High Level of Circulating Microparticles in Patients with BCR/ABL Negative Myeloproliferative Neoplasm - a Pilot Study.

BACKGROUND: Microparticles (MPs) are small (0.1-1 μm) cell-derived vesicles released during activation or apoptosis, with a surface-exposed phosphatidylserine along with antigens indicating the cellular origin. The level of MPs is known to be elevated in thromboembolic diseases and malignancies; it is believed that MPs are not only amplifying but can also initiate the thrombogenesis processes. BCR/ABL negative myeloproliferative neoplasms (MPNs) are clonal haematopoietic diseases, which include polycythemia vera, essential thrombocythemia and primary myelofibrosis. One of the main problems of MPN patients is high risk and incidence of thrombosis which affect the survival, quality of life and life expectancy. PATIENTS AND METHODS: The clinical significance of circulating MPs was assessed in a group of 179 patients with BCR/ABL-negative MPNs. Analysis of MPs was done using flow cytometry on 417 samples, and MPs procoagulation activity was performed using a functional assay called Zymuphen MP-activity (Hyphen Biomed, Neuville-sur-oise, France) on 274 samples. RESULTS: Significantly higher absolute and relative count of platelet MPs was found in MPN patients when compared with healthy group, respectively (p = 0.001, p = 0.043). Erythrocyte MPs were also significantly higher in MPN patients than in the healthy group (p < 0.001). Procoagulation activity of MPs was as well significantly higher in patients compared to the control group (p < 0.001). Patients with primary myelofibrosis had decreased absolute and relative count of platelet MPs compared to polycythemia vera and essential thrombocythemia patients, respectively (p = 0.008, p = 0.014). Presence of JAK2V617F mutation was associated with higher absolute and relative count of platelet MPs, respectively (p = 0.045, p = 0.029). CONCLUSION: Although some literature data support the hypothesis of a direct relation between MPs and thrombotic events in MPN patients, further studies are needed to evaluate the clinical implication of MPs in the hypercoagulation state of MPN patients.

Minimal Residual Disease Assessment in Multiple Myeloma by Multiparametric Flow Cytometry.

BACKGROUND: Progress in treatment of multiple myeloma extensively increased patient remission rates, so minimal residual disease (MRD) detection becomes essential to assess the effectivity of treatment and depth of complete response. Nowadays, multiparametric flow cytometry (MFC) is the most used method for monitoring of MRD presence in the bone marrow of multiple myeloma patients; however, detection on molecular level can be used as well. It is evident that choice of protocol used for MFC-MRD assessment can significantly affect required results; nevertheless, standardized and highly sensitive approach of "next generation flow" is already available. Although benefit of MRD assessment as an independent predictor of progression-free survival and overall survival is known, very recent research showed that MRD-negative status surpasses the prognostic value of complete response achievement for progression-free survival and overall survival. AIM: This review is focused on use MFC in MRD assessment in multiple myeloma. The technical aspects and clinical benefits of this approach are mentioned as well. CONCLUSION: The information about MRD level detected by highly sensitive and reproducible MFC can be potentially used as a biomarker to evaluate the efficacy of different treatment strategies, help on treatment decisions and act as a surrogate for overall survival in multiple myeloma patients.Key words: multiple myeloma - minimal residual disease - flow cytometry - plasma cells.

Whole Exome Sequencing of Aberrant Plasma Cells in a Patient with Multiple Myeloma Minimal Residual Disease.

Multiple myeloma is a plasma cell dyscrasia. It is the second most common hematological malignancy which is characterized by proliferation of clonal plasma cells producing harmful monoclonal immunoglobulin. Despite treatment modalities greatly evolved during the last decade, small amount of aberrant residual cells reside in patients after therapy and can cause relapse of the disease. Characterization of the residual, resistant clones can help to reveal important therapeutic targets for application of effective and precious treatment. We use CD38, CD45, CD56 and CD19 sorted aberrant plasma cells to perform next generation sequencing of their exome. Among the 213 genes in which at least one variant was present, the most interesting was found gene NRAS, one of the most often mutated gene in multiple myeloma, and homologs of 88 gene panel previously used for multiple myeloma sequencing among which was a gene previously identified as gene meaningful in bortezomib resistance. Nevertheless, the results of next generation exome sequencing need to be interpreted with caution, since they rely on bioinformatical analysis, which is still being optimized. The results of next generation sequencing will also have to be confirmed by Sanger sequencing. Final results supported by larger cohort of patients will be published soon.Key words: multiple myeloma - minimal residual disease - exome - next generation sequencing.

Circulating Plasma Cells in Monoclonal Gammopathies.

BACKGROUND: Monoclonal gammopathies are characterized by presence of clonal plasma cells in the bone marrow, although peripheral blood circulating plasma cells can be found in a significant proportion of patients. The number of circulating plasma cells is an independent prognostic marker associated with shorter survival, but it can also help to predict early relapse. The reason and mechanism of plasma cell expansion from the bone marrow to enter peripheral blood is still not entirely clear, but possible changes in the expression of adhesion molecules are probably involved. Multiparametric flow cytometry allows simple and exact enumeration of circulating plasma cells in different types of cell suspensions, even in their low quantity. The phenotype profile and confirmation of clonality regarding to their bone marrow clonal counterparts should be verified as well. There is no uniform method used in clinical laboratories for circulating plasma cells analyses at this moment. AIM: Review is focused on use of multiparametric flow cytometry for circulating plasma cells analysis in peripheral blood. It is comparing possibilities of their detection by different methods and on clinical relevance of that assessment. The standardization of analyses is the main goal. CONCLUSION: Multiparametric flow cytometry is a very sensitive method for detection of circulating plasma cells, so using a standardized approach can lead to determination and implementation of the flow cytometry diagnostic threshold in plasma cell leukemia suspicious cases as well as in prognostication of monoclonal gammopathies patients. Moreover, analysis of plasma cells phenotypic profile could probably clarify their future behaviour.Key words: monoclonal gammopathies - circulating plasma cells - plasma cell leukemia - flow cytometry.

Impact of anakinra treatment on cytokine and lymphocytes/ monocytes profile of an Erdheim-Chester patient.

BACKGROUND: Erdheim-Chester disease (ECD) is a rare non-Langerhans cells histiocytosis associated with intense immune activation. In our clinical center, an ECD patient was treated with anakinra, IL1RA (interleukin1 receptor antagonist), resulting in clinical improvement and major decrease of pathological fatigue. The aim of the study was to evaluate changes in cytokine profile and shift of immune cells estimated by flow cytometric analysis of ECD patient before, during initial stages of anakinra treatment as well as after treatment ceased in comparison to healthy donors. METHODS: Singleplex reactions of 19 individual cytokines from serum of ECD patient were measured by FACS array. Flow cytometric analyses were performed on peripheral blood cells. RESULTS: The most striking result is substantial decrease of IL6 immediately after anakinra treatment started suggesting a major role of IL1 pathway in ECD pathophysiology. As for flow cytometric analysis, increased number of CD16+ monocytes before treatment is a new finding. CONCLUSION: Our results suggest that IL6 may be a marker of early treatment response of ECD patients treated with anakinra.

[Cold agglutinin disease -  no response to glucocorticoids and rituximab, what treatment is best for the 3rd line of therapy? Case report and review of the literature]. / Nemoc chladových aglutininu nereagující na lécbu glukokortikoidy a na lécbu rituximabem. Jaký postup zvolit pro III. linii lécby? Popis prípadu a prehled literatury.

Acquired autoimmune haemolytic anaemia is divided according to the characteristics of immunoglobulin causing haemolysis. The most frequent are haemolytic anaemia with thermal antibodies. They bind to erythrocytes and initiate their destruction in the reticuloendothelial system cells, leading to extravascular haemolysis. Cold agglutinin disease differs significantly from haemolytic anaemia with thermal antibodies. Agglutination is caused by monoclonal antibodies, in most cases class IgM and very rarely class IgG. Under cold conditions they bind to erythrocytes and cause their agglutination and subsequent disorder of blood circulation in body parts with a lower temperature. Agglutinins binding initiate the binding of the complement to the erythrocytes. Under warm conditions the binding becomes loose but the parts of the complement, which are already bound, cause haemolysis, which is mainly of an intravascular nature. The loose haemoglobin causes haemoglobinuria. Description of a patient with the disease. The 1st symptoms of the disease, i.e. anaemia + circulatory disorders in the acral parts of the body, disappearing under warm conditions followed with haemoglobinuria, led to the dia-gnosis of cold agglutinin disease. The 1st line treatment, prednison, did not show any response. The 2nd line treatment used was rituximab and dexametazon. Rituximab was administered in doses of 500 mg/ m2 to 4 times in a row in weekly intervals. Dexametazon was administered in doses of 40 mg from 1st to 4th day and from 15th to 18th day of the cycle. This treatment, however, did not show any response either. Therefore this article brings an overview of all publications regarding the disease treatment with the aim of choosing the most effective treatment options in the case of failure of the monotherapy using rituximab. The 1st line treatment for cold agglutinin disease is rituximab in monotherapy, usually administered once per week at least for 4 weeks. This treatment shows a response in about one  half of treated patients and the remission duration median after rituximab administration is 11 months. A combination of rituximab with fludarabin was more effective, though more toxic; this combination, in a clinical study, led to 75% of patients responding to treatment, including 20% experiencing complete remission. The treatment response median reached over 66 months. In a small study (10 patients) an increase in the amount of rituximab administrations from 4 to 8 led to a treatment response in 6 patients in whom administration of 4 doses of rituximab had no response. When treating Waldenström macroglobulinemia, effectiveness of the following drugs and their combinations was proven: rituximab, chlorambucil, cyclophosphamide, fludarabin, bortezomib, lenalidomid, bendamustin and alemtuzumab. The same drugs and treatment procedures are used for the treatment of the cold agglutinin disease as for Waldenström macroglobulinemia. Successful treatment with vortezomibem, combinations of rituximab + bendamustin, rituximab + cyclophosphamide or rituximab + fludarabin + cyclophosphamide, were recorded in the form of a description as regards the cold agglutinin disease treatment. An important benefit is also shown through treatment with the monoclonal antibody antiC5, eculizumab, which is otherwise used for the treatment of paroxysmal nocturnal haemoglobinuria. Eculizumab blocks the C5 element of the component and thus stops haemolysis in a patient with cold agglutinin disease. As cold agglutinin disease is very rare, there are only a few clinical studies and when treating this rare disease we have no other option than to take into account the information contained in the descriptions of the particular cases of cold agglutinin disease and the experience of Waldenström macroglobulinemia disease treatment. The discussion seeks to solve the issue regarding what 3rd line treatment option to use in the described patient.

[Molecular basis of Waldenström macroglobulinemia]. / Molekulární podstata Waldenströmovy makroglobulinemie.

Waldenström macroglobulinemia is a rare lymphoproliferative disease that is currently classified into lymphomas with incidence of 3 cases per million. This disease comprises about 1-2% of hematological malignancies and is characterized by infiltration of malignant B cells into the bone marrow and presence of monoclonal immunoglobulin IgM in serum. WM is still an incurable disease with median survival of 5 years. Molecular basis of this disease remains unclear even though deletion of 6q, trisomy of chromosomes 4 and 8, deletion of 13q and increased expression of IL-6 seem to be typical for this disease. The most important changes of microRNA are increased expression of miR-155 and decreased expression of miR-9*. This work aims to describe current knowledge about the molecular basis of this disease.

[Methylene blue in the therapy of vasoplegic syndrome after cardiac surgery procedure]. / Metylenová modr v lécbe vazoplegického syndromu po kardiochirurgické operaci.

Vasoplegic syndrome after cardiac surgery with cardiopulmonary bypass is severe complication with high morbidity and mortality. Without appropriate therapy the syndrome advances to the shock state with subsequent multiorgan failure. Basic haemodynamic parameters of vasoplegic syndrome include low systemic vascular resistance with severe hypotension, tachycardia, and normal or increased cardiac output and low filling pressures. In therapy norepinephrine and vasopressin or its analogues are used. Methylene blue is other therapeutic option. The case of successful application of methylene blue for the treatment of vasoplegic syndrome is presented.

L-Proline transport in Saccharomyces cerevisiae.

Transport of L-proline into Saccharomyces cerevisiae K is mediated by two systems, one with a KT of 31 microM and Jmax of 40 nmol . s-1 . (g dry wt.)-1, the other with KT greater than 2.5 mM and Jmax of 150-165 nmol . s-1 . (g dry wt.)-1. The kinetic properties of the high-affinity system were studied in detail. It proved to be highly specific, the only potent competitive inhibitors being (i) L-proline and its analogs L-azetidine-2-carboxylic acid, sarcosine, D-proline and 3,4-dehydro-DL-proline, and (ii) L-alanine. The other amino acids tested behaved as noncompetitive inhibitors. The high-affinity system is active, has a sharp pH optimum at 5.8-5.9 and, in an Arrhenius plot, exhibits two inflection points at 15 degrees C and 20-21 degrees C. It is trans-inhibited by most amino acids (but probably only the natural substrates act in a trans-noncompetitive manner) and its activity depends to a considerable extent on growth conditions. In cells grown in a rich medium with yeast extract maximum activity is attained during the stationary phase, on a poor medium it is maximal during the early exponential phase. Some 50-60% of accumulated L-proline can leave cells in 90 min (and more if washing is done repeatedly), the efflux being insensitive to 0.5 mM 2,4-dinitrophenol and uranyl ions, the pH between 3 and 7.3, as well as to the presence of 10-100 mM unlabeled L-proline in the outside medium. Its rate and extent are increased by 1% D-glucose and by 10 micrograms nystatin per ml.

Anilinonaphthalene sulfonate fluorescence and amino acid transport in yeast.

Fluorescence of 1-anilinonaphthalene-8-sulfonate in yeast membranes appears to be caused predominantly by binding to lipids (ANS protein:ANS lipid approximately 1 : 20) as indicated by the fluorescence lifetime, degree of polarization, and excitation spectra. It was insensitive to short-circuiting the membrane potential. Fluorescence intensity increased as cells (especially after pretreatment with energy donors such as glucose) were exposed to some amono acids, in particular, aspartic and glutamic acids. The character of fluorescence shifted to that of protein-bound ANS, suggesting an exposure of new protein sites accessible to the probe. This shift could be prevented by inhibitors of energy transduction as well as of transport. The K1/2 of the shift was at 2.5 mM aspartic acid.

Stimulation of amino acid transport in Saccharomyces cerevisiae by metabolic inhibitors.

Inhibitors of energy metabolism (3-chlorophenylhydrazonomalononitrile, antimycin A, iodoacetamide, dicyclohexylcarbodiimide) but not of transport (uranyl ions) stimulate at low concentrations the uptake of L-leucine, L-glutamic acid, L-arginine and, to a lesser degree, of 2-aminoisobutyric acid in Saccharomyces cerevisiae. The effect is apparent only after augmenting the energy reserves of cells by preincubation with D-glucose or, more strikingly, with ethanol. It is absent in a mutant (op1) lacking the translocation system for ADP--ATP in mitochondria. The presence of two different energy reserves for amino acid transport is indicated (one in energy-poor, the other in energy-rich cells). The stimulating effect appears to be caused by a retarded degradation of the transport proteins as occurs at a lowered level of mitochondria-produced ATP.

Specificity of trans-inhibition of amino acid transport in baker's yeast.

The trans-inhibition potency of intracellular amino acids on the transport of various amino acids follows the same sequence, viz. Pro(Lys), Phe, Glu, Ala, Gly, Leu, and alpha-aminoisobutyric acid. The same sequence was found for the reciprocal of trans-inhibition constants. It appears that the intracellular amino acid itself or a derivative thereof acts on a component that is common to all amino acid transport systems of baker's yeast.

Loss of inducible D-galactose transport by baker's yeast after osmotic treatment.

The ability of Saccharomyces cerevisiae to transport D-galactose and related sugars with an axial hydroxyl group at C-4, acquired by induction with D-galactose, was lost either by exposing early exponential-phase cells to an osmotic shock involving incubation in 0.6M NaC1O4, 0.66M sucrose and 1mM histidine and transfer to 5mM Tris-HC1 with 2mM dithiothreitol, or simply by transferring them to distilled water. The total amount of protein thus released was 0.1--0.35 and 0.1 mg per mg dry wt., respectively. The shock fluid contained at least six proteins, among them a galactose-binding component. L-Arabinose transport could not be restored by adding the concentrated shock fluid to depleted cells but cells remained viable after the shock and resynthesized the transport system if incubated in a galactose-containing growth medium.

Transport of acyclic polyols in Saccharomyces cerevisiae.

Acyclic polyols (erythritol, xylitol, ribitol, D-arabinitol, mannitol, sorbitol and galactitol) are not metabolized by Saccharomyces cerevisiae. They are taken up by a fast non-active process, reaching 40-70% distribution referred to total cell water. The uptake is insensitive to temperature, pH (between 4 and 8), 2,4-dinitrophenol and uranyl ions. Its initial rate rises linearly with concentration from 10(-5)M to 1M. The process resembles simple diffusion through large pores or the trapping of the whole solution on the surface. Protoplasts behave like whole cells in this respect. Only erythritol shows a second type of uptake which is inhibitor-insensitive but temperature-dependent.