Leukemia Patients In Remission Research Articles

Identifying Differences in the Quality of Life of Patients with Acute Leukemia: A Global Survey

Identifying Differences in the Quality of Life of Patients with Acute Leukemia: A Global Survey

Impact of Donor Type on Outcome after Allogeneic Hematopoietic Cell Transplantation for Acute Leukemia

Allogeneic hematopoietic cell transplantation (alloHCT) is considered the most potent postremission antileukemic therapy in adults with acute leukemia. We analyzed 172 consecutive acute leukemia patients transplanted in complete remission after a T cell–replete alloHCT from either a matched related (MRD, n = 54), unrelated (MUD, n = 67), or haploidentical (haplo, n = 51) donor to look for patient-, disease-, and transplant-related factors associated with post-transplant outcomes. Patients included 123 acute myeloid leukemia patients (first complete remission [CR], n = 94; second CR, n = 28; third CR, n = 1) and 49 acute lymphoblastic leukemia (ALL) patients (first CR, n = 39; second CR, n = 9; third CR, n = 1) with a median age of 50 years (range, 19 to 74). Median follow-up for surviving patients was 38 months. Cumulative incidence of nonrelapse mortality at 1 and 3 years was 6% and 17%, respectively. The estimated rates of 3-year overall survival, disease-free survival, and relapse incidence were 59%, 50%, and 33%, respectively. In multivariate analysis, risk factors for inferior survival included diagnosis of ALL, high risk disease risk index, and use of a female donor for a male recipient. Donor type (MRD, MUD, haplo) had no impact on any transplant outcome. Given the favorable outcomes associated with alloHCT in acute leukemia and lack of effect of donor type, a strong case can be made for transplanting acute leukemia patients in remission as soon as any donor becomes available.

Disease Risk and Host Factors, Not Transplant Type, Predict Outcome Following Allogeneic Hematopoietic Stem Cell Transplantation for Acute Leukemia

Allogeneic hematopoietic stem cell transplantation (HSCT) is considered the most potent post-remission antileukemic therapy in adults with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL), although these benefits must be balanced by the increased morbidity and mortality associated with this procedure. We analyzed 172 consecutive acute leukemia patients transplanted in remission following a T cell-replete allogeneic HSCT from either a matched related, unrelated, or haploidentical marrow of PBSC donor, in order to look for patient-, disease-, and transplant-related factors associated with post-transplant outcomes. Patients were transplanted at a single institution between 3/15/06 to 12/19/14 and include 123 AML patients (CR1[94], CR2[28], CR3[1]) and 49 ALL patients (CR1[39], CR2[9], CR3[1]), median age 50 (range 19-74), median KPS 80 (70-90), median hematopoietic cell transplantation comorbidity index (HCT-CI) 2 (range 1-11), disease risk index (DRI) low, intermediate, and high in 5, 130, and 37 patients respectively per the revised Dana Farber/CIBMTR criteria. Transplant type was matched related donor (MRD), matched unrelated donor (MUD) and haploidentical (haplo) in 54 (31%), 67 (39%), and 51 (30%) patients respectively. Myeloablative chemotherapy was utilized in 122 (71%) patients, and PBSC was the source of stem cells in 142 (83%) patients. Compared to AML patients, ALL patients were more likely to be younger (median age 46 vs. 52, p=0.002) and had a trend for more myeloablative conditioning (82% vs. 67%, pp=0.063). Median f/u for surviving patients was 38 months. Acute GVHD grade II-IV occurred in 36% of patients, whereas chronic GVHD was seen in 46%. Estimated one year non-relapse mortality (NRM) at 1 and 3 years was 6% and 17% respectively. Three-year NRM was significantly higher for patients ≥50 years (24% vs. 10%) and for patients with ALL vs. AML (29% vs. 12%, p=0.022). The estimated 3 year OS, DFS, and relapse was 59%, 50%, and 33% respectively. Estimated 3-year OS was 70% for AML patients <50 years, compared with 59%, 58%, and 30% for AML ≥50, ALL <50, and ALL ≥50 respectively. In multivariate analysis, favorable risk factors for survival included a diagnosis of AML, non-high risk DRI, Age <50, and KPS ≥90 (Table 1). Myeloablative chemotherapy demonstrated a protective effect on relapse (HR 0.58, CI 0.37 - 0.93) and DFS (HR 0.62, CI 0.42 - 0.93), but was not a significant determinant of OS or NRM. Chronic GVHD had opposing effects on relapse (HR 0.48, CI 0.25 - 0.94) and NRM (HR 3.81, CI 1.44 - 10.1), with no impact on DFS or OS. Donor type (MRD, MUD, haploidentical) had no impact on any transplant outcome (figure 1). Following T cell-replete allogeneic HSCT for acute leukemia patients in remission, the primary determinants of success are type of leukemia, disease risk index, age, and performance status. Given the favorable outcomes associated with allogeneic HSCT in acute leukemia patients and lack of effect of donor type, we would argue that all patients with non-favorable risk acute leukemia should be offered an allogeneic HSCT as soon as any donor (MRD, MUD, or haploidentical) becomes available. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Abstract 954: The landscape of kinase fusions in cancer

Abstract Human cancer genomes harbor a variety of alterations leading to the deregulation of key pathways in tumor cells. The genomic characterization of tumors has uncovered numerous genes recurrently mutated, deleted or amplified, but gene fusions have not been studied as extensively. Kinase fusions represent ideal targets for the development of cancer drugs because they often confer oncogenic dependency in hematopoietic and solid malignancies as demonstrated by the success of several kinase inhibitors. For example, imatinib induces remission in leukemia patients who are positive for BCR-ABL1 fusions, and crizotinib and ceritinib have produced significant clinical benefit in patients with lung adenocarcinomas and mesenchymal tumors harboring ALK fusions. We have developed heuristics for reliably detecting gene fusion events in RNA-seq data sets and apply them to nearly 9,000 samples from The Cancer Genome Atlas. Fusions between any two genes were identified based on the number of chimeric reads and split reads. Then a number of filtering criteria were applied to flag false positive and non-functional fusions, including the removal of kinase fusions observed in a panel of more than 3,500 normal samples from diverse origins. Finally, we reviewed all recurrent kinase fusions manually to identify putative oncogenic drivers with distinctive characteristics of functional kinase fusions. We thereby were able to recapitulate most known translocation events in solid tumors (i.e., ALK, BRAF, EGFR, FGFR1, 2 and 3, NTRK1, 2 and 3, PDGFRA, PRKCA, RAF1, RET, ROS1). Interestingly, we identified new tumor types harboring such fusions and discovered several novel fusion partners for these kinases. We also detected several low-frequency, pan-cancer kinase fusion events, for example in the neurotrophic tyrosine receptor kinases NTRK1, NTRK2 and NTRK3, that drive tumorigenesis in a small fraction of multiple cancers, regardless of tissue type. Using our computational pipeline, we identified several novel and recurrent kinase fusions involving the MET proto-oncogene and PIK3CA. These bona fide oncogenes have not been shown previously to be activated by fusion events. Our analysis also uncovered novel, recurrent fusions in kinases with no known tumorigenic genomic alterations (e.g., FGR and PKN1), potentially resulting in active and oncogenic fusion proteins that represent putative targets for drug discovery. These findings have immediate diagnostic and clinical implications and expand the therapeutic options for cancer patients, as approved or exploratory drugs exist for many of these kinases. Citation Format: Nicolas Stransky, Ethan Cerami, Stefanie Schalm, Joseph L. Kim, Klaus Hoeflich, Christoph Lengauer. The landscape of kinase fusions in cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 954. doi:10.1158/1538-7445.AM2015-954

Recombinant immunotoxin for cancer treatment with low immunogenicity by identification and silencing of human T-cell epitopes.

Nonhuman proteins have valuable therapeutic properties, but their efficacy is limited by neutralizing antibodies. Recombinant immunotoxins (RITs) are potent anticancer agents that have produced many complete remissions in leukemia, but immunogenicity limits the number of doses that can be given to patients with normal immune systems. Using human cells, we identified eight helper T-cell epitopes in PE38, a portion of the bacterial protein Pseudomonas exotoxin A which consists of the toxin moiety of the RIT, and used this information to make LMB-T18 in which three epitopes were deleted and five others diminished by point mutations in key residues. LMB-T18 has high cytotoxic and antitumor activity and is very resistant to thermal denaturation. The new immunotoxin has a 93% decrease in T-cell epitopes and should have improved efficacy in patients because more treatment cycles can be given. Furthermore, the deimmunized toxin can be used to make RITs targeting other antigens, and the approach we describe can be used to deimmunize other therapeutically useful nonhuman proteins.

Comparison of Infection Rates Among Acute Leukemia Patients in Remission Receiving Alternative Donor Hematopoietic Cell Transplantation

Comparison of Infection Rates Among Acute Leukemia Patients in Remission Receiving Alternative Donor Hematopoietic Cell Transplantation

Long-term follow-up of children conditioned with Treosulfan: German and Austrian experience

We report the long-term follow-up of children transplanted with Treosulfan (TREO)-based conditioning in Germany and Austria. Nine centres reported a total of 109 transplantations. Patients were stratified according to the paediatric TRM risk score derived from the paediatric BMT registry (PRST) and compared with the historical transplant population of this registry. Underlying diseases were malignancies, immunodeficiencies, and haematologic and metabolic disorders. TREO total dose ranged from 21-42 g/m(2). Additional conditioning drugs included fludarabine, thiotepa, melphalan, CY and/or TBI. EFS at 3 years for non-malignant and malignant diseases was 88% and 49%, respectively. Leukaemia patients in remission had a survival of 51% at 3 years; nonremission patients relapsed and died within 18 months. TRM and OS in the low-risk groups 0 and 1 were similar to PRST controls. TRM in the high-risk groups 2 and 3 was markedly lower (9% vs 28% and 13% vs 53%, respectively) than in the PRST group, but OS was similar. In conclusion, TREO-based conditioning regimens in children resulted in excellent engraftment and long-term survival in nonmalignant disease. In high-risk malignancy, low acute toxicity was followed by low TRM but it did not translate into increased survival.

Tyrosine kinase gene fusions in cancer: translating mechanisms into targeted therapies

Tyrosine kinase fusion genes represent an important class of oncogenes associated with leukaemia and solid tumours. They are produced by translocations and other chromosomal rearrangements of a subset of tyrosine kinase genes, including ABL, PDGFRA, PDGFRB, FGFR1, SYK, RET, JAK2 and ALK. Based on recent findings, this review discusses the common mechanisms of activation of these fusion genes. Enforced oligomerization and inactivation of inhibitory domains are the two key processes that switch on the kinase domain. Activated tyrosine kinase fusions then signal via an array of transduction cascades, which are largely shared. In addition, the fusion partner provides a scaffold for the recruitment of proteins that contribute to signalling, protein stability, cellular localization and oligomerization. The expression level of the fusion protein is another critical parameter. Its transcription is controlled by the partner gene promoter, while translation may be regulated by miRNA. Several mechanisms also prevent the degradation of the oncoprotein by proteasomes and lysosomes, leading to its accumulation in cells. The selective inhibition of the tyrosine kinase activity by adenosine-5′-triphosphate competitors, such as imatinib, is a major therapeutic success. Imatinib induces remission in leukaemia patients that are positive for BCR-ABL or PDGFR fusions. Recently, crizotinib produced promising results in a subtype of lung cancers with ALK fusion. However, resistance was reported in both cases, partially due to mutations. To tackle this problem, additional levels of therapeutic interventions are suggested by the complex mechanisms of fusion tyrosine kinase activation. New approaches include allosteric inhibition and interfering with oligomerization or chaperones.

MRNA export and cancer

Studies in the past several years highlight important features of the messenger RNA (mRNA) export process. For instance, groups of mRNAs acting in the same biochemical processes can be retained or exported in a coordinated manner thereby impacting on specific biochemistries and ultimately on cell physiology. mRNAs can be transported by either bulk export pathways involving NXF1/TAP or more specialized pathways involving chromosome region maintenance 1 (CRM1). Studies on primary tumor specimens indicate that many common and specialized mRNA export factors are dysregulated in cancer including CRM1, eukaryotic translation initiation factor 4E (eIF4E), HuR, nucleoporin 88, REF/Aly, and THO. This positions these pathways as potential therapeutic targets. Recently, specific targeting of the eIF4E-dependent mRNA export pathway in a phase II proof-of-principle trial with ribavirin led to impaired eIF4E-dependent mRNA export correlating with clinical responses including remissions in leukemia patients. Here, we provide an overview of these mRNA export pathways and highlight their relationship to cancer.

Dynamic Contrast-enhanced MR Imaging Measurement of Vertebral Bone Marrow Perfusion May Be Indicator of Outcome of Acute Myeloid Leukemia Patients in Remission

To examine whether dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging measurement of bone marrow perfusion in acute myeloid leukemia (AML) patients in complete remission (CR) is associated with outcome and survival. After institutional review board approval and informed consent were obtained, from September 2004 to October 2007, 51 patients (29 women, 22 men; mean age, 43.5 years; range, 17-66 years) agreed to undergo DCE MR imaging to assess bone marrow perfusion, among 96 patients with newly diagnosed de novo AML who had received induction chemotherapy and achieved CR. Two semiquantitative parameters (peak and slope) and another three quantitative parameters (amplitude, K(ep) [efflux rate constant], and K(el) [elimination rate constant]) were calculated. Overall survival (OS) and relapse-free survival (RFS) were assessed with the Kaplan-Meier model, while differences between patient groups with high and low DCE MR imaging parameter values were assessed by using the two-sided log-rank test. The median follow-up was 25.9 months. Univariate analysis results showed that high values of peak (≥0.42), slope (≥0.0235), amplitude (≥0.03), and K(ep) (≥0.0082) were associated with shorter OS (P = .004, 0.01, 0.034, and 0.026, respectively). Besides, a high value of K(ep) was also associated with shorter RFS (P = .008). When age, sex, and initial karyotype at diagnosis were included in multivariate Cox proportional hazards analysis, the results showed that only K(ep), but not other DCE MR imaging parameters, was an independent factor for OS (relative risk [RR], 30.305; P = .021) and RFS (RR, 6.477; P = .009). Bone marrow perfusion measured with DCE MR imaging in AML patients in CR can be an indicator of outcome and survival. K(ep) measured with kinetic modeling was useful and significantly associated with RFS, while heuristic parameters (peak and slope) were not.

Patients' Peripheral Blood as a Possible Source of Donor-Derived NK Cells for Ex Vivo Expansion and Genetic Modification for Post-Transplant Cellular Immunotherapy In Cord Blood Recipients

AbstractAbstract 2094Haploidentical natural killer (NK) cells can induce and consolidate remission in patients with high-risk acute myeloid leukemia (AML) (Rubnitz et al. J Clin Onc 24: 371, 2010). Recently, significantly reduced relapse rates were observed in AML patients who received killer immunoglobulin-like receptor ligand-mismatched cord blood, suggesting effective alloreactivity of cord blood-derived NK cells (Willemze et al. Leukemia 23: 492, 2009). Cord blood transplantation (CBT) is an effective alternative source for allogeneic hematopoietic cell transplantation in both children and adults. However, its therapeutic efficacy for malignant diseases is limited by the lack of available donor effector cells, such as cytotoxic T lymphocytes, lymphokine-activated killer cells, NK-like T cells and NK cells, for treatment of hematological relapse and posttransplant lymphoproliferative disorder and/or for scheduled posttransplant cellular immunotherapy against refractory diseases. We previously reported a method that induces NK cells to proliferate and reliably allows their genetic modification in healthy individuals and leukemia patients in remission receiving maintenance chemotherapy (Imai et al. Blood 106: 376, 2005). To explore the possibility of using patients' peripheral blood as a source for posttransplant NK cell therapy, we used our method to expand donor-derived NK cells from peripheral blood of CBT recipients early after engraftment. We also examined whether NK cells can be rendered cytotoxic against original leukemia blasts by transferring an antigen-specific artificial immunoreceptor gene. This study was approved by an institutional ethical committee. Patients received CBT for consolidation of hematological malignancy (n=7), neuroblastoma (n=1) or resolution of refractory EBV-associated hemophagocytic syndrome (n=1) with myeloablative (n=7) or reduced intensity conditioning (RIC) regimens (n=2). The patients were enrolled in the study after engraftment and peripheral blood was obtained after appropriate written consent was obtained. A chimerism study using short tandem repeat assays showed complete donor chimerism in all patients except one who received RIC-CBT. The peripheral blood was obtained at a median of 92 days post-CBT (range: 46–303 days) and subjected to ex vivo activation and expansion using a previously described protocol with slight modifications. Briefly, peripheral blood was coincubated with modified K562 cells expressing membrane-bound IL-15 and 4-1BB ligand (K562-mb15-41BBL) in the presence of low-dose IL-2 (10 U/mL). Most patients were on maintenance immunosuppressive therapy with calcineurin inhibitors with (n=3) or without (n=6) systemic corticosteroids. After 7 days of culture, a median 11.0-fold expansion (range: 5.3–28.9-fold) was observed in all but one patient who had been administered chemotherapy with Mylotarg for relapsed AML a few days before the blood sampling. The expansion rate in the first week was less efficient in CBT recipients than in healthy individuals (>20-fold), probably because of the immunosuppressants administered. However, an additional 2-week culture in the presence of high-dose IL-2 (1000 U/mL) yielded a median 206-fold expansion (range: 101–1381-fold in 21 days). The expanded NK cells exhibited upregulation of activating receptors including NKG2D, NCRp30 and NCRp44, and vigorous cytotoxicity against K562 cells (86.8–97.7% at an E/T ratio of 1:1). The NK cells were susceptible to retroviral genetic modification with the MSCV-IRES-GFP vector (median GFP-positive cells, 52.7%, n=10). Finally, peripheral NK cells from patients with acute lymphoblastic leukemia were expanded and transduced with the chimeric immunoreceptor gene anti-CD19-BB-ζ. The donor-derived NK cells expressed large amounts of anti-CD19 chimeric receptors on their surface and killed original leukemia blasts that were highly resistant to NK cell lysis (e.g. anti-CD19 vs. non-signaling receptor: 69% vs. 0% at an E/T ratio of 1:1). These results suggest that, in CBT recipients, ex vivo expansion and genetic modification of donor-derived NK cells from the patients' peripheral blood is feasible. Because peripheral blood can be easily and repeatedly obtained, the method described here will allow multiple scheduled infusions. This preliminary study may lead to a novel strategy for posttransplant donor-NK cell therapy in CBT recipients. Disclosures:No relevant conflicts of interest to declare.

Role of autotransplantation in the treatment of acute promyelocytic leukemia patients in remission: Fukuoka BMT Group observations and a literature review

We retrospectively analyzed the outcomes of 26 patients with acute promyelocytic leukemia (APL) in the first CR (CR1) or second CR (CR2), who underwent autologous PBSCT (auto-PBSCT) between 1992 and 2008. All patients received all-trans retinoic acid-based induction therapy. After two courses of consolidation chemotherapy, upfront auto-PBSCT was performed in 20 patients in the CR1. Five patients had a high WBC count of more than 10 × 10(9)/L (high risk), while 15 patients had a count of less than 10 × 10(9)/L (low risk) at initial presentation. In addition, six patients, who were considered as low-risk patients at presentation, had a relapse after three cycles of consolidation and 2 years of maintenance therapy, but gained the molecular remission after re-induction and consolidation, and underwent auto-PBSCT in the CR2. In 26 recipients, engraftment was rapid and no TRM was documented. All 20 patients autotransplanted in CR1 were still in CR at a median of 133 months (73-193 months), and six patients who underwent auto-PBSCT in CR2 were also still in CR at a median of 41 months (2-187 months) without maintenance therapy. PML/RARα chimeric mRNA was undetectable in PBSC or BM samples examined before auto-PBSCT. Despite a small number of cases studied, our retrospective observations suggest that auto-PBSCT may be an effective treatment option to continue durable CR in the treatment of high-risk APL. We review previous reports and discuss the role of autotransplantation in the treatment of APL patients in CR.

A survey of fully haploidentical hematopoietic stem cell transplantation in adults with high-risk acute leukemia: a risk factor analysis of outcomes for patients in remission at transplantation

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is an alternative treatment to patients with high-risk acute leukemia lacking a human leukocyte antigen-matched donor. We analyzed 173 adults with acute myeloid leukemia (AML) and 93 with acute lymphoblastic leukemia (ALL) who received a haplo-HSCT in Europe. All grafts were T cell-depleted peripheral blood progenitor cells from a direct family or other related donor. At transplantation, there were 25 patients with AML in CR1 (complete remission 1), 61 in more than or equal to CR2, and 87 in nonremission, and 24 with ALL in CR1, 37 in more than or equal to CR2, and 32 in nonremission. Median follow-up was 47 months in AML and 29 months in the ALL groups. Engraftment was observed in 91% of the patients. Leukemia-free survival at 2 years was 48% plus or minus 10%, 21% plus or minus 5%, and 1% for patients with AML undergoing transplantation in CR1, more than or equal to CR2, and nonremission, and 13% plus or minus 7%, 30% plus or minus 8%, and 7% plus or minus 5% in ALL patients, respectively. In conclusion, haplo-HSCT can be an alternative option for the treatment of high-risk acute leukemia patients in remission, lacking a human leukocyte antigen-matched donor.

CD8 T cells with high avidity TCR-ab specific for serine protease self-determinants for use in adoptive immunotherapy of human leukemia (48.35)

Abstract Specific cytotoxic T-lymphocyte (CTL) immunity against the serine protease-derived PR1 peptide has been correlated with clinical response (CR) to interferon-α, allogeneic bone marrow transplantation or PR1-peptide vaccination in leukemia patients. However, some patients failed to demonstrate a CR, despite an immunological response. Patients with CR have functional PR1-CTL with a preferentially higher avidity T cell receptor (HTCR). These HTCR PR1-CTL were more susceptible to apoptosis by high PR1 peptide expression on leukemia cells compared to low avidity (LTCR) PR1-CTL, suggesting deletional tolerance mediated by the leukemia cells. We hypothesized that the adoptive transfer of HTCR PR1-CTL could induce remission in leukemia patients. Clonal, HTCR and LTCR PR1-CTL were elicited from an HLA-A2 healthy donor using low (2 μM) or high (200 μM) concentration of PR1 peptide, respectively. TCR affinity of these clones correlated with tetramer fluorescence intensity and importantly, effector function. Jurkat and primary T cells transduced with HTCR or LTCR by lentivirus vectors expressed cell surface PR1-specific TCR complex and specifically recognized the HLA-A2/PR1 tetramers. HTCR-αβ genes transduction represents a powerful strategy for adoptive immunotherapy in leukemia patients.

Markers of Iron Overload Are Poor Prognostic Factors in Stem Cell Transplantation.

Transfusional iron overload is common in survivors of acute leukemia and hematopoietic stem cell transplantation and might cause long-term liver dysfunction. Routine evaluation for iron overload in such patients is recommended because excess iron can be readily removed from the body via phlebotomy or chelation. Iron overload might be associated with worse survival after stem cell transplantation in these diseases. We were interested in determining whether levels of the iron binding protein ferritin or the serum transferrin receptor (TfR) were predictive for survival. In a prospective study, we examined the correlation between iron parameters at the time of transplantation and overall survival. Serum ferritin, transferrin saturation, and TfR were measured before preparative regimen on patients who underwent hematopoietic stem cell transplantation between 1999 and 2004 for the diagnosis of aplastic anemia, MDS or acute leukemia (n=79). We used the number of transfusions before transplantation as a measure of iron load. Among these iron markers, serum ferritin correlated the most with the number of transfusions, regardless of remission status. High ferritin (>1,500 ng/ml), low TfR (≤4 μg/ml) and low TfR/log ferritin ratio (≤2) were associated with shorter survival (p=0.005, 0.04, and 0.001 respectively)(Figure 1). Among acute leukemia patients in remission, there was no difference in overall survival between patients with high or low iron markers. Markers of iron excess (serum ferritin >1,500 ng/ml, TfR/log ferritin ratio ≤2) at the time of stem cell transplantation is associated with shorter survival in MDS, aplastic anemia and acute leukemia with active disease. These results demonstrate that knowledge of patient ferritin and TfR levels can aid in risk stratification. The results also suggest that patients with high levels of ferritin may benefit from iron chelation before treatment. [Display omitted]

Unexpectedly high incidence of hypoplastic/aplastic foci in bone marrow biopsies of hairy cell leukemia patients in remission following 2-chlorodeoxyadenosine therapy.

Treatment with the purine analog 2-chlorodeoxyadenosine (2-CDA) achieves a complete response in close to 90% of patients with hairy cell leukemia, with approximately 75% remaining in prolonged remission. Recently, we unexpectedly noted foci of hypoplasia and aplasia in routine follow-up bone marrow biopsies of several hairy cell leukemia patients in remission with normal blood counts. Because of this finding we examined all available biopsies to assess the incidence of this phenomenon. A total of 94 biopsies in 31 patients were reviewed. Of these, 23 were prior to 2-CDA therapy and 71 (in 30 patients) were obtained 2-76 (mean 22) months following one or more courses of treatment. Nine patients had also received prior interferon and 7 (of whom 3 had also received interferon) had undergone splenectomy. Hypocellular foci were found in only 3 (13%) of the pre-therapy biopsies. Forty-seven of the 71 post-therapy biopsies (in 23 patients) (66%) had a total of 176 hypocellular foci. Of these 47 biopsies, 39 were without evidence of disease. A simultaneous complete blood count was normal in 34 of the 47 hypoplastic biopsies (72%). This suggests that these hypoplastic areas may not be representative of the entire bone marrow and that normal hematopoiesis may take place at other sites. However, since the longest follow-up is less than 7 yr, the potential long-term significance of these findings, such as progressive bone marrow aplasia or dysplasia, may still be unrecognised.

Metabolism of benz[ a]anthracene by human bone marrow in vitro

The metabolism of polycyclic aromatic hydrocarbons by bone marrow, mononuclear cells from normal donors and leukaemia patients in remission has been investigated. When benz[ a]anthracene (BA) was included with marrow under cell culture conditions, it was converted to materials which were resolved into three peaks by normal phase HPLC and which had the Chromatographic characteristics of BA-dihydrodiols. Formation of hydroxymethylor dihydrodiol-derivatives of 7,12-dimethylbenz[ a]anthracene were not detected under the same conditions. The BA-metabolites were identified as BA-5,6-dihydrodiol, BA-10,11-dihydrodiol BA-8,9-dihydrodiol. This identification was based upon Chromatographic properties of the metabolites during normal and reverse phase chromatography and on UV spectral and fluorometric characterization. It was not possible to detect the formation of BA-3, 4-dihydrodiol since this dihydrodiol co-elutes with BA-8,9-dihydrodiol and BA-10,11-dihydrodiol during normal phase and reverse phase chromatography, respectively. The UV spectra of BA-3,4-dihydrodiol does not have features which enable it to be readily identified in the presence of these other compounds. Formation of the dihydrodiol-metabolites was dependent on cell number and temperature. Two general cytochrome P450 inhibitors, carbon monoxide and piperonyl butoxide, blocked the formation of metabolites but the cyclooxygenase inhibitor, indomethacin had no effect. Large variations were observed in the capacity of marrow from different individuals to form benz[ a]anthracene-dihydrodiols but, in each sample where dihydrodiols were formed, the relative amount of each metabolite was BA-8,9- dihydrodiol 2 ̆ BA-5,6- dihydrodiol > BA-10,11- dihydrodiol . Factors which may contribute to this variation, including disease status, genetic and environmental agents, are considered.

Clinical significance of serum total and heat-stable alkaline phosphatase in leukemia patients.

Variations in serum alkaline phosphatase (ALP) and placental-like (heat stable) alkaline phosphatase (PLAP) are found to be clinically useful in cancer patients. The present study evaluated serum ALP and PLAP levels to establish a blood-based biochemical index for leukemia patients. ALP and PLAP levels were determined in 145 untreated leukemia patients, 77 anemia patients, 150 healthy individuals (controls), 47 leukemic patients in remission and 23 patients with persistent leukemic activity/accelerated leukemic phase (P. Leu./A. Leu.). The enzymes were estimated with highly specific spectrophotometric methods. Serum ALP and PLAP levels were significantly elevated in anemia patients and leukemia patients compared to controls. Comparison between anemia patients and leukemia patients showed insignificant differences for ALP, whereas PLAP levels were significantly raised (p < 0.001) in leukemia patients. ALP showed insignificant difference between untreated leukemia patients, patients with P. Leu./A. Leu. and leukemia patients in remission. PLAP levels were comparable in patients with P. Leu./A. Leu. and were significantly lower (p < 0.02) in leukemia patients in remission than in untreated leukemia patients. The results indicate that serum PLAP levels are a useful biochemical marker for diagnosis and treatment monitoring of leukemia patients. However, serum ALP levels have limited utility for leukemia patients.

THE EFFECT OF GROWTH HORMONE (GH) AND IGF-I ON CLOHOGENIC GROWTH OF HEMATOPOIETIC CELLS IN LEUKEMIC PATIENTS DURING ACTIVE DISEASE AND DURING REMISSION

The number of survivors of childhood leukemia treated with GH for growth failure is increasing. The debate around the direct or indirect relationship of GH and IGF-I to the occurence of malignancy, especially in the case of GH therapy in patients with leukemia, is still unresolved. After we have studied the effect of GH and IGF-I on bone marrow (BM) of patients with acute leukemia (ALL and AML) in active disease, we studied patients with chronic myelogenous leukemia (CML) in remission. We have shown that GH increases blast colony count (BCC) by a mean of 68% and 77% at a GH concentrations of 250 and 300 ng/ml respectively. IGF-I increased BCC in all patients by 50, 93 and 105% at IGF-I concentrations of 0.05, 0.25 and 0.5 ng/ml respectively and in AML patients by 33, 58 and 65% in the presence of same concentrations. In colony forming assay did not reveal stimulation of peripheral blood blast colony forming by GH or IGF-I. In contrats with our in vitro data (as previously reported by us) that suggest that GH and IGF-I may promote blast cell proliferation, this effect was not on cells obtained from leukemia patients in remission.

Human growth hormone and insulin-like growth factor-1 enhance the proliferation of human leukemic blasts.

As the number of long-term survivors of childhood leukemia increases, growth retardation has emerged as a significant complication. Treatment of these children with growth hormone (GH) has been suggested and sporadically implemented. We, therefore, studied the effect of human GH (hGH) and its by-product insulin-like growth factor-1 (IGF-1) on the growth of leukemic cells in vitro. Under serum-free conditions hGH and IGF-1 induced a significant dose-dependent proliferative effect on promyelocytic leukemia (HL60) and Burkitt's lymphoma (Daudi) cell lines. Anti-hGH antibodies negated the stimulatory effect of hGH and anti-IGF-1 serum abrogated the growth-promoting effect enhanced by IGF-1. Similar statistically significant stimulatory properties were found when freshly obtained marrow cells from four of five acute lymphoblastic leukemia (ALL) of childhood and four acute myelogenous leukemia (AML) patients were studied in ALL and AML blast-cell clonogenic assays. ALL colonies increased numerically by 72% (P less than .025) and AML colonies by 92% (P less than .01) in the presence of hGH at concentrations of 2.5 x 10(2) and 3.0 x 10(2) ng/mL, respectively. IGF-1 stimulated ALL and AML blast-colony growth at concentrations ranging from 0.05 to 0.5 ng/mL by up to 105% (P less than .025) and 65% (P less than .03), respectively. Our in vitro data suggest that circulating hGH and IGF-1 may promote leukemic blast cell replication in vivo, and the supplemental administration of hGH to leukemia patients in remission must be carefully monitored for early relapse.