Thrombin Generation Testing in Patients with Myelofibrosis.

BACKGROUND: Primary myelofibrosis (PMF) is a chronic clonal myeloid disorder. Together with essential thrombocythemia (ET) and polycythemia vera (PV), it belongs to a group of Philadelphia chromosome-negative myeloproliferative neoplasms. Thrombotic events are serious complications negatively influencing the quality and length of these patients' lives. The confirmed risk factors for venous thromboembolism are age over 60 years, a positive history of thromboembolism, presence of common cardiovascular risks, JAK2 V617F mutation and, according to some authors, leukocytosis. Various opinions on the role of thrombocythemia have been published. The present study was undertaken to evaluate the benefit of thrombin generation test and its potential use in predicting the risk of thrombosis in MF patients. METHODS: The analysis included plasma samples obtained from 36 patients diagnosed with MF in our center from 2004 to 2016 (JAK2 V617-positive 53%; CALR-positive 31%; MPL-positive 14%; triple negative 2%) and a control group comprising 20 healthy volunteer blood donors. Thrombin generation was measured in platelet-rich plasma using the TECHNOTHROMBIN® TGA kit (Technoclone, Austria) and the fully automated system Ceveron® Alpha (Technoclone). The results were correlated with clinical and laboratory parameters of the patients. RESULTS: There were differences in thrombin generation as expressed by endogenous thrombin potential (ETP) between patients and healthy controls, with ETP being lower in the patient group (p = 0.0003). Analysis confirmed a significant correlation between thrombin generation and platelet counts, with higher thrombin generation in patients with thrombocythemia > 400 x 109/L (p = 0.04). ETP values were consistently higher in earlier disease stages and lower in CALR-mutated myelofibrosis. CONCLUSIONS: In MF patients, thrombin generation is mainly influenced by platelet counts and, to a lesser extent, by mutation status, activity, and progression of the disease. Thrombin generation test results have confirmed that thrombocythemia is a potential risk factor for thrombotic complications.

Effect of CALR and JAK2 mutations on the clinical and hematological phenotypes of the disease in patients with myelofibrosis - long-term experience from a single center.

Primary myelofibrosis (PMF) is a chronic clonal myeloid disorder. Together with essential thrombocythemia (ET) and polycythemia vera (PV), it belongs to a group of Philadelphia chromosome-negative myeloproliferative neoplasms. An integral part of laboratory tests carried out in this disease group is detecting the presence of mutations in the Janus kinase 2 gene at position 617 (JAK2 V617F) and in the gene encoding for the receptor for thrombopoietin (myeloproliferative leukemia virus oncogene, MPL) found in approximately 60% of PMF patients. The discovery of mutations affecting exon 9 of the calreticulin (CALR) gene was of great benefit to the diagnosis of the diseases in JAK2 V617F and MPL unmutated cases. This is a study of the effect of a mutation in the CALR gene on the clinical course in patients with primary, post-ET and post-PV myelofibrosis. Analysis of 66 patients (54.5% JAK2 V617F; 34.8% CALR; 6.1% MPL; 3.0% triple negative; 1.5% coincidence of CALR and JAK2 V617F) confirmed a different phenotype of the disease in CALR-mutated patients as compared with CALR-unmutated individuals. Those with CALR mutation were significantly younger and had borderline higher platelet counts, less pronounced splenomegaly and less frequent B symptoms at diagnosis. The study suggests that the driver mutation types define variations in the biological basis, clinical manifestations and course of the disease. The presence of CALR mutation has been shown to be an independent prognostic favorable factor. Careful risk stratification of these patients is of great importance to adequate therapeutic decision-making and aids in selecting high-risk patients eligible  for allogeneic hematopoietic stem cell transplantation which continues to be the only treatment modality for myelofibrosis having curative potential.

Allogeneic stem cell transplantation after fludarabine, melphalan and thymoglobulin followed by early withdrawal of prophylactic immunosuppression in patients with acute lymphoblastic leukemia - update of single center study.

Presented are updated results of allogeneic hematopoietic stem cell transplantations (HSCTs) in 25 adult patients with acute lymphoblastic leukemia (ALL) in complete remission (CR) after a reduced intensity conditioning (RIC) combining fludarabine (150 mg/m2) and melphalan (140 mg/m2) with thymoglobulin (4.5 mg/kg or recently 4.0 mg/kg) followed by early initiation of reduction and withdrawal of prophylactic posttransplant immunosuppression. The median post-transplant follow-up was 32 (range, 4-87) months. Stable engraftment of donor's hematopoiesis was achieved in all patients. Acute graft versus host disease (GVHD) as well as the chronic one were equally observed in four cases (16%). Five patients (20%) relapsed with ALL in the median of 9 (range, 3-15) months after HSCT. During the above post-transplant follow-up, 4 recipients (16%) died. Disease progression and posttransplant complications were the cause of death in three (12%) and one (4%) of them, respectively. The probabilities of 2-year event-free (EFS) and overall survival (OS) were 70.3% (95% CI 51.9-88.7%) and 86.1% (95% CI 71.6-100%), respectively. Presented study confirmed our previously reported promising results and this approach may be considered as an alternative to traditional HSCTs performed in high-risk patients with ALL.

Allogeneic stem cell transplantation after fludarabine, melphalan and thymoglobulin followed by early withdrawal of prophylactic immunosuppression could be an effective approach to patients with acute lymphoblastic leukemia.

Presented are results of allogeneic hematopoietic stem cell transplantations (HSCTs) in 13 patients with high-risk acute lymphoblastic leukemia (ALL) in the first complete remission after a reduced intensity conditioning combining fludarabine (150 mg/m2) and melphalan (140 mg/m2) with thymoglobulin (4.5 mg/kg). The immunosuppressive effect of T-cell depletion reducing the risk of graft-versus-host disease (GVHD) and non-relapse mortality was compensated by early initiation of reduction and withdrawal of prophylactic immunosuppression aimed at maintaining effective immunological antileukemic control. The median post-transplant follow-up was 23 (range, 10-65) months. Stable engraftment of donor's hematopoiesis was achieved in all patients. Acute GVHD was observed in two cases (15.4%); the chronic form was not noted. Two patients (15.4%) relapsed with ALL at 3 and 16 months after transplantation. During the above post-transplant follow-up, all 13 recipients were alive, with a probability of 2-year disease-free survival of 76.9% (95% CI 51-100%). Although the results were obtained with a small pilot study group it may be assumed that, given the prognostic risk of most patients and the nearly 2-year median post-transplant follow-up, the approach may be considered as an alternative to HSCTs after traditional myeloablative or reduced conditioning regimens with standard GVHD prophylaxis.

Acute promyelocytic leukemia successfully treated also in elderly patients with significant comorbidities: a 20-year single-center experienc.

UNLABELLED: Acute promyelocytic leukemia is a unique entity among acute leukemias. Introduction of all-trans retinoic acid and, subsequently, arsenic trioxide in its treatment has markedly improved treatment outcomes for this once frequently fatal disease. Improved outcomes have also been observed in elderly patients, including those in whom standard intensive therapy is contraindicated because of comorbidities.In our center, a total of 60 APL patients were treated in 1993-2013, of whom 9 were aged 60 or more years. Although most of them had significant comorbidities at the time of diagnosis, eight achieved complete remission. At the time of the analysis, six patients were alive and in long-term remission; two patients died of causes other than APL. The median follow-up was 59 months.Included is case report of a patient with a high comorbidity score whose treatment was markedly reduced and individualized.Our experience shows that, in APL patients a curative approach is generally tolerated and should always be attempted regardless of age and comorbidities. KEYWORDS: APL - elderly patients - comorbidity.

FcγRIIIA receptor genotype does not influence an outcome in patients with follicular lymphoma treated with risk-adapted immunochemotherapy.

Antibody (rituximab) dependent cellular cytotoxicity is a key mechanism in killing CD20+ lymphoma cells. FcγRIIIA-158 V/F gene polymorphism results in expression of 3 variants of the FcγRIIIA receptor (FcγRIIIA) on cytotoxic lymphocytes with different receptor affinity. We studied 102 patients with newly diagnosed FL to assess whether the FcγRIIIA genotype influences outcome in patients treated with risk-adapted immunochemotherapy. The median age was 52 years (31-84); 90% of the patients had advanced (III/IV) clinical stages. The Follicular Lymphoma International Prognostic Index (FLIPI) scores were as follows: low 18.9%, intermediate 33.7% and high 47.4%. The front-line treatment was stratified according to the commonly used risk factors (FLIPI, beta-2-microglobuline and serum-Tyrosine-Kinase levels, bulky disease) into 3 treatment groups: (1) patients with FLIPI 0-1 treated with (R)-CHOP (51%), (2) patients under 60 (65) years of age with intermediate-risk disease (FLIPI 2) indicated for an intensive protocol (ProMACE-CytaBOM or sequential chemotherapy) (21%), and (3) patients under 60 (65) years with high-risk disease (FLIPI ≥3) treated with intensive chemotherapy plus autologous stem cell transplantation (28%). Rituximab was added to front-line chemotherapy in 59% of the patients. Generally, complete remission (CR) or unconfirmed CR was achieved in 85% of the patients, 11% had partial remission and 4% stable disease. Molecular CR (CRm) was achieved in 67.4% of 86 evaluable patients. Overall survival (OS) at 5 years reached 84% (95% CI 0.74-0.93); event-free survival (EFS) at 5 years was 58% (95% CI 0.45-0.71). The frequencies of FcγRIIIA-158 gene polymorphisms V/V, V/F and F/F were 8%, 50% and 42%, respectively. The FLIPI score distribution was not different in F/F patients as compared to V/F+V/V carriers (chi-square, P=0.7). The treatment modalities (treatment arm or rituximab administration) had the same distribution in V/V+V/F vs F/F patients (chi-square, P=0.16 and P=0.62, respectively). The CRm rates were similar in both subgroups of V/V+V/F vs F/F patients (chi-square, P=0.92). Survival curves for OS and EFS were not significantly different when comparing the subgroups of V/V+V/F vs F/F patients (P=0.28 and P=0.57, respectively). We found no difference in the quality of treatment response or survival after front-line immunochemotherapy between FcγRIIIA subgroups. FcγRIIIA polymorphism have no influence on the outcome of patients treated with risk-adapted chemotherapy with or without rituximab.

[Principle and importance of using the array CGH in hematooncology]. / Princip a význam metody arrayCGH v hemato-onkologii.

Identification of chromosomal changes and variation in DNA copy number allows us to understand pathogenesis of tumors. To the frequently diagnosed chromosomal changes belong acquired gains and losses of chromosomal regions carring genes involved in cellular proliferation and differentiation as well as oncogenes and tumor suppressor genes. The determination of gene changes is limited by techniques used for their identification. The introduction of genom-wide microarray technology, resolution has rapidly increased. Array comparative genomic hybridization (arrayCGH) offers higher resolution for genome-wide detection of chromosomal alteration and it is able to analyze hundreds to thousands of genes presented on microarray in one experiment. The aim of this study was to perform arrayCGH technology and to stress its value for the identification of chromosomal imbalances in hematological malignancies.

High incidence of unbalanced chromosomal changes in mantle cell lymphoma detected by comparative genomic hybridization.

Comparative genomic hybridization (CGH) was carried out in 30 mantle cell lymphoma (MCL) patients at the time of diagnosis. CGH results were supported by conventional cytogenetics (CC), FISH, molecular genetic PCR methods and 2 patients were examined by array CGH. Using all cytogenetic, molecular cytogenetic and PCR methods, chromosomal changes were detected in 28 (93%) patients. Using CGH, unbalanced chromosomal changes were detected in 24 (80%) cases. The most frequent aberrations were losses of 1p (8 cases), 8p (10 cases), 9q (6 cases), 11q (11 cases), 13q (10 cases) and 17p (9 cases), and gains of chromosome 3 and 3q (12 cases) and 8q (7 cases). Total number of 60 gains and 116 losses were detected. The primary chromosomal change t(11;14) was detected using FISH and/or PCR in 20 (66.6%) patients, and in 9 of them, the breakpoint was determined using PCR in the major translocation cluster (MTC). The evaluation of the frequencies of CGH changes in groups of patients with and without t(11;14) revealed the differences only in losses 6q and 9q, which were only found in patient with t(11;14). An important result was obtained using array CGH method. In a patient without the primary t(11;14), the gain of CCND1 gene was found. Our results show high heterogeneity of the additional chromosomal changes in MCL cases, which involved specific chromosomal subregions. We did not confirm the importance of subdividing of MCL cases with and without t(11;14). Also, statistical significance in survival rates between both subgroups was not confirmed.

Non-anemic homozygous beta(o) thalassemia in an African-American family: association of high fetal hemoglobin levels with beta thalassemia alleles.

We have studied a four-generation (23 subjects) African-American family with beta(o) thalassemia and high fetal hemoglobin (HbF) levels. The beta(o) thalassemia in this family is due to the splicing site mutation, beta IVS2+1G-->A, that leads to aberrant mRNA processing and the absence of beta globin. Two members of this family are homozygous for beta(o) thalassemia and are non-anemic. All family members who are heterozygous for the beta IVS2+1G-->A mutation have elevated HbF, with the exception of two individuals who also have severe alpha-globin chain deficiency. We excluded linkage with the hereditary persistence of fetal hemoglobin loci on chromosomes 6 and X. We also excluded the presence of all previously described determinants in the beta globin gene cluster associated with elevated HbF production. One thalassemia allele is in the Cameroon-like (HS2)/Benin-like beta globin gene cluster haplotype, and the other is in the Senegal-like (HS2)/Benin-like beta globin gene cluster haplotype. We speculate that in the homozygotes, those erythroid cells that express low to absent levels of gamma globin are selectively destroyed. In contrast, in the heterozygotes, the presence of the normal beta globin allele would ameliorate the globin chain imbalance and thus allow survival of erythroid cells that express the abnormal transcript, leading to a typical beta(o) thalassemia phenotype. Thus, the heterocellular gamma globin expression together with in vivo preferential survival of HbF-containing erythroid cells ameliorates Cooley's anemia in the beta(o) thalassemia homozygotes. It remains to be determined what sequences linked to each thalassemia allele and what trans-acting factors contribute to high HbF levels.

[New beta0-thalassaemic insertion mutation (CD 7/8, +G) in a Slovak family, associated with the Mediterranean haplotype IX]. / Nová beta0-talasemická posunová mutace (CD 7/8, +G) ve slovenské rodine asociovaná s mediteránním haplotypem IX.

The authors describe a newly identified beta0-thalassaemic mutation found in two subjects from two generations of a Slovak family. The beta0-thalassaemic allele developed by insertion of one nucleotide (+G, CD 7/8) into the first exon of the beta-globin gene. The mutation causes a shift of the open globin reading frame which leads to the development of a terminal codon in codon 22. The thalassaemic allele is associated with the mediterranean haplotype IX. The mutation has in both heterozygotes the phenotype of beta0-thalassaemia minor with a slightly elevated level of HbF.

[Hemoglobin Sydney--alpha beta 2 67 (E11) Val-Ala and hemoglobin Olomouc alpha 2 beta 2 86 (F 2) Ala-Asp in Czech families. DNA sequence analysis for a more accurate diagnosis of hemoglobinopathies]. / Hemoglobin Sydney--alpha 2 beta 2 67 (E11) Val-Ala a hemoglobin Olomouc alpha 2 beta 2 86 (F 2) Ala-Asp v ceských rodinách. Prínos sekvenacní analýzy DNA pro zpresnení diagnostiky hemoglobinopatií.

The paper demonstrates the importance of sequence analysis of DNA for the identification of Hb-Sydney [alpha2-beta2 67 (E11) Val-Ala]. The latter was considered erroneously, based on results of biochemical analyses to be Hb-M-Milwaukee [alpha2 beta2 67 (E 11) Val-Glu]. With the unstable Hb-Sydney correspond also phenotypical manifestations of disease (haemolytic anaemia with Heinz bodies in red blood cells). Sequence analysis of DNA of patients with Hb-Olomouc [alpha 2 beta 2 (F 2) Ala-Asp] revealed that mutation of Ala-Asp in position 86 (F 2) of the beta globin chain is coded by mutation C-->A (GCC-GAC).

[Hemoglobin Haná or alpha 2 beta 2 63 (E7) His-Asn: a new unstable hemoglobin variant with a paradoxically different clinical manifestations in smokers and non-smokers in the same family]. / Hemoglobin Haná nebo alpha 2 beta 2 63 (E7) His-Asn: nová nestabilní varianta hemoglobinu s paradoxne rozdílnou klinickou manifestací u kuráku a nekuráku téze rodiny.

The authors describe the identification and the clinical manifestations of a new structural variant of haemoglobin found in three subjects from two generations of a Moravian family. It is manifested by mild haemolytic anaemia with Heinz bodies in the proband and a slightly elevated value of methaemoglobin. The sequential analysis of the beta-globin gene provided evidence that the cause is mutation CAT-AAT in codon 63 which leads to the exchange of distal histidine /E7/ for asparagine. The ratio of beta X:beta A is 38:62. The mother with the same mutation is asymptomatic. The relative amount of beta X:beta A mRNA transcripts in mother and daughter are equal. This indicates that the clinical differences are not due to a different gene expression. The mother is a heavy smoker with an elevated CO-Hb level that probably protect the mutant against oxidative denaturation and increases thus the stability of Hb-Haná. The authors discuss also the finding of two abnormal stripes assessed by three electrophoretic methods.

[Unstable Santa Ana hemoglobin or alpha 2 beta 2 88 (F4) Leu-Pro detected in a Slovak girl]. / Nestabilní hemoglobin Santa Ana nebo alpha 2 beta 2 88 (F4) Leu-Pro identifikovaný u slovenské dívky.

The unstable haemoglobin variant Ana (alpha 2 beta 2 88 (F4) Leu-Pro) was identified to cause haemolysis in a 10-year-old Slovak girl. She was followed for haemolytic anaemia symptoms since two years of age. Clinical signs are hepatosplenomegaly and moderate haemolytic anaemia not requiring blood transfusions. It is the first case of an unstable haemoglobinopathy found in Slovak Republic as far as we know. Hypothesis of 'de novo' origin of the mutation in the propositus is supported by the parents' and brother's laboratory findings.