Plasma and whole blood exchange in meningococcal sepsis

Contains fulltext : 4755.pdf (publisher's version ) (Open Access

The diagnosis and treatment of invasive aspergillosis in Dutch haematology units facing a rapidly increasing prevalence of azole-resistance

Patients with haematological malignancies are at risk for invasive fungal diseases (IFD). A survey was conducted in all Dutch academic haematology centres on their current diagnostic, prophylactic and therapeutic approach towards IFD in the context of azole-resistance. In all 8 centres, a haematologist and microbiologist filled in the questionnaire that focused on different subgroups of haematology patients. Fungal prophylaxis during neutropaenia was directed against Candida and consisted of fluconazole and/or amphotericin B suspension. Mould-active prophylaxis was given to acute myeloid leukaemia patients during chemotherapy in 2 of 8 centres. All centres used azole prophylaxis in a subset of patients with graft-versus-host disease. A uniform approach towards the diagnosis and treatment of IFD and in particular azole-resistant Aspergillus fumigatus was lacking. In 2017, all centres agreed to implement a uniform diagnostic and treatment algorithm regarding invasive aspergillosis with a central role for comprehensive diagnostics and PCR-based detection of azole-resistance. This study (DB-MSG 002) will re-evaluate this algorithm when 280 patients have been treated. A heterogeneous approach towards antifungal prophylaxis, diagnosis and treatment was apparent in the Netherlands. Facing triazole-resistance, consensus was reached on the implementation of a uniform diagnostic approach in all 8 centres

Biology of stem cells and myeloid progenitor cells in myelodysplastic syndromes.

Contains fulltext : 52863.pdf (publisher's version ) (Open Access)RU Radboud Universiteit Nijmegen, 7 februari 2007Promotor : Witte, T.J.M. de Co-promotor : Raymakers, R.A.P.149 p

Biology of stem and myeloid progenitor cells in myelodysplastic syndromes.

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Stem cell transplantation for leukemias following myelodysplastic syndromes or secondary to cytotoxic therapy.

Item does not contain fulltextTwo main forms of therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML) have been recognized. The most frequent type, occurring after treatment with alkylating agents, is characterized by abnormalities of chromosomes 5 and/or 7 and t-MDS/AML following treatment with topoisomerase II inhibitors and is associated with molecular aberrations of MLL (11q23) and AML-1 (21q22). Individuals with certain polymorphisms associated with impaired detoxification of cytotoxic agents have an increased risk of developing MDS or AML after treatment of unrelated cancers. Multidrug chemotherapy is less effective for patients with MDS, or AML following MDS, or t-MDS/AML when compared with primary AML, and results in lower complete remission (CR) rates and lower long-term survival. Patients with good risk cytogenetic features, such as t(15; 17), t(8; 21) and inversion 16 are an exception as their treatment outcome is comparable with primary AML patients. Patients who attain a polyclonal and/or a cytogenetic CR may be candidates for autologous stem cell transplantation. For the remaining patients, the only curative option is allogeneic stem cell transplantation with stem cells from a histocompatible sibling or an alternative donor. Reduced intensity conditioning regimens may be considered for patients older than 50 years or patients with comorbidities. The advice is to treat patients early after diagnosis and preferably before progression as these patients have the highest chance of a favorable outcome

Bone marrow mononuclear cells of MDS patients are characterized by in vitro proliferation and increased apoptosis independently of stromal interactions.

Contains fulltext : 52870.pdf (publisher's version ) (Closed access)Enhanced proliferation of MDS progenitors is abrogated by increased apoptosis of their progeny in vivo. We investigated whether bone marrow mononuclear cells (BMMNC) of MDS patients also showed enhanced proliferation and apoptosis in vitro in comparison with acute myeloid leukemia (AML) and normal BM (NBM). NBM showed a decrease in the number of clusters in time due to apoptosis of clusters and due to development of clusters into colonies with low apoptotic level. In MDS patients, about two-fold more clusters have developed at day 4, and in contrast with NBM, the total number of clusters at day 7 remained high in spite of an increasing percentage of apoptotic clusters (from 52 to 76%) in combination with more colony formation. The number of clusters and colonies showed a sharp decrease at day 10 because of persistently high apoptosis at cluster level and increasing apoptosis in colonies. BMMNC of AML patients showed a decreased proliferation with enhanced apoptosis at cluster level in contrast to a relatively low apoptotic levels in the colony-forming cells. This data show that increased proliferation is abrogated by enhanced apoptosis in MDS, whereas AML showed decreased proliferation with a low level of apoptosis in colony-forming cells. These growth profiles of BMMNC are independent of stromal influences and may represent intrinsic features of the MDS progenitors and accessory cell interactions

The dynamic process of apoptosis analyzed by flow cytometry using Annexin-V/propidium iodide and a modified in situ end labeling technique.

Item does not contain fulltextBACKGROUND: To study the apoptotic process in time, we used the following flow cytometric (FCM) techniques: phosphatidylserine (PS) translocation by Annexin-V (AnV), DNA fragmentation by in situ end labeling (ISEL), and propidium iodide (PI) staining. Because PS translocation is assumed to be an early feature of programmed cell death (PCD), we questioned if AnV positivity implies inevitable cell death. METHODS: Apoptosis was induced in Jurkat cells by gamma-irradiation, incubation with camptothecin (CPT), or cytosine beta-D-arabinofuranoside (Ara-C). At different time intervals, PCD was quantified by AnV/PI and ISEL. To analyze the influence of cell handling procedures on PCD, we applied these three FCM techniques on CD34+ bone marrow (BM) stem cells after selection and after a freeze-thaw procedure. Various AnV/PI- CD34+ fractions were cultured in a single-cell single-well (SCSW) assay. RESULTS: Jurkat cells under three different detrimental conditions showed essentially the same pattern of apoptosis in time. Initially developed AnV+/PI- cells subsequently (within 1 h) showed ISEL positivity, after which they turned into AnV+/PI++ cells with even higher levels of ISEL positivity (80-90%). Eventually, they lost some of their PI and ISEL positivity and formed the AnV+/PI+ fraction. Cell handling of CD34+ cells caused high and variable AnV+/PI- fractions (overall range 23-62%). Within total AnV+ and AnV+/PI- populations, only a minority of CD34+ cells showed ISEL positivity (range 4-8% and 0.8-6%, respectively). Different fractions of AnV+/PI- CD34+ cells did have clonogenic capacity. CONCLUSIONS: PCD of cell suspensions in vitro can be followed accurately in time by these three FCM techniques. PS translocation is followed rapidly (within 1 h) by oligo-nucleosomal DNA fragmentation, after which cell (and nuclear) membrane leakage occurs. Detection of PS asymmetry by AnV-fluorescein isothiocyanate (FITC) is not always associated with (inevitable) apoptosis, as can be concluded from the proliferative capacity of AnV+ /PI- CD34+ cells in the SCSW assay

Programmed cell death is an intrinsic feature of MDS progenitors, predominantly found in the cluster-forming cells.

Contains fulltext : 47947.pdf (publisher's version ) (Closed access)OBJECTIVE: Bone marrows (BM) of myelodysplastic syndrome (MDS) patients show increased proliferation and premature programmed cell death (PCD) in vivo as well as in vitro. We explored the proliferative capacity and apoptotic propensity of CD34+ progenitor cells of MDS patients excluding accessory cell interference. MATERIALS AND METHODS: CD34+/CD3-/CD19- cells of 5 MDS patients and 5 normal BM were sorted as single cells into single wells and were cultured in liquid medium. Wells were evaluated on days 4, 7, 10, and 14. PCD was determined by staining with annexin V-FITC. Growth rate and cell doubling time (Td) were calculated for each colony-forming cell. RESULTS: Normal BM CD34+ cells formed clusters and colonies and both showed increasing PCD in time, although within colonies the degree of apoptosis was twice as high (about 25%) as compared with clusters at all time points. In MDS increased cluster formation was observed at all evaluation points when compared to normal BM, whereas the number of colonies was markedly reduced (1/7 of normal). These colonies were also smaller, usually smaller than 100 cells. Significantly enhanced levels of PCD of clusters (53-79%) in combination with longer cell doubling times explain this slower formation of smaller colonies. Surprisingly, these colonies showed considerably lower levels of PCD (7-32%) as compared to normal (1-48%, median values). CONCLUSIONS: In the absence of stromal influences and accessory cells, this study in MDS patients showed intrinsically enhanced proliferation and apoptosis of cluster-forming cells, as the opposite was true for colony-forming cells

Follicular non-Hodgkin's lymphoma with refractory paraneoplastic pemphigus: case report with review of novel treatment modalities.

In this paper a patient with a non-Hodgkin's lymphoma (NHL) and paraneoplastic pemphigus (PNP) is described. PNP is a very rare, painful mucocutaneous intraepithelial blistering disease associated with occult or confirmed malignancy. Patients with PNP show severe, progressive mucocutaneous disease with a high mortality rate, because of drug-induced infectious complications. The patients sometimes benefit from high doses of oral corticosteroids. However, pulse therapy with high doses of prednisolone (or dexamethasone) in combination with other immunosuppressants induces variable and inconstant results. Intravenous immunoglobulin (IVIg) has been applied in different cases of PNP with encouraging results. Plasmapheresis or plasma exchange (PE) in combination with corticosteroids and/or cyclophosphamide or azathioprine showed similar rapid and beneficial results in association with decreasing auto-antibody levels in this group of refractory pemphigus. Another interesting therapeutic option is rituximab, a chimeric monoclonal antibody directed against the CD20 antigen, which is found on the surface of normal and malignant B-lymphocytes. Administration of rituximab for patients with PNP in combination with follicular NHL is not always successful regarding oral lesions as we report in this case. PE leading to prompt depletion of autoreactive antibodies combined with immunosuppressants or synchronisation of PE with IVIg seems the best treatment modality for this refractory group, but the therapeutic value and appropriate timing of rituximab obviously deserve further evaluation in patients with low grade NHL and PNP