Macrophages Provide Essential Support for Erythropoiesis, and Extracellular ATP Contributes to a Erythropoiesis-Supportive Microenvironment during Repeated Psychological Stress.

Psychological stress is a significant contributor to various chronic diseases and affects multiple physiological processes including erythropoiesis. This study aimed to examine the tissue-specific contributions of macrophages and extracellular ATP, as a signal of disturbed tissue homeostasis, to erythropoiesis under conditions of repeated psychological stress. Adult male BALB/c mice were subjected to 2 h daily restraint stress for seven consecutive days. Clodronate-liposomes were used to deplete resident macrophages from the bone marrow and spleen two days prior to the first restraint procedure, as well as newly recruited macrophages, every third day for the duration of the experiment. Repeated stress induced a considerable increase in the number of erythroid progenitor cells as well as in the percentage of CD71+/Ter119+ and CD71-/Ter119+ cells in the bone marrow and spleen. Macrophage depletion completely abolished the stimulative effect of repeated stress on immature erythroid cells, and prevented stress-induced increases in ATP levels, P2X7 receptor (P2X7R) expression, and ectonucleotidase CD39 activity and expression in the bone marrow and spleen. The obtained results demonstrate the stimulative effects of repeated stress on erythroid cells, extracellular ATP levels, P2X7R expression, CD39 activity and expression within the bone marrow and spleen, as well as the essential role of macrophages in stress-induced changes.

Inhibition of C3 with pegcetacoplan results in normalization of hemolysis markers in paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired hematologic disorder characterized by complement-mediated hemolysis. C5 inhibitors (eculizumab/ravulizumab) control intravascular hemolysis but do not prevent residual extravascular hemolysis. The newly approved complement inhibitor, pegcetacoplan, inhibits C3, upstream of C5, and has the potential to improve control of complement-mediated hemolysis. The PADDOCK and PALOMINO clinical trials assessed the safety and efficacy of pegcetacoplan in complement inhibitor-naïve adults (≥ 18 years) diagnosed with PNH. Patients in PADDOCK (phase 1b open-label, pilot trial) received daily subcutaneous pegcetacoplan (cohort 1: 180 mg up to day 28 [n = 3]; cohort 2: 270-360 mg up to day 365 [n = 20]). PALOMINO (phase 2a, open-label trial) used the same dosing protocol as PADDOCK cohort 2 (n = 4). Primary endpoints in both trials were mean change from baseline in hemoglobin, lactate dehydrogenase, haptoglobin, and the number and severity of treatment-emergent adverse events. Mean baseline hemoglobin levels were below the lower limit of normal in both trials (PADDOCK: 8.38 g/dL; PALOMINO: 7.73 g/dL; normal range: 11.90-18.00 g/dL), increased to within normal range by day 85, and were sustained through day 365 (PADDOCK: 12.14 g/dL; PALOMINO: 13.00 g/dL). In PADDOCK, 3 serious adverse events (SAE) led to study drug discontinuation, 1 of which was deemed likely related to pegcetacoplan and 1 SAE, not deemed related to study drug, led to death. No SAE led to discontinuation/death in PALOMINO. Pegcetacoplan was generally well tolerated and improved hematological parameters by controlling hemolysis, while also improving other clinical PNH indicators in both trials. These trials were registered at www.clinicaltrials.gov (NCT02588833 and NCT03593200).

Prognosis of patients with chronic myeloid leukemia presenting in advanced phase is defined mainly by blast count, but also by age, chromosomal aberrations and hemoglobin.

Chronic myeloid leukemia (CML) is usually diagnosed in chronic phase, yet there is a small percentage of patients that is diagnosed in accelerated phase or blast crisis. Due to this rarity, little is known about the prognosis of these patients. Our aim was to identify prognostic factors for this cohort. We identified 283 patients in the EUTOS population-based and out-study registries that were diagnosed in advanced phase. Nearly all patients were treated with tyrosine kinase inhibitors. Median survival in this heterogeneous cohort was 8.2 years. When comparing patients with more than 30% blasts to those with 20-29% blasts, the hazard ratio (HR) was 1.32 (95%-confidence interval (CI): [0.7-2.6]). Patients with 20-29% blasts had a significantly higher risk than patients with less than 20% blasts (HR: 2.24, 95%-CI: [1.2-4.0], P = .008). We found that the blast count was the most important prognostic factor; however, age, hemoglobin, basophils and other chromosomal aberrations should be considered as well. The ELTS score was able to define two groups (high risk vs non-high risk) with an HR of 3.01 (95%-CI: [1.81-5.00], P < .001). Regarding the contrasting definitions of blast crisis, our data clearly supported the 20% cut-off over the 30% cut-off in this cohort. Based on our results, we conclude that a one-phase rather than a two-phase categorization of de novo advanced phase CML patients is appropriate.

Oxidative and nitrosative stress in myeloproliferative neoplasms: the impact on the AKT / mTOR signaling pathway.

PURPOSE: A common feature of malignancies is increased reactive oxygen species (ROS) and reactive nitrogen species (RNS). We analyzed the influence of oxidative and nitrosative stress on the activation of AKT/mTOR signaling pathway in myeloproliferative neoplasms (MPN). METHODS: Oxidative stress-induced gene expression in circulatory CD34+ cells of MPN patients was studied by microarray analysis. Biomarkers of oxidative and nitrosative stress were determined using spectrophotometry in plasma and erythrocyte lysate. The levels of nitrotyrosine, inducible NO synthase (iNOS) and AKT/mTOR/p70S6K phosphorylation were determined by immunocytochemistry and immunoblotting in granulocytes of MPN patients. RESULTS: Antioxidants superoxide dismutase 2 (SOD2) and glutathione peroxidase 1 (GPx1) gene expression were increased in circulatory CD34+ cells, while SOD1 and GPx enzymes were reduced in the erythrocytes of MPN. Plasma malonyl-dialdehyde and protein carbonyl levels were elevated in MPN. The total antioxidant capacity in plasma and erythrocyte catalase (CT) activities was the most prominent in primary myelofibrosis (PMF) with JAK2V617F heterozygosity. The total nitrite/nitrate (NOx) level was augmented in the plasma of PMF patients (p<0.001), while nitrotyrosine and iNOS were generally increased in the granulocytes of MPN patients. Activation of AKT/mTOR signaling was the most significant in PMF (p<0.01), but demonstrated JAK2V617F dependence and consequent p70S6K phosphorylation in the granulocytes of essential thrombocytemia (ET) and polycythemia vera (PV) patients. Hydrogen peroxide stimulated mTOR pathway, iNOS and nitrotyrosine quantities, the last one prevented by the antioxidant n-acetyl-cysteine (NAC) in the granulocytes of MPN. CONCLUSION: Our study showed increased levels of oxidative and nitrosative stress parameters in MPN with JAK2V617F dependence. The ROS enhanced the constitutive activation of AKT/mTOR signaling and nitrosative parameters in MPN.

8p11 myeloproliferative syndrome: diagnostic challenges and pitfalls.

8p11 myeloproliferative syndrome (EMS) is a very rare clinicopathological entity which is characterized by the appearance of a myeloproliferative neoplasm in the bone marrow, peripheral lymphadenopathy, usually caused by T or B lymphoblastic lymphoma/leukemia, and a reciprocal translocation involving chromosome 8p11. Herein we describe a 22-year-old male patient with unusual clinical presentation of EMS. Namely, he initially presented with prolonged epistaxis. Complete blood count showed elevated hemoglobin (17.7g/dl), thrombocytopenia (98x109/l) and leukocytosis (57x109/l). Bone marrow aspirate and biopsy findings corresponded with the presence of a myeloproliferative neoplasm while cytogenetic analysis revealed t(8;13)(p11q12). After that ZMYM2-FGFR1 in-frame fusion was confirmed at the molecular level. Immediately after establishing the diagnosis of a myeloproliferative neoplasm (MPN) generalized lymphadenopathy was developed. Histopathologic examination of lymph node sample confirmed the diagnosis of a T cell lymphoblastic lymphoma without bone marrow involvement. Four cycles of Hyper CVAD chemotherapy were administered with complete morphological and cytogenetic remission. Four weeks after evaluation, patient developed peripheral blood monocytosis and eosinophilia without bone marrow criteria for acute leukemia. Cytogenetic analysis showed t(8;13) accompanied by complex numerical and structural aberrations. The patient underwent allogeneic stem cell transplantation (allo-SCT) from HLA matched sister and he subsequently achieved complete remission. In conclusion, patients with MPN and translocations involving chromosome 8 need to be carefully evaluated for EMS. However, having in mind the very aggressive clinical course of EMS allo-SCT is the only potential curative option.

Gene expression profile of circulating CD34(+) cells and granulocytes in chronic myeloid leukemia.

PURPOSE: We compared the gene expression profile of peripheral blood CD34(+) cells and granulocytes in subjects with chronic myeloid leukemia (CML), with the accent on signaling pathways affected by BCR-ABL oncogene. METHODS: The microarray analyses have been performed in circulating CD34(+) cells and granulocytes from peripheral blood of 7 subjects with CML and 7 healthy donors. All studied BCR-ABL positive CML patients were in chronic phase, with a mean value of 2012±SD of CD34(+)cells/µl in peripheral blood. RESULTS: The gene expression profile was more prominent in CML CD34(+) cells (3553 genes) compared to granulocytes (2701 genes). The 41 and 39 genes were significantly upregulated in CML CD34(+) cells (HINT1, TXN, SERBP1) and granulocytes, respectively. BCR-ABL oncogene activated PI3K/AKT and MAPK signaling through significant upregulation of PTPN11, CDK4/6, and MYC and reduction of E2F1, KRAS, and NFKBIA gene expression in CD34(+) cells. Among genes linked to the inhibition of cellular proliferation by BCR-ABL inhibitor Imatinib, the FOS and STAT1 demonstrated significantly decreased expression in CML. CONCLUSION: The presence of BCR-ABL fusion gene doubled the expression quantity of genes involved in the regulation of cell cycle, proliferation and apoptosis of CD34(+) cells. These results determined the modified genes in PI3K/AKT and MAPK signaling of CML subjects.

Idarubicin induces mTOR-dependent cytotoxic autophagy in leukemic cells.

We investigated if the antileukemic drug idarubicin induces autophagy, a process of programmed cellular self-digestion, in leukemic cell lines and primary leukemic cells. Transmission electron microscopy and acridine orange staining demonstrated the presence of autophagic vesicles and intracellular acidification, respectively, in idarubicin-treated REH leukemic cell line. Idarubicin increased punctuation/aggregation of microtubule-associated light chain 3B (LC3B), enhanced the conversion of LC3B-I to autophagosome-associated LC3B-II in the presence of proteolysis inhibitors, and promoted the degradation of the selective autophagic target p62, thus indicating the increase in autophagic flux. Idarubicin inhibited the phosphorylation of the main autophagy repressor mammalian target of rapamycin (mTOR) and its downstream target p70S6 kinase. The treatment with the mTOR activator leucine prevented idarubicin-mediated autophagy induction. Idarubicin-induced mTOR repression was associated with the activation of the mTOR inhibitor AMP-activated protein kinase and down-regulation of the mTOR activator Akt. The suppression of autophagy by pharmacological inhibitors or LC3B and beclin-1 genetic knockdown rescued REH cells from idarubicin-mediated oxidative stress, mitochondrial depolarization, caspase activation and apoptotic DNA fragmentation. Idarubicin also caused mTOR inhibition and cytotoxic autophagy in K562 leukemic cell line and leukocytes from chronic myeloid leukemia patients, but not healthy controls. By demonstrating mTOR-dependent cytotoxic autophagy in idarubicin-treated leukemic cells, our results warrant caution when considering combining idarubicin with autophagy inhibitors in leukemia therapy.

BCL2 positive and BCL6 negative diffuse large B cell lymphoma patients benefit from R-CHOP therapy irrespective of germinal and non germinal center B cell like subtypes.

PURPOSE: Despite major advances in the treatment of diffuse large B cell lymphoma (DLBCL), approximately one third of the patients progress or die, suggesting the existence of additional oncogenic events. The purpose of this study was to evaluate the prognostic value of the "Hans classifier", and BCL2 and MYC protein expression and gene alterations in DLBCL patients treated with CHOP or R-CHOP chemotherapy over a 5-year period. Furthermore, we tried to correlate these parameters with the International Prognostic Index (IPI). METHODS: The immunohistochemical (IHC) expression of CD10, BCL6, MUM1 and BCL2 on paraffin-embedded formalin-fixed tumor samples from 103 centroblastic DLBCLs was analyzed. IHC expression of MYC and fluorescence in situ hybridization (FISH) for MYC and BCL2 gene alterations was performed on 67 samples using the tissue microarray (TMA) method. RESULTS: The Hans algorithm was not predictive of survival in both therapy groups. No significant difference in BCL2 and MYC alterations or MYC protein expression in relation to complete response (CR), event-free survival (EFS) and overall survival (OS) was observed in our study. High IPI correlated significantly with poor outcome and it was identified as independent prognostic factor for OS and EFS (both p=0.000). The 5-year OS was 61% in the R-CHOP compared to 38% in the CHOP group (p=0.007). Rituximab significantly improved the OS in the BCL2 positive (60 vs 29%, p=0.008), and the BCL6 negative (73 vs 25%, p=0.001) cases. CONCLUSION: IPI is an independent prognosticator for DL-BCL patients and the addition of rituximab significantly improved survival. Furthermore, patients with BCL2+ and BCL6-DLBCL benefited from R-CHOP.

A single institution experience on 314 newly diagnosed advanced Hodgkin lymphoma patients: the role of ABVD in daily practice.

Based on the results of clinical trials, there is no global consensus on the optimal first-line therapy for patients with advanced Hodgkin lymphoma (HL) with both ABVD and BEACOPP currently being used. However, the results of clinical trials are usually better than those in daily practice. We thus describe here our experience on 314 advanced classical HL patients treated with ABVD at the Clinical Center of Serbia and associated centers between 1997 and 2008. The median follow-up for all patients was 91 months; the estimated 5-yr event-free survival was 62% and the 5-yr overall survival (OS) 76%. Multivariate Cox regression analysis revealed that patients with IPS ≥ 3 and extranodal disease involving more than one site have a poorer outcome. The data presented here show on overall improvement in outcome as compared to more previous data and illustrate the problems of treating advanced stage HL outside the setting of a clinical trial.

Does Double Mean Trouble? Coexistence of Myeloproliferative and Lymphoproliferative Neoplasms.

Background: The occurrence of myeloproliferative neoplasms (MPNs) that evolve into each other is well-described, as is this occurrence of lymphoproliferative neoplasms (LPNs). However, less is known about rare MPN/LPN coexistence, and the aim of our study was to analyze charachteristics of these patients after long term follow-up. Methods: Fourteen patients with MPN/LPN coexistence were diagnosed and treated according to guidelines at a single university center across two decades. Results: The overall median age was 53 years (22-69). MPNs patients with subsequent LPNs had a shorter period of second malignancy development and a more aggressive course of LPN, which can cause fatal outcomes. Polycythemia vera and chronic lymphocytic leukemia were most commonly associated (36%). The JAK2V617F mutation had 2/3 and cytogenetic abnormalities occurred in 1/3 of patients. MPN/LPN coexistence cases had significantly higher thrombotic potential (42.8%) and a higher third malignancy accruement frequency (21.4%) versus those without such malignancies. Conclusions: Considering the younger ages at MPN diagnosis, it is recommended to check regularly for blood lymphocytosis or lymphadenopathy occurrences and organomegaly progression faster than expected for MPN, with the aim of timely LPN diagnoses. The presence of molecular-cytogenetic abnormalities in a majority of patients indicate possible genetic instability and increased risk of development of multiple neoplasms, thus elevating thrombotic risk.

Safety and Efficacy of Pegcetacoplan in Adult Patients with Paroxysmal Nocturnal Hemoglobinuria over 48 Weeks: 307 Open-Label Extension Study.

INTRODUCTION: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, life-threatening disease characterized by complement-mediated hemolysis and thrombosis. Pegcetacoplan, the first targeted complement component 3 (C3) PNH therapy, was safe and efficacious in treatment-naive and pre-treated patients with PNH in five clinical trials. METHODS: The 307 open-label extension (OLE) study (NCT03531255) is a non-randomized, multicenter extension study of long-term safety and efficacy of pegcetacoplan in adult patients with PNH who completed a pegcetacoplan parent study. All patients received pegcetacoplan. Outcomes at the 48-week data cutoff (week 48 of 307-OLE or August 27, 2021, whichever was earlier) are reported. Hemoglobin concentrations, Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scores, and transfusion avoidance were measured. Hemoglobin > 12 g/dL and sex-specific hemoglobin normalization (i.e., male, ≥ 13.6 g/dL; female, ≥ 12 g/dL) were assessed as percentage of patients with data available and no transfusions 60 days before data cutoff. Treatment-emergent adverse events, including hemolysis, were reported. RESULTS: Data from 137 patients with at least one pegcetacoplan dose at data cutoff were analyzed. Mean (standard deviation [SD]) hemoglobin increased from 8.9 (1.22) g/dL at parent study baseline to 11.6 (2.17) g/dL at 307-OLE entry and 11.6 (1.94) g/dL at data cutoff. At parent study baseline, mean (SD) FACIT-Fatigue score of 34.1 (11.08) was below the general population norm of 43.6; scores improved to 42.8 (8.79) at 307-OLE entry and 42.4 (9.84) at data cutoff. In evaluable patients, hemoglobin > 12 g/dL occurred in 40.2% (43 of 107) and sex-specific hemoglobin normalization occurred in 31.8% (34 of 107) at data cutoff. Transfusion was not required for 114 of 137 patients (83.2%). Hemolysis was reported in 23 patients (16.8%). No thrombotic events or meningococcal infections occurred. CONCLUSION: Pegcetacoplan sustained long-term improvements in hemoglobin concentrations, fatigue reduction, and transfusion burden. Long-term safety findings corroborate the favorable profile established for pegcetacoplan. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT03531255.

Easily Applicable Predictive Score for Differential Diagnosis of Prefibrotic Primary Myelofibrosis from Essential Thrombocythemia.

Essential thrombocythemia (ET) and prefibrotic primary myelofibrosis (prePMF) initially have a similar phenotypic presentation with thrombocytosis. The aim of our study was to determine significant clinical-laboratory parameters at presentation to differentiate prePMF from ET as well as to develop and validate a predictive diagnostic prePMF model. This retrospective study included 464 patients divided into ET (289 pts) and prePMF (175 pts) groups. The model was built using data from a development cohort (229 pts; 143 ET, 86 prePMF), which was then tested in an internal validation cohort (235 pts; 146 ET, 89 prePMF). The most important prePMF predictors in the multivariate logistic model were age ≥ 60 years (RR = 2.2), splenomegaly (RR = 13.2), and increased lactat-dehidrogenase (RR = 2.8). Risk scores were assigned according to derived relative risk (RR) for age ≥ 60 years (1 point), splenomegaly (2 points), and increased lactat-dehidrogenase (1 point). Positive predictive value (PPV) for pre-PMF diagnosis with a score of ≥points was 69.8%, while for a score of ≥3 it was 88.2%. Diagnostic performance had similar values in the validation cohort. In MPN patients with thrombocytosis at presentation, the application of the new model enables differentiation of pre-PMF from ET, which is clinically relevant considering that these diseases have different prognoses and treatments.

Myositis-specific autoantibodies in a non-traveler, patient from a non-endemic country, with Plasmodium vivax malaria.

INTRODUCTION: Autoantibodies (AAb) are a hallmark of immune-mediated inflammatory diseases. Malaria is a parasitic disease caused by Plasmodium protozoa. Individuals with malaria may present with a wide range of symptoms. It is frequently linked to the development of different AAb. CASE DESCRIPTION: A 35-year-old male presented with repeated episodes of fever, malaise, myalgia, dark urine, and yellowish sclera. Initial diagnostic workup revealed severe Coombs-positive anemia, increased C-reactive protein, and procalcitonin, pathological liver tests, high concentration of serum IgE, IgG, IgM, IgA, positive antinuclear antibodies (ANA), and positive antineutrophil cytoplasmatic antibodies (ANCA). In addition, myositis-specific antibodies directed to polymiositis-scleroderma 75 protein (PmScl75), threonyl-tRNA synthetase (PL-7), alanyl-tRNA synthetase (PL-12), Mi-2 antigen (Mi-2), Ku DNA helicase complex (Ku), signal recognition particle (SRP), and antiaminoacyl tRNA synthetase (EJ) were detected. The patient was suspected of having systemic lupus erythematosus and sent to the Clinic of Allergy and Immunology for further evaluation and treatment. A peripheral blood film examined by the hematologist during an episode of fever revealed intra-erythrocytic parasitic forms of Plasmodium vivax (P. vivax). After being diagnosed with P. vivax malaria, he was transferred to the Clinic for Infective and Tropical Diseases. The therapy consisted of artesunate/mefloquine and prednisone led to a complete clinical recovery and autoantibodies gradually disappeared. CONCLUSIONS: Malaria would not normally be considered during the initial diagnostic workup in a non-traveler and a patient from a non-endemic country. However, a thorough parasitic evaluation in patients presenting with a broad range of autoantibodies might be of particular importance.

Wax Composition of Serbian Dianthus spp. (Caryophyllaceae): Identification of New Metabolites and Chemotaxonomic Implications.

Although ethnopharmacologically renowned, wax constituents of Dianthus species were sporadically studied. A combination of GC-MS analysis, synthesis, and chemical transformations enabled the identification of 275 constituents of diethyl-ether washings of aerial parts and/or flowers of six Dianthus taxa (Dianthus carthusianorum, D. deltoides, D. giganteus subsp. banaticus, D. integer subsp. minutiflorus, D. petraeus, and D. superbus) and one Petrorhagia taxon (P. prolifera) from Serbia. Seventeen of these constituents (nonacosyl benzoate, additional 12 benzoates with anteiso-branched 1-alkanols, eicosyl tiglate, triacontane-14,16-dione, dotriacontane-14,16-dione, and tetratriacontane-16,18-dione) and two additional synthesized eicosyl esters (angelate and senecioate) represent completely new compounds. The structures of the tentatively identified ß-ketones were confirmed by analysis of the mass fragmentation of the corresponding pyrazoles and silyl enol ethers obtained by transformations of crude extracts and extract fractions. Silylation allowed the identification of 114 additional constituents, including a completely new natural product (30-methylhentriacontan-1-ol). The results obtained by multivariate statistical analyses showed that the chemical profile of Dianthus taxa's surface waxes is subject to both genetic and ecological factors, whereas the latter seemingly takes a more important role for the studied Dianthus samples.

High-dose imatinib induction followed by standard-dose maintenance in pre-treated chronic phase chronic myeloid leukemia patients--final analysis of a randomized, multicenter, phase III trial.

BACKGROUND: Previous data suggest that the response of chronic myeloid leukemia cells to imatinib is dose-dependent. The potential benefit of initial dose intensification of imatinib in pre-treated patients with chronic phase chronic myeloid leukemia remains unknown. DESIGN AND METHODS: Two hundred and twenty-seven pre-treated patients with chronic myeloid leukemia in chronic phase were randomly assigned to continuous treatment with a standard dose of imatinib (400 mg/day; n=113) or to 6 months of high-dose induction with imatinib (800 mg/day) followed by a standard dose of imatinib as maintenance therapy (n=114). RESULTS: The rates of major and complete cytogenetic responses were significantly higher in the high-dose arm than in the standard-dose arm at both 3 and 6 months (major cytogenetic responses: 36.8% versus 21.2%, P=0.01 and 50.0% versus 34.5%, P=0.018; complete cytogenetic responses: 22.8% versus 6.2%, P<0.001 and 40.4% versus 16.8%, P<0.001) on the basis of an intention-to-treat analysis. At 12 months, the difference between treatment arms remained statistically significant for complete cytogenetic responses (40.4% versus 24.8%, P=0.012) but not for major cytogenetic responses (49.1% versus 44.2%, P=0.462). The rate of major molecular responses was also significantly better at 3 and 6 months in the high-dose arm (month 3: 14.9% versus 3.5%, P=0.003; month 6: 32.5% versus 8.8%, P<0.001). Overall and progression-free survival rates were comparable between arms, but event-free survival was significantly worse in the high-dose arm (P=0.014). CONCLUSIONS: Standard-dose imatinib remains the standard of care for pre-treated patients with chronic phase chronic myeloid leukemia (Clinicaltrials.gov identifier: NCT00327262).

Cyclohexyl analogues of ethylenediamine dipropanoic acid induce caspase-independent mitochondrial apoptosis in human leukemic cells.

We investigated the cytotoxicity of recently synthesized (S,S)-ethylendiamine-N,N'-di-2-(3-cyclohexyl)propanoic acid esters toward human leukemic cell lines and healthy blood mononuclear cells. Cell viability was assessed by acid phosphatase assay, apoptosis, and differentiation were analyzed by flow cytometry and electron microscopy, while intracellular localization of apoptosis-inducing factor (AIF) was determined by immunoblotting. It was demonstrated that methyl, ethyl, and n-propyl esters were toxic to HL-60, REH, MOLT-4, KG-1, JVM-2, and K-562 leukemic cell lines, while the nonesterified parental compound and n-butyl ester were devoid of cytotoxic action. The ethyl ester exhibited the highest cytotoxic activity (IC50 10.7 µM-45.4 µM), which was comparable to that of the prototypical anticancer drug cisplatin. The observed cytotoxic effect in HL-60 cells was associated with an increase in superoxide production and mitochondrial membrane depolarization, leading to apoptotic cell death characterized by phosphatidylserine externalization and DNA fragmentation in the absence of autophagic response. DNA fragmentation preceded caspase activation and followed AIF translocation from mitochondria to nucleus, which was indicative of caspase-independent apoptotic cell death. HL-60 cells treated with subtoxic concentration of the compound displayed morphological signs of granulocytic differentiation (nuclear indentations and presence of cytoplasmic primary granules), as well as an increased expression of differentiation markers CD11b and CD15. The cyclohexyl analogues of ethylenediamine dipropanoic acid were also toxic to peripheral blood mononuclear cells of both healthy controls and leukemic patients, the latter being more sensitive. Our data demonstrate that the toxicity of the investigated cyclohexyl compounds against leukemic cell lines is mediated by caspase-independent apoptosis associated with oxidative stress, mitochondrial dysfunction, and AIF translocation.

Prognostic significance of Bcl-2, tumor-associated macrophages, and total neoplastic and inflammatory lymph node involvement in advanced stage classical Hodgkin's lymphoma.

BACKGROUND: Although Hodgkin's lymphoma (HL) is a curable cancer, current treatment strategies based on risk stratification and response modulation are not precise enough. The predictive power of biological and morphological parameters is controversial, with prognostic models not reaching wide acceptance. PATIENTS AND METHODS: We analyzed the prognostic relevance of 8 parameters in 85 advanced stage classical HL patients, in order to determine whether tissue-based variables could add prognostic value to standard clinical parameters, thus contributing to better risk stratification at presentation. RESULTS: Univariate analysis confirmed 5 indicators of shorter overall survival (OS): Bcl-2 overexpression; increased CD68+ tumor-associated macrophages (TAM); international prognostic score (IPS) > 2; bulky disease; and total lymph node involvement (TLNI) with regard to neoplastic and inflammatory cells. Apart from TLNI, these parameters influenced lower event-free survival (EFS). Multivariate analysis identified 5 independent factors for OS: Bcl-2 overexpression; increased CD68+ TAM; TLNI; IPS > 2; and bulky disease. Increased CD68+ TAM, IPS > 2, and bulky disease affected the EFS. Utilizing the cumulative score of unfavorable prognostic factors for OS, we designed a prognostic model stratifying patients into 4 risk groups (with 0-1, 2, 3, or 4-5 factors), each with progressively reduced OS (p < 0.001). CONCLUSION: Our findings support the combination of tissue-based variables with clinical parameters at diagnosis, identifying patients who are at higher risk of poor outcome.

Correlation between leukocyte-platelet aggregates and thrombosis in myeloproliferative neoplasms.

INTRODUCTION: The impact of activated blood and endothelial cells on the thrombosis in myeloproliferative neoplasms (MPN) has not yet been clarified. We prospectively analyzed correlation between circulating leukocyte-platelet aggregates and soluble selectins to thrombosis occurrence in MPN, in the context of standard and cardiovascular risk factors, and different clinical and biological characteristics. METHODS: Flow cytometric analysis of neutrophil-platelet (Neu-Plt) and monocyte-platelet (Mo-Plt) aggregates in peripheral blood, as well as quantification of soluble E-/L-/P-selectins by enzyme immunoassay, was performed on 95 newly diagnosed MPN patients. RESULTS: During the follow-up, thrombosis occurred in 12.6% MPN patients (arterial 9.4%, venous 3.2%), with a mean time of 39 months. The overall incidence rate of main thrombotic events was 4.36 per 100 patient-years. The incidence of arterial hypertension (HTA) was significantly higher in patients with thrombosis, compared to those without thrombosis (P < .05). The level of soluble P-selectin was significantly higher in patients with thrombosis compared to those without thrombosis (346.89 ng/mL vs 286.39 ng/mL, P = .034). The mean level of Neu-Plt (26.7% vs 22.4%) and Mo-Plt (17.8% vs 12.3%) aggregates did not differ significantly between the groups with and without thrombosis. A multivariate COX proportional hazard regression model confirmed an independent predictive significance of Mo-Plt aggregates (HR = 1.561, 95% CI: 1.007-2.420, P = .046), as well as the cumulative effect of Mo-Plt aggregates and HTA (HR = 1.975, 95%CI: 1.215-3.212, P = .006) for thrombosis occurrence. CONCLUSION: Monocyte-platelet aggregates represent an independent risk factor for thrombosis occurrence, further on supported by HTA.

Inflammation Promotes Oxidative and Nitrosative Stress in Chronic Myelogenous Leukemia.

Chronic inflammation is characterized by the production of reactive oxygen species (ROS), reactive nitrogen species, and inflammatory cytokines in myeloproliferative neoplasms (MPNs). In addition to these parameters, the aim of this study was to analyze the influence of ROS on the proliferation-related AKT/mTOR signaling pathway and the relationship with inflammatory factors in chronic myelogenous leukemia (CML). The activity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, and catalase is reduced in erythrocytes while levels of the oxidative stress markers malondialdehyde and protein carbonyl are elevated in the plasma of patients with CML. In addition, nitrogen species (nitrotyrosine, iNOS, eNOS) and inflammation markers (IL-6, NFkB, and S100 protein) were increased in granulocytes of CML while anti-inflammatory levels of IL-10 were decreased in plasma. CML granulocytes exhibited greater resistance to cytotoxic H2O2 activity compared to healthy subjects. Moreover, phosphorylation of the apoptotic p53 protein was reduced while the activity of the AKT/mTOR signaling pathway was increased, which was further enhanced by oxidative stress (H2O2) in granulocytes and erythroleukemic K562 cells. IL-6 caused oxidative stress and DNA damage that was mitigated using antioxidant or inhibition of inflammatory NFkB transcription factor in K562 cells. We demonstrated the presence of oxidative and nitrosative stress in CML, with the former mediated by AKT/mTOR signaling and stimulated by inflammation.

COVID-19 Presented with Deep Vein Thrombosis in a Patient with Paroxysmal Nocturnal Haemoglobinuria.

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare, acquired clonal haematological disease characterized by complement-mediated haemolysis, bone marrow failure and venous thrombosis. Anticomplement therapy eculizumab improves survival and reduces complications. Severe acute respiratory distress syndrome corona virus 2 (SARS-CoV-2) disease 2019 (COVID-19) is associated with high incidence of both venous and arterial thrombosis in hospitalized patients with pneumonia. Deep venous thrombosis (DVT) as the presenting symptom of COVID-19 is a rare event. We describe a well-controlled PNH patient on eculizumab for more than 5 years who presented with DVT, while on warfarin, as the first sign of COVID-19. To our knowledge, this is the first described case of DVT in a PNH patient with COVID-19.