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Systemic mastocytosis (SM) is a hematopoietic neoplasm characterized by pathologic expansion of tissue mast cells in one or more extracutaneous organs. In most children and most adult patients, skin involvement is found. Childhood patients frequently suffer from cutaneous mastocytosis without systemic involvement, whereas most adult patients are diagnosed as suffering from SM. In a smaller subset of patients, SM without skin lesions develops which is a diagnostic challenge. In the current article, a diagnostic algorithm for patients with suspected SM is proposed. In adult patients with skin lesions and histologically confirmed mastocytosis in the skin (MIS), a bone marrow biopsy is recommended regardless of the serum tryptase level. In adult patients without skin lesions who are suffering from typical mediator-related symptoms, the basal serum tryptase level is an important diagnostic parameter. In those with slightly elevated tryptase (15-30 ng/ml), additional non-invasive investigations, including a KIT mutation analysis of peripheral blood cells and sonographic analysis, is performed. In adult patients in whom i) KIT D816V is detected or/and ii) the basal serum tryptase level is clearly elevated (> 30 ng/ml) or/and iii) other clinical or laboratory features are suggesting the presence of occult mastocytosis, a bone marrow biopsy should be performed. In the absence of KIT D816V and other indications of mastocytosis, no bone marrow investigation is required, but the patient's course and the serum tryptase levels are examined in the follow-up.

Systemic mastocytosis (SM) is characterized by accumulation of neoplastic mast cells and is classified into indolent and aggressive forms. The latter include aggressive SM (ASM), mast cell leukemia (MCL), and SM associated with a myeloid neoplasm wherein 1 or both disease compartments exhibit advanced features. These variants, henceforth collectively referred to as advanced SM for the purposes of this report, are typically characterized by organ damage and shortened survival duration. In contrast to indolent SM, in which symptoms are usually managed by noncytotoxic antimediator therapy, cytoreduction is usually necessary for disease control in advanced SM. Unfortunately, current drug treatment of these patients rarely results in complete clinical and histopathologic remissions or improved survival time. Previously defined response criteria were adapted to the heterogeneous presentations of advanced SM and the limited effects of available drugs. However, recent advances in understanding the molecular pathogenesis of SM and the corresponding prospect in targeted therapy make it a priority to modify these criteria. Our current study is the product of an international group of experts and summarizes the challenges in accomplishing this task and forwards a new proposal for response criteria, which builds on prior proposals and should facilitate response evaluation in clinical trials.

The European Competence Network on Mastocytosis (ECNM) was initiated in 2002 as a multidisciplinary and multinational cooperative approach to increase awareness and to improve diagnosis and therapy of mastocytosis. The network is composed of local centers, physicians, and scientists who have dedicated their work to patients with mastocytosis. A strategic goal of the ECNM is to provide the best available information about the disease to patients and physicians. During the past 10 years, the ECNM has expanded to various countries and contributed successfully to the development of markers, definitions, and standards in the field of mastocytosis. Members of the ECNM organized Annual Meetings in Europe and two Working Conferences on Mastocytosis in Vienna (in 2005 and 2010), and initiated and supported several preclinical and clinical trials. In all these activities, representatives of the ECNM cooperate closely with their US colleagues, with patient-organizations in Europe and in the USA, and with other scientific networks. The ECNM also launched a mastocytosis registry that has been activated in 2012. Using the central database of this registry, cooperative multicenter studies, which should include sufficient numbers of patients and robust evaluations, will be conducted. These studies will increase our knowledge about optimal management and therapy of patients with mastocytosis in the future.

Acute myeloid leukemia (AML) is a life-threatening stem cell disease characterized by uncontrolled proliferation and accumulation of myeloblasts. Using an advanced RNAi screen-approach in an AML mouse model we have recently identified the epigenetic 'reader' BRD4 as a promising target in AML. In the current study, we asked whether inhibition of BRD4 by a small-molecule inhibitor, JQ1, leads to growth-inhibition and apoptosis in primary human AML stem- and progenitor cells. Primary cell samples were obtained from 37 patients with freshly diagnosed AML (n=23) or refractory AML (n=14). BRD4 was found to be expressed at the mRNA and protein level in unfractionated AML cells as well as in highly enriched CD34⁺/CD38⁻ and CD34⁺/CD38⁺ stem- and progenitor cells in all patients examined. In unfractionated leukemic cells, submicromolar concentrations of JQ1 induced major growth-inhibitory effects (IC₅₀ 0.05-0.5 µM) in most samples, including cells derived from relapsed or refractory patients. In addition, JQ1 was found to induce apoptosis in CD34+/CD38⁻ and CD34⁺/CD38⁺ stem- and progenitor cells in all donors examined as evidenced by combined surface/Annexin-V staining. Moreover, we were able to show that JQ1 synergizes with ARA-C in inducing growth inhibition in AML cells. Together, the BRD4-targeting drug JQ1 exerts major anti-leukemic effects in a broad range of human AML subtypes, including relapsed and refractory patients and all relevant stem- and progenitor cell compartments, including CD34⁺/CD38⁻ and CD34⁺/CD38⁺ AML cells. These results characterize BRD4-inhibition as a promising new therapeutic approach in AML which should be further investigated in clinical trials.

Patients with malignancies are considered to be at increased risk of acquiring influenza. Because of higher complication and case fatality rates, preventive measures such as vaccination are of great interest. The objective of this study was to assess the acceptability, tolerability and immunogenicity of an adjuvant-free whole-virion pandemic influenza A (H1N1) vaccine in cancer patients with ongoing anticancer treatment during a 'pandemic situation'. Adult patients with hematologic malignancies or solid tumors and concurrent cytotoxic, targeted, and/or hormone therapy were recruited during the influenza A (H1N1) pandemic in 2009/2010 and were offered free vaccine. Antibody titers were measured using virus-specific hemagglutination inhibition assay and ELISA. Among 285 patients with solid tumors who were offered vaccination during their therapy, 260 (91.2%) declined and 25 (8.8%) accepted. Seventeen patients with hematologic malignancies were also vaccinated during therapy; 23 healthy individuals served as a control group. When measured using hemagglutination-inhibition assays, rates of seroprotection, seroconversion, and geometric mean titer ratios after the second vaccination were 96%, 70%, and 4.1 respectively among the healthy individuals, 90%, 52%, and 4.3 among patients with solid tumors, and 67%, 13%, and 1.5 among patients with hematologic malignancies during therapy (P<0.05). When measured using ELISA, seropositivity differed significantly among the three groups after the second vaccination: healthy individuals 74%, patients with solid tumors 57%, those with hematologic malignancies 13% (P<0.001). The vaccine was well tolerated. Our results demonstrate a low uptake of the well tolerated adjuvant-free influenza A (H1N1) vaccine by cancer patients receiving anticancer treatment during the pandemic of 2009/2010. Among the vaccinated patients, the immune response was weaker than that in healthy individuals. The immune response in patients with hematological malignancies was low. Two doses of vaccine are needed in these immunosuppressed patients., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The International Prognostic Scoring System (IPSS) is an important standard for assessing prognosis of primary untreated adult patients with myelodysplastic syndromes (MDS). To refine the IPSS, MDS patient databases from international institutions were coalesced to assemble a much larger combined database (Revised-IPSS [IPSS-R], n = 7012, IPSS, n = 816) for analysis. Multiple statistically weighted clinical features were used to generate a prognostic categorization model. Bone marrow cytogenetics, marrow blast percentage, and cytopenias remained the basis of the new system. Novel components of the current analysis included: 5 rather than 3 cytogenetic prognostic subgroups with specific and new classifications of a number of less common cytogenetic subsets, splitting the low marrow blast percentage value, and depth of cytopenias. This model defined 5 rather than the 4 major prognostic categories that are present in the IPSS. Patient age, performance status, serum ferritin, and lactate dehydrogenase were significant additive features for survival but not for acute myeloid leukemia transformation. This system comprehensively integrated the numerous known clinical features into a method analyzing MDS patient prognosis more precisely than the initial IPSS. As such, this IPSS-R should prove beneficial for predicting the clinical outcomes of untreated MDS patients and aiding design and analysis of clinical trials in this disease.

Eosinophilia is an important indicator of various neoplastic and nonneoplastic conditions. Depending on the underlying disease and mechanisms, eosinophil infiltration can lead to organ dysfunction, clinical symptoms, or both. During the past 2 decades, several different classifications of eosinophilic disorders and related syndromes have been proposed in various fields of medicine. Although criteria and definitions are, in part, overlapping, no global consensus has been presented to date. The Year 2011 Working Conference on Eosinophil Disorders and Syndromes was organized to update and refine the criteria and definitions for eosinophilic disorders and to merge prior classifications in a contemporary multidisciplinary schema. A panel of experts from the fields of immunology, allergy, hematology, and pathology contributed to this project. The expert group agreed on unifying terminologies and criteria and a classification that delineates various forms of hypereosinophilia, including primary and secondary variants based on specific hematologic and immunologic conditions, and various forms of the hypereosinophilic syndrome. For patients in whom no underlying disease or hypereosinophilic syndrome is found, the term hypereosinophilia of undetermined significance is introduced. The proposed novel criteria, definitions, and terminologies should assist in daily practice, as well as in the preparation and conduct of clinical trials., (Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

Mastocytosis is a heterogeneous group of disorders defined by abnormal growth and accumulation of clonal mast cells. CM is the predominant variant in childhood, whereas the majority of adult patients present with systemic mastocytosis. In over 80% of the latter patients, the KIT mutation D816V is detectable. Whereas childhood mastocytosis often resolves spontaneously before adolescence and has a good prognosis, in most adult patients mastocytosis is a persistent systemic disorder. The course and prognosis in these patients are variable; in indolent variants, the clinical course remains stable over years or even decades. In advanced mastocytosis, the prognosis is less favorable despite novel drugs counteracting growth of neoplastic mast cells. Although WHO criteria are clearly separating prognostic subsets of mastocytosis, little is known about specific prognostic factors predicting the outcome in individual patients. In this article, we review current concepts in mastocytosis, including prognostic parameters for indolent and advanced systemic mastocytosis.

The recent identification of DNMT3A mutations in de novo acute myeloid leukemia prompted us to determine their frequency, patterns and clinical impact in a cohort of 98 patients with either therapy-related or secondary acute myeloid leukemia developing from an antecedent hematologic disorder. We identified 24 somatic mutations in 23 patients with a significantly higher frequency in secondary acute myeloid leukemia (35.1%) as compared to therapy-related acute myeloid leukemia (16.4%, P=0.0486). DNMT3A mutations were associated with a normal karyotype and IDH1/2 mutations, but did not affect survival. In contrast to de novo acute myeloid leukemia, most mutations did not affect arginine on position 882, but were predominantly found in the methyltransferase domain. All DNMT3A mutations identified in secondary acute myeloid leukemia were already present in the antecedent disorders indicating an early event. Reduction to homozygosity by uniparental disomy was observed in 2 patients with secondary acute myeloid leukemia during disease progression.

Background: CD33 is a well-known stem cell target in acute myeloid leukemia. So far, however, little is known about expression of CD33 on leukemic stem cells in chronic leukemias., Design and Methods: We analyzed expression of CD33 in leukemic progenitors in chronic myeloid leukemia by multi-color flow cytometry and quantitative polymerase chain reaction. In addition, the effects of a CD33-targeting drug, gemtuzumab/ozogamicin, were examined., Results: As assessed by flow cytometry, stem cell-enriched CD34(+)/CD38(-)/CD123(+) leukemic cells expressed significantly higher levels of CD33 compared to normal CD34(+)/CD38(-) stem cells. Moreover, highly enriched leukemic CD34(+)/CD38(-) cells (>98% purity) displayed higher levels of CD33 mRNA. In chronic phase patients, CD33 was found to be expressed invariably on most or all stem cells, whereas in accelerated or blast phase of the disease, the levels of CD33 on stem cells varied from donor to donor. The MDR1 antigen, supposedly involved in resistance against ozogamicin, was not detectable on leukemic CD34(+)/CD38(-) cells. Correspondingly, gemtuzumab/ozogamicin produced growth inhibition in leukemic progenitor cells in all patients tested. The effects of gemtuzumab/ozogamicin were dose-dependent, occurred at low concentrations, and were accompanied by apoptosis in suspension culture. Moreover, the drug was found to inhibit growth of leukemic cells in a colony assay and long-term culture-initiating cell assay. Finally, gemtuzumab/ozogamicin was found to synergize with nilotinib and bosutinib in inducing growth inhibition in leukemic cells., Conclusions: CD33 is expressed abundantly on immature CD34(+)/CD38(-) stem cells and may serve as a stem cell target in chronic myeloid leukemia.

Background: In chronic myeloid leukaemia (CML), clonal evolution with resistance to tyrosine kinase inhibitors (TKIs) is often triggered by BCR/ABL1 mutations. However, in the context of the complex pro-oncogenic signalling networks which ultimately lead to clonal expansion and disease progression, the exact contribution of BCR/ABL1 mutants remains uncertain. Recent data indicate that detection of BCR/ABL1 mutant subclones does not permit prediction of their expansion dynamics and their potential to become drivers of resistant disease., Methods: To determine the patterns of clonal evolution and the distinct proliferation kinetics of individual BCR/ABL1 mutants during treatment, we employed ligase-dependent polymerase chain reaction (LD-PCR) analysis for quantitative surveillance of CML subclones with various tyrosine kinase domain (TKD) mutations including M244V, L248V, G250E, E255K, T315I, F317L-A/G, M351T and F359V., Findings: Inadequate treatment responses were observed in 27 of 100 patients investigated and 16 were found to bear one or more BCR/ABL1 TKD mutations in separate subclones. Rapid subclone expansion upon onset or switch of TKI treatment was common and sometimes preceded corresponding changes in BCR/ABL1 transcript levels. Mutant subclones were found to respond differentially and sometimes unexpectedly to various treatment modalities. Decline and persistent depletion of specific mutation-bearing subclones in response to treatment could be documented by LD-PCR surveillance., Interpretation: The observations show that quantitative monitoring of mutant BCR/ABL1 subclones by LD-PCR is a powerful tool for detection of clonal evolution, subclone-expansion and subclone-depletion and can contribute to optimised management of patients with CML., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: Mediator-related symptoms in patients with systemic mastocytosis (SM) range from mild episodic to severe life-threatening events., Methods: We examined a series of 137 consecutive patients with mastocytosis (63 females and 74 males) referred to our center between 1988 and 2010. Almost all patients received prophylactic histamine receptor (HR1 and HR2) antagonists., Results: Forty-two patients suffered from one or more mediator-related symptoms (hypotension, headache, flush, abdominal cramping, diarrhea) requiring therapy (SM(SY)). Severe life-threatening events (grade IV) occurred in 17 patients (12%). In 4 of these 17 patients, a deteriorating clinical course was recorded. One patient died of an apallic syndrome 1.5 years after an hymenoptera sting and cerebral hypoxia. One patient was disabled for months after an insect sting and cerebral hypoxia. Two patients with smoldering SM (SSM) suffered from severe recurrent hypotension requiring hospitalization and repeated resuscitation. Symptoms in these SSM patients did not respond to any of the antimediator-type drugs applied. However, after therapy with cladribine (2CdA), a major durable response was obtained in both cases. In patients with aggressive SM and mast cell leukemia (n = 6), life-threatening mediator-related events (grade IV) were not recorded., Conclusions: SM may be accompanied by life-threatening mediator-related symptoms. Most of these patients have indolent SM or SSM. In patients with SSM(SY) with uncontrolled symptoms (grade IV), therapy with 2CdA should be considered., (Copyright © 2011 S. Karger AG, Basel.)

It is now generally appreciated that hematologic neoplasms can develop over many years if not decades, often being initially occult or showing minimal (subdiagnostic) abnormalities. However, whereas such early neoplastic conditions have been defined in some detail in lymphoproliferative neoplasms, little is known about minimal lesions preceding the manifestation of an overt myeloid neoplasm, about underlying mechanisms, the clinical course and outcome, and the prognostic significance of such conditions. Members of several groups have recently described two 'premalignant' myeloid conditions, namely idiopathic cytopenia of undetermined significance (ICUS) and idiopathic bone marrow dysplasia of uncertain significance (IDUS). At least in some patients these are neoplastic conditions. Both conditions may progress to an overt myelodysplastic syndrome (MDS), but may also progress to another myeloid neoplasm such as acute myeloid leukemia, a myeloproliferative neoplasm (MPN), or a mast cell disorder (mastocytosis). In ICUS the dysplasia is mild and does not fulfill the WHO criteria for MDS but cytopenias can be severe. In IDUS the dysplasia is prominent but cytopenias, if detectable, are mild. In both conditions it is possible that a neoplastic clone has already replaced most or all of normal bone marrow cells when ICUS or IDUS is detected, but evidence to support this possibility is not necessarily available. For both groups of patients we recommend a thorough hematologic follow up because of the potential of disease-manifestation and the unpredictable form and time of progression. In the present review, we discuss current concepts relating to ICUS and IDUS as well as diagnostic approaches and available criteria., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Activation of tissue mast cells (MCs) and their abnormal growth and accumulation in various organs are typically found in primary MC disorders also referred to as mastocytosis. However, increasing numbers of patients are now being informed that their clinical findings are due to MC activation (MCA) that is neither associated with mastocytosis nor with a defined allergic or inflammatory reaction. In other patients with MCA, MCs appear to be clonal cells, but criteria for diagnosing mastocytosis are not met. A working conference was organized in 2010 with the aim to define criteria for diagnosing MCA and related disorders, and to propose a global unifying classification of all MC disorders and pathologic MC reactions. This classification includes three types of 'MCA syndromes' (MCASs), namely primary MCAS, secondary MCAS and idiopathic MCAS. MCA is now defined by robust and generally applicable criteria, including (1) typical clinical symptoms, (2) a substantial transient increase in serum total tryptase level or an increase in other MC-derived mediators, such as histamine or prostaglandin D(2), or their urinary metabolites, and (3) a response of clinical symptoms to agents that attenuate the production or activities of MC mediators. These criteria should assist in the identification and diagnosis of patients with MCAS, and in avoiding misdiagnoses or overinterpretation of clinical symptoms in daily practice. Moreover, the MCAS concept should stimulate research in order to identify and exploit new molecular mechanisms and therapeutic targets., (Copyright © 2011 S. Karger AG, Basel.)

Heat shock protein 32 (Hsp32), also known as heme oxygenase 1 (HO-1), has recently been identified as a potential target in various hematologic malignancies. We provide evidence that Hsp32 is constitutively expressed in primary leukemic cells in patients with acute myeloid leukemia (AML) and in various AML cell lines (HL60, U937, KG1). Expression of Hsp32 mRNA was demonstrable by qPCR, and expression of the Hsp32 protein by immunocytochemistry and Western blotting. The stem cell-enriched CD34+/CD38+ and CD34+/CD38- fractions of AML cells were found to express Hsp32 mRNA in excess over normal CD34+ progenitor cells. Two Hsp32-targeting drugs, pegylated zinc-protoporphyrin (PEG-ZnPP) and styrene-maleic-acid-copolymer-micelle-encapsulated ZnPP (SMAZnPP), were found to inhibit cytokine-dependent and spontaneous proliferation in all 3 AML cell lines as well as in primary AML cells. Growth inhibitory effects of SMA-ZnPP and PEG-ZnPP were dose-dependent with IC50 values ranging between 1 and 20 μM, and were accompanied by apoptosis as evidenced by light- and electron microscopy, Tunel assay, and caspase-3 activation. Finally, we were able to demonstrate that SMA-ZnPP inhibits cytokine-dependent proliferation of CD34+/CD38+ and CD34+/CD38- AML progenitor cells in vitro in all patients as well as leukemiainitiation of AML stem cells in NOD-SCID IL-2Rγ(-/-) (NSG) mice in vivo. Together, our data suggest that Hsp32 plays an important role as a survival factor in leukemic stem cells and as a potential new target in AML.

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment option for various hematologic disorders. However, life-threatening adverse events resulting from treatment-related toxicity, severe infections, and/or graft-versus-host disease (GvHD) can occur. We report on a 64-year-old patient suffering from secondary acute myeloid leukemia (AML) who underwent successful allogeneic HSCT while on invasive mandatory ventilation (IMV). The patient received reduced intensity conditioning (RIC) according to the FLAMSA-protocol. Acute respiratory failure occurred one day before scheduled HSCT. Following emergency endotracheal intubation the patient was transferred to the intensive care unit (ICU). Because of respiratory deterioration, stem cell infusion was postponed. After stabilization of respiratory parameters, HSCT was performed during IMV which was continued for seven days. Following hematopoietic regeneration the patient was discharged in good condition on day 35 after HSCT. This case illustrates that intubation and mechanical ventilation do not necessarily exclude leukemic patients from HSCT.

Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal hematopoietic stem cell disorders that are preferentially diagnosed in the elderly. Aberrant expression of the adhesion receptor CD44 correlates with poor prognosis in various neoplasms. To evaluate the prognostic impact of CD44 in MDS serum levels of soluble CD44 standard (solCD44s) were measured in 130 MDS patients (median age 68 years) using an enzyme-linked immunosorbent assay (ELISA). solCD44s levels were significantly elevated in MDS patients as compared to those of healthy donors (p<0.001) and were found to correlate with distinct FAB and WHO subtypes. The highest levels of solCD44s were found in patients with CMML, in RAEB and in patients with MDS transformed into secondary acute myeloid leukaemia (AML). In univariate analysis elevated levels of solCD44s (cut-off level>688.5ng/ml) correlated significantly with shorter overall survival in MDS patients (12 versus 39 months; p<0.001). In multivariate analysis solCD44s displayed prognostic significance independent of the International Prognosis Scoring System (IPSS). To test for refined prognostication, IPSS risk groups were split into two separate categories based on the solCD44s levels. Using this approach, MDS patients with a shorter survival were identified both in the IPSS low-risk (p=0.037) and in the IPSS intermediate-1-risk group (p=0.015). The CD44s-adjusted IPSS defines a cohort of MDS patients with unfavorable prognosis, which might be helpful in risk stratification and in therapeutic algorithms., (2010 Elsevier Ireland Ltd. All rights reserved.)

In acute lymphoblastic leukemia (ALL), the Philadelphia chromosome (Ph) is associated with a poor prognosis. For these patients, hematopoietic stem cell transplantation (HSCT) and BCR/ABL tyrosine kinase inhibitors (TKIs) are considered standard of therapy. However, it remains unclear whether BCR/ABL TKIs should be administered lifelong as maintenance post-HSCT, and whether the presence of minimal residual disease (MRD) is invariably associated with relapse. We report on two patients with Ph+ ALL who were successfully treated with polychemotherapy and consecutive autologous HSCT. Both patients are in continuous hematologic remission after an observation period of 12 years and 18 years, respectively, despite measurable MRD and although no maintenance therapy was initiated. BCR/ABL transcript-levels ranged between 0.1 and 3% in patient 1, and 0.01 and 0.1% in patient 2 during the observation time. Collectively, these data suggest that not all Ph+ subclones even those that persist after HSCT in Ph+ ALL, may have the potential to cause a hematologic relapse. We hypothesize that these small-sized clones are derived from neoplastic stem cells that have not (yet) accumulated a sufficient number of pro-oncogenic hits required for full transformation to ALL-initiating (stem) cells and thus overt leukemia.

We report on 17 patients with influenza A H1N1v-associated Adult Respiratory Distress Syndrome who were admitted to the intensive care unit (ICU) between June 11th 2009 and August 10th 2010 (f/m: 8/9; age: median 39 (IQR 29-54) years; SAPS II: 35 (29-48)). Body mass index was 26 (24-35), 24% were overweight and 29% obese. The Charlson Comorbidity Index was 1 (0-2) and all but one patient had comorbid conditions. The median time between onset of the first symptom and admission to the ICU was 5 days (range 0-14). None of the patients had received vaccination against H1N1v. Nine patients received oseltamivir, only two of them within 48 hours of symptom onset. All patients developed severe ARDS (PaO(2)/FiO(2)-Ratio 60 (55-92); lung injury score 3.8 (3.3-4.0)), were mechanically ventilated and on vasopressor support. Fourteen patients received corticosteroids, 7 patients underwent hemofiltration, and 10 patients needed extracorporeal membrane-oxygenation (ECMO; 8 patients veno-venous, 2 patients veno-arterial), three patients Interventional Lung Assist (ILA) and two patients pump driven extracorporeal low-flow CO(2)-elimination (ECCO(2)-R). Seven of 17 patients (41%) died in the ICU (4 patients due to bleeding, 3 patients due to multi-organ failure), while all other patients survived the hospital (59%). ECMO mortality was 50%. The median ICU length-of-stay was 26 (19-44) vs. 21 (17-25) days (survivors vs. nonsurvivors), days on the ventilator were 18 (14-35) vs. 20 (17-24), and ECMO duration was 10 (8-25) vs. 13 (11-16) days, respectively (all p = n.s.). Compared to a control group of 241 adult intensive care unit patients without H1N1v, length of stay in the ICU, rate of mechanical ventilation, days on the ventilator, and TISS 28 scores were significantly higher in patients with H1N1v. The ICU survival tended to be higher in control patients (79 vs. 59%; p = 0.06). Patients with H1N1v admitted to either of our ICUs were young, overproportionally obese and almost all with existing comorbidities. All patients developed severe ARDS, which could only be treated with extracorporeal gas exchange in an unexpectedly high proportion. Patients with H1N1v had more complicated courses compared to control patients.

Background: Acute myeloid leukemia is a life-threatening disease associated with high mortality rates. A substantial number of patients require intensive care. This investigation analyzes risk factors predicting admission to the intensive care unit in patients with acute myeloid leukemia eligible for induction chemotherapy, the outcome of these patients, and prognostic factors predicting their survival., Design and Methods: A total of 406 consecutive patients with de novo acute myeloid leukemia (15-89 years) were analyzed retrospectively. Markers recorded at the time of diagnosis included karyotype, fibrinogen, C-reactive protein, and Charlson comorbidity index. In patients requiring critical care, the value of the Simplified Acute Physiology Score II, the need for mechanical ventilation, and vasopressor support were recorded at the time of intensive care unit admission. The independent prognostic relevance of the parameters was tested by multivariate analysis., Results: Sixty-two patients (15.3%) required intensive care, primarily due to respiratory failure (50.0%) or life-threatening bleeding (22.6%). Independent risk factors predicting intensive care unit admission were lower fibrinogen concentration, the presence of an infection, and comorbidity. The survival rate was 45%, with the Simplified Acute Physiology Score II being the only independent prognostic parameter (P<0.05). Survival was inferior in intensive care patients compared to patients not admitted to an intensive care unit. However, no difference between intensive care and non-intensive care patients was found concerning continuous complete remission at 6 years or survival at 6 years in patients who survived the first 30 days after diagnosis (non-intensive care patients: 28%; intensive care patients: 20%, P>0.05)., Conclusions: Ongoing infections, low fibrinogen and comorbidity are predictive for intensive care unit admission in acute myeloid leukemia. Although admission was a risk factor for survival, continuous complete remission and survival of patients alive at day 30 were similar in patients who were admitted or not admitted to an intensive care unit.

Background: Acute myeloid leukemia (AML) is a life-threatening malignancy with limited treatment options in chemotherapy-refractory patients. A first-in-human dose study was designed to investigate a safe and biologically effective dose range for LY2457546, a novel multikinase inhibitor, in patients with relapsed AML., Methods: In this nonrandomized, open-label, dose escalation Phase I study, LY2457546 was administered orally once a day. Safety, pharmacokinetics, changes in phosphorylation of target kinases in AML blasts, and risk of drug-drug interactions (DDI) were assessed., Results: Five patients were treated at the starting and predicted minimal biologically effective dose of 50 mg/day. The most commonly observed adverse events were febrile neutropenia, epistaxis, petechiae, and headache. The majority of adverse events (81%) were Grade 1 or 2. One patient had generalized muscle weakness (Grade 3), which was deemed to be a dose-limiting toxicity. Notably, the pharmacokinetic profile of LY2457546 showed virtually no elimination of LY2457546 within 24 hours, and thus prevented further dose escalation. No significant DDI were observed. Ex vivo flow cytometry studies showed downregulation of the phosphoproteins, pcKIT, pFLT3, and pS6, in AML blasts after LY2457546 administration. No medically relevant responses were observed in the five treated patients., Conclusion: No biologically effective dose could be established for LY2457546 in chemotherapy-resistant AML patients. Lack of drug clearance prevented safe dose escalation, and the study was terminated early. Future efforts should be made to develop derivatives with a more favorable pharmacokinetic profile.

Minimal diagnostic criteria for myelodysplastic syndromes (MDS) include constant cytopenia recorded for at least 6 months, dysplasia, and exclusion of other causes of cytopenia and dysplasia. However, there are patients with dysplastic bone marrow features with or without a karyotype, who have only mild if any cytopenia. This condition has been termed idiopathic dysplasia of unknown significance (IDUS). Out of a series of 1,363 patients with suspected MDS or mild cytopenia seen between 1997 and 2010, we have identified 10 patients with IDUS, and analyzed their clinical course and outcome as well as features potentially involved in disease-evolution. Follow-up ranged between 2 and 13 years. Progression to an overt myeloid neoplasm was observed in 4 patients: two progressed to frank MDS, one to chronic myelomonocytic leukemia, and one to a myelodysplastic/myeloproliferative neoplasm exhibiting 5q-and JAK2 V617F. Consecutive studies revealed that most IDUS patients have an adequate production of erythropoietin (EPO) and sufficient numbers of EPO-responsive erythroid progenitors, features rarely seen in MDS. The erythropoiesis-promoting JAK2 mutation V617F was only detectable in one case. We hypothesize that the dysplastic clone in IDUS cannot manifest as frank MDS because i) the clone retains responsiveness against EPO, and ii) an adequate EPO-production counteracts anemia. Evolution of IDUS to low risk MDS may thus depend on the biological properties of the clone as well as patient-related factors such as EPO production. The latter often decreases with age and may thus explain why MDS often manifests in the elderly.

Although imatinib has become standard first-line therapy in chronic myelogenous leukemia (CML), allogeneic hematopoietic stem cell transplantation (HSCT) is still considered to be an important treatment alternative for patients with drug resistance or advanced disease. We retrospectively analyzed 175 adult CML patients who underwent HSCT at our institution between 1983 and 2007, with the aim to compare outcomes in patient subgroups and to identify prognostic variables. The median follow-up was 65 months. The probability of overall survival (OS) for all patients was 62%, with a significant improvement seen in the imatinib-era (2001-2007) compared to previous time periods (P <.05). Furthermore, a significantly better outcome for patients with chronic phase CML compared to patients with accelerated or blast phase could be observed (P < .05). Cumulative incidence (CI) of treatment-related mortality (TRM) was 9.7% at 100 days and 1 year after HSCT. CI of relapse was 5% at 1 year and 7.5% at 3 years after HSCT. Post-HSCT outcome was not influenced by pretreatment therapy with imatinib, donor type, or a conditioning regimen with total body irradiation (TBI). These data confirm earlier observations and suggest that allogeneic HSCT is still an important treatment option for high-risk patients with CML, and should thus remain an integral component in current and future treatment algorithms., (2011 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Advanced systemic mastocytosis (SM) is a rare myeloid neoplasm characterized by uncontrolled accumulation of neoplastic mast cells (MCs) in various organs with consecutive impairment of organ function, drug resistance, and a poor prognosis. Advanced SM may present as smoldering or slowly progressing neoplasm but may also present as rapidly progressing aggressive SM or even as MC leukemia. Approximately half of the patients have an associated hematologic non-MC-lineage disease (SM-AHNMD) or develop an AHNMD over time. Drug resistance may not only result from the KIT mutant D816V that is found in most patients, but also from KIT-independent pro-oncogenic signaling pathways that play a role in disease evolution. In patients with slow progression, advanced SM can often be kept under control for months with interferon-α or 2CdA. By contrast, in rapidly progressing aggressive SM and MC leukemia, even polychemotherapy and hematopoietic stem cell transplantation may fail, which points to the need to develop new drugs and treatment concepts for these patients. In SM-AHNMD, separate treatment plans should be established for the SM component and the AHNMD component of the disease, with recognition that the AHNMD often has to be managed and treated as a secondary and thus a high-risk neoplasm.

The diagnosis, classification, and prognostication of patients with myelodysplastic syndromes (MDS) are usually based on clinical parameters, analysis of peripheral blood and bone marrow smears, and cytogenetic determinants. However, a thorough histologic and immunohistochemical examination of the bone marrow is often required for a final diagnosis and exact classification in these patients. Notably, histology and immunohistology may reveal dysplasia in megakaryocytes or other bone marrow lineages and/or the presence of clusters of CD34-positive precursor cells. In other cases, histology may reveal an unrelated or co-existing hematopoietic neoplasm, or may support the conclusion the patient is suffering from acute myeloid leukemia rather than MDS. Moreover, histologic investigations and immunohistology may reveal an increase in tryptase-positive cells, a coexisting systemic mastocytosis, or bone marrow fibrosis, which is of prognostic significance. To discuss diagnostic algorithms, terminologies, parameters, and specific issues in the hematopathologic evaluation of MDS, a Working Conference involving a consortium of US and EU experts, was organized in June 2010. The outcomes of the conference and resulting recommendations provided by the faculty, are reported in this article. These guidelines should assist in the diagnosis, classification, and prognostication in MDS in daily practice as well as in clinical trials.

Objective: In most patients with systemic mastocytosis (SM), including aggressive SM (ASM) and mast cell (MC) leukemia (MCL), neoplastic cells express the oncogenic KIT mutation D816V, which confers resistance to imatinib. Cladribine (2CdA) is a nucleoside analog that has been introduced as a promising agent for treatment of advanced SM., Materials and Methods: We examined the in vitro effects of 2CdA on growth of neoplastic MC, and the in vivo effects of 2CdA (0.13 mg/kg/day intravenously, days 1-5; three to eight cycles) in seven patients with advanced SM., Results: Cladribine was found to inhibit growth of primary MC and the MC line HMC-1 in a dose-dependent manner, with lower IC(50) values recorded in HMC-1.2 cells harboring KIT D816V (IC(50): 10 ng/mL) compared to HMC-1.1 cells lacking KIT D816V (IC(50): 300 ng/mL). In two patients with progressive smoldering SM, 2CdA produced a long-lasting response with a sustained decrease in serum tryptase levels, whereas in patients with progressive ASM or MCL, 2CdA showed little if any effects. The drug was well-tolerated in most cases. However, one patient developed a massive generalized purulent long-lasting skin rash. The antiproliferative effects of 2CdA on MC were found to be associated with morphologic signs of apoptosis and caspase cleavage. Cladribine did not counteract the kinase activity of KIT D816V or KIT-downstream signaling molecules., Conclusions: Cladribine may be a promising agent for treatment of progressive smoldering KIT D816V(+) SM. In rapidly progressing ASM or MCL, additional or alternative drugs are required to induce long-lasting antineoplastic effects.

Mast cells (MC) are specialized immune cells that play a key role in anaphylactic reactions. Growth, differentiation, and function of these cells are regulated by a complex network of cytokines, surface receptors, signaling molecules, the microenvironment, and the genetic background. A number of previous and more recent data suggest that MC are heterogeneous in terms of cytokine-regulation, expression of cytoplasmic and cell surface antigens, and response to ligands. MC heterogeneity is often organ-specific and is considered to be related to MC plasticity, disease-associated factors, and the maturation stage of the cells. The stem cell factor (SCF) receptor KIT (CD117) is expressed on all types of MC independent of maturation and activation-status. In systemic mastocytosis (SM), KIT is often expressed in MC in a mutated and constitutively activated form. In these patients, MC aberrantly display CD2 and CD25, diagnostic markers of neoplastic MC in all SM variants. In advanced SM, MC co-express substantial amounts of CD30, whereas CD2 expression on MC may be decreased compared to indolent SM. Other surface molecules, such as CD63 or CD203c, are overexpressed on neoplastic MC in SM, and are further upregulated upon cross-linking of the IgE receptor. Some of the cell surface antigens expressed on MC or their progenitors may serve as therapeutic targets in the future. These targets include CD25, CD30, CD33, CD44, and CD117/KIT. The current article provides an overview on cell surface antigens and target receptors expressed by MC in physiologic and reactive tissues, and in patients with SM, with special reference to phenotypic heterogeneity and clinical implications., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

The KIT mutation D816V is associated with autonomous growth of mast cells (MC) and is detectable in most patients with systemic mastocytosis (SM), including cases with associated hematologic non-MC-lineage disease (AHNMD). Recently, KIT D816V was reported to be expressed in patients with acute myeloid leukemia (AML). However, it was not clarified whether these patients have co-existing occult SM. We investigated neoplastic cells in 101 patients with AML for expression of KIT D816V. In 7/101 patients (6.9%), KIT D816V was detectable. After a thorough histologic, molecular, and biochemical analysis, all 7 cases were found to have an associated SM, leading to the final diagnosis SM-AML. Microdissected tryptase+ MC displayed KIT D816V in all patients tested, whereas CD34+ blasts exhibited KIT D816V in only 2/4 patients. In one AML patient, SM without KIT D816V was detected. In all other patients, no associated SM was found, and leukemic blasts were negative for KIT D816V. In summary, our data show that KIT D816V in AML is highly associated with co-existing SM (SM-AML). Moreover, our data show that AML blasts may lack this transforming target-mutant, which may be important when considering the use of KIT D816V-targeting drugs for treatment of patients with KIT D816V-positive AML., ((c) 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

Background: Lineage involvement and maturation arrest are considered to have prognostic significance in patients with myelodysplastic syndromes (MDS). However, although the prognostic value of neutropenia, thrombocytopenia, and monocytosis have been documented, little is known about the impact of eosinophils and basophils., Methods: The authors examined the prognostic significance of eosinophils and basophils in 1008 patients with de novo MDS. Patients were enrolled from 3 centers of the Austrian-German MDS Working Group and were analyzed retrospectively. Blood eosinophils and basophils were quantified by light microscopy, and their impact on survival and leukemia-free survival was calculated by using Cox regression., Results: Eosinophilia (eosinophils >350/microL) and basophilia (basophils >250/microL) predicted a significantly reduced survival (P < .05) without having a significant impact on leukemia-free survival. In multivariate analysis, eosinophilia and basophilia were identified as lactate dehydrogenase (LDH)-independent prognostic variables with International Prognostic Scoring System (IPSS)-specific impact. Although elevated LDH was identified as a major prognostic determinant in IPSS low-risk, intermediate-1 risk, and high-risk subgroups, the condition "eosinophilia and/or basophilia" was identified as a superior prognostic indicator in the IPSS intermediate-2 risk subgroup., Conclusions: The evaluation of eosinophils and basophils in patients with MDS was helpful and may complement the spectrum of variables to optimize prognostication in MDS., ((c) 2010 American Cancer Society.)

We used nonpegylated liposomal doxorubicin (NPLD) in cytostatic drug combinations to treat 37 patients with non-Hodgkin's lymphoma and pre-existing cardiac disorder or elderly patients with reduced physical state who were ineligible for conventional anthracycline-containing therapy. High remission rates were observed in this poor-risk population: Complete remission rates were 75% for diffuse large B cell lymphoma (DLBCL) and 55% for T/NK cell neoplasm (overall response rate of 80% and 89%, respectively). Twenty-seven patients (73%) are still alive after a median observation time of 14 months. No major cardiac or gastrointestinal toxicity was observed. Extravasation of NPLD in two patients resulted in mild inflammation without tissue damage. Hematologic toxicity was comparable to that of conventional anthracycline-containing regimens. We conclude that NPLD is highly active in combination chemotherapy for lymphoma with low cardiac toxicity in patients with pre-existing cardiac disorders or higher age. Moreover, we also observed remarkable efficacy in T/NK cell lymphomas.

Background: The International Prognostic Scoring System (IPSS) is the golden standard to assess prognosis in myelodysplastic syndromes (MDS). The aim of this analysis was to study age and gender as interacting variables for individualized prognostication., Patients and Methods: In all, 897 patients with primary MDS treated with supportive care only were examined in a retrospective multicenter study. A Cox model was developed to determine the prognostic impact of age and gender on survival and to examine their modulating influence on IPSS results. Based on main effects and interactions of these variables, we established an individualized age- and gender-adapted scoring system to improve prognostication in MDS., Results: While the risk of a patient in the IPSS is best represented by the values 0 (low), +1 (intermediate-1), +2 (intermediate-2), and +3 (high), these values were found to vary between -1.9 and +3.5 in the same patients when including age and gender. Whereas in low-risk MDS, male patients were found to have a less favorable survival, a particularly high risk (+3.5) was found in younger (< or = 66 years) high-risk female patients., Conclusion: The inclusion of age and gender and their respective interactions contribute to improved and individualized prognostication in MDS.

Background: The evaluation of comorbidity is of increasing importance in patients with hematologic disorders., Patients and Methods: In the present study, the influence of comorbidity on survival and acute myeloid leukemia (AML) evolution was analyzed retrospectively in 419 patients with de novo myelodysplastic syndromes (MDS) (observation period: 1985-2007). The median age was 71 years (range 24-91 years). Two different scoring systems, the hematopoietic stem-cell transplantation-specific comorbidity index (HCT-CI) and the Charlson comorbidity index (CCI) were applied., Results: The HCT-CI was found to be a significant prognostic factor for overall survival (OS, P < 0.05) as well as event-free survival (EFS, P < 0.05) in our patients, whereas the CCI was of prognostic significance for OS (P < 0.05), but not for EFS. For AML-free survival, neither the HCT-CI nor the CCI were of predictive value. A multivariate analysis including age, lactate dehydrogenase, ferritin, karyotype, number of cytopenias, French-American-British groups, and comorbidity was applied. Comorbidity was found to be an independent prognostic factor in patients with low- or int-1-risk MDS (P < 0.05) regarding OS and EFS., Conclusions: Together, our data show that comorbidity is an important risk factor for OS and EFS in patients with MDS.

Background: The mammalian target of rapamycin (mTOR) has recently been identified as a potential target in acute myeloid leukemia (AML)., Methods: We treated 5 patients with chemotherapy-refractory AML with the mTOR-inhibitor rapamycin at 2mg per os daily for 14 days, with dose adjustment allowed to reach a target serum rapamycin concentration of 10-20 ng/mL. Four of five patients received additional hydroxyurea at constant dose during treatment with rapamycin., Results: Two patients achieved a leukocyte response, in one of them, a prolonged response was seen. In the other patients, blast counts remained stable or increased during rapamycin therapy. We did not observe severe hematologic or non-hematologic side effects of rapamycin., Conclusion: Rapamycin at 2mg per day acts mildly cytoreductive in a subgroup of patients with refractory AML. Higher doses and drug combinations may be required to obtain long lasting anti-leukemic effects in these patients.

Background: Minimally differentiated acute myeloid leukemia is heterogeneous in karyotype and is defined by immature morphological and molecular characteristics. This originally French-American-British classification is still used in the new World Health Organization classification when other criteria are not met. Apart from RUNX1 mutation, no characteristic molecular aberrations are recognized., Design and Methods: We performed whole genome single nucleotide polymorphism analysis and extensive molecular analysis in a cohort of 52 patients with minimally differentiated acute myeloid leukemia., Results: Many recurring and potentially relevant regions of loss of heterozygosity were revealed. These point towards a variety of candidate genes that could contribute to the pathogenesis of minimally differentiated acute myeloid leukemia, including the tumor suppressor genes TP53 and NF1, and reinforced the importance of RUNX1 in this leukemia. Furthermore, for the first time in this minimally differentiated form of leukemia we detected mutations in the transactivation domain of RUNX1. Mutations in other acute myeloid leukemia associated transcriptions factors were infrequent. In contrast, FLT3, RAS, PTPN11 and JAK2 were often mutated. Irrespective of the RUNX1 mutation status, our results show that RAS signaling is the most important pathway for proliferation in minimally differentiated acute myeloid leukemia. Importantly, we found that high terminal deoxynucleotidyl transferase expression is closely associated with RUNX1 mutation, which could allow an easier diagnosis of RUNX1 mutation in this hematologic malignancy., Conclusions: Our results suggest that in patients without RUNX1 mutation, several other molecular aberrations, separately or in combination, contribute to a common minimally differentiated phenotype.

Background: Recent data suggest that tryptase, a mast cell enzyme, is expressed in neoplastic cells in myeloid leukaemias. In several of these patients, increased serum tryptase levels are detectable., Materials and Methods: We have determined serum tryptase levels in 914 patients with haematological malignancies, including myeloproliferative disorders (n = 156), myelodysplastic syndromes (MDS, n = 241), acute myeloid leukaemia (AML, n = 317), systemic mastocytosis (SM, n = 81), non-Hodgkin's lymphoma (n = 59) and acute lymphoblastic leukaemia (n = 26). Moreover, tryptase was measured in 136 patients with non-neoplastic haematological disorders, 102 with non-haematological disorders and 164 healthy subjects., Results: In healthy subjects, the median serum tryptase was 5.2 ng mL(-1). Elevated serum tryptase levels were found to cluster in myeloid neoplasm, whereas almost all patients with lymphoid neoplasms exhibited normal tryptase. Among myeloid neoplasms, elevated tryptase levels (> 15 ng mL(-1)) were recorded in > 90% of patients with SM, 38% with AML, 34% with CML and 25% with MDS. The highest tryptase levels, often > 1000 ng mL(-1), were found in advanced SM and core-binding-factor leukaemias. In most patients with non-neoplastic haematological disorders and non-haematological disorders analysed in our study, tryptase levels were normal, the exception being a few patients with end-stage kidney disease and helminth infections, in whom a slightly elevated tryptase was found., Conclusions: In summary, tryptase is a new diagnostic marker of myeloid neoplasms and a useful test in clinical haematology.

Background: Transfusion-related morbidity is an emerging problem in chronically transfused patients with myelodysplastic syndromes (MDS). Although several iron-chelating drugs are available, the optimal way of treatment of iron-overload remains uncertain. A major disadvantage of deferoxamine is that the drug has to be applied as continuous subcutaneous infusion. Therefore, novel oral agents have been developed. One of these drugs is deferasirox (Exjade)., Materials and Methods: We report on 14 MDS patients who were treated with deferasirox (500-1500 mg daily) for up to 24 months. In these patients, treatment responses were recorded by determining serum ferritin levels before and during therapy and by applying recently established response criteria., Results: In all patients except one, ferritin levels decreased during therapy. Four patients showed a complete response, one a minor response and five a stable iron load. In the responding patients, initially elevated liver enzymes decreased substantially. No substantial change in transferrin saturation or transfusion frequency was recorded. Side effects were mild and tolerable in most patients. In one patient, treatment with deferasirox was stopped because of impaired kidney function., Conclusion: Our data show that treatment with deferasirox is a reasonable approach to counteract iron overload in patients with MDS.

Background: The mammalian target of rapamycin (mTOR) has recently been implicated in leukaemic cell growth, tumour-associated angiogenesis and expression of vascular endothelial growth factor (VEGF). We examined whether mTOR plays a role as regulator of growth and VEGF-expression in acute myeloid leukaemia (AML). Three mTOR-targeting drugs, rapamycin, everolimus (RAD001) and CCI-779, were applied. The effects of these drugs on growth, survival, apoptosis and VEGF expression in primary AML cells and various AML cell lines were examined., Materials and Methods: Growth of AML cells and AML-derived cell lines was assessed by (3)H-thymidine incorporation, survival was examined by light- and electron microscopy, by Tunel assay and by AnnexinV-staining, and the expression of VEGF by Northern blotting, RT-PCR and ELISA., Results: Rapamycin was found to counteract growth in the AML cell lines U937 and KG1a as well as in primary AML cells in 14/18 patients examined. The effects of rapamycin and its derivatives were dose-dependent (IC(50): 10 pM-100 nM). It was also found that exposure to mTOR-targeting drugs resulted in apoptosis and in decreased expression of VEGF in leukaemic cells., Conclusions: mTOR-targeting drugs exert antileukaemic effects on AML cells in vitro through multiple actions, including direct inhibition of proliferation, induction of apoptosis and suppression of VEGF. Based on this study and other studies, mTOR can be regarded as a potential drug target in AML.

Background: Recent data suggest that, among other factors, comorbidity may be an important prognostic variable in patients with myelodysplastic syndromes (MDS) who are eligible for haematopoietic stem cell transplantation (SCT)., Patients and Methods: We examined the overall survival (OS) and underlying risk factors in 45 adult patients with MDS (n = 38), chronic myelomonocytic leukaemia (n = 1), or secondary acute myeloid leukaemia (AML) arising from MDS (n = 6), who underwent allogeneic SCT at our Institution., Results: With a median follow-up of 37 months, OS for all patients was 23%, post-transplant relapse occurred in 11 patients, and 10 patients died from treatment-related complications. The overall outcome and survival was independent of cytogenetic abnormalities and International Prognostic Scoring System (IPSS). However, we identified comorbidity as defined by the haematopoietic cell transplantation specific comorbidity index (HCT-CI), as a significant adverse prognostic variable in our MDS patients., Conclusions: Based on these data and similar published data we recommend selecting patients with MDS or secondary AML for SCT according to the presence of comorbidities.

Background: Systemic mastocytosis (SM) is a mast cell neoplasm in which neoplastic cells usually display the D816V-mutated variant of KIT. Cladribine (2CdA) and dasatinib are two drugs that counteract the in vitro growth of neoplastic mast cells in SM. However, only little is known about the in vivo effects of these drugs in SM., Patient and Methods: We report on a patient with highly aggressive interferon-alpha-resistant SM who was treated with 2CdA and dasatinib. In vitro pretesting revealed a response of neoplastic mast cells to both compounds with reasonable IC(50) values., Results: The patient was treated with six cycles of 2CdA (0.13 mg kg(-1) intravenously daily on 5 consecutive days). Despite a short-lived major clinical response and a decrease in serum tryptase, the patient progressed to mast cell leukaemia after the sixth cycle of 2CdA. The patient then received two further courses of 2CdA followed by treatment with dasatinib (100 mg per os daily). However, no major response was obtained and the patient died from disease progression after 2 months., Conclusions: In a patient with rapidly progressing aggressive SM, neither 2CdA nor dasatinib produced a long-lasting response in vivo, despite encouraging in vitro results. For such patients, alternative treatment strategies have to be developed.

Therapy-related acute promyelocytic leukemia (t-APL) with t(15;17) translocation is a well-recognized complication of cancer treatment with agents targeting topoisomerase II. However, cases are emerging after mitoxantrone therapy for multiple sclerosis (MS). Analysis of 12 cases of mitoxantrone-related t-APL in MS patients revealed an altered distribution of chromosome 15 breakpoints versus de novo APL, biased toward disruption within PML intron 6 (11 of 12, 92% vs 622 of 1022, 61%: P = .035). Despite this intron spanning approximately 1 kb, breakpoints in 5 mitoxantrone-treated patients fell within an 8-bp region (1482-9) corresponding to the "hotspot" previously reported in t-APL, complicating mitoxantrone-containing breast cancer therapy. Another shared breakpoint was identified within the approximately 17-kb RARA intron 2 involving 2 t-APL cases arising after mitoxantrone treatment for MS and breast cancer, respectively. Analysis of PML and RARA genomic breakpoints in functional assays in 4 cases, including the shared RARA intron 2 breakpoint at 14 446-49, confirmed each to be preferential sites of topoisomerase IIalpha-mediated DNA cleavage in the presence of mitoxantrone. This study further supports the presence of preferential sites of DNA damage induced by mitoxantrone in PML and RARA genes that may underlie the propensity to develop this subtype of leukemia after exposure to this agent.

The ectoenzyme E-NPP3 (CD203c) has recently been identified as a novel activation-linked cell surface antigen on basophils. In the present study, we examined expression of CD203c on normal mast cells (MC)and bone marrow (bm) MC derived from 85 patients with systemic mastocytosis (SM), including cases with indolent SM (ISM, n=72), SM with associated clonal hematologic non-MC-lineage disease (SM-AHNMD, n=6), aggressive SM (ASM, n=3), and mast cell leukemia (MCL, n=4). Surface expression of CD203c was analyzed by multicolor flow cytometry. In patients with SM, bm MC expressed significantly higher amounts of CD203c compared to normal bm MC (median MFI in controls: 260 versus median MFI in SM: 516, p<0.05). Slightly lower amounts of CD203c were detected on MC in SM-AHNMD and ASM compared to ISM. To demonstrate CD203c expression in MC at the mRNA level, neoplastic MC were highly enriched by cell sorting, and were found to express CD203c mRNA in RT-PCR analysis. Cross-linking of the IgE receptor on MC resulted in a substantial upregulation of CD203c, whereas the KIT-ligand stem cell factor (SCF) showed no significant effects. In conclusion, CD203c is a novel activation-linked surface antigen on MC that is upregulated in response to IgE receptor cross-linking and is overexpressed on neoplastic MC in patients with SM.

Myelodysplastic syndromes (MDS) represent a heterogeneous group of myeloid neoplasms that are preferentially diagnosed in the elderly. With the increase in older patients with MDS in the Western world and the availability of more therapeutic options, new strategies and algorithms for optimal management and treatment of these patients must be developed. Although age is recognized as an important adverse variable affecting survival, most scoring systems have not included age in score risk calculations. Comorbidity is of particular importance and a frequent covariable in elderly patients with MDS. However, although comorbidity scores have been established and used for risk assessment in younger high-risk patients scheduled to undergo intensive therapy, these scores are only just being applied to elderly patients, with relevant results. Advanced age should not exclude a patient with MDS from appropriate treatment, and age alone should not be considered a surrogate marker for functional decline or comorbidities. This article discusses the need to improve scoring systems, individualized risk-assessment, and treatment algorithms for elderly patients with MDS by including age and comorbidities.

Background: Basophilic crisis and eosinophilia are well recognized features of advanced chronic myeloid leukaemia. In other myeloid neoplasms, however, transformation with marked basophilia and eosinophilia is considered unusual., Design: We examined the long-term follow-up of 322 patients with de novo myelodysplastic syndromes (MDS) to define the frequency of basophilic, eosinophilic and mixed lineage (basophilic and eosinophilic) transformation., Results: Of all patients, only one developed mixed lineage crisis (>or= 20% basophils and >or= 20% eosinophils). In this patient, who initially suffered from chronic myelomonocytic leukaemia, basophils increased to 48% and eosinophils up to 31% at the time of progression. Mixed lineage crisis was not accompanied by an increase in blast cells or organomegaly. The presence of BCR/ABL and other relevant fusion gene products (FIP1L1/PDGFRA, AML1/ETO, PML/RAR alpha, CBF beta/MYH11) were excluded by PCR. Myelomastocytic transformation/myelomastocytic leukaemia and primary mast cell disease were excluded by histology, KIT mutation analysis, electron microscopy and immunophenotyping. Basophils were thus found to be CD123+, CD203c+, BB1+, KIT- cells, and to express a functional IgE-receptor. Among the other patients with MDS examined, 4(1.2%) were found to have marked basophilia (>or= 20%) and 7(2.1%) were found to have massive eosinophilia ( >or= 20%), whereas mixed-lineage crisis was detected in none of them., Conclusions: Mixed basophil/eosinophil crisis may develop in patients with MDS but is an extremely rare event.

Patients with systemic mastocytosis (SM) may acquire an associated hematologic non-mast cell (MC)-lineage disease (AHNMD). In most cases, a myeloid neoplasm is diagnosed, whereas the occurrence of a lymphoproliferative disease is an extremely rare event. We report on a patient with indolent SM associated with small lymphocytic lymphoma (SLL). The patient presented with lymphadenopathy, maculopapular exanthema, and elevated serum tryptase. The bone marrow biopsy showed focal MC aggregates together with SLL. As assessed by immunostaining, neoplastic MC were found to exhibit CD117 and CD25 but did not display CD5 or CD20, whereas SLL cells were found to coexpress CD5 and CD20 but did not express MC antigens. The KIT mutation D816V was detected in sorted CD34(+) cells and unfractionated marrow cells but not in CD5(+) SLL cells, confirming the coexistence of 2 distinct neoplasms.

Background: Early recognition of disease progression in low-risk myelodysplastic syndromes (MDS) is an important decision point concerning intensive therapies. In a screen program searching for dynamic prognostic determinants, we have identified lactate dehydrogenase (LDH) as a most suitable follow-up parameter., Patients and Methods: LDH levels were serially determined in 221 patients with de novo MDS (median age 70 years, range 24-94). The increase in LDH was correlated with survival and acute myeloid leukemia (AML) evolution., Results: Confirming previous data, an elevated LDH at diagnosis was found to be associated with an increased probability of AML evolution and decreased probability of survival (P < 0.05). In the follow-up, we found that in patients who progressed (to higher IPSS category or AML), LDH levels were significantly higher in the two 3-month period preceding progression compared with the initial two 3-month period (P < 0.005). In a subgroup of patients, the increase in LDH was accompanied or followed by other signs of disease progression, such as occurrence of thrombocytopenia or appearance of circulating blasts. In multivariate analyses, the LDH increase was found to be an independent prognostic variable., Conclusions: LDH is an interesting follow-up parameter in MDS, which may assist in early recognition of disease progression and thus help in risk stratification and patient selection for interventional therapies.

Oncogenic tyrosine kinases (TK) usually convert growth factor-dependent cells to factor independence with autonomous proliferation. However, TK-driven neoplasms often are indolent and characterized by cell differentiation rather than proliferation. A prototype of an indolent TK-driven neoplasm is indolent systemic mastocytosis. We found that the D816V-mutated variant of KIT, a TK detectable in most patients with systemic mastocytosis, induces cluster formation and expression of several mast cell differentiation and adhesion Ags, including microphthalmia transcription factor, IL-4 receptor, histamine, CD63, and ICAM-1 in IL-3-dependent BaF3 cells. By contrast, wild-type KIT did not induce cluster formation or mast cell differentiation Ags. Additionally, KIT D816V, but not wild-type KIT, induced STAT5 activation in BaF3 cells. However, despite these intriguing effects, KIT D816V did not convert BaF3 cells to factor-independent proliferation. Correspondingly, BaF3 cells with conditional expression of KIT D816V did not form tumors in nude mice. Together, the biologic effects of KIT D816V in BaF3 cells match strikingly with the clinical course of indolent systemic mastocytosis and with our recently established transgenic mouse model, in which KIT D816V induces indolent mast cell accumulations but usually does not induce a malignant mast cell disease. Based on all these results, it is hypothesized that KIT D816V as a single hit may be sufficient to cause indolent systemic mastocytosis, whereas additional defects may be required to induce aggressive mast cell disorders.