Hereditary Haemorrhagic Telangiectasia (HHT) Marked by ACVRL1C1120T Variant Displays Hypopigmented Naevi and Frequent Bleeding Episodes if CYP2C9 Co-Mutated: Clinical Notes & Rationale of Patient Registry.

Hereditary haemorrhagic telangiectasia (HHT) exhibits considerable phenotypic heterogeneity. Therefore, precise mutation screening and evaluation of patient risk must be determined in every HHT family. We present an HHT-2 case with an initial life-threatening bleeding episode that led to identification of a relatively large HHT family. Exome sequencing of the family members determined HHT-associated ACVRL1C1120T variant resulting in Arg374Trp substitution at the Ser/Thr-kinase domain region. The affected members display typical epistaxis symptomatology from early childhood resulting in sideropoenia. In addition, the HHT patients also displayed dermatology findings such as facial teleangiectasias and trunk/limb white spots representing post-inflammatory hypopigmentation. Interestingly, co-segregating with modifying cytochrome P450 (CYP2C) variant in the HHT patients led to NSAID intolerance marked by increased frequency of bleeding episodes. No arterial-venous malformation of the visceral organs and brain or association with cancer were observed. The heterogeneity of clinical presentation and the role of other variants support the need of regular patient monitoring and development of a nation-wide patient registry.

ASXL1 gene alterations in patients with isolated 20q deletion.

Deletion 20q is a recurrent abnormality in myeloid malignancies. In our previous study, we identified fusion of the additional sex combs-like 1 (ASXL1) and teashirt zinc finger homeobox 2 genes in a patient with myelodysplastic syndrome. The objective of this study was to determine the frequency of ASXL1 breakpoints in a cohort of 36 patients with deletion 20q as the sole cytogenetic aberration. A combination of molecular cytogenetic methods was used to confirm ASXL1 gene alterations in 19 of the 36 patients, and the determination of ASXL1 gene changes in patients with deletion 20q revealed clinical and prognostic impacts.

Aggressive acute myeloid leukemia in PU.1/p53 double-mutant mice.

PU.1 downregulation within hematopoietic stem and progenitor cells (HSPCs) is the primary mechanism for the development of acute myeloid leukemia (AML) in mice with homozygous deletion of the upstream regulatory element (URE) of PU.1 gene. p53 is a well-known tumor suppressor that is often mutated in human hematologic malignancies including AML and adds to their aggressiveness; however, its genetic deletion does not cause AML in mouse. Deletion of p53 in the PU.1(ure/ure) mice (PU.1(ure/ure)p53(-/-)) results in more aggressive AML with shortened overall survival. PU.1(ure/ure)p53(-/-) progenitors express significantly lower PU.1 levels. In addition to URE deletion we searched for other mechanisms that in the absence of p53 contribute to decreased PU.1 levels in PU.1(ure/ure)p53(-/-) mice. We found involvement of Myb and miR-155 in downregulation of PU.1 in aggressive murine AML. Upon inhibition of either Myb or miR-155 in vitro the AML progenitors restore PU.1 levels and lose leukemic cell growth similarly to PU.1 rescue. The MYB/miR-155/PU.1 axis is a target of p53 and is activated early after p53 loss as indicated by transient p53 knockdown. Furthermore, deregulation of both MYB and miR-155 coupled with PU.1 downregulation was observed in human AML, suggesting that MYB/miR-155/PU.1 mechanism may be involved in the pathogenesis of AML and its aggressiveness characterized by p53 mutation.

[Myelodysplastic syndromes --  therapy progress over the last two decades]. / Myelodysplastický syndrom -  pokrok v lécbe v 21. století

Myelodysplastic syndrome is one of the most common hematology diseases in the age over the 60. Until recently the therapy of this disease was frustrating and often based only on supportive care. The last decade witnessed the emergence of promising drugs that represent a major breakthrough in the therapy and interest of decoding of the pathogenesis of this disease. In our work we summarize the evolution of MDS therapy with accent on the new drugs contribution.

Numerical analysis of non-Newtonian blood flow and wall shear stress in realistic single, double and triple aorto-coronary bypasses.

Considering the fact that hemodynamics plays an important role in the patency and overall performance of implanted bypass grafts, this work presents a numerical investigation of pulsatile non-Newtonian blood flow in three different patient-specific aorto-coronary bypasses. The three bypass models are distinguished from each other by the number of distal side-to-side and end-to-side anastomoses and denoted as single, double and triple bypasses. The mathematical model in the form of time-dependent nonlinear system of incompressible Navier-Stokes equations is coupled with the Carreau-Yasuda model describing the shear-thinning property of human blood and numerically solved using the principle of the SIMPLE algorithm and cell-centred finite volume method formulated for hybrid unstructured tetrahedral grids. The numerical results computed for non-Newtonian and Newtonian blood flow in the three aorto-coronary bypasses are compared and analysed with emphasis placed on the distribution of cycle-averaged wall shear stress and oscillatory shear index. As shown in this study, the non-Newtonian blood flow in all of the considered bypass models does not significantly differ from the Newtonian one. Our observations further suggest that, especially in the case of sequential grafts, the resulting flow field and shear stimulation are strongly influenced by the diameter of the vessels involved in the bypassing.

5-azacitidine in aggressive myelodysplastic syndromes regulates chromatin structure at PU.1 gene and cell differentiation capacity.

Epigenetic 5-azacitidine (AZA) therapy of high-risk myelodysplastic syndromes (MDS) and acute myelogenous leukemia (AML) represents a promising, albeit not fully understood, approach. Hematopoietic transcription factor PU.1 is dynamically regulated by upstream regulatory element (URE), whose deletion causes downregulation of PU.1 leading to AML in mouse. In this study a significant group of the high-risk MDS patients, as well as MDS cell lines, displayed downregulation of PU.1 expression within CD34+ cells, which was associated with DNA methylation of the URE. AZA treatment in vitro significantly demethylated URE, leading to upregulation of PU.1 followed by derepression of its transcriptional targets and onset of myeloid differentiation. Addition of colony-stimulating factors (CSFs; granulocyte-CSF, granulocyte-macrophage-CSF and macrophage-CSF) modulated AZA-mediated effects on reprogramming of histone modifications at the URE and cell differentiation outcome. Our data collectively support the importance of modifying the URE chromatin structure as a regulatory mechanism of AZA-mediated activation of PU.1 and induction of the myeloid program in MDS.

[The results of patients with essentials thrombocythemia and other myeloproliferation-related thrombocythemia--a report of patients treated with Thromboreductin]. / Výsledky lécby nemocných s esentiální trombocytemií a dalsími myeloproliferacemi provázenými trombocytemií--zpráva z registru pacientu lécených Thromboreductinem.

The registry of patients treated with Thromboreductin (anagrelide) in the Czech Republic contains data concerning patients that have been treated using this drug since 2004. As of June 2009, the total number of patients was 549. The current analysis focused mainly on evaluation of anagrelide dosage needed to achieve a complete response in high-risk patients: reduction in platelet count to below 400 x 10(9)/l, which was also considered as reaching the therapeutic goal. The outcomes of the registry confirm that although anagrelide (Thromboreductin) is a very effective platelet-reducing agent, the administration of which is related to a low incidence of adverse effects and complications, the therapeutic goal is not achieved in all cases and or despite a quick treatment response, the therapeutic goal is achieved more slowly.

[Lenalidomid (Revlimid) in the treatment of multiple myeloma--first experience in the Czech Republic]. / Lenalidomid (Revlimid) v lécbe mnohocetného myelomu-- první zkusenosti v Ceské republice.

The prognosis of multiple myeloma (MM) has substantially improved during last decades due to new, so-called targeted drugs--proteasome inhibitor bortezomib and immunomodulatory drugs (ImiDs), thalidomide and lenalidomide. They could be used in various combinations and/or sequentially thanks to different mechanism of action and toxicity. Both bortezomib and thalidomide are widely used in Czech republic, however, lenalidomide was approved for the treatment of MM (and MDS) at the very latest and its usage is limited due to high costs, as well. According to the results of clinical trials lenalidomide is effective in myeloma refractory to various therapy including other new drugs. First time in the Czech republic the combination of lenalidomide and dexamethasone was given in our center to 2 patients with relapsed myeloma as 7th and 10th line of therapy. Acceptable results of treatment with improved clinical status in the first patient enabled to suspend his therapeutic plasmaferesis. Disease stabilization lasting three months was observed also in the second patient.

[Auto- and alloreactivity of T lymphocytes in myelodysplastic syndrome]. / Auto- a aloreaktivita T lymfocytu u myelodysplastického syndromu.

BACKGROUND: Successful therapy with ATG and cyclosporine A in some myelodysplastic syndrome (MDS) patients led us to study the existence of T cells attacking autologous hemopoietic cells. In our study, we attempted to give the direct prove of autoreactive T cells in MDS (autoreactivity analysis). Simultaneously, we analysed the capacity of MDS patients to respond to allogeneic cells from unrelated individuals (alloreactivity analysis). METHODS AND RESULTS: Autoreactive lymphocytes directed against own bone marrow mononuclear cells were analysed using the modification of cell mediated cytotoxic reaction. With one exception we did not confirm the presence of autoreactive T cells among 10 patients examined. Analysis of alloreactivity was performed by means of standard cell mediated cytotoxic reaction and mixed lymphocyte reaction. Surprisingly, the cytotoxic response to allogeneic cells was negative in 11 MDS patients from 16 analysed. When comparing refractory anaemia (RA) and refractory anaemia with ring sideroblasts (RARS) patients, the proportion of negative results was higher in RA (78 %) than in RARS (40 %). In mixed lymphocyte reaction, the response of MDS cells to allogeneic cells of unrelated individual was positive in all tested patients. The preliminary testing of TNF and IFNgamma secretion examined in supernatants of effector cells showed impaired levels of both cytokines in RA and normal levels in RARS in accordance with the findings achieved in alloreactivity analysis. CONCLUSIONS: Autoreactive T cells were not found in MDS patients using our experimental arrangement. Analysis of alloreactivity showed the defect in effector--cytotoxic--phase of cell mediated cytotoxic reaction in the majority of MDS patients. The initial phase of this reaction represented in vitro by mixed lymphocyte reaction gave normal results. The possible reasons of disturbed alloreactivity and its relevance to immunity in MDS are commented in discussion.

[Use of cyclosporin A in hematology]. / Pouzití cyklosporinu A v hematologii.

We present an overview of clinical conditions where cyclosporin A (CyA) could be used in the treatment of hematological diseases. CyA is an effective immunosuppressive agent. It has long been successfully used in organ transplants and bone marrow transplants. The strong immunosuppressive effect of CyA makes this agent useful in various autoimmune diseases. The indication of CyA in certain hematological diseases has recently been steadily expanding. Based on the influence of CyA on cell immunity, the creation of cytokines and subsequently on humoral immunity we try to elucidate or justify its use in specific hematological diseases with regards to their pathophysiology. The common denominator to the diseases discussed below is a certain form of autoaggression. We include for example idiopathic autoimmune hemolytic anemia (AIHA) idiopathic thrombocytopenic (ITP), Evans syndrome, pure red cell aplasia. In certain sense we can include here even aplastic anemia (AA) and myelodysplastic syndrome (MDS). Furthermore, it is possible to use CyA for its ingerence to the proliferation and activation of T-cells in some T-lymphoproliferations and in histiocytoses. In B-lymphoproliferation the use of CyA will probably require further studies. We briefly note the possibility of influencing multiple drug resistance (MDR) with CyA.

Cyclosporin A therapy in hypoplastic MDS patients and certain refractory anaemias without hypoplastic bone marrow.

We report 17 cytopenic patients with myelodysplastic syndrome (MDS) of refractory anaemia (RA) subtype with hyper-, normo- or hypo-cellular bone marrow (BM), who were treated with cyclosporin A (CyA). Substantial haematological response was observed in 14 patients (82%): their anaemia improved and all transfusion-dependent patients achieved transfusion independence. Complete trilineage recovery was observed in four patients (23%). The CyA therapy has not yet failed in any of the 14 successfully treated patients during follow-up times ranging from 5 to 30 months. CyA was well tolerated in 14 patients; serious side-effects required termination of the therapy in three patients in whom the blood count rapidly deteriorated to former levels upon cessation of therapy. Two patients benefited from a combination therapy of CyA and erythropoietin. Six patients experienced various autoimmune phenomena. CyA could thus offer an alternative treatment for certain MDS patients with RA regardless of hyper-, normo- or hypo-cellularity of bone marrow (BM). The mechanism of the beneficial effect of CyA is discussed and remains the subject of an ongoing study.

[Retrograde intravenous perfusion--a therapeutic method in trophic defects of the lower extremities. Experience in patients with primary thrombocythemia]. / Retrográdní intravenózní perfuze--metoda lécby trofických defektu dolních koncetin. Zkusenosti u pacientu s primární trombocytémií.

Retrograde intravenous perfusion (RIP), so-called Bier's blockade is a relatively new method of treatment of critical ischaemia of the extremities. It is based on the principle of retrograde, i.e. transvenous perfusion of the capillary circulation during which at the time of artificially discontinued circulation in the extremities a high concentration of effective substances in the target tissues is achieved. In addition to the mentioned critical ischaemia Bier's blockade can be successfully used in the treatment of so-called "diabetic foot". It is also possible to implement by this method a local medicamentously induced block of the sympathetic nerves by administration of Guanethidine. In patients with contraindications of systemic fibrinolytic treatment local thrombolysis can be made in phlebothromboses and acral vascular occlusions. In the treatment of tumours on the extremities, e.g. melanoblastome, it is possible to achieve by local administration of cytostatics comparable results, while the incidence of undesirable effects is smaller. The objective of the present work was to make the professional public familiar with this method. On the example of four patients with trophic defects of the lower extremities which developed as a result of primary thrombocythemia the application of Bier's method was demonstrated.

[Mixed myelodysplastic and myeloproliferative syndromes]. / Smísené myelodysplastické a myeloproliferativní syndromy.

BACKGROUND: An injury to the hemopoietic stem cell may lead to the aplasia of hemopoiesis, myelodysplasia and to an unregulated myeloproliferation. There is not a strict demarcation of them, so that mixed syndromes can develop as are hypoplastic syndromes on one side and mixed myelodysplastic and myeloproliferative syndromes (MDS-MPS) on the other side. METHODS AND RESULTS: Among our 616 pts with MDS we looked for those cases, who had beside myelodysplasia signs of myeloproliferation with increased number of blood cells. They were examined in detail including bone-marrow histology, bone marrow cultivation, cytogenetics and bcr-abl gen. Signs of MDS-MPS were found in 22 patients at the first contact with the patient (13 patients had thrombocytemia and 9 patients had leukocytosis). Further 7 patients were diagnosed as MDS, proliferative syndrome developed after several months (MDS-MPS in evolution). The level of thrombocytemia was relatively stable, the number of leukocytes was progressive. All subtypes of MDS were found. All subjects had variable degree of anemia. Ring-sideroblasts and myelofibrosis were frequent finding in MDS-MPS. Men prevailed in patients with leukocytosis. Cytogenetic and cultivation findings were similar to MDS cases, deletion of long arm of chromosome 20 was present in 3 patients. Five patients transformed to acute myeloid leukemia. CONCLUSIONS: Sings of myelodysplasia and myeloproliferation were found in 4% of our MDS patients, designated as mixed myelodysplastic and myeloproliferative syndrome (MDS-MPS). In this syndrome beside evident signs of myelodysplasia thrombocythemia or leukocytosis with the release of bone marrow precursors are present. In only one case polycythemia was encountered.

[Recombinant human erythropoietin in the treatment of anemia associated with lymphoproliferative diseases--chronic lymphadenosis and multiple myeloma]. / Rekombinantní lidský erytropoetin v lécbe anémie lymfoproliferativních chorob--chronické lymfadenózy a mnohocetného myelomu.

UNLABELLED: The etiology of anaemia associated with tumours is multifactorial. One of the mechanisms of development of anaemia in tumours are so-called chronic diseases anaemias, the main feature of which is inadequate production of endogenous erythropoietin (EPO). The objective of the investigation was to test the effect of recombinant human erythropoietin (rHuEPO) in the treatment of anaemia (rise of haematocrit, Hb) in patients with chronic lymphatic leukaemia (CLL) and multiple myeloma (MM) and the effect of this treatment on the quality of life. The authors evaluated at the same time the impact of the endogenous EPO level before treatment and its predictive value as regards the therapeutic response. PATIENTS: The investigation comprised a total of 14 patients (6 CLL, 8 MM). The basic criterion for inclusion in the group was a Ht value lower than 0.32 and Hb less than 105 g/l. The examination protocol was focused on elimination of other causes of anaemia. During the 12-week investigation the patients completed a questionnaire "Quality of life" which reflected their subjective evaluation of the effect of treatment. The patients themselves administered r-HuEPO three times a week by the s.c. route--an initial dose of 150 U/kg with the possibility to increase the dose to 300 U/kg. RESULTS: A therapeutic response was obtained in four patients with CLL and eight patients with MM. Respondents with CLL had endogenous EPO values lower than 300 U/l, seven MM respondents lower than 200 U/l, one 400 U/l. The Hb level of the patients rose and the quality of life improved. All patients tolerated treatment very well and the authors did not observe any serious undesirable effects. CONCLUSION: The investigation confirmed the therapeutic effect of r-HuEPO in patients with a lower baseline value of EPO. Subjective evaluation (questionnaire) correlated with objective evaluation (Ht, Hb). Assessment of the endogenous EPO level before treatment is according to the authors one of the important primary predictive parameters and EPO values between 200 and 300 U/l are the upper range where a therapeutic effect can be expected with the highest probability. The authors conclude also that a secondary predictive criterion of the response is evaluation of the therapeutic effect after 4-5 weeks treatment when a rise of Hb by at least 20 g/l is an argument for further treatment.