Oxidative stress, microparticles, and E-selectin do not depend on HIV suppression

BACKGROUND

Oxidative stress and inflammation are considered predictors of diseases associated with aging. Markers of oxidative stress, inflammation, and endothelial activation were investigated in people with HIV on antiretroviral treatment to determine whether they had an immunosenescent phenotype that might predispose to the development of premature age-related diseases.

PATIENTS AND METHODS

This study was conducted on 213 subjects with HIV. The control groups consisted of healthy HIV-negative adults. The level of oxidative stress was measured by assessing the production of malondialdehyde levels, which were detected by thiobarbituric acid reactive substance (TBARS) assay. The level of microparticles indicated the presence of inflammation and endothelial activation was measured by E-selectin levels. Significant differences were determined by appropriate statistical tests, depending on the distribution of variables. Relationships between continuous variables were quantified using Spearman's rank correlation coefficient.

RESULTS

TBARS, and microparticle and E-selectin levels were significantly higher in untreated and treated subjects with HIV compared with HIV-negative controls (P<0.001). The levels of the investigated markers were not significantly different between untreated and treated patients and no significant correlation of these markers was found with CD4+ count, CD4+/CD8+ ratio, and the number of HIV-1 RNA copies.

CONCLUSIONS

Elevated markers of oxidative stress, inflammatory and endothelial activation were independent of the virologic and immunologic status of people with HIV. These results support the hypothesis that residual viremia in cellular reservoirs of various tissues is a key factor related to the premature aging of the immune system and predisposition to the premature development of diseases associated with aging.

Bleeding pattern and consumption of factor VIII concentrate in adult patients with haemophilia A without inhibitors in the Czech Republic between 2013 and 2021 (Czech National Haemophilia Programme registry data)

The manuscript provides an overview of treatment and its changes in adult patients with haemophilia A without inhibitors in the Czech Republic between 2013 and 2021 using data from the registry of the Czech National Haemophilia Programme (CNHP). Over a 9-year period, we focused on the reduction in the annual bleeding rate (ABR), joint bleeding rate (AJBR) and factor VIII consumption when patients with severe haemophilia A switched from on-demand treatment to prophylaxis. The ABR and AJBR include both patient-reported home treatment and treated hospitalisation episodes. All adult patients with severe haemophilia A were categorised into three groups according to the therapeutic regimen. The first group was patients on prophylaxis during the follow-up period, the second group consisted of patients on on-demand treatment, and the third group was patients who received both treatment regimens during follow-up. With an increase in the proportion of patients with severe haemophilia A on prophylaxis from 37 to 74% between 2013 and 2021, the ABR for all patients with severe haemophilia A decreased approximately 6.9-fold, and the AJBR decreased 8.7-fold. Expectedly, the factor consumption increased by approximately 68.5%. In the group of patients with severe haemophilia A who had switched from an on-demand to a prophylactic regimen, the total number of bleeding events decreased 3.5-fold, and the number of joint bleeding episodes decreased 3.9-fold. Factor VIII consumption increased by 78.4%. Our study supports a previously reported positive effect of prophylaxis on bleeding control. We believe that the substantial improvement in ABR justifies the increased treatment costs.

More Than 2% of Circulating Tumor Plasma Cells Defines Plasma Cell Leukemia-Like Multiple Myeloma

PURPOSE

Primary plasma cell leukemia (PCL) is the most aggressive monoclonal gammopathy. It was formerly characterized by ≥ 20% circulating plasma cells (CTCs) until 2021, when this threshold was decreased to ≥ 5%. We hypothesized that primary PCL is not a separate clinical entity, but rather that it represents ultra-high-risk multiple myeloma (MM) characterized by elevated CTC levels.

METHODS

We assessed the levels of CTCs by multiparameter flow cytometry in 395 patients with newly diagnosed transplant-ineligible MM to establish a cutoff for CTCs that identifies the patients with ultra-high-risk PCL-like MM. We tested the cutoff on 185 transplant-eligible patients with MM and further validated on an independent cohort of 280 transplant-ineligible patients treated in the GEM-CLARIDEX trial. The largest published real-world cohort of patients with primary PCL was used for comparison of survival. Finally, we challenged the current 5% threshold for primary PCL diagnosis.

RESULTS

Newly diagnosed transplant-ineligible patients with MM with 2%-20% CTCs had significantly shorter progression-free survival (3.1 v 15.6 months; P < .001) and overall survival (14.6 v 33.6 months; P = .023) than patients with < 2%. The 2% cutoff proved to be applicable also in transplant-eligible patients with MM and was successfully validated on an independent cohort of patients from the GEM-CLARIDEX trial. Most importantly, patients with 2%-20% CTCs had comparable dismal outcomes with primary PCL. Moreover, after revealing a low mean difference between flow cytometric and morphologic evaluation of CTCs, we showed that patients with 2%-5% CTCs have similar outcomes as those with 5%-20% CTCs.

CONCLUSION

Our study uncovers that ≥ 2% CTCs is a biomarker of hidden primary PCL and supports the assessment of CTCs by flow cytometry during the diagnostic workup of MM.

JAK2V617F mutation and circulating extracellular vesicles in essential thrombocythemia

The clinical course of essential thrombocythemia (ET) is complicated with thrombosis which significantly impacts patients' mortality. Studies have identified JAK2V617F mutation as an independent risk factor for thrombosis. Circulating extracellular vesicles (EVs) were evaluated in several studies regarding myeloproliferative neoplasms and thrombosis as potential biomarkers. The present study investigates the relationship between JAK2V617F mutation and EVs levels in 119 ET patients. Our analyses revealed that JAK2V617F-positive patients are at a significantly increased risk of thrombosis within five years before the ET diagnosis (hazard ratio [95% CI]: 11.9 [1.7-83.7], P = 0.013), and that JAK2V617F mutation is an independent risk factor for thrombosis at ET diagnosis or during the follow-up (hazard ratio [95% CI]: 3.56 [1.47-8.62], P = 0.005). ET patients have higher levels of platelet-EVs, erythrocyte-EVs and procoagulant activity of EVs than the healthy population. Absolute and relative counts of platelet-EVs are increased in the presence of JAK2V617F mutation (P = 0.018, P = 0.024, respectively). In conclusion, our results support the role of JAK2V617F mutation in the pathogenesis of thrombosis in essential thrombocythemia through enhancing platelet activation.

Venous thromboembolism in antiphosholipid syndrome

Antiphosholipid syndrome (APS) is defined by the presence of clinical and laboratory criteria, it means by presence of antiphospholipid antibodies. Venous thromboembolism belongs to the most frequent clinical manifestation of this syndrome. Here we summarised basic pathophysiological mechanisms of venous thrombosis and lung embolism development, epidemiology of APS, and also the situations when this syndrome should be considered. The possible difficulties of laboratory diagnosis and their therapy involvement are mentioned.

Analysis of von Willebrand Disease in the "Heart of Europe"

Background  von Willebrand disease (VWD) is a genetic bleeding disorder caused by defects of von Willebrand factor (VWF), quantitative (type 1 and 3) or qualitative (type 2). The laboratory phenotyping is heterogenic making diagnosis difficult.

Objectives  Complete laboratory analysis of VWD as an expansion of the previously reported cross-sectional family-based VWD study in the Czech Republic (BRNO-VWD) and Slovakia (BRA-VWD) under the name “Heart of Europe,” in order to improve the understanding of laboratory phenotype/genotype correlation.

Patients and Methods  In total, 227 suspected VWD patients were identified from historical records. Complete laboratory analysis was established using all available assays, including VWF multimers and genetic analysis.

Results  A total of 191 patients (from 119 families) were confirmed as having VWD. The majority was characterized as a type 1 VWD, followed by type 2. Multimeric patterns concordant with laboratory phenotypes were found in approximately 83% of all cases. A phenotype/genotype correlation was present in 84% (77% type 1, 99% type 2, and 61% type 3) of all patients. Another 45 candidate mutations (23 novel variations), not found in the initial study, could be identified (missense 75% and truncating 24%). An exon 1–3 gene deletion was identified in 14 patients where no mutation was found by direct DNA sequencing, increasing the linkage up to 92%, overall.

Conclusion  This study provides a cross-sectional overview of the VWD population in a part of Central Europe. It is an addition to the previously published BRNO-VWD study, and provides important data to the International Society of Thrombosis and Haemostasis/European Association for Haemophilia and Allied Disorders VWD mutation database with identification of novel causal mutations.

Risk factors of thrombosis in a cohort of 206 patients with BCR-ABL1 negative myeloproliferative neoplasms

Thrombosis is the most common complication in BCR-ABL1 negative myeloproliferative neoplasms (MPN) that significantly impacts patients' mortality. Generally, there is an agreement on risk factors that possibly contribute to the increased risk of thrombosis, including age, history of thrombosis, JAK2V617F mutation, and cardiovascular risk factors. This study retrospectively investigates MPN-related and patient-related variables in relation to the thrombosis occurrence in MPN. Our analyses show that JAK2V617F-mutated patients are at a significantly increased risk of thrombosis within five years before the MPN diagnosis point with a hazard ratio (HR) of 15.49 (p=0.006). In multivariate analyses, independent risk factors for thrombotic complications during the follow-up are history of thrombosis (HR=2.23, p=0.019), age over 60 years at diagnosis (HR=1.56, p=0.037), the presence of JAK2V617F mutation (HR=3.01, p=0.002), and tobacco smoking (HR=1.75, p=0.01). Our results support the multifactorial mechanism of thrombosis in MPN patients, which demands individual and complex management.

The Clinical Significance of Circulating Microparticles Concerning Thrombosis in BCR/ABL1-negative Myeloproliferative Neoplasms

BACKGROUND/AIM

This work aimed to prospectively evaluate the clinical significance of circulating microparticles (MPs) in relation to thrombotic risk factors and thrombotic complications in patients with BCR/ABL1-negative myeloproliferative neoplasms (MPN).

PATIENTS AND METHODS

In a cohort of 206 patients with MPN, MPs' procoagulant activity was measured by the Zymuphen functional assay in 429 samples, while platelet- and erythrocyte-MPs were enumerated by flow cytometry in 558 samples.

RESULTS

MPN patients had higher MP levels than the control group. The levels of MPs were higher in male patients, smokers, and those who were older than 60 years, and in the presence of JAK2^V617F mutation, history of thrombosis, platelets >400×10⁹/l, hematocrit >45%, or leukocytes >10×10⁹/l. Cytoreductive treatment reduced MP levels, with anagrelide being associated with lower MP levels than hydroxyurea.

CONCLUSION

The relationship with thrombotic risk factors indicates a possible role of MPs in the complex thrombotic mechanism, though cytoreductive treatment seems to affect this role through reducing MP levels.

Necessity of flow cytometry assessment of circulating plasma cells and its connection with clinical characteristics of primary and secondary plasma cell leukaemia

Plasma cell leukaemia (PCL) is a rare and very aggressive plasma cell disorder. Preventing a dismal outcome of PCL requires early diagnosis with appropriate analytical tools. Therefore, the investigation of 33 patients with primary and secondary PCL was done when the quantity of circulating plasma cells (PCs) using flow cytometry (FC) and morphology assessment was evaluated. The phenotypic profile of the PCs was also analysed to determine if there is an association with clinical outcomes and to evaluate the prognostic value of analysed markers. Our results revealed that FC is an excellent method for identifying circulating PCs as a significantly higher number was identified by FC than by morphology (26·7% vs. 13·5%, P = 0·02). None of secondary PCL cases expressed CD19 or CD20. A low level of expression with similar positivity of CD27, CD28, CD81 and CD117 was found in both PCL groups. A decrease of CD44 expression was detected only in secondary PCL. Expression of CD56 was present in more than half of PCL cases as well as cytoplasmic nestin. A decreased level of platelets, Eastern Cooperative Oncology Group score of 2-3 and lack of CD20⁺ PC were associated with a higher risk of death. FC could be incorporated in PCL diagnostics not only to determine the number of circulating PCs, but also to assess their phenotype profile and this information should be useful in patients' diagnosis and possible prognosis.

Plasmacytoid Dendritic Cells in Patients with MGUS and Multiple Myeloma

Background: Plasmacytoid dendritic cells (pDCs) play prominent roles in mediating innate and adaptive immune responses. However, it is unclear how pDCs contribute to the immunosuppressive tumor microenvironment described in multiple myeloma (MM). Methods: Newly diagnosed myeloma patients (MM, n = 37) were analyzed to determine the pDC counts in comparison to peripheral blood (PB, n = 53) and bone marrow (BM, n = 10) samples of age-matched healthy donors (HD) using flow cytometry. Second, proliferation of myeloma tumor cells in the presence of freshly isolated pDCs was examined. Third, production of IFNα by pDCs co-cultured with MM cells was determined by intracellular staining. Results: We found a highly significant reduction of circulating pDCs (p < 0.0001) and in bone marrow (p < 0.0001) of MM patients compared to HD. We also observed a significant decrease of pDCs (p = 0.004) in BM in patients with monoclonal gammopathy of undetermined significance (MGUS, n = 12). Importantly, we determined that pDCs promote proliferation specifically of MM cells and not the stromal cells and that pDCs secrete IFNα upon co-culture with MM tumor cells. Conclusions: Our results show altered pDC frequencies in the BM microenvironment in MGUS and MM patients at diagnosis. We showed the tumor-promoting function of pDCs that may mediate immune deficiencies affecting long-term disease control and treatment outcome.

Pancytopenia as the main manifestation of human immunodeficiency virus infection in the AIDS stage The authors present a case

The authors present a case report of 59-years-old woman examined for pancytopenia recently diagnosed during hospitalization for bilateral interstitial pneumonia without any confirmed etiological agents. Concomitantly, some systemic symptoms like lack of appetite and weight loss were present. Primary hematological disease was ruled out. Positivity of serological screening for HIV-1,2 was rather surprising. Absolute count of CD4+ lymphocytes was 8/&#956;l. Thus, HIV infection was already in stage of AIDS and retrospectively, the interstitial pneumonia has to be judged as AIDS-indicative illness.

Optimizing clinical approaches to COVID-19 patients in primary care

There is insufficient evidence from medical studies for clinical approaches to patients with COVID-19 in primary care. Patients often urge the therapeutic use and preventive administration of various medicines, often controlled by studies insufficiently or completely unverified. The aim of the project, commissioned by the Committee of the Society of General Practice of the Czech Medical Association JEP, was to compensate for this deficiency by interdisciplinary consensus and thus provide general practitioners (GPs) with a basic support in accessing patients with COVID-19. Representatives of GPs identified the most common questionable diagnostic or therapeutic approaches and formulated 17 theses, taking into account their own experience, existing Czech and foreign professional recommendations. The RAND/UCLA Appropriateness Method, modified for the needs of pandemic situation, was chosen to seek consensus. Representatives of 7 medical specialties accepted the participation in the 20-member panel. The panel evaluated in 2 rounds, with the comments and opinions of others available to all panelists before the second round. The outcome of the evaluation was agreement on 10 theses addressing the administration of vitamin D, inhaled corticosteroids in patients with COPD and bronchial asthma, acetylsalicylic acid, indications for D-dimer levels examination, preventive administration of LMWH, importance of pulse oximetry, indication for emergency services, indication for antibiotics and rules for distant contact. The panel disagreed on 6 theses recommending the administration of ivermectin, isoprinosine, colchicine and corticosteroids in patients with COVID-19 in primary care. One thesis, taking into account the use of D-dimers in primary care was evaluated as uncertain. The most discussed theses, on which there was also no agreement, were outpatient administration of corticosteroids and the importance of elevation of D-dimers levels or their dynamic increase in a symptomatic patient with COVID-19 as an indication for referral to hospital. The results of the consensus identified topics that need to be further discussed and on which it is appropriate to focus further research.

Pembrolizumab-induced hypothyreosis and subcutaneous bleeding

Pembrolizumab belongs to so called immune checkpoint inhibitors. Frequent adverse event of this therapy is hypothyroidism. The authors present a case report of patient treated with pembrolizumab for non-small cell lung carcinoma, in whom severe hypothyroidism followed quite rapidly after transient phase of subclinical hyperthyroidism - at this time point new and spontaneous onset of large subcutaneous hematomas was observed. Acquired von Willebrand syndrome, acquired hemophilia A, dysfibrinogenemia, activation of fibrinolysis and thrombocytopathy were all actively ruled out in hematological differential diagnosis. Concomittantly, laboratory markers of secondary autoimmune disease and myositis were excluded. Despite continuous pembrolizumab treatment, there were no other bleeding complications seen after intensification of endocrine substitution therapy with thyroid hormones. Causal relationship between subcutaneous hematomas and severe drug-induced hypothyroidism is established per exclusionem.

Liver transplantation as potential curative method in severe hemophilia A: case report and literature review

The authors present clinical case of orthotopic liver transplantation for cirhosis due to chronic viral hepatitis C in a subject with severe hemophilia A. Preoperatively performed pharmacokinetic study with recombinant F VIII confirmed satisfactory in vivo recovery of 2.1 %. A bolus application of 52 units F VIII/kg body weight with target F VIII activity over 100.0 % was administred shortly before the transplantation started. Totally, 30 000 units of recombinant F VIII, 3 thrombocyte concentrates, 2 erythrocyte concentrates, 5 units of virally inactivated plasma, 1 unit of fresh frozen plasma and 3 500 antithrombin units were used. There were no perioperative or postoperative bleeding complications, F VIII substitution was stopped on postoperative day 3. The patient was discharged on twentieth postoperative day.

Heparin-induced thrombocytopenia: a case report and literature overview

Heparin-induced thrombocytopenia (HIT) is an immunologically-mediated complication, which usually follows heparin exposition, less frequently exposition to other drugs or even occurs spontaneously. The type of heparin, its dose and mode of application as well as the exposition time, major trauma or operation, and obesity represent the main risk factors for HIT. The probability of HIT correlates with so-called 4T-score. A confirmatory laboratory diagnostic should be exclusively reserved for patients with a medium to a high probability of HIT development (more than 3 points in 4T-score). The screening method is based on serological detection of antibodies against heparin-platelet factor-4 complexes; confirmation tests aim to identify the activation of platelets. The treatment of HIT requires an immediate interruption of heparin application and rigorous antithrombotic treatment with an alternative agent. Herein authors describe a clinical case of HIT manifested as an extreme urticarial reaction in the location of nadroparin application as well as thrombosis of deep subcutaneous veins in a polymorbid obese patient with an extensive and infected burn. Due to timely diagnosis and fondaparinux treatment, no more severe thrombotic events occurred in this patient.

Increasing procoagulant activity of circulating microparticles in patients living with HIV

OBJECTIVES

HIV-infected individuals are at higher risk of non-AIDS diseases associated with procoagulant status. Microparticles are elevated in disorders associated with thrombosis (e.g., cardiovascular diseases). We investigated the association between microparticle levels in untreated and treated HIV-infected subjects, and determined the association with immune status, viral replication, and duration of antiretroviral therapy.

PATIENTS AND METHODS

We included 144 HIV-infected subjects, including 123 on antiretroviral therapy (ART) and 21 before treatment initiation. A control group of 40 HIV-negative healthy adults matched for age and sex was used for comparison of microparticle levels. Treated subjects were divided into five groups depending on the period of antiretroviral exposure. Statistically significant differences were determined by Kruskal-Wallis test and Chi² test. The relation between microparticles and other parameters was assessed using Spearman's coefficient of correlation.

RESULTS

Microparticle levels were significantly higher in treated and untreated HIV-infected subjects than in non-HIV-infected controls (P<0.001). The microparticle level was similar between the groups on treatment (P=0.913). No association between the microparticle level and CD4+ count, CD4+/CD8+ ratio, number of HIV-1 RNA copies, or duration of exposure to antiretroviral treatment was observed.

CONCLUSION

Increased levels of microparticles may be due to processes independent of viral replication and CD4+ cell count, and microparticle release might persist even during viral suppression by antiretroviral treatment. Elevated microparticle levels might occur in response to other triggers.

Pharmacokinetic Comparison of Subcutaneous and Intravenous Nadroparin Administration for Thromboprophylaxis in Critically Ill Patients on Vasopressors

INTRODUCTION

Critically ill patients are exposed to a high risk of developing thromboembolism. Moreover, standard prophylaxis with subcutaneous (SC) heparin is less efficient in patients requiring vasopressors. The aim is a comparison of pharmacokinetics between SC and intravenous (IV) applied nadroparin.

METHODS

Thirty-eight ventilated ICU patients requiring vasopressor support were randomized into a single dose of nadroparin 3,800 IU (0.4 mL) subcutaneously (SC group) or 1,900 IU (0.2 mL) intravenously (IV group). Anti-factor Xa activity (anti-Xa) was observed over 24 h; data are stated as median (IQR).

RESULTS

Peak anti-Xa was significantly higher in the IV group 0.42 (0.39-0.43) IU/mL than in the SC group 0.16 (0.09-0.18) IU/mL (p < 0.001). There was a trend towards higher area under the curve (AUC) of anti-Xa in the SC group 1.41 (0.41-1.80) IU/mL × h than in the IV group 1.04 (0.93-1.13) IU/mL × h (p = 0.08). In the SC group, there was a negative correlation between anti-Xa AUC and both capillary refill time Xa (r = -0.86) and norepinephrine dose (r = -0.68). In the IV group, anti-Xa decrease half-life was 1.6 (1.4-2.0) h.

CONCLUSIONS

IV administration of 1,900 IU of nadroparin led to a predictable effective peak anti-Xa. After SC administration, anti-Xa was heterogeneous and significantly influenced by peripheral perfusion.

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

BACKGROUND

Microparticles (MPs) are small (0.1-1 &#956;m) 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 &lt; 0.001). Procoagulation activity of MPs was as well significantly higher in patients compared to the control group (p &lt; 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.

Biomarkers in Immunoglobulin Light Chain Amyloidosis

Immunoglobulin light chain amyloidosis (AL amyloidosis - ALA) is a monoclonal gammopathy characterized by presence of aberrant plasma cells producing amyloidogenic immunoglobulin light chains. This leads to formation of amyloid fibrils in various organs and tissues, mainly in heart and kidney, and causes their dysfunction. As amyloid depositing in target organs is irreversible, there is a big effort to identify biomarker that could help to distinguish ALA from other monoclonal gammopathies in the early stages of disease, when amyloid deposits are not fatal yet. High throughput technologies bring new opportunities to modern cancer research as they enable to study disease within its complexity. Sophisticated methods such as next generation sequencing, gene expression profiling and circulating microRNA profiling are new approaches to study aberrant plasma cells from patients with light chain amyloidosis and related diseases. While generally known mutation in multiple myeloma patients (KRAS, NRAS, MYC, TP53) were not found in ALA, number of mutated genes is comparable. Transcriptome of ALA patients proves to be more similar to monoclonal gammopathy of undetermined significance patients, moreover level of circulating microRNA, that are known to correlate with heart damage, is increased in ALA patients, where heart damage in ALA typical symptom.Key words: amyloidosis - plasma cell - genome - transcriptome - microRNA.

Analysis of von Willebrand Disease in the South Moravian Population (Czech Republic): Results from the BRNO-VWD Study

BACKGROUND

 von Willebrand disease (VWD) is an inherited bleeding disorder caused by a quantitative (type 1 and 3) or qualitative (type 2) defect of von Willebrand factor (VWF). The heterogeneity of laboratory phenotyping makes diagnosing difficult.

OBJECTIVE

 A cross-sectional, family-based VWD study in a collaboration between University Hospital Brno (Czech Republic) and Antwerp University Hospital (Belgium) to improve the understanding of laboratory phenotype/genotype correlation.

PATIENTS AND METHODS

 A total of 205 patients with suspected VWD were identified from historical records. Complete laboratory analysis was established using all available VWD assays including VWF multimers and genetic analysis.

RESULTS

 Based on the current International Society of Thrombosis and Haemostasis (ISTH) - Scientific and Standardization Committee VWD classification and type 2A sub-division into 2A/IIA, IID, IIC and IIE, the majority was characterized as a type 1 VWD, followed by type 2. Proposed laboratory phenotypes were confirmed by their multimeric pattern within 98% of this cohort. All type 2, 3 and 75% of type 1 VWD patients were confirmed by underlying causative mutations. Forty-six different causal mutations (117 not previously described in the literature) could be identified. Fifty per cent of all cases was represented by eight individual mutations, mainly p.Pro812ArgfsX31. Thirteen patients had a large heterozygous gene alteration.

CONCLUSION

 Although an extensive panel of tests was used, VWD classification and (sub)typing remains difficult and fluid. This study provides a cross-sectional overview of the VWD population in the Czech Republic and provides important data to the ISTH/European Association for Haemophilia and Allied Disorders VWD mutation database in linking causal mutations with unique VWD (sub)types. It also identifies new, as not previously described in the literature, causal mutations.

Spontaneous retroperitoneal hematoma - our experience with surgical approach

Spontaneous retroperitoneal hematoma is a serious complication of anticoagulation and antiplatelet therapy. Its incidence has increased in recent years due to an increasing number of patients on this treatment. A number of case series have been described in the literature. In the vast majority of cases, the hemodynamically stable patients were treated either conservatively or by selective radiological embolization of the bleeding source. A surgical approach is reported as a last choice in the cases where the conservative therapy fails, radiological intervention is unavailable, in patients with continuous bleeding or in patients who develop abdominal compartment syndrome. In our case report, we present a patient on anticoagulation therapy for deep venous thrombosis complicated by massive retroperitoneal bleeding: surgery was used as the method of first choice and the treatment was successful. Key words: retroperitoneal hematoma bleeding anticoagulation treatment surgery.

Pancytopenia, panhypopituitarism and liver cirrhosis: analysis of a difficult clinical case

Panhypopituitarism following craniopharyngioma resection has systemic impact with potential influence on physio-logical hematopoiesis. There is a growing body of evidence of liver fibrosis/cirrhosis risk development due to altered metabolism and lipid accumulation. The authors present a case report of a woman with a history of craniopharyngioma resection followed by aggravating pancytopenia with suspected indolent lymphoproliferative disorder and possible acquired bone marrow aplasia syndrome due to paroxysmal nocturnal hemoglobinuria. A complex hemostasis disorder with deficiency of multiple coagulation factors (FXII, FXI, FX, FIX, FVII, FX, FV, FXIII, antitrombin, protein C, protein S) was accidentally detected. Despite normal sonographic liver imaging, all possible causes of chronic liver disease were systematically excluded (viral hepatitis, hemochromatosis, Wilson´s disease, &#945;-1-antitrypsin deficiency); anti-LKM-1 and anti-ENA antibodies were detected. Finally, the magnetic resonance imaging confirmed image of liver cirrhosis - with signs of portal hypertension.

Circulating exosomal long noncoding RNA PRINS-First findings in monoclonal gammopathies

Multiple myeloma is the second most common hematological malignancy characterized by focal lesions of malignant plasma cells in the bone marrow. These lesions contain subclones that directly influence survival of patients. Bone marrow biopsies are single-site biopsies and thus cannot contain all information about the tumor. In contrast, liquid biopsies analyze circulating cells and molecules that are secreted from all sites of the tumor. Long noncoding RNA molecules are one class of these molecules. We performed a two-phase biomarker study investigating lncRNA expression profiles in exosomes of peripheral blood serum of newly diagnosed multiple myeloma (MM) patients, monoclonal gammopathy of undetermined significance (MGUS) patients in comparison with healthy donors (HD). Surprisingly, this analysis revealed dysregulation of only one exosomal lncRNA PRINS in MM vs HD. Overall, MM and MGUS patients were distinguished from HD with sensitivity of 84.9% and specificity of 83.3%. Our study suggests a possible diagnostic role for exosomal lncRNA PRINS in monoclonal gammopathies patients.

Selected Genetic Polymorphisms Associated with Hypoxia and Multidrug Resistance in Monoclonal Gammopathies Patients

BACKGROUND

Adaptive response to hypoxia is regulated by several mechanisms and transcription factors, including hypoxia-inducible factors (HIFs). Activation of HIF-1α is associated with increased expression of P-glycoprotein and multidrug resistance in cancer cells. In this retrospective study, we analyzed candidate single-nucleotide polymorphisms (SNPs) in HIF-1α and HIF-1β associated with risk of monoclonal gammopathy of undetermined significance (MGUS) or multiple myeloma (MM).

PATIENTS AND METHODS

Genotypes of SNPs associated with hypoxia were determined in an independent cohort of monoclonal gammopathies (MG) (275 MM and 228 MGUS patients) and in 219 cancer-free controls by real time polymerase chain reaction allelic discrimination.

RESULTS

When MM patients were compared to controls, protective role of CG genotype compared to CC in HIF-1β (rs2228099) for MM development was observed (OR = 0.65; CI 0.45-0.95; p = 0.026). Even after adjustment for patients' age and body mass index (BMI), there were significantly lower odds (OR = 0.55; p = 0.045) of developing MM patients of CG genotype in comparison to CC genotype. Log-rank test confirmed association of GT haplotype (rs11549467, rs2057482) in HIF-1α with better overall survival (median 41.8 months; (CI 35.1-48.5)) for "none GT" and median 93.8 months (CI 31.3-156.4) for "at least one GT" haplotype (p = 0.0500). Further, significant associations between SNPs in MDR1 and outcome of MM were found in 110 MM patients that underwent bortezomib-based treatment.

CONCLUSION

Our study showed a genetic predisposition for risk of MG development and/or outcome of MM patients; nevertheless, further studies are needed to confirm our initial analysis.

Recommendations for the diagnosis and treatment of patients with polycythaemia vera

OBJECTIVES

To present the Central European Myeloproliferative Neoplasm Organisation (CEMPO) treatment recommendations for polycythaemia vera (PV).

METHODS

During meetings held from 2015 through 2017, CEMPO discussed PV and its treatment and recent data.

RESULTS

PV is associated with increased risks of thrombosis/thrombo-haemorrhagic complications, fibrotic progression and leukaemic transformation. Presence of Janus kinase (JAK)-2 gene mutations is a diagnostic marker and standard diagnostic criterion. World Health Organization 2016 diagnostic criteria for PV, focusing on haemoglobin levels and bone marrow morphology, are mandatory. PV therapy aims at managing long-term risks of vascular complications and progression towards transformation to acute myeloid leukaemia and myelodysplastic syndrome. Risk stratification for thrombotic complications guides therapeutic decisions. Low-risk patients are treated first line with low-dose aspirin and phlebotomy. Cytoreduction is considered for low-risk (phlebotomy intolerance, severe/progressive symptoms, cardiovascular risk factors) and high-risk patients. Hydroxyurea is suspected of leukaemogenic potential. IFN-α has demonstrated efficacy in many clinical trials; its pegylated form is best tolerated, enabling less frequent administration than standard interferon. Ropeginterferon alfa-2b has been shown to be more efficacious than hydroxyurea. JAK1/JAK2 inhibitor ruxolitinib is approved for hydroxyurea resistant/intolerant patients.

CONCLUSIONS

Greater understanding of PV is serving as a platform for new therapy development and treatment response predictors.

[The current role of warfarin]

Well-managed warfarin therapy remains an important method of anticoagulation in the 21st century, despite the introduction of new antithrombotics into the clinical practice. The main advantages of warfarin are decades of treatment experience, the possibility to monitor its anticoagulant effect using the INR and the last, but not least, the low cost. Currently, approximately 75 % of anticoagulated patients in the Czech Republic are treated with warfarin and warfarin remains the only option for oral anticoagulant therapy in certain clinical conditions (particularly in patients with valvular atrial fibrillation or mechanical heart valves). For physicians across specialties it is still indispensable to master the basics of safe and effective warfarin therapy, including the management of treatment complications.Key words: anticoagulant therapy - INR - thrombosis - warfarin.

Antithrombotics today

Over the last 10 years some new drugs affecting blood clotting - antithrombotics - were invented. For more than half a century only warfarin and heparin were available. A better understanding of the pathways involved in activation of blood clotting, the links between these systems, and the impact of thrombosis on inflammation, have led to identification of new targets and development of new drugs, especially new antiplatelet drugs and anticoagulants. With the advent of new drugs into clinical practice, treatment options of thrombotic complications are expanding. However, it is always necessary to get familiar with the drug and its properties and to know its limitations. This is the only way to offer patients the best practices. Key words: anticoagulant - antithrombotic - Direct Oral AntiCoagulant (DOAC) - laboratory monitoring - Low-Molecu-lar-Weight Heparins (LMWH) - New Oral Anticoagulants/Non-vitamin K Oral AntiCoagulants (NOAC) - unfractionated heparin (UFH) - warfarin.

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.

Biobanking - the First Step to Successful Liquid Biopsy Experiments

BACKGROUND

Archiving of biological materials in biobanks is considered to be the initial crucial part of research activities. Most often, biobanks are founded for research purposes since they allow collection of sufficient material for analysis of new or testing of previously identified biomarkers. Biobanking needs to quickly react to current needs of researchers as well as clinicians, it is not a rigid system. Laboratory analyses of monoclonal gammopathies are based on separation of plasma cells from bone marrow of patients. A specific problem is usually a lack of tumor cell fraction, which is due to location of tumor cell in bone marrow in combination with low infiltration. One of the challenges in clinical research is the necessity of changes in biobanking for samples allowing detection of minimal residual disease in the bone marrow but also from peripheral blood by the so-called liquid biopsies.

AIM

The aim of this review is to show the importance of archiving biological material in the Czech Republic and to show concrete examples of its usage in hematooncology.

CONCLUSION

A general problem in solving many research questions is the availability of a critical amount of specimens for statistical analysis. Obtaining critical amount of specimens of biological material can be quickly archived by cooperation of biobanks sharing both methodological standards and informations about the availability of samples for research projects.Key words: archiving - biological material - informed consent - multiple myeloma - plasma cells.

Deregulated expression of long non-coding RNA UCA1 in multiple myeloma

OBJECTIVES

Long non-coding RNAs (lncRNAs) are RNA transcripts longer than 200 nucleotides that are not translated into proteins. They are involved in pathogenesis of many diseases including cancer and have a potential to serve as diagnostic and prognostic markers. We aimed to investigate lncRNA expression profiles in bone marrow plasma cells (BMPCs) of newly diagnosed multiple myeloma (MM) patients in comparison to normal BMPCs of healthy donors (HD) in a three-phase biomarker study.

METHODS

Expression profile of 83 lncRNA was performed by RT2 lncRNA PCR Array (Qiagen), followed by quantitative real-time PCR using specific TaqMan non-coding RNA assays analyzing 84 newly diagnosed MM patients and 25 HD.

RESULTS

Our analysis revealed dysregulation of two lncRNAs; NEAT1 (sensitivity of 55.0% and specificity of 79.0%) and UCA1 (sensitivity of 85.0% and specificity of 94.7%). UCA1 levels correlated with albumin and monoclonal immunoglobulin serum levels, cytogenetic aberrations, and survival of MM patients.

CONCLUSION

Our study suggests a possible prognostic impact of UCA1 expression levels on MM patients.

[Current Recommendations for the Prevention and Treatment of Venous Thromboembolism in Cancer Patients]

About 20% of patients suffer from venous thromboembolism (VTE) during oncology disease. Active cancer, along with cancer therapy, increases the risk of VTE, especially in the first 6 months after diagnosis. Most often VTE accompanies haematological malignancies and CNS tumours, and gastrointestinal, breast, lung, ovary and uterine cancer. The presence of distant metastases, together with the implantation of a central venous catheter, increases the risk even more. A cancer patient also has a 2-5× higher risk of recurrence of VTE during anticoagulant therapy than patients without a malignancy, as well as a 2-6× higher risk of serious bleeding. Thromboembolic disease is also an independent prognostic factor for death in patients with malignant tumours. Management of VTE is a part of everyday oncological practice, and oncologists should be aware of the basic recommendations regarding individual medical procedures and the clinical situations that may occur in cancer patients. They should also be able to adequately treat VTE when it occurs. It is necessary to consider some specificity during prophylaxis, diagnostics and treatment of venous thromboembolism in cancer care. The International Initiative on Thrombosis and Cancer (ITAC-CME) has created a mobile application based on international guidelines for the prevention and treatment of venous thromboembolism. It is a simple schematic algorithm for making decisions, and it helps in choosing the best therapeutic strategy and supports the judicious and appropriate use of anticoagulants for prophylaxis and treatment of VTE in cancer patients. This text contains a summary of the recommendations applicable in routine clinical practice.Key words: venous thromboembolism - cancer - central venous catheter thrombosis - guidelines This work was supported by Czech Ministry of Health - RVO (MMCI, 00209805). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 1. 8. 2016Accepted: 26. 10. 2016.

[Medication adherence to non-vitamin K antagonist oral anticoagulants at non-valvular atrial fibrillation - the literature review]

Medication adherence is a complex problem reflecting variations in terms of medication taking behavior. It is essential in maximizing of the effect and risk minimization of the therapy and health care costs reduction, even in the case of oral anticoagulants (non-vitamin K antagonist oral anticoagulants - NOACs). The aim of this paper was to review the published literature and to discuss results in the field of medication adherence to NOACs in patients with non-valvular atrial fibrillation (NVAF). Based on the searching in databases Embase and PubMed 25 studies were identified, of which conclusions were summarized in this paper. Patients treated with dabigatran reported poorer medication adherence than patients with rivaroxaban. However, medication adherence is influenced by many circumstances as well as included studies were not sufficiently uniform, therefore, a prerequisite for further investigation of this issue is expected.Key words: apixaban - atrial fibrillation - dabigatran - medication adherence - patient compliance - rivaroxaban.

[Is it necessary to revaccinate against hepatitis B virus when the titer of anti-HBs drops below 10 IU/L?]

Viral hepatitis B still represents a major epidemiological issue worldwide. After recombinant vaccine administration, a titer of anti-HBs antibodies ≥ 10 IU/L has long been considered to be seroprotective. Persons without this antibody level after complete vaccination are referred to as non-responders. A progressive decline in anti-HBs levels over years is also commonly seen in responders. Recently, there has been increasing evidence that the titer of anti-HBs ≥ 10 IU/L does not provide 100 % protection against infection and clinically manifest illness. Additionally, an important role of cellular immune memory has been demonstrated - without any correlation with anti-HBs titer. Based on current knowledge, there is no need for regular anti-HBs titer testing or booster vaccination in immunocompetent individuals with anti-HBs ≤ 10 IU/L. At present, regular serological testing and, if need be, revaccination to maintain anti-HBs ≥ 10 IU/L are recommended in immunocompromised persons and after liver transplantation.

Changing insights in the diagnosis and classification of autosomal recessive and dominant von Willebrand diseases 1980-2015

The European Clinical Laboratory and Molecular (ECLM) criteria define 10 distinct Willebrand diseases (VWD): recessive type 3, severe 1, 2C and 2N; dominant VWD type 1 secretion/clearance defect, 2A, 2B, 2E, 2M and 2D; and mild type 1 VWD (usually carriers of recessive VWD). Recessive severe 1 and 2C VWD are characterized by secretion and multimerization defects caused by mutations in the D1-D2 domain. Recessive 2N VWD is a mild hemophilia due to D’-FVIII-von Willebrand factor (VWF) binding site mutations. Dominant 2E VWD caused by heterozygous missense mutations in the D3 domain is featured by a secretion-clearance-multimerization VWF defect. Dominant VWD type 2M due to loss of function mutations in the A1 domain is characterized by decreased ristocetin-induced platelet aggregation and VWF:RCo, normal VWF multimers and VWF:CB, a poor response of VWF:RCo and good response of VWF:CB to desmopressin (DDAVP). Dominant VWD type 2A induced by heterozygous mutations in the A2 domain results in hypersensitivity of VWF for proteolysis by ADAMTS13 into VWF degradation products, resulting in loss of large VWF multimers with triplet structure of each individual VWF band. Dominant VWD type 2B due to a gain of function mutation in the A1 domain is featured by spontaneous interaction between platelet glycoprotein Ib (GPIb) and mutated VWF A1 followed by increased proteolysis with loss of large VWF multimers and presence of each VWF band. A new category of dominant VWD type 1 secretion or clearance defect due to mutations in the D3 domain or D4-C1-C5 domains consists of two groups: Those with normal or smeary pattern of VWF multimers.

Diagnostic Differentiation of von Willebrand Disease Types 1 and 2 by von Willebrand Factor Multimer Analysis and DDAVP Challenge Test

The European Clinical Laboratory and Molecular (ECLM) classification of von Willebrand disease (vWD) is based on the splitting approach which uses sensitive and specific von Willebrand factor (vWF) assays with regard to the updated molecular data on structure and function of vWF gene and protein defects. A complete set of FVIII:C and vWF ristocetine cofactor, collagen binding, and antigen, vWF multimeric analysis in low- and medium-resolution gels, and responses to desmopressin (DDAVP) of FVIII:C and vWF parameters are mandatory. The ECLM classification distinguishes recessive types 1 and 3 vWD from recessive vWD 2C due to mutations in the D1 and D2 domains and vWD 2N due to mutations in the D'-FVIII-binding domain of vWF. The ECLM classification differentiates between mild vWD type 1 with variable penetrance of bleedings from symptomatic dominant type 1 vWD secretion defect and/or clearance defect with normal vWF multimers versus vWD 1M and 2M with normal or smeary vWF multimers in low- and medium-resolution gels. High-quality multimeric analysis of vWF in medium-resolution gels based on a DDAVP challenge test clearly delineates and distinguishes each of the dominant type 2 vWDs 1/2E, 2M, 2B, 2A, and 2D caused by vWF gene mutations in the D3 multimerization domain, loss or gain-of-function mutations in the glycoprotein Ib receptor A1 domain, gene mutations in the A2 proteolytic domain, and the C-terminal dimerization domain, respectively.

Activity of aldehyde dehydrogenase in B-cell and plasma cell subsets of monoclonal gammopathy patients and healthy donors

BACKGROUND

Aldehyde dehydrogenase (ALDH) is highly active in physiological stem cells as well as in tumor-initiating cells of some malignancies including multiple myeloma (MM). Finding higher activity of ALDH in some cell subsets in monoclonal gammopathies (MG) could identify potential source of myeloma-initiating cells (MICs).

METHODS

Bone marrow of 12 MM, 9 monoclonal gammopathy of undetermined significance (MGUS), and 10 healthy donors (HD) were analyzed by flow cytometry. ALDH activity of B-cells and plasma cells (PC) was analyzed using Aldefluor.

RESULTS

Similar changes of ALDH activity were found during B-cell development in HD and MG. Decreasing of ALDH activity from immature to naïve B-cells was found. In postgerminal stages, the activity started to increase, and in PCs, the ALDH activity was the same as in immature B-cells. Increased ALDH activity of all PC subsets compared to naïve B-cells was found in MM as well as in HD, while in MGUS, only CD19^- PCs have higher ALDH activity. In HD, ALDH activity was higher in CD19⁺ PCs compared with MG.

CONCLUSIONS

Our results indicate that changes of ALDH activity are the natural phenomenon in B-cell development; thus, high ALDH activity as a single marker is not appropriate for MICs identification.

[Treatment with rituximab as an opportunity for the prevention of infectious complications]

Rituximab, a monoclonal antibody against the surface antigen of B-lymphocytes CD20 is beeing used in the treatment of numerous hematological, hematooncological and autoimmune disorders. After administration of ritu-ximab, quick and almost complete depletion of B-lymphocytes with the exception of pre-B-lymphocytes and plasma cells occur. Neutropenia and low serum antibody levels in classes IgA, IgM and IgG may also develop. These changes usually persist for 6-12 months, rarely for several years. In the consequence, patients with the rituximab treatment are more prone to infections - usually of bacterial and viral origin. Concomitantly, rituximab treatment influences negatively postvaccination antibody production and therefore adequate preventive measures are necessary before the beginning of the treatment. The authors offer complex overview of actual literature, emphasize adequate education of patients as well as of healthcare providing staff and discuss the vaccination recommendation against preventable communicable diseases like influenza, pneumococcal diseases, tetanus, diphtheria and pertussis.

KEY WORDS

autoimmune disease - immunosupression - infectious complications - prevention - rituximab - vaccination.

[New - direct oral anticoagulants: actual review]

In recent years the options of anticoagulant/antithrombotic therapy have extended with new - direct oral anticoagulants, comprising direct thrombin inhibitors (dabigatran etexilate) and direct factor Xa inhibitors (rivaroxaban, apixaban). These agents represent another progress towards "the ideal antithrombotic drug", and thus towards a safe and effective antithrombotic therapy. The following article provides actual review and recommendations for clinical practice, including laboratory assessment and management of emergency situations. The approval of idarucizumab as a specific antidote for dabigatran has marked an important step in safety of this treatment.Key words: apixaban - dabigatran - DOAC - NOAC - rivaroxaban.

Cytogenetics in multiple myeloma patients progressing into extramedullary disease

BACKGROUND

Extramedullary disease in multiple myeloma patients is an uncommon event occurring either at the time of diagnosis, or during disease progression/relapse. This manifestation is frequently associated with poor outcome and resistance to treatment. We evaluated chromosomal alterations of plasma cells of multiple myeloma patients with extramedullary relapse, either in the bone marrow (BM) or at extramedullary sites, and in previous BM collection by interphase fluorescence in situ hybridization.

MATERIAL AND METHODS

Thirty-one patients [25 BM plasma cells (BMPCs), 18 extramedullary tumor plasma cells], of which 12 had paired samples of BM and extramedullary plasma cells and 14 had previous collection of BM, were investigated for the presence of chromosomal aberrations (CHAs): del(17)(p13), del(13)(q14), 14q32 disruption, t(4;14)(p16;q32), t(14;16)(q32;q23), gain(1)(q21), and hyperdiploidy status.

RESULTS

Overall, in unrelated samples, t(4;14) was more prevalent in extramedullary plasma cells, and hyperdiploidy was more frequent in BMPCs. In paired samples, there was a higher frequency of del(13)(q14) and 14q32 disruption in BMPCs. Frequency of all studied CHAs was higher in BMPCs of extramedullary patients than in their previous sample collection.

CONCLUSION

These data show that plasma cells harbor more aberrations during their transformation into extramedullary form.

[Guidelines of Czech Association for Thrombosis and Haemostasis of the Czech Medical Association of J. E. Purkyně for safety treatment with new oral anticoagulants (NOAC) - dabigatran etexilate, apixaban and rivaroxaban]

There are presently new oral anticoagulants (NOAC) for prevention and the treatment of thromboembolic diseases and they are registered in CZ. It concerns of orally direct inhibitors of thrombin (dabigatran etexilate), inhibitors of factor Xa (apixaban, rivaroxaban), respectively, with advantage of some properties not being seen in "classical" anticoagulants. In the use of new anticoagulants, however, are some problems - such as laboratory monitoring in urgent situations of effective treatment and the absence of specific antidote - resolved. The text below brings indications, dosage of the drugs, their elimination, follow-up of efficacy of the treatment or risk of the bleeding as well as the therapy of bleeding complications.Key words: apixaban - dabigatran etexilate - NOAC - rivaroxaban.

Increased mean platelet volume and immature platelet fraction as potential predictors of thrombotic complications in BCR/ABL-negative myeloproliferative neoplasms

BCR/ABL-negative myeloproliferative neoplasms (MPNs) are considered to be acquired thrombophilic conditions. Persistently enhanced platelet activation has been described in polycythaemia vera and essential thrombocythaemia (ET), and shown to contribute to a higher risk of arterial and venous thrombotic complications. Recent studies have shown that mean platelet volume (MPV) and immature platelet fraction (IPF) can serve as useful markers of platelet activation and increased risk of thrombosis. The aim of the present study was to investigate the relationship between these parameters and thrombotic events in BCR/ABL-negative MPN. MPV values in patients with BCR/ABL-negative MPN were significantly higher than MPV values of healthy individuals (P < 0.001). No significant difference in MPV or IPF was observed between groups of patients with and without thrombotic complications (P = 0.441; P = 0.110); the difference in IPF values was close to the significance level for patients with ET (P = 0.073). Higher values of IPF were more frequently detected in patients with JAK2 V617F positivity (P = 0.030). These patients had higher MPV more frequently than others, and this difference was close to the significance level (P = 0.056). Further studies should validate the use of platelet parameters to identify patients at high risk.

Second malignancies in philadelphia-negative myeloproliferative neoplasms-single-center experience

AIM

The aim of this work was to retrospectively analyze patients with Philadelphia-negative myeloproliferative neoplasms through evaluation of frequency and characteristics of second malignancies (other than acute leukaemia and myelodysplastic syndrome).

PATIENTS AND METHODS

Records of 172 patients were reviewed; an analysis was performed on data from 66 patients treated with hydroxyurea, 105 patients treated with other cytoreductive therapy, and 25 patients without treatment.

RESULTS

A higher occurrence of second malignancies was found in the group treated with hydroxyurea (7.6%; other cytoreduction: 1.2%; without therapy: 0). After a median follow-up of 89 months in the hydroxyurea group, 13 patients developed second cancer during hydroxyurea therapy, located on the skin (68.75%) and other sites (31.25%).

CONCLUSION

The incidence of second malignancies during hydroxyurea therapy in our cohort patient was significantly higher than the incidence of malignancies in the Czech population of corresponding age.

[The place of JAK2 inhibitors in the treatment of myelofibrosis. An amendment to the recommendations for diagnosis and treatment of Ph negative myeloproliferations of the Czech group for Ph- myeloproliferative disorders (CZEMP)]

Primary myelofibrosis (PMF) belongs to Ph- myeloproliferative diseases. The only curative treatment is hematopoietic stem cell transplantation (HSCT). Conservative treatment options comprise supportive care, especially administration of red blood cell and platelet transfusions, and medication. Hydroxyurea, interferon α, anagrelide, corticosteroids, androgens, or inhibitors of angiogenesis (thalidomide, lenalidomide, pomalidomide) may be used for treatment of PMF, depending on the clinical stage and disease symptoms present. Also splenectomy or radiotherapy of enlarged spleen have palliative potential. JAK2 kinase inhibitors represent a novel class of drugs with a very dynamic development. Ruxolitinib, an oral selective inhibitor of JAK1 and JAK2 kinases, has shown high efficacy in patients with high-risk PMF (or with myelofibrosis following polycythemia vera or essential thrombocythemia) to ameliorate disease symptoms and to reduce splenomegaly in randomized trials COMFORT-I and COMFORT-II. Long-term monitoring of the enrolled patients demonstated prolongation of overall survival. The drug is well-tolerated, the most common side effects of treatment with ruxolitinib being deepening of thrombocytopenia and temporary worsening of anemia. The current review deals with the place of JAK2 inhibitors (and the only drug already approved for clinical use - ruxolitinib) in the management of PMF, as an addendum to the Summary of recommendations for the diagnosis and therapy of BCR/ABL-negative myeloproliferations of the Czech Hematological Societys CZEMP.