Day 15 bone marrow driven double induction in young adult patients with acute myeloid leukemia: feasibility, toxicity, and therapeutic results

The strategy named double induction (DI) in acute myeloid leukemia (AML) consists of two courses of chemotherapy irrespective of the degree of cytoreduction in the bone marrow (BM) after the first course, unless severe complications prohibit its application. We describe treatment results from a series of 33 patients in whom DI was adopted only after demonstration of persistence of more than 10% blast cells at day 15 (D15) examination of BM. All patients received as induction idarubicin, cytarabine, and etoposide. As second induction, we administered the combination of fludarabine, intermediate dose cytarabine, and Granulocyte colony stimulating factor (G-CSF). The median blast count at D15 was 30 (15-90). Overall, 30 of 33 patients were judged as eligible to receive DI, reasons for exclusion being in all cases active infection in the context of severe pancytopenia. Nineteen patients (63%) had unfavorable karyotype and 11 (37%) normal karyotype; seven of these had Fms-like tyrosine kinase gene internal tandem duplication (FLT3/ITD) mutation. Overall, complete remission (CR) was achieved in 20/30 patients (67%), while eight patients (27%) were refractory and two died of infectious complications. All refractory patients had unfavorable cytogenetics. All patients achieving CR were programmed to receive allogeneic stem cell transplantation (allo-SCT), which was actually performed in 11 patients. Our study suggest that D15 driven DI represents a feasible and effective therapeutic strategy in young adult AML patients, improving therapeutic results and not compromising feasibility of allo-SCT. When compared with conventional DI, it offers the potential to avoid unnecessary toxicity in a consistent proportion of patients.

Megakaryocytic blast crisis at presentation in a pediatric patient with chronic myeloid leukemia

Patients with chronic myeloid leukemia (CML) infrequently present in blast crisis (BC). While most BC are of myeloid origin, megakaryocytic BC is rare, especially at the time of CML diagnosis. We describe the first pediatric patient presenting with megakaryocytic leukemia and having BCR-ABL1 translocation as the single chromosomal abnormality. Clinical features were more suggestive of CML in megakaryocytic blast crisis than Philadelphia chromosome positive de novo AML. The patient was treated with AML-directed chemotherapy and imatinib mesylate followed by umbilical cord blood stem cell transplantation. The patient was in complete molecular response 16 months after stem cell transplantation.

Natural killer cell killing of acute myelogenous leukemia and acute lymphoblastic leukemia blasts by killer cell immunoglobulin-like receptor-negative natural killer cells after NKG2A and LIR-1 blockade

Although the study of natural killer (NK) cell alloreactivity has been dominated by studies of killer cell immunoglobulin-like receptors (KIRs), we hypothesized that NKG2A and LIR-1, present on 53% +/- 13% and 36% +/- 18% of normal NK cells, respectively, play roles in the NK cell killing of primary leukemia targets. KIR(-) cells, which compose nearly half of the circulating NK cell population, exhibit tolerance to primary leukemia targets, suggesting signaling through other inhibitory receptors. Both acute myelogenous leukemia and acute lymphoblastic leukemia targets were rendered susceptible to lysis by fresh resting KIR(-) NK cells when inhibitory receptor-major histocompatibility class I interactions were blocked by pan-HLA antibodies, demonstrating that these cells are functionally competent. Blockade of a single inhibitory receptor resulted in slightly increased killing, whereas combined LIR-1 and NKG2A blockade consistently resulted in increased NK cell cytotoxicity. Dual blockade of NKG2A and LIR-1 led to significant killing of targets by resting KIR(-) NK cells, demonstrating that this population is not hyporesponsive. Together these results suggest that alloreactivity of a significant fraction of KIR(-) NK cells is mediated by NKG2A and LIR-1. Thus strategies to interrupt NKG2A and LIR-1 in combination with anti-KIR blockade hold promise for exploiting NK cell therapy in acute leukemias.

Process to evaluate hematological parameters that reflex to manual differential cell counts in a pediatric institution

BACKGROUND

Each institution sets specific parameters obtained by automated hematology analyzers to trigger manual counts. We designed a process to decrease the number of manual differential cell counts without impacting patient care.

METHODS

We selected new criteria that prompt manual counts and studied the impact these changes had in 2 days of work and in samples of patients with newly diagnosed leukemia, sickle cell disease, and presence of left shift.

RESULTS

By using fewer parameters and expanding our ranges we decreased the number of manual counts by 20%. The parameters that prompted manual counts most frequently were the presence of blast flags and nucleated red blood cells, 2 parameters that were not changed. The parameters that accounted for a decrease in the number of manual counts were the white blood cell count and large unstained cells. Eight of 32 patients with newly diagnosed leukemia did not show blast flags; however, other parameters triggered manual counts. In 47 patients with sickle cell disease, nucleated red cells and red cell variability prompted manual review. Bands were observed in 18% of the specimens and 4% would not have been counted manually with the new criteria, for the latter the mean band count was 2.6%.

CONCLUSIONS

The process we followed to evaluate hematological parameters that reflex to manual differential cell counts increased efficiency without compromising patient care in our hospital system.

Triptolide induces cell death independent of cellular responses to imatinib in blast crisis chronic myelogenous leukemia cells including quiescent CD34+ primitive progenitor cells

The advent of Bcr-Abl tyrosine kinase inhibitors (TKI) has revolutionized the treatment of chronic myelogenous leukemia (CML). However, resistance evolves due to BCR-ABL mutations and other mechanisms. Furthermore, patients with blast crisis CML are less responsive and quiescent CML stem cells are insensitive to these inhibitors. We found that triptolide, a diterpenoid, at nanomolar concentrations, promoted equally significant death of KBM5 cells, a cell line derived from a Bcr-Abl-bearing blast crisis CML patient and KBM5STI571 cells, an imatinib-resistant KBM5 subline bearing the T315I mutation. Similarly, Ba/F3 cells harboring mutated BCR-ABL were as sensitive as Ba/F3Bcr-Abl(p210wt) cells to triptolide. Importantly, triptolide induced apoptosis in primary samples from blast crisis CML patients, who showed resistance to Bcr-Abl TKIs in vivo, with less toxicity to normal cells. Triptolide decreased X-linked inhibitor of apoptosis protein, Mcl-1, and Bcr-Abl protein levels in K562, KBM5, and KBM5STI571 cells and in cells from blast crisis CML patients. It sensitized KBM5, but not KBM5STI571, cells to imatinib. More importantly, triptolide also induced death of quiescent CD34(+) CML progenitor cells, a major problem in the therapy of CML with TKIs. Collectively, these results suggest that triptolide potently induces blast crisis CML cell death independent of the cellular responses to Bcr-Abl TKIs, suggesting that triptolide could eradicate residual quiescent CML progenitor cells in TKI-treated patients and benefit TKI-resistant blast crisis CML patients.

Blast count and cytogenetics correlate and are useful parameters for the evaluation of different phases in chronic myeloid leukemia

Staging of chronic myeloid leukemia (CML) phases is based on cytomorphological criteria that vary considerably between different staging systems. Thus, staging of CML is heterogeneous and causes problems with respect to the comparison of therapeutical strategies and clinical outcome. We evaluated 59 patients with CML in different stages of the disease. In order to define which cytomorphological parameters correlate with cytogenetics we investigated cytomorphology and cytogenetics in parallel in all cases. As a result, bone marrow blast count demonstrated a highly significant correlation with the respective cytogenetic results of the patients and was clearly linked to the frequency and complexity of clonal evolution. We therefore propose to focus staging systems of CML on the correlation of the percentage of bone marrow blasts and the cytogenetic results.

Differentiation and hematopoietic-support of clonal cells in myelodysplastic syndromes

Studies were performed to obtain evidence of the differentiating and hematopoietic potential of marrow clone-original cells in patients with myelodysplastic syndromes (MDS). First, results of correlation analysis between bone marrow clonal cells and blast percentages for a total of 60 MDS showed that almost all cases had higher clonal (mean 50.1%) than blast proportion (mean 7.0%) (p < 0.001). In contrast, in 16 AML patients, mean clone/blasts disparity was nearly zero. Secondly, the amount of clone-original individual cells were defined in mature hematopoietic cells, mean 47.9% in segmented granulocytes, 47.1% in orthochromatic normoblasts and 37.8% in mature megakaryocytes. In addition, FISH examination showed approximately similar proportions of clonal cells in peripheral blood and marrow for all 22 tested cases (mean 39.1% in blood vs 49.8% in marrow). Moreover, the neutrophils in MDS peripheral blood oxidized dihydrorhodamine123 (DHR) nearly the same as neutrophils in a normal donor's circulation, while obviously poor function was observed in neutrophils from AML blood. Of note, research on clonality had an unexpected outcome as most of the typical morphological dysplastic cells possessed normal karyotypes. These findings lead to the proposal that the biological features of MDS clones are distinctive from those of AML clones.

Prognostic implication of N-RAS gene mutations in Egyptian adult acute myeloid leukemia

The pathogenesis of acute myeloid leukemia (AML) involves the cooperation of mutations promoting proliferation/survival and those impairing differentiation. Point mutations of the N-RAS gene are the most frequent somatic mutations causing aberrant signal-transduction in acute myeloid leukemia (AML). The aim of the present work is to study the frequency and prognostic significance of N-RAS gene mutations (N-RASmut) in de novo Egyptian adult AML. Bone marrow specimens from 150 patients with de novo acute myeloid leukemia and controls were analyzed by genomic PCR-SSCP at codons 12, 13 (exon 1), and 61 (exon 2) for N-RAS mutations. In 12.7% (19/150) AML cases, N-RAS gene mutations were found and were observed more frequently in the FAB subtype M4eo (P = 0.028) and with codon 12, 13 (14 of 19; 73.7%). Patients with N-RAS mutation had a significant lower peripheral and marrow blasts (P = 0.004, P = 0.03) and clinical outcome did not improve more than in patients without mutation. In patients with N-RAS gene mutation vs. those without, complete remission rate was (63.2% vs. 56.5%; P = 0.46), resistant disease (15.8% vs. 23.6%; P = 0.51), three years overall survival (44% vs 42%; P= 0.85) and disease free survival (42.1% vs. 38.9%, P = 0.74). Multivariate analysis showed that age was the strongest unfavorable factor for overall survival (relative risk [RR], 1.9; P = 0.002), followed by cytogenetics (P = 0.004). FAB types, N-RAS mutation and leukocytosis were the least important. In conclusion, the frequency and spectrum of N-RAS gene mutation differ between biologically distinct subtypes of AML but do not significantly influence prognosis and clinical outcome in patients with AML.

The spectrum of adult B-lymphoid leukemias with BCR-ABL: molecular diagnostic, cytogenetic, and clinical laboratory perspectives

The Philadelphia (Ph) chromosome is characteristic of chronic myelogenous leukemia (CML), but it is also the most frequent cytogenetic abnormality in precursor B-lymphoblastic leukemia (ALL) of adults. The vast majority of CML patients have a BCR-ABL translocation that yields a 210 kD (p210) oncoprotein, whereas adult Ph-positive ALL cases can present with either a p190 or a p210 oncoprotein, or both. Considering that 30% of the patients with CML that progress to blast crisis will have a lymphoblastic presentation, adults presenting with a p210 ALL may have either a de novo ALL or CML presenting for the first time in lymphoblastic phase. To identify the distinguishing features, cases of p190-ALL, p210-ALL, and lymphoblastic CML were compared. In spite of significant overlap between the three entities, a number of features were found to aid in their differentiation. p210-ALL patients present at a younger age with blasts that frequently show loss of expression of CD34, whereas p190-ALL patients present with marked increase in peripheral blast percentage. Interestingly, bone marrow findings characteristic of a myeloproliferative disorder are specific, but are not sensitive for lymphoblastic CML. This study suggests that despite the similarities between these leukemias, p190-ALL, p210-ALL, and lymphoblastic phase CML likely represent three distinct diseases.

The absence of peripheral blood blasts at diagnosis may predict CNS involvement or CNS relapse in pediatric acute lymphoblastic leukemia patients

A high tumor burden at the time of diagnosis of childhood acute lymphoblastic leukemia has an unfavorable outcome. Peripheral white blood cell count is commonly used to reflect the leukemic burden and is used as one of the most important factors during determination of the risk-based treatment. However, peripheral blood blast count may not always reflect the tumor burden if leukocytes are not in blast nature. In the present study, we observed no central nervous system involvement at the time of diagnosis in patients with no peripheral blood blasts at the beginning, and furthermore, none of the patients with no peripheral blasts at the diagnosis had central nervous system relapse.

Phenotype of blasts in chronic myeloid leukemia in blastic phase-Analysis of bone marrow trephine biopsies and correlation with cytogenetics

We identified different phenotypic subsets among 62 cases of chronic myeloid leukemia (CML) in blast crisis (BC) (26% B-lymphoblastic, and 74% various myeloblastic subsets) on bone marrow trephines and correlated the blast-phenotype with cytogenetics. Five of myeloid-BC had an associated 3q26 abnormality and two of these showed a megakaryoblastic-phenotype. While myeloid-BC was associated with additional copies of Philadelphia (Ph) (29%) (p=0.08), numerical abnormalities (51%) (p=0.007), trisomy-8 (29%) (p=0.08) and 17p-loss (22%), none of lymphoid-BC showed these abnormalities. Among myeloid-BC, CD34-negative cases were more often associated with trisomy-8, 17p-loss and numerical abnormalities, and the CD117-negative subset with additional copies of Ph (p<0.05).

Day 14 bone marrow biopsy in predicting complete remission and survival in acute myeloid leukemia

We retrospectively analyzed 194 previously untreated acute myeloid leukemia (AML) patients to evaluate the role of Day 14 bone marrow (BM) biopsy in predicting complete remission (CR). Sixty-seven percent received induction therapy. Achieving Day 14 BM < or =5% blasts was strongly predictive of Day 28 CR with 90% sensitivity and 79% positive predictive value; but weak 43% specificity and 29% negative predictive value. Day 14 BM biopsy is highly sensitive in predicting CR, but did not predict overall survival. Some patients with BM blast >5% at Day 14 may still achieve a Day 28 CR, and not necessarily need reinduction therapy though high risk cytochemical or cytogenetic phenotype predicts a need for retreatment.

Advanced CML: therapeutic options for patients in accelerated and blast phases

Tyrosine kinase inhibitor (TKI) therapy has impacted the natural course of chronic myelogenous leukemia (CML), because patients diagnosed as having chronic-phase disease can experience long-lasting responses. However, for patients with advanced CML (accelerated and blast phases), the efficacy of all current therapies is reduced. For these patients, allogeneic stem cell transplantation remains the preferred treatment if a donor is available, although TKIs play a valuable role as a bridging therapy. For patients with accelerated-phase CML, imatinib, dasatinib, and nilotinib have been shown to produce meaningful rates of hematologic and cytogenetic response. Imatinib and dasatinib are also approved for blast-phase CML. Studies with the newer agents have involved heavily pretreated patients; however, response rates have been at least comparable to those achieved with imatinib in previous studies. Therefore, these newer, more potent TKIs will probably be more likely to induce a deep response in previously untreated patients. Moreover, because fewer mechanisms appear to exist for secondary resistance to dasatinib and nilotinib, reducing the potential for disease to escape TKI therapy, these agents may result in improved longer-term outcomes. However, BCR-ABL-independent pathways may also become more important, indicating that other therapeutic targets may also have a future role in managing patients with advanced CML.

Chronic myeloid leukemia stem cells

Chronic myeloid leukemia (CML) is typified by robust marrow and extramedullary myeloid cell production. In the absence of therapy or sometimes despite it, CML has a propensity to progress from a relatively well tolerated chronic phase to an almost uniformly fatal blast crisis phase. The discovery of the Philadelphia chromosome followed by identification of its BCR-ABL fusion gene product and the resultant constitutively active P210 BCR-ABL tyrosine kinase, prompted the unraveling of the molecular pathogenesis of CML. Ground-breaking research demonstrating that BCR-ABL was necessary and sufficient to initiate chronic phase CML provided the rationale for targeted therapy. However, regardless of greatly reduced mortality rates with BCR-ABL targeted therapy, most patients harbor quiescent CML stem cells that may be a reservoir for disease progression to blast crisis. While the hematopoietic stem cell (HSC) origin of CML was first suggested over 30 years ago, only recently have the HSC and progenitor cell-specific effects of the molecular mutations that drive CML been investigated. This has provided the impetus for investigating the genetic and epigenetic events governing HSC and progenitor cell resistance to therapy and their role in disease progression. Accumulating evidence suggests that the acquired BCR-ABL mutation initiates chronic phase CML and results in aberrant stem cell differentiation and survival. This eventually leads to the production of an expanded progenitor population that aberrantly acquires self-renewal capacity resulting in leukemia stem cell (LSC) generation and blast crisis transformation. Therapeutic recalcitrance of blast crisis CML provides the rationale for targeting the molecular pathways that drive aberrant progenitor differentiation, survival and self-renewal earlier in disease before LSC predominate.

Early peripheral blood blast clearance during induction chemotherapy for acute myeloid leukemia predicts superior relapse-free survival

In childhood acute lymphoblastic leukemia (ALL), a rapid decline of circulating leukemic blasts in response to induction chemotherapy or prednisone is one of the most important prognostic factors, not only for achieving remission but also for relapse-free survival (RFS). However, in acute myeloid leukemia (AML) parameters of chemosensitivity have been restricted mainly to the rapidity of achievement of complete remission (CR) or the assessment of residual leukemic bone marrow blasts during aplasia. We hypothesized that the time to circulating peripheral blood blast clearance, as a potential surrogate for in vivo chemosensitivity, would have prognostic relevance in AML also. In a retrospective analysis of a cohort of 86 adult patients with AML receiving uniform induction and consolidation chemotherapy, we demonstrate that the time to clearance of circulating blasts during induction chemotherapy is an independent prognostic marker of RFS, superseding other known or established risk factors, including karyotype and number of inductions to achieve CR.

Granulocytic sarcoma of the gingiva: two case reports

The intraoral occurrence of granulocytic sarcoma is extremely rare. This article describes 2 cases of granulocytic sarcoma of the gingiva in different clinical situations: one as a precursor to acute myeloid leukemia in a 50-year-old man and the other as a sign of blast crisis in a 59-year-old man with chronic myelomonocytic leukemia. Clinicians and oral surgeons should consider the possibility of tumorous lesion and systemic disease when an intractable ulcer is encountered in an oral cavity. Early diagnosis may improve prognosis and increase expectancy of survival.

FTY720, a new alternative for treating blast crisis chronic myelogenous leukemia and Philadelphia chromosome-positive acute lymphocytic leukemia

Blast crisis chronic myelogenous leukemia (CML-BC) and Philadelphia chromosome-positive (Ph1-positive) acute lymphocytic leukemia (ALL) are 2 fatal BCR/ABL-driven leukemias against which Abl kinase inhibitors fail to induce a long-term response. We recently reported that functional loss of protein phosphatase 2A (PP2A) activity is important for CML blastic transformation. We assessed the therapeutic potential of the PP2A activator FTY720 (2-amino-2-[2-(4-octylphenyl)ethyl]-1,3-propanediol hydrochloride), an immunomodulator in Phase III trials for patients with multiple sclerosis or undergoing organ transplantation, in CML-BC and Ph1 ALL patient cells and in in vitro and in vivo models of these BCR/ABL+ leukemias. Our data indicate that FTY720 induces apoptosis and impairs clonogenicity of imatinib/dasatinib-sensitive and -resistant p210/p190(BCR/ABL) myeloid and lymphoid cell lines and CML-BC(CD34+) and Ph1 ALL(CD34+/CD19+) progenitors but not of normal CD34+ and CD34+/CD19+ bone marrow cells. Furthermore, pharmacologic doses of FTY720 remarkably suppress in vivo p210/p190(BCR/ABL)-driven [including p210/p190(BCR/ABL)(T315I)] leukemogenesis without exerting any toxicity. Altogether, these results highlight the therapeutic relevance of rescuing PP2A tumor suppressor activity in Ph1 leukemias and strongly support the introduction of the PP2A activator FTY720 in the treatment of CML-BC and Ph1 ALL patients.

Safety of imatinib in chronic myeloid leukemia in blastic crisis presenting as cholestatic jaundice

Acute leukemia presenting as cholestatic jaundice is rare. It can occur due to granulocytic sarcoma compressing the bile ducts in case of acute myeloid leukemia. Rarely, diffuse infiltration of the liver sinusoids by the leukemic blasts can present as cholestatic jaundice. We report a case of chronic myeloid leukemia in lymphoid blast cell crisis presenting with severe cholestatic jaundice due to diffuse infiltration of the liver sinusoids with lymphoblasts. This patient tolerated imatinib well and, coinciding with the hematological response, there was marked reduction in the cholestasis due to blast clearance from the hepatic sinusoids. He was subsequently treated with combination chemotherapy and achieved morphological and cytogenetic remission.