Low-dose alemtuzumab (Campath®) in myeloablative allogeneic stem cell transplantation for CD52-positive malignancies: decreased incidence of acute graft-versus-host-disease with unique pharmacokinetics

Alemtuzumab is effective in reducing the risk of acute graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (ASCT). Alemtuzumab may also delay immune reconstitution and reduce graft-versus-leukemia effects. The optimal dose has not been established. We investigated engraftment, acute GVHD incidence and severity, and pharmacokinetics of alemtuzumab associated with the use of low-dose alemtuzumab/cyclophosphamide/total body irradiation and ASCT for patients with aggressive CD52-positive hematologic malignancies. In all, 12 patients were treated. Alemtuzumab 10 mg daily on days -7 to -3 was given intravenously. Tacrolimus and methotrexate were used for GVHD prophylaxis. Alemtuzemab was not detected in any of the 36 sequential serum samples tested between days -1 and +21 of transplant. All patients engrafted rapidly; the median time to an absolute neutrophil count >0.5 x 10(9)/l was 14 days (range 11-17 days), and the median time to a platelet count >20 x 10(9)/l was 16 days (range 6-30 days). By 1 month after transplant, nine patients had 100% donor chimerism, while three had mixed donor chimerism. At 3 months, 11 had achieved 100% donor chimerism. No cases of grade III/IV acute GVHD occurred. At a median follow-up interval of 14.7 months (range 4-24), seven patients remained alive, and five remained free of disease.

Mitochondrial DNA mutations in primary leukemia cells after chemotherapy: clinical significance and therapeutic implications

Mitochondrial DNA (mtDNA) codes for 13 respiratory chain subunits and is more vulnerable to damage than nuclear DNA due, in part, to a lack of histone protection and a weak repair capacity. While mtDNA alterations have been observed in human cancer, their roles in oncogenesis and chemosensitivity remain unclear. We investigated the relationship between mtDNA mutations, reactive oxygen species (ROS) generation, and clinical outcomes in chronic lymphocytic leukemia (CLL) patients. An analysis of mtDNA from 20 CLL patients revealed that primary CLL cells from patients with prior chemotherapy had a significantly higher frequency of heteroplasmic mutations than did those from untreated patients. Overall, mtDNA mutations appeared to be associated with increased ROS generation. Patients refractory to conventional therapeutic agents tended to have higher mutation rates than patients who responded to treatment. Analysis of paired blood samples from the same patient led to the identification of a heteroplasmic mutation in the cytochrome c oxidase II gene several months after chemotherapy. The mutation was associated with increased ROS generation. Our results suggest for the first time that chemotherapy with DNA-damaging agents may cause mtDNA mutations in primary leukemia cells, which often exist in heteroplasmy, and are associated with increased ROS generation.

Outcome in patients with nonleukemic granulocytic sarcoma treated with chemotherapy with or without radiotherapy

Granulocytic sarcoma (GS) is an extramedullary tumor composed of immature myeloid cells. The objectives of this study were to describe the frequency, presenting characteristics, and survival in patients with nonleukemic GS by conducting a review of all untreated patients presenting to the MD Anderson Cancer Center between January 1990 and June 2002. In all, 21 patients with nonleukemic GS, 1520 patients with acute myeloid leukemia (AML), and 402 patients with high-risk myelodysplastic syndrome (MDS) were identified. GS occurred in 1.4% of patients with AML, and 1.1% of patients with AML or high-risk MDSs. The median patient age was 57 years (range, 7-81). Among 20 patients with available cytogenetics in tissue and/or bone marrow, six had chromosome 8 abnormalities. The median follow-up of surviving patients is 12 months (range, 7-75). In all, 20 patients were treated. Patients were treated with AML-type chemotherapy (n=16), chemotherapy and radiotherapy (n=3), or radiotherapy alone (n=1). A total of 13 patients (65%) achieved complete remission and one patient (5%) achieved partial remission. The median overall survival was 20 months (range, 1-75), median overall failure-free survival was 12 months (range, 1-75). The median survival of patients with chromosome 8 abnormalities was 12 months compared with 40 months of those without (P=0.17). Novel therapies for patients with GS are required.

Better detection of FLT3 internal tandem duplication using peripheral blood plasma DNA

Somatic mutation of the FLT3 gene as an internal tandem duplication (ITD) of the juxtamembrane domain-coding sequence causes constitutive tyrosine phosphorylation and activation. Tumor-specific DNA has been documented in the sera of patients with solid tumors even when it is in an early stage. We compared the detection of FLT3 ITD in DNA extracted from cells of bone marrow (BM) aspirations with DNA extracted from peripheral blood (PB) plasma in patients newly diagnosed with acute myeloid leukemia (AML; 85 patients), myelodysplastic syndrome (MDS; 16 patients), and acute lymphocytic leukemia (ALL; 16 patients). FLT3 ITD was detected in 18 (21%) AML samples and in one (6%) MDS sample in both cellular and plasma DNA but in none of the ALL samples. Hemizygous/homozygous FLT3 ITD was detected in five (28%) of the FLT3 ITD-positive AML using plasma DNA, whereas only four of these cases showed hemizygous/homozygous FLT3 ITD using cellular DNA. The presence of FLT3 ITD was associated with significantly shorter survival (P = 0.02) when only patients younger than 50 years of age (48 AML+MDS patients) were considered. This finding was independent of cytogenetics in this age group. However, patients with the FLT3 ITD hemizygous/homozygous phenotype had even shorter survival (P = <0.001). As expected, the presence of FLT3 ITD correlated with higher white blood cell (WBC) counts. These data demonstrate that plasma DNA is a reliable alternative resource for detecting FLT3ITD, especially the hemizygous/homozygous genotype. Furthermore, the data derived from this study support the notion that the presence of FLT3 ITD in conjunction with the absence of the wild-type FLT3 allele predicts an especially poor prognosis for patients with AML.

More cell death in refractory anemia with excess blasts in transformation than in acute myeloid leukemia

Refractory anemia with excess blasts in transformation (RAEB-T) is a subgroup of myelodysplastic syndrome (MDS) in which the bone marrow blast count ranges from 20% to 30%. The recently proposed World Health Organization Classification of Hematologic Malignancies eliminated this category from MDS by lowering the blast count cutoff for acute myeloid leukemia (AML) from 30% to 20%. However, MDS is distinguished from AML by a significant increase in apoptosis. To investigate the difference in apoptosis between RAEB-T, AML, and other categories of MDS, we prospectively analyzed fresh bone marrow samples using the Annexin V and mitochondrial potential assays. There was a significantly higher level of apoptosis in RAEB-T than in AML according to both assays, while no significant differences between RAEB-T and other categories of MDS were noted. The data suggest that RAEB-T is more likely to be an advanced stage of MDS and biologically different from AML.

Expression profile of 11 proteins and their prognostic significance in patients with chronic lymphocytic leukemia (CLL)

It has been suggested that the expansion of the leukemic cells in chronic lymphocytic leukemia (CLL) is due to dysregulation of pathways of programmed cell death (apoptosis) rather than cell proliferation, although differences may exist in early vs late and treated vs untreated patients. In the present study, we analyzed the expression of 11 proteins in CLL cells that are implicated in the control of apoptosis, proliferation, and differentiation, and correlated this expression profile with survival. Using a quantitative solid-phase radioimmunoassay (RIA), we measured the cellular protein levels of Bcl-2, cyclin D1, PCNA, ATM, Fas, Bax, retinoic acid receptor alpha (RARalpha), retinoic acid receptor beta (RXRbeta), Flt1, VEGF, and cellular beta2-microglobulin in 230 samples of CLL. Univariate analysis using the Cox proportional hazard model showed a correlation with survival of only the following proteins: Bcl-2 (P < 0.001), cyclin D1 (P = 0.027), Fas (P = 0.055), PCNA (P < 0.001), and ATM (P = 0.028). In a multivariate analysis using classification and regression tree analysis (CART), five groups of patients (nodes) could be generated with significant differences of survival expectation (P < 0.0001) based on levels of expression of the above proteins. Based on CART analysis, Bcl-2 levels emerge as the most important protein in predicting survival between all 11 proteins studied. Patients with marked elevation in Bcl-2 levels had the worst outcome while patients with intermediate levels, but with high levels of PCNA and cyclin D1 or abnormal ATM expression had intermediate survival. These data indicate that intracellular levels of proteins such as Bcl-2, ATM, cyclin D1, and PCNA can be used as markers to predict clinical behavior and survival in patients with CLL. The pathways in which these proteins are involved may also represent possible targets for future therapeutic trials in CLL.

Angiogenesis in acute myeloid leukemia and myelodysplastic syndrome

Increased angiogenesis is important in the pathophysiology of solid tumors. Recent studies show that angiogenesis and angiogenic factors play an important role in hematological malignancies. Both acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) are associated with a substantial increase in vascularity in the bone marrow as well as increased levels of various angiogenic factors including vascular endothelial growth factor (VEGF), basic fibroblast growth factor, angiogenin, angiopoietin-1, platelet-derived growth factor, hepatocyte growth factor, epidermal growth factor, tumor necrosis factor-alpha, and transforming growth factor-alpha and transforming growth factor-beta. Most of these angiogenic factors appear to be secreted by the neoplastic hematopoietic cells and appear to promote the growth and proliferation of the leukemic cells in an autocrine fashion. More importantly, angiogenic factors play a role in the clinical behavior and outcome of both AML and MDS. Despite significant overlap between MDS and AML in many aspects, higher levels of cellular VEGF and lower levels KDR are seen in MDS than in AML. Antiangiogenic therapy may play a role in AML and MDS and some differences in response may exist between MDS and AML.

Antiangiogenic therapy in leukemia

Angiogenesis is a fundamental element of the physiological processes of embryogenesis and wound healing. During malignant transformation, dysregulation of angiogenesis leads to the formation of a vascular network of tumor-associated capillaries promoting survival and proliferation of the cancerous cells. Activation, migration, proliferation and differentiation of endothelial cells into mature blood vessels is driven by several cytokines and growth factors, known to be dysregulated in hematological malignancies. Thus, therapeutic interventions designed to eradicate the malignant clone should incorporate modulation of the angiogenic cascade. Antiangiogenic agents which target different components of the neovascularization process are being investigated in various solid tumors known to have increased vascularity. The role of angiogenesis in hematological malignancies, the rationale for the use of angiosuppressive therapy for these entities, and the status of novel antiangiogenic agents in clinical trials are discussed.

Significance of the levels of bone marrow lymphoid infiltrate in chronic lymphocytic leukemia patients with nodular partial remission

Patients with chronic lymphocytic leukemia (CLL) are considered in nodular partial remission (nPR) when they are in remission but bone marrow biopsies show rare nodules. The significance of the level of residual disease in nPR is not known. We studied 91 previously untreated CLL patients who were treated with fludarabine alone, fludarabine with prednisone, or fludarabine with cyclophosphamide and achieved nPR at the end of six courses. We compared bone marrow lymphoid infiltration before therapy and at the end of three and six courses of therapy as evaluated by a pathologist in retrospective fashion with that of the routine evaluation at the time of performing bone marrow biopsy. We then compared these results with those obtained by computer-aided histomorphometry in 28 patients in nPR. There was significant correlation (P < 0.05) between pathologists as well as between pathologists and histomorphometry. Upon correlation with clinical characteristics, there was significant correlation (P 0.01) between marrow involvement before therapy and white blood cell counts (wbc), hemoglobin (hgb), absolute lymphocyte counts, and beta2-microglobulin (beta2-m) but none of these parameters correlated with the lymphoid infiltrate at the end of three or six courses of therapy. more importantly, lymphoid infiltration after three and six courses did not correlate with time to progression (ttp) or overall survival (os). however, patients with >70% marrow involvement before therapy had a significantly shorter TTP (P = 0.02). All 91 patients showed similar results. However, we found reverse correlation between marrow lymphoid infiltrate at the end of three courses and OS (P = 0.01).

Clinical significance of fragile histidine triad gene expression in adult acute lymphoblastic leukemia

The FHIT (fragile histidine triad) gene, which is located on 3p14.2 and believed to be a tumor suppressor gene, has been reported to lose its expression in several solid tumors and hematologic malignancies, including acute lymphoblastic leukemia (ALL). The clinical relevance of the loss of FHIT expression in ALL is not known. We used western blot and solid-phase radioimmunoassay (RIA) to analyze Fhit protein expression in 90 patients with ALL. Eighteen (20%) of the tested patients had severely reduced Fhit protein (undetectable by western blot), and 43 patients (47%) had levels lower than those detected in normal bone marrows. Interestingly, seven patients (8%) expressed very high levels (>two-fold the level detected in normal bone marrow). A parallel pattern of FHIT RNA expression was also observed. Of the 90 patients, 39 received induction therapy consisting of hyper-CVAD (hyperfractionated cyclophosphamide, vencristine, adriamycine, and dexamethasone) and were followed in our institution. Patients with low Fhit protein levels showed no statistically significant difference in survival or complete remission duration (CRD) from patients with normal levels (P=0.12 and 0.24, respectively). Our study confirms that FHIT is aberrantly expressed in ALL, but suggests it does not have a role as a prognostic factor. Studies with large numbers of patients and evaluation of the mechanisms of FHIT function in ALL are needed.

"T-cell-rich B-cell lymphoproliferative disorder" of the bone marrow

We report four cases of a "T-cell-rich B-cell chronic lymphoproliferative disorder" involving the bone marrow and not extramedullary sites. The neoplastic B-cell proliferation in these cases was composed predominantly of small lymphoid cells with features of both hairy cell leukemia and lymphoplasmacytoid lymphoma. All cases presented with neutropenia and with difficulty in diagnosis. We present the clinical, morphologic, cytochemical, and immunophenotypic findings in these cases and discuss this entity.

Higher levels of surface CD20 expression on circulating lymphocytes compared with bone marrow and lymph nodes in B-cell chronic lymphocytic leukemia

Differential expression of CD20 surface antigen in B-cell neoplasms at different sites is largely unknown. The number of CD20 antibodies bound per cell (CD20 ABC) in bone marrow (BM), peripheral blood (PB), and lymph node aspirate (LNA) samples from patients with B-cell chronic lymphocytic leukemia (B-CLL) or other B-cell disease was studied using quantitative flow cytometry. CD20 ABC differed significantly with the specimen type in B-CLL, being highest in PB (mean, 9,051) and lower in BM (mean, 4,067) and LNA (mean, 3,951). No difference in CD20 ABC between BM and PB samples was found in splenic lymphoma, mantle cell lymphoma, or follicular lymphoma. Also, we found a significant difference of CD20 ABC by type of disease: lowest in B-CLL; higher in splenic, follicular, and mantle cell lymphoma; and highest in hairy cell leukemia. The lower CD20 surface antigen levels in BM and LNA than in PB in B-CLL may have clinical relevance with regard to the efficacy of rituximab therapy.

Significance of angiogenin plasma concentrations in patients with acute myeloid leukaemia and advanced myelodysplastic syndrome

Human angiogenin is a potent inducer of angiogenesis. The association between angiogenin and cancer progression and poor outcome in solid tumours has been documented, but its significance in leukaemias has not been evaluated. We evaluated plasma angiogenin levels in 101 previously untreated patients with acute myeloid leukaemia (AML) (59 patients) and advanced myelodysplastic syndrome (MDS) (42 patients). Angiogenin levels were significantly higher in AML and advanced MDS patients than in healthy individuals (P < 0.00001). Angiogenin levels were also significantly higher in advanced MDS than in AML (P = 0.001). Higher levels of angiogenin correlated with prolonged survival periods in both AML and advanced MDS patients (P = 0.02 and 0.01 respectively). We found no correlation between angiogenin plasma level and various patient characteristics, including age, performance status, antecedent haematological disorder, haemoglobin, white blood cell and platelet counts, and poor prognosis cytogenetics. There was no significant correlation between angiogenin level and complete remission rate and duration in AML or advanced MDS patients. In multivariate analysis, angiogenin concentration retained its significance as a prognostic factor in AML (P = 0.03), together with age (P = 0.00007) and haemoglobin (P = 0.03).

Plasma hepatocyte growth factor is a prognostic factor in patients with acute myeloid leukemia but not in patients with myelodysplastic syndrome

Hepatocyte growth factor (HGF) is a potent angiogenic factor. The aim of our study was to evaluate plasma HGF levels and their prognostic significance in patients with newly diagnosed acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). The sandwich enzyme immunoassay technique was used to quantify HGF in stored samples obtained before treatment from patients with AML (59 patients) and MDS (42 patients) treated at The University of Texas MD Anderson Cancer Center. HGF levels were significantly higher in patients with AML or MDS than in healthy individuals (P < 0.0001). Higher HGF levels in both AML and MDS correlated significantly with white blood cell (P = 0.000001 for both groups) and monocyte counts (P = 0.0004 and 0.003, respectively), and with poor performance status (P = 0.03 and 0.001, respectively). Using Cox proportional hazard model and HGF levels as a continuous variable, plasma levels of HGF correlated with shorter survival of AML (P = 0.001), but not MDS (P = 0.34) patients. No significant correlation was observed between HGF levels and complete remission rate or duration. In the multivariate analysis HGF retained its significance as prognostic factor in AML (P = 0.02), along with age (P = 0.0005).

High expression of the receptor tyrosine kinase Tie-1 in acute myeloid leukemia and myelodysplastic syndrome

The tyrosine kinase receptor Tie-1 has been shown to play a role in angiogenesis and hematopoiesis. We evaluated the level of expression and clinical significance of Tie-1 protein in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). We used western blot analysis to confirm and radioimmunoassay to quantify Tie-1 protein expression in bone marrow samples obtained from untreated patients having AML (66 patients) or MDS (29 patients). Samples obtained from these patients contained significantly higher levels of Tie-1 protein than did control samples (P < 0.001). Also, Tie-1 levels were significantly higher in AML patients than MDS patients (P < 0.0001). Tie-1 levels did not correlate with complete remission or survival duration in patients having either disease. These data suggest that Tie-1 expression is increased in AML and MDS but that the level of expression does not influence the response to current therapy. The role of Tie-1 overexpression in the reported increased vascularity in the bone marrow of AML and MDS patients requires further investigation.

CD38 expression as an important prognostic factor in B-cell chronic lymphocytic leukemia

CD38 is a transmembrane glycoprotein expressed on the surface of leukemic cells in a significant percentage of patients with B-cell chronic lymphocytic leukemia (B-CLL). A recent study suggested that CD38 expression has prognostic value in CLL. Peripheral blood samples from 218 patients with B-CLL were analyzed by flow cytometry for CD38 expression on CD5/19(+) leukemic cells. Various patient characteristics were studied including age, sex, Rai and Binet stages, splenomegaly, hepatomegaly, hemoglobin (Hgb) level, beta-2 microglobulin (beta2M) level in the serum, number of nodal sites involved with disease, and length of survival. The Kaplan-Meier method was used to construct survival curves, and the log-rank statistic was used to compare these curves. CD38 was expressed in 20% or more of leukemic cells in 43% of the patients. Patients with high CD38 expression (20% or more) had significantly shorter survival times (P =.00005). Multivariate analyses showed that CD38 expression is an important prognostic factor associated with high incidence of lymph node involvement (P =.004), lower hemoglobin level (P =.001), hepatomegaly (P =.05), and high beta2M level (P =.00005). CD38 expression identified a group of patients with aggressive disease that was considered by Rai staging to be early-stage disease (Rai stages 0-II). Patients with CD38(+) samples have significantly aggressive disease regardless of their clinical stage. Measurement of CD38 expression by flow cytometry should become a routine test in the evaluation of patients with CLL.

Fractionated cyclophosphamide, vincristine, liposomal daunorubicin (daunoXome), and dexamethasone (hyperCVXD) regimen in Richter's syndrome

Approximately 3 to 5% of patients with chronic lymphocytic leukemia (CLL) develop an aggressive large cell non Hodgkin's lymphoma (NHL) known as Richter's syndrome (RS). RS has a poor prognosis and a response rate of < 10% with fludarabine-based or other cytotoxic combination regimens. The aim of this study was to evaluate the efficacy and toxicity of the hyperCVXD regimen in RS. Twenty-nine patients, median age 61 years (36-75) 23 males, were treated. Prior diagnosis was CLL in 26 patients, NHL in 2, and Prolymphocytic leukemia in 1. Treatment consisted of fractionated cyclophosphamide, vincristine, daunoXome and dexamethasone. Six patients (20%) died while receiving study therapy, 4 (14%) during the first cycle of whom 2 had started therapy with overt pneumonia. Grade 4 granulocytopenia occurred in all 95 cycles of therapy with a median time to recovery of 14 days. Twenty three (24%) cycles were complicated by fever, and 15 (15%) by pneumonia. Sepsis was documented in 8 (8%) cycles, and neuropathy in 5 (5%) of cycles. Twenty three patients had a platelet count < 100 x 10(9)/l prior to therapy: a greater than 50% decrease in platelet count over pre-therapy level occurred in 79% of first cycles, overt bleeding occurred in 4 (4%) of all cycles. Eleven of 29 (38%) patients achieved complete remission (CR), 4 of whom have relapsed after 5, 6, 9, and 12 months of remission. Two of 11 CR patients presented with RS without any prior CLL therapy. One patient had a partial remission. Thus the overall response rate was 12/29 (41%). Overall median survival was 10 months, 19 months in patients who achieved CR, 3 months in those who did not (p = 0.0008). A landmark analysis performed at 2 months from start of therapy comparing patients alive in CR versus patients alive but not in CR showed a median survival of 19 months versus 6 months, respectively (p 0.0017). In conclusion the hyper CVXD regimen has a relatively high response rate, significant toxicity and a moderate impact on survival in RS.

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.