetic instability of mismatch repair gene linked microsatellite and the evolution of CML]

OBJECTIVE

To explore the relationship between the genetic instability of microsatellite linked with mismatch repair gene and the evolution of CML to blast crisis.

METHODS

The loss of heterozygosity (LOH) and microsatellite instability (MSI) of two polymorphic microsatellite markers, D2s123 and D3s1298, linked with mismatch repair gene hMSH2 and hMLH1 respectively, were detected by PCR-silver staining method on the bone marrow cells of 18 CML patients, who clinically progressed from the chronic phase to accelerated phase or blast crisis.

RESULTS

Differences in microsatellite D2s123 and D3s1298 at the CML accelerated phase or blast crisis in 5 (27.8%) of the 18 patients were demonstrated compared with chronic phase. For D2s123, MSI and LOH were observed in 1 of 8 patients with accelerated phase (12.5%) and 2 of 10 patients in blast crisis (20%). For D3s1298, MSI and LOH were observed in 2 of 10 patients in blast crisis (20%).

CONCLUSION

The genetic alteration of microsatellite D2s123 and D3s1298 may play a role in the progress of some CML cases.

The exodus subfamily of CC chemokines inhibits the proliferation of chronic myelogenous leukemia progenitors

Chemokines are a family of related proteins that regulate leukocyte infiltration into inflamed tissue and play important roles in disease processes. Among the biologic activities of chemokines is inhibition of proliferation of normal hematopoietic progenitors. However, chemokines that inhibit normal progenitors rarely inhibit proliferation of hematopoietic progenitors from patients with chronic myelogenous leukemia (CML). We and others recently cloned a subfamily of CC chemokines that share similar amino-terminal peptide sequences and a remarkable ability to chemoattract T cells. These chemokines, Exodus-1/LARC/MIP-3alpha, Exodus-2/SLC/6Ckine/TCA4, and Exodus-3/CKbeta11/MIP-3beta, were found to inhibit proliferation of normal human marrow progenitors. The study described here found that these chemokines also inhibited the proliferation of progenitors in every sample of marrow from patients with CML that was tested. This demonstration of consistent inhibition of CML progenitor proliferation makes the 3 Exodus chemokines unique among chemokines. (Blood. 2000;95:1506-1508)