A Novel Type of Monocytic Leukemia Stem Cell Revealed by the Clinical Use of Venetoclax-Based Therapy

The BCL2 inhibitor venetoclax has recently emerged as an important component of acute myeloid leukemia (AML) therapy. Notably, use of this agent has revealed a previously unrecognized form of pathogenesis characterized by monocytic disease progression. We demonstrate that this form of disease arises from a fundamentally different type of leukemia stem cell (LSC), which we designate as monocytic LSC (m-LSC), that is developmentally and clinically distinct from the more well-described primitive LSC (p-LSC). The m-LSC is distinguished by a unique immunophenotype (CD34-, CD4+, CD11b-, CD14-, CD36-), unique transcriptional state, reliance on purine metabolism, and selective sensitivity to cladribine. Critically, in some instances, m-LSC and p-LSC subtypes can co-reside in the same patient with AML and simultaneously contribute to overall tumor biology. Thus, our findings demonstrate that LSC heterogeneity has direct clinical significance and highlight the need to distinguish and target m-LSCs as a means to improve clinical outcomes with venetoclax-based regimens.

SIGNIFICANCE

These studies identify and characterize a new type of human acute myeloid LSC that is responsible for monocytic disease progression in patients with AML treated with venetoclax-based regimens. Our studies describe the phenotype, molecular properties, and drug sensitivities of this unique LSC subclass. This article is featured in Selected Articles from This Issue, p. 1949.

Machine Learning–Based Exploratory Clinical Decision Support for Newly Diagnosed Patients With Acute Myeloid Leukemia Treated With 7 + 3 Type Chemotherapy or Venetoclax/Azacitidine

PURPOSE

There are currently limited objective criteria to help assist physicians in determining whether an individual patient with acute myeloid leukemia (AML) is likely to do better with induction with either standard 7 + 3 chemotherapy or targeted therapy with venetoclax plus azacitidine. The study goal was to address this need by developing exploratory clinical decision support methods.

PATIENTS AND METHODS

Univariable and multivariable analysis as well as comparison of a range of machine learning (ML) predictors were performed using cohorts of 120 newly diagnosed 7 + 3-treated AML patients compared with 101 venetoclax plus azacitidine–treated patients.

RESULTS

A variety of features in the two patient cohorts were identified that may potentially correlate with short- and long-term outcomes, toxicities, and other considerations. A subset of these diagnostic features was then used to develop ML-based predictors with relatively high areas under the curve of short- and long-term outcomes, hospital stays, transfusion requirements, and toxicities for individual patients treated with either venetoclax/azacitidine or 7 + 3.

CONCLUSION

Potential ML-based approaches to clinical decision support to help guide individual patients with newly diagnosed AML to either 7 + 3 or venetoclax plus azacitidine induction therapy were identified. Larger cohorts with separate test and validation studies are necessary to confirm these initial findings.

Low ferroportin expression in AML is correlated with good risk cytogenetics, improved outcomes and increased sensitivity to chemotherapy

Iron metabolism is altered in a variety of cancers; however, little is known about the role of iron metabolism in the biology and response to therapy of acute myeloid leukemia (AML). Here we show that SLC40A1, the gene encoding the iron exporter ferroportin (FPN), is variably expressed among primary AMLs and that low levels are associated with good prognosis and improved outcomes. In particular, core binding factor (CBF) AMLs, which are associated with good outcomes with chemotherapy, consistently have low level of SLC40A1 expression. AML cell lines that expressed relatively low levels of FPN endogenously, or were engineered via gene knockdown, had an increased sensitivity to chemotherapy relative to controls expressing high levels of FPN. Primary FPN^low AML bulk cells also had increased sensitivity to Ara-C treatment, iron treatment and the combination of Ara-C and iron relative to FPN^high cells. FPN^low leukemic stem cells (LSCs) had decreased viability following addition of iron alone and in combination with Ara-C treatment relative to FPN^high LSCs. Together these observations suggest a model where FPN mediated iron metabolism may play a role in chemosensitivity and outcome to therapy in AML.

Targeted therapy for a subset of acute myeloid leukemias that lack expression of aldehyde dehydrogenase 1A1

Aldehyde dehydrogenase 1A1 (ALDH1A1) activity is high in hematopoietic stem cells and functions in part to protect stem cells from reactive aldehydes and other toxic compounds. In contrast, we found that approximately 25% of all acute myeloid leukemias expressed low or undetectable levels of ALDH1A1 and that this ALDH1A1⁻ subset of leukemias correlates with good prognosis cytogenetics. ALDH1A1⁻ cell lines as well as primary leukemia cells were found to be sensitive to treatment with compounds that directly and indirectly generate toxic ALDH substrates including 4-hydroxynonenal and the clinically relevant compounds arsenic trioxide and 4-hydroperoxycyclophosphamide. In contrast, normal hematopoietic stem cells were relatively resistant to these compounds. Using a murine xenotransplant model to emulate a clinical treatment strategy, established ALDH1A1⁻ leukemias were also sensitive to in vivo treatment with cyclophosphamide combined with arsenic trioxide. These results demonstrate that targeting ALDH1A1⁻ leukemic cells with toxic ALDH1A1 substrates such as arsenic and cyclophosphamide may be a novel targeted therapeutic strategy for this subset of acute myeloid leukemias.

Aldehyde dehydrogenases in acute myeloid leukemia

Acute myeloid leukemia (AML) affects approximately 15,000 persons per year in the United States and is the sixth leading cause of cancer-related deaths. The treatment of AML has advanced little in the past thirty years, in part because of the biologic heterogeneity of the disease and the difficulty in targeting AML cells while sparing normal hematopoietic cells. Advances in preventing and treating AML are likely to occur once the cellular and molecular differences between leukemia and normal hematopoietic cells are better understood. Aldehyde dehydrogenase (ALDH) activity is highly expressed in hematopoietic stem cells (HSCs), while, in contrast, a subset of AMLs are lacking this activity. This difference may be relevant to the development of AML and may also provide a better avenue for treating this disease. In this review, we summarize what is known about the ALDHs in normal HSCs and AML and propose strategies for capitalizing on these differences in the treatment of acute leukemia, and possibly other cancers as well.

Effects of the aldehyde dehydrogenase inhibitor disulfiram on the plasma pharmacokinetics, metabolism, and toxicity of benzaldehyde dimethane sulfonate (NSC281612, DMS612, BEN) in mice

PURPOSE

Benzaldehyde dimethane sulfonate (DMS612, NSC281612, BEN) is an alkylator with activity against renal cell carcinoma, currently in phase I trials. In blood, BEN is rapidly metabolized into its highly reactive carboxylic acid (BA), presumably the predominant alkylating species. We hypothesized that BEN is metabolized to BA by aldehyde dehydrogenase (ALDH) and aimed to increase BEN exposure in blood and tissues by inhibiting ALDH with disulfiram, thereby shifting BA production from blood to tissues.

METHODS

Female CD2F1 mice were dosed with 20 mg/kg BEN iv alone or 24 h after 300 mg/kg disulfiram ip. BEN, BA, and metabolites were quantitated in plasma and urine, and toxicities were assessed.

RESULTS

BEN had a plasma t½ <5 min and produced at least 12 products. The metabolite half-lives were <136 min. Disulfiram increased BEN plasma exposure 368-fold (AUC0-inf from 0.11 to 40.5 mg/L min), while plasma levels of BA remained similar. Urinary BEN excretion increased (1.0-1.5 % of dose), while BA excretion was unchanged. Hematocrit, white blood cell counts, and percentage lymphocytes decreased after BEN administration. Coadministration of disulfiram appeared to enhance these effects. Profound liver pathology was observed in mice treated with disulfiram and BEN.

CONCLUSIONS

BEN plasma concentrations increased after administration of disulfiram, suggesting that ALDH mediates the rapid metabolism of BEN in vivo, which may explain the increased toxicity seen with BEN after administration of disulfiram. Our results suggest that the coadministration of BEN with drugs that inhibit ALDH to patients that are ALDH deficient may cause liver damage.

Disorders in glucidic metabolism and congenital heart diseases: detection and prevention

The identification of gestational diabetes (GDM) through appropriate screening and its subsequent treatment have not been demonstrated to limit neonatal malformations to date. This study aimed to detect congenital heart diseases in newborns of mothers with GDM by evaluating the existence of a correlation with maternal glycemic control. This observational prospective study investigated newborns of mothers with GDM enrolled during a period of 9 months. Four subgroups were considered according to the type of maternal glucidic alteration during pregnancy and the home treatment: impaired glucose tolerance, insulin-dependent gestational diabetes mellitus (IDDM), non-insulin-dependent gestational diabetes mellitus (NIDDM), and gestational diabetes not controlled (NC: untreated diabetes). Student's t test was used to compare the subgroups. The study enrolled 65 newborns (30 boys) born to 82 of mothers with impaired glucidic metabolism. Patent ductus arteriosus was observed in 11 patients (16.9 %), pulmonary stenosis of mild grade in 4 patients ( 6.2 %), and hypertrophy of the ventricular septum in 22 patients (33.8 %). A total of 14 patients had increased thickness in the left ventricle posterior wall, and 17 patients had an abnormal electrocardiogram. Hyperglycemia can influence the development of the fetal heart, affecting both its structure and its function. A treatment with insulin for women with GDM is supported by the study data.

Deletion of the RNA-editing enzyme ADAR1 causes regression of established chronic myelogenous leukemia in mice

Patients with chronic myelogenous leukemia (CML) respond well to tyrosine kinase inhibitors (TKIs) of the Bcr-Abl oncoprotein. However, intolerance and resistance to these agents remains a challenge, and TKIs are unable to eradicate rare leukemia-initiating cells. Leukemia treatment would benefit from a better understanding of molecular signals that are necessary for the survival of leukemia-initiating cells but dispensable for normal hematopoietic stem cells. Leukemia-initiating cells in CML can arise from myeloid progenitor cells, a population that we have reported in normal hematopoiesis to depend on the RNA-editing enzyme adenosine deaminase acting on RNA-1 (ADAR1). We now report that Bcr-Abl transformed leukemic cells were ADAR1-dependent in a conditional ADAR1 knockout mouse model. ADAR1 deletion reversed leukocytosis and splenomegaly, and preferentially depleted primitive Lin-Sca+Kit+ (LSK) leukemic cells but not LSK cells lacking the leukemic oncoprotein. ADAR1 deletion ultimately normalized the peripheral white blood count, eliminating leukemic cells as assessed by PCR. These results uncover a novel requirement for ADAR1 in myeloid leukemic cells and indicate that ADAR1 may comprise a new molecular target for CML-directed therapeutics.

Helicobacter pylori Eradication Therapy: Current Availabilities

Background. Though Helicobacter pylori (HP) infections have progressively declined throughout most of the industrialized countries, a gradual increase in failure of HP eradication treatments is observed. Aim. To critically review evidence on the efficacy of the therapeutic availabilities for HP eradication, as yet. Methods. A selection of Clinical Trials, Systematic Reviews and Meta-analyses within the time period 2010–2012, was performed through a Medline search. Previous references were included when basically supporting the first selection. Results. An increasing rise in HP resistance rates for antimicrobial agents is currently observed. Further causes of HP treatment failure include polymorphisms of the CYP 2C19, an increased body mass index (BMI), smoking, poor compliance and re-infections. Alternative recent approaches to standard triple therapy have been attempted to increase the eradication rate, including bismuth-containing quadruple therapy, non-bismuth containing quadruple therapy, sequential therapy and levofloxacin-containing regimens. Conclusions. The main current aims should be the maintenance of a high eradication rate (>85%) of HP and the prevention of any increase in antimicrobial resistance. In the next future, the perspective of a tailored therapy could optimize eradication regimens within the different countries.

Varying levels of aldehyde dehydrogenase activity in adult murine marrow hematopoietic stem cells are associated with engraftment and cell cycle status

Aldehyde dehydrogenase (ALDH) activity is a widely used marker for human hematopoietic stem cells (HSCs), yet its relevance and role in murine HSCs remain unclear. We found that murine marrow cells with a high level of ALDH activity as measured by Aldefluor staining (ALDH(br) cells) do not contain known HSCs or progenitors. In contrast, highly enriched murine HSCs defined by the CD48(-)EPCR(+) and other phenotypes contain two subpopulations, one that stains dimly with Aldefluor (ALDH(dim)) and one that stains at intermediate levels (ALDH(int)). The CD48(-)EPCR(+)ALDH(dim) cells are virtually all in G(0) and yield high levels of engraftment via both intravenous and intrabone routes. In contrast the CD48(-)EPCR(+)ALDH(int) cells are virtually all in G(1), have little intravenous engraftment potential, and yet can engraft long-term after intrabone transplantation. These data demonstrate that Aldefluor staining of unfractionated murine marrow does not identify known HSCs or progenitors. However, varying levels of Aldefluor staining when combined with CD48 and EPCR detection can identify novel populations in murine marrow including a highly enriched population of resting HSCs and a previously unknown HSC population in G(1) with an intravenous engraftment defect.

Effects of fenoldopam on myocardial function (strain rate) in patients with coronary artery disease undergoing cardiac surgery

BACKGROUND

This study aimed to assess the effects of fenoldopam, an antihypertensive agent with nephroprotective properties, on myocardial function. The global systolic and diastolic function and the strain rate, a new parameter used to quantify regional myocardial function, were measured with transesophageal echocardiography.

METHODS

Forty patients undergoing elective coronary artery surgery were analyzed in a prospective nonrandomized clinical trial. Patients were divided into two groups, a group that received 0.05-mcg/kg/min fenoldopam (20 patients) and a control group (20 patients). Only patients with serum creatinine levels > or =120 micromol/L and critical coronary stenosis were selected. The ejection fraction (EF), the E and A waves, and the E/A ratio were measured with transesophageal echocardiography, and the strain rate was calculated using a strain quantification program to measure the peak systolic strain rate (PSSR) and the peak diastolic strain rate (PDSR).

RESULTS

Fenoldopam did not change the systolic and diastolic global function (EF, E wave, A wave and E/A). Regarding regional myocardial function, fenoldopam significantly increased the PSSR from -1.09+/-0.8 1/s to -2.24+/-2.26 1/s (P=0.038) and the PDSR from 1.04+/-0.69 1/s to 1.69+/-0.87 1/s (P=0.012).

CONCLUSION

Low doses of fenoldopam increased the regional myocardial function, as assessed by the myocardial strain rate, in patients undergoing cardiac surgery.

FuGEFlow: data model and markup language for flow cytometry

Background

Flow cytometry technology is widely used in both health care and research. The rapid expansion of flow cytometry applications has outpaced the development of data storage and analysis tools. Collaborative efforts being taken to eliminate this gap include building common vocabularies and ontologies, designing generic data models, and defining data exchange formats. The Minimum Information about a Flow Cytometry Experiment (MIFlowCyt) standard was recently adopted by the International Society for Advancement of Cytometry. This standard guides researchers on the information that should be included in peer reviewed publications, but it is insufficient for data exchange and integration between computational systems. The Functional Genomics Experiment (FuGE) formalizes common aspects of comprehensive and high throughput experiments across different biological technologies. We have extended FuGE object model to accommodate flow cytometry data and metadata.

Methods

We used the MagicDraw modelling tool to design a UML model (Flow-OM) according to the FuGE extension guidelines and the AndroMDA toolkit to transform the model to a markup language (Flow-ML). We mapped each MIFlowCyt term to either an existing FuGE class or to a new FuGEFlow class. The development environment was validated by comparing the official FuGE XSD to the schema we generated from the FuGE object model using our configuration. After the Flow-OM model was completed, the final version of the Flow-ML was generated and validated against an example MIFlowCyt compliant experiment description.

Results

The extension of FuGE for flow cytometry has resulted in a generic FuGE-compliant data model (FuGEFlow), which accommodates and links together all information required by MIFlowCyt. The FuGEFlow model can be used to build software and databases using FuGE software toolkits to facilitate automated exchange and manipulation of potentially large flow cytometry experimental data sets. Additional project documentation, including reusable design patterns and a guide for setting up a development environment, was contributed back to the FuGE project.

Conclusion

We have shown that an extension of FuGE can be used to transform minimum information requirements in natural language to markup language in XML. Extending FuGE required significant effort, but in our experiences the benefits outweighed the costs. The FuGEFlow is expected to play a central role in describing flow cytometry experiments and ultimately facilitating data exchange including public flow cytometry repositories currently under development.

MIFlowCyt: the minimum information about a Flow Cytometry Experiment

A fundamental tenet of scientific research is that published results are open to independent validation and refutation. Minimum data standards aid data providers, users, and publishers by providing a specification of what is required to unambiguously interpret experimental findings. Here, we present the Minimum Information about a Flow Cytometry Experiment (MIFlowCyt) standard, stating the minimum information required to report flow cytometry (FCM) experiments. We brought together a cross-disciplinary international collaborative group of bioinformaticians, computational statisticians, software developers, instrument manufacturers, and clinical and basic research scientists to develop the standard. The standard was subsequently vetted by the International Society for Advancement of Cytometry (ISAC) Data Standards Task Force, Standards Committee, membership, and Council. The MIFlowCyt standard includes recommendations about descriptions of the specimens and reagents included in the FCM experiment, the configuration of the instrument used to perform the assays, and the data processing approaches used to interpret the primary output data. MIFlowCyt has been adopted as a standard by ISAC, representing the FCM scientific community including scientists as well as software and hardware manufacturers. Adoptionof MIFlowCyt by the scientific and publishing communities will facilitate third-party understanding and reuse of FCM data.

Near-maximal expansions of hematopoietic stem cells in culture using NUP98-HOX fusions

OBJECTIVE

Strategies to expand hematopoietic stem cells (HSCs) ex vivo are of key interest. The objective of this study was to resolve if ability of HOXB4, previously documented to induce a significant expansion of HSCs in culture, may extend to other HOX genes and also to further analyze the HOX sequence requirements to achieve this effect.

METHODS

To investigate the ability of Nucleoporin98-Homeobox fusion genes to stimulate HSC self-renewal, we evaluated their presence in 10- to 20-day cultures of transduced mouse bone marrow cells. Stem cell recovery was measured by limiting-dilution assay for long-term competitive repopulating cells (CRU Assay).

RESULTS

These experiments revealed remarkable expansions of Nucleoporin98-Homeobox-transduced HSCs (1000-fold to 10,000-fold over input) in contrast to the expected decline of HSCs in control cultures. Nevertheless, the Nucleoporin98-Homeobox-expanded HSCs displayed no proliferative senescence and retained normal lympho-myeloid differentiation activity and a controlled pool size in vivo. Analysis of proviral integration patterns showed the cells regenerated in vivo were highly polyclonal, indicating they had derived from a large proportion of the initially targeted HSCs. Importantly, these effects were preserved when all HOX sequences flanking the homeodomain were removed, thus defining the homeodomain as a key and independent element in the fusion.

CONCLUSION

These findings create new possibilities for investigating HSCs biochemically and genetically and for achieving clinically significant expansion of human HSCs.

Data quality assessment of ungated flow cytometry data in high throughput experiments

BACKGROUND

The recent development of semiautomated techniques for staining and analyzing flow cytometry samples has presented new challenges. Quality control and quality assessment are critical when developing new high throughput technologies and their associated information services. Our experience suggests that significant bottlenecks remain in the development of high throughput flow cytometry methods for data analysis and display. Especially, data quality control and quality assessment are crucial steps in processing and analyzing high throughput flow cytometry data.

METHODS

We propose a variety of graphical exploratory data analytic tools for exploring ungated flow cytometry data. We have implemented a number of specialized functions and methods in the Bioconductor package rflowcyt. We demonstrate the use of these approaches by investigating two independent sets of high throughput flow cytometry data.

RESULTS

We found that graphical representations can reveal substantial nonbiological differences in samples. Empirical Cumulative Distribution Function and summary scatterplots were especially useful in the rapid identification of problems not identified by manual review.

CONCLUSIONS

Graphical exploratory data analytic tools are quick and useful means of assessing data quality. We propose that the described visualizations should be used as quality assessment tools and where possible, be used for quality control.

High-content flow cytometry and temporal data analysis for defining a cellular signature of graft-versus-host disease

Acute graft-versus-host disease (GVHD) is diagnosed by clinical and histologic criteria that are often nonspecific and typically apparent only after the disease is well established. Because GvHD is mediated by donor T cells and other immune effector cells, we sought to determine whether changes within a wide array of peripheral blood lymphocyte populations could predict the development of GvHD. Peripheral blood samples from 31 patients undergoing allogeneic blood and marrow transplant were analyzed for the proportion of 121 different subpopulations defined by 4-color combinations of lymphocyte phenotypic and activation markers at progressive time points posttransplant. Samples were processed using a newly developed high content flow cytometry technique and subjected to a spline- and functional linear discriminant analysis (FLDA)-based temporal analysis technique. This strategy identified a consistent posttransplant increase in the proportion and extent of fluctuation of CD3+CD4+CD8beta+ cells in patients who developed GVHD compared to those that did not. Although larger prospective clinical studies will be necessary to validate these results, this study demonstrates that high-content flow cytometry coupled with temporal analysis is a powerful approach for developing new diagnostic tools, and may be useful for developing a sensitive and specific predictive test for GVHD.

Chronic myeloid leukemia stem cells possess multiple unique features of resistance to BCR-ABL targeted therapies

The leukemic stem cells in patients with chronic myeloid leukemia (CML) are well known to be clinically resistant to conventional chemotherapy and may also be relatively resistant to BCR-ABL-targeted drugs. Here we show that the lesser effect of imatinib mesylate (IM) on the 3-week output of cells produced in vitro from lin(-)CD34(+)CD38(-) CML (stem) cells compared with cultures initiated with the CD38(+) subset of lin(-)CD34(+) cells is markedly enhanced (>10-fold) when conditions of reduced growth factor stimulation are used. Quantitative analysis of genes expressed in these different CML subsets revealed a differentiation-associated decrease in IL-3 and G-CSF transcripts, a much more profound decrease in expression of BCR-ABL than predicted by changes in BCR expression, decreasing expression of ABCB1/MDR and ABCG2 and increasing expression of OCT1. p210(BCR-ABL) and kinase activity were also higher in the lin(-)CD34(+)CD38(-) cells and formal evidence that increasing BCR-ABL expression decreases IM sensitivity was obtained from experiments with a cell line model. Nevertheless, within the entire CD34(+) subset of CML cells, BCR-ABL expression was not strongly affected by changes in cell cycle status. Taken together, these results provide the first evidence of multiple mechanisms of innate IM resistance in primitive and quiescent CML cells.

Identification of compounds that enhance the anti-lymphoma activity of rituximab using flow cytometric high-content screening

In this report, we describe a new flow cytometry technique termed flow cytometric high-content screening (FC-HCS) which involves semi-automated processing and analysis of multiparameter flow cytometry samples. As a first test of the FC-HCS technique, we used it to screen a 2000-compound library, called the National Cancer Institute (NCI) Diversity Set, to identify agents that would enhance the anti-lymphoma activity of the therapeutic monoclonal antibody rituximab. FC-HCS identified 15 compounds from the Diversity Set that significantly enhanced the ability of rituximab to inhibit cell cycle progression and induce apoptosis in lymphoma cells. The validity of the screening results was confirmed for several compounds using additional assays of cell proliferation, apoptosis and cell growth. The FC-HCS technique was relatively simple and reliable and could process up to 1000 samples/day on a single flow cytometer. The FC-HCS technique may be useful for a variety of applications including drug discovery, immunologic monitoring of patients, functional genomics studies and tissue engineering efforts.

Histone deacetylase inhibitor LAQ824 both lowers expression and promotes proteasomal degradation of Bcr-Abl and induces apoptosis of imatinib mesylate-sensitive or -refractory chronic myelogenous leukemia-blast crisis cells

Treatment with LAQ824 (Novartis Pharmaceutical, Inc.), a cinnamyl hydroxamic acid analogue inhibitor of histone deacetylases, depleted the mRNA and protein expression of Bcr-Abl in human chronic myeloid leukemia blast crisis (CML-BC) cells. Exposure to LAQ824 induced the expression of the cell cycle-dependent kinase inhibitors p21 and p27 and caused cell cycle G(1)-phase accumulation and apoptosis of CML-BC cells. LAQ824 also induced acetylation of heat shock protein 90. This inhibited the chaperone association of Bcr-Abl with heat shock protein 90, thereby promoting the proteasomal degradation of Bcr-Abl. Cotreatment with LAQ824 increased imatinib mesylate-induced apoptosis of CML-BC cells. Additionally, LAQ824 down-regulated the levels of mutant Bcr-Abl possessing the T315I point mutation, as well as induced apoptosis of imatinib-refractory primary CML-BC cells. Therefore, LAQ824 may be a promising therapeutic agent in the treatment of imatinib-sensitive or -refractory human leukemia.

Mobilization of dendritic cells from patients with breast cancer into peripheral blood stem cell leukapheresis samples using Flt-3-Ligand and G-CSF or GM-CSF

Treatment with myeloablative chemotherapy and autologous peripheral blood stem cell (PBSC) transplantation followed by vaccination with autologous dendritic cells (DCs) treated with tumor antigens is a promising therapeutic strategy for several types of cancer. Obtaining sufficient numbers of both PBSCs and DCs is central to this approach. Previously, it has been shown that administration of Flt-3-Ligand (FL) combined with either G-CSF or GM-CSF mobilizes large numbers of PBSCs in patients with cancer. In the current study, we sought to determine whether these same cytokines could simultaneously mobilize DCs into the PBSC leukapheresis collection. DCs were analysed in PBSC leukapheresis samples obtained from five patients with high-risk breast cancer who received G-CSF alone as priming prior to leukapheresis, four patients who received FL+G-CSF and five patients who received FL+GM-CSF. DCs were defined as cells with a lin(dim/-) HLA-DR+ CD11c+ phenotype. The proportions of DCs in the FL+G-CSF and FL+GM-CSF samples were significantly higher than in pre-mobilization peripheral blood and G-CSF leukapheresis samples. The mean yield of DCs/kg in the FL+GM-CSF samples was also significantly higher than the mean yield of DCs in the G-CSF samples. The FL+G-CSF and FL+GM-CSF mobilized DCs were immature by morphologic and phenotypic criteria but stimulated allogeneic T-cells at levels similar to DCs generated in culture from PBMCs. Overnight culture?of the immature DCs obtained from patients receiving either FL+G-CSF or FL+GM-CSF in TNF-alpha?resulted in the generation of mature DCs. In summary, administration of FL in combination with GM-CSF and G-CSF to patients with breast cancer can mobilize large numbers of immature DCs into PBSC leukapheresis collections.

[Prognostic systems in intensive care: TRISS, SAPS II, APACHE III]

BACKGROUND

To validate the accuracy of SAPS II, APACHE III and TRISS for the prediction of mortality in Intensive Care Unit (ICU) at polytrauma patients admission. The outcome of multiple trauma patients is often linked to the degree of physiologic dysfunction and to the extension of anatomic lesions, the age of the patient and the lesion mechanism.

METHODS

The study population consisted of 93 cases of multiple injured patients hospitalised at the ICU of the Padua hospital from October 1998 to October 1999; the term polytraumatized patient is referred to patients who have multiple lesions of which at least one potentially endangers, immediately or in a short term, their life. These cases were evaluated with the APACHE III, SAPS II, Revised Trauma Score and Injury Severity Score. The predictive power of each system was evaluated by using decision matrix analysis to compare observed and predicted outcome with a decision criterion of 0.50 and 0.40 for risk of hospital death.

RESULTS

All trauma score systems under study showed high accuracy rates, above all if they are used with a 40% positive test.

CONCLUSIONS

The prognostic scales used in this study showed a good correlation between expected and observed cases, particularly with TRISS and APACHE III systems. The APACHE III system seems to be the most reliable of the different methods analysed. These prognostic systems are seldom or occasionally used in the ICU, in Padua and in the whole of Italy, so Italian data are not suitable to be compared to international ones. Due to urgency, the importance of the evaluation scales is often underestimated, but even if they require time and attention, they surely can be useful in the evaluation of the treatment, and not only of a polytraumatized patient.

Induction chemotherapy followed by simultaneous hyperfractionated radiochemotherapy in advanced head and neck cancer. A pilot study

PURPOSE

To evaluate the feasibility of induction chemotherapy followed by concomitant chemotherapy and hyperfractionated irradiation in locally advanced, inoperable head and neck cancer.

METHODS

A pilot study was undertaken comprising 3 cycles of cisplatinum (100 mg/m2, day 1) and 5-fluorouracil (1000 mg/m2 in continuous intravenous infusion over the first 120 h) followed by bifractionated radiotherapy applied to tumor/involved lymph nodes up to the dose of 74.4 Gy given in 2 fractions of 1.2 Gy daily for 5 days a week combined with concomitant weekly cisplatinum infusion (50 mg/m2).

RESULTS

Six patients were enrolled in the study. All of them completed the protocol therapy. Severe mucositis and myelotoxicity were the most common acute side effects observed in all and in 5 of the patients, respectively. Acute toxicity required interruption of concomitant chemotherapy in 5 cases and in 2 interruption of radiotherapy was necessary. Opioid analgesic parenteral therapy was administered in 4 patients. Three of them had to be hospitalized. One patient experienced cerebral stroke 1 day after the completion of therapy and died 7 days later. Due to high acute toxicity, patient accrual was terminated after 6 patients. At the mean follow-up of 17 months, 4 patients are alive, 3 of them are free of disease and in 1 local progression has been diagnosed.

CONCLUSIONS

High acute toxicity of induction cisplatinum and 5-fluorouracil followed by concomitant cisplatinum and hyperfractionated irradiation calls for less toxic treatment schedules in locally advanced inoperable head and neck cancer.