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Clinical Cancer Research : An Official... Sep 2023Myelofibrosis (MF) is a clonal myeloproliferative neoplasm characterized by systemic symptoms, cytopenias, organomegaly, and bone marrow fibrosis. JAK2 inhibitors afford...
PURPOSE
Myelofibrosis (MF) is a clonal myeloproliferative neoplasm characterized by systemic symptoms, cytopenias, organomegaly, and bone marrow fibrosis. JAK2 inhibitors afford symptom and spleen burden reduction but do not alter the disease course and frequently lead to thrombocytopenia. TGFβ, a pleiotropic cytokine elaborated by the MF clone, negatively regulates normal hematopoiesis, downregulates antitumor immunity, and promotes bone marrow fibrosis. Our group previously showed that AVID200, a potent and selective TGFβ 1/3 trap, reduced TGFβ1-induced proliferation of human mesenchymal stromal cells, phosphorylation of SMAD2, and collagen expression. Moreover, treatment of MF mononuclear cells with AVID200 led to increased numbers of progenitor cells (PC) with wild-type JAK2 rather than JAK2V617F.
PATIENTS AND METHODS
We conducted an investigator-initiated, multicenter, phase Ib trial of AVID200 monotherapy in 21 patients with advanced MF.
RESULTS
No dose-limiting toxicity was identified at the three dose levels tested, and grade 3/4 anemia and thrombocytopenia occurred in 28.6% and 19.0% of treated patients, respectively. After six cycles of therapy, two patients attained a clinical benefit by IWG-MRT criteria. Spleen and symptom benefits were observed across treatment cycles. Unlike other MF-directed therapies, increases in platelet counts were noted in 81% of treated patients with three patients achieving normalization. Treatment with AVID200 resulted in potent suppression of plasma TGFβ1 levels and pSMAD2 in MF cells.
CONCLUSIONS
AVID200 is a well-tolerated, rational, therapeutic agent for the treatment of patients with MF and should be evaluated further in patients with thrombocytopenic MF in combination with agents that target aberrant MF intracellular signaling pathways.
Topics: Humans; Primary Myelofibrosis; Myeloproliferative Disorders; Janus Kinase 2; Cytokines; Immunologic Factors; Thrombocytopenia
PubMed: 37439808
DOI: 10.1158/1078-0432.CCR-23-0276 -
Journal of Thrombosis and Haemostasis :... Dec 2023Vaccine-induced immune thrombocytopenia and thrombosis (VITT) is a rare syndrome associated with adenoviral vector vaccines for COVID-19. The syndrome is characterized...
BACKGROUND
Vaccine-induced immune thrombocytopenia and thrombosis (VITT) is a rare syndrome associated with adenoviral vector vaccines for COVID-19. The syndrome is characterized by thrombosis, anti-platelet factor 4 (PF4) antibodies, thrombocytopenia, high D-dimer, and hypofibrinogenemia.
OBJECTIVES
To investigate abnormalities in fibrinolysis that contribute to the clinical features of VITT.
METHODS
Plasma samples from 18 suspected VITT cases were tested for anti-PF4 by ELISA and characterized as meeting criteria for VITT (11/18) or deemed unlikely (7/18; non-VITT). Antigen levels of PAI-1, factor XIII (FXIII), plasmin-αantiplasmin (PAP), and inflammatory markers were quantified. Plasmin generation was quantified by chromogenic substrate. Western blotting was performed with antibodies to fibrinogen, FXIII-A, and plasminogen.
RESULTS
VITT patients 10/11 had scores indicative of overt disseminated intravascular coagulation, while 0/7 non-VITT patients met the criteria. VITT patients had significantly higher levels of inflammatory markers, IL-1β, IL-6, IL-8, TNFα, and C-reactive protein. In VITT patients, both fibrinogen and FXIII levels were significantly lower, while PAP and tPA-mediated plasmin generation were higher compared to non-VITT patients. Evidence of fibrinogenolysis was observed in 9/11 VITT patients but not in non-VITT patients or healthy controls. Fibrinogen degradation products were apparent, with obvious cleavage of the fibrinogen α-chain. PAP complex was evident in those VITT patients with fibrinogenolysis, but not in non-VITT patients or healthy donors.
CONCLUSION
VITT patients show evidence of overt disseminated intravascular coagulation and fibrinogenolysis, mediated by dysregulated plasmin generation, as evidenced by increased PAP and plasmin generation. These observations are consistent with the clinical presentation of both thrombosis and bleeding in VITT.
Topics: Humans; Fibrinolysis; Purpura, Thrombocytopenic, Idiopathic; Fibrinolysin; Disseminated Intravascular Coagulation; COVID-19 Vaccines; Thrombocytopenia; Thrombosis; Vaccines; Fibrinogen
PubMed: 37734715
DOI: 10.1016/j.jtha.2023.09.007 -
Seminars in Thrombosis and Hemostasis Jul 2023Heparin-induced thrombocytopenia (HIT) and vaccine-induced immune thrombotic thrombocytopenia (VITT) are rare, iatrogenic immune-mediated conditions with high rates of... (Review)
Review
Heparin-induced thrombocytopenia (HIT) and vaccine-induced immune thrombotic thrombocytopenia (VITT) are rare, iatrogenic immune-mediated conditions with high rates of thrombosis-related morbidity and mortality. HIT is a long-recognized reaction to the administration of the common parenterally administered anticoagulant heparin (or its derivatives), while VITT is a new, distinct syndrome occurring in response to adenovirus-based vaccines against coronavirus disease 2019 and potentially other types of vaccines. A feature of both HIT and VITT is paradoxical thrombosis despite a characteristic low platelet count, mediated by the presence of platelet-activating antibodies to platelet factor 4. Several additional factors have also been suggested to contribute to clot formation in HIT and/or VITT, including monocytes, tissue factor, microparticles, endothelium, the formation of neutrophil extracellular traps, complement, procoagulant platelets, and vaccine components. In this review, we discuss the literature to date regarding mechanisms contributing to thrombosis in both HIT and VITT and explore the pathophysiological similarities and differences between the two conditions.
Topics: Humans; COVID-19; Thrombocytopenia; Purpura, Thrombocytopenic, Idiopathic; Vaccines; Thrombosis; Platelet Factor 4
PubMed: 36706782
DOI: 10.1055/s-0043-1761269 -
Circulation Research Oct 2023Thrombocytopenia has been consistently described in patients with extracorporeal membrane oxygenation (ECMO) and associated with poor outcome. However, the prevalence...
BACKGROUND
Thrombocytopenia has been consistently described in patients with extracorporeal membrane oxygenation (ECMO) and associated with poor outcome. However, the prevalence and underlying mechanisms remain largely unknown, and a device-related role of ECMO in thrombocytopenia has been hypothesized. This study aims to investigate the mechanisms underlying thrombocytopenia in ECMO patients.
METHODS
In a prospective cohort of 107 ECMO patients, we investigated platelet count, functions, and glycoprotein shedding. In an ex vivo mock circulatory ECMO loop, we assessed platelet responses and VWF (von Willebrand factor)-GP Ibα (glycoprotein Ibα) interactions at low- and high-flow rates, in the presence or absence of red blood cells. The clearance of human platelets subjected or not to ex vivo perfusion was studied using an in vivo transfusion model in NOD/SCID (nonobese diabetic/severe combined Immunodeficient) mice.
RESULTS
In ECMO patients, we observed a time-dependent decrease in platelet count starting 1 hour after device onset, with a mean drop of 7%, 35%, and 41% at 1, 24, and 48 hours post-ECMO initiation (=0.00013, <0.0001, and <0.0001, respectively), regardless of the type of ECMO. This drop in platelet count was associated with a decrease in platelet GP Ibα expression (before: 47.8±9.1 versus 24 hours post-ECMO: 42.3±8.9 mean fluorescence intensity; =0.002) and an increase in soluble GP Ibα plasma levels (before: 5.6±3.3 versus 24 hours post-ECMO: 10.8±4.1 µg/mL; <0.0001). GP Ibα shedding was also observed ex vivo and was unaffected by (1) red blood cells, (2) the coagulation potential, (3) an antibody blocking VWF-GP Ibα interaction, (4) an antibody limiting VWF degradation, and (5) supraphysiological VWF plasma concentrations. In contrast, GP Ibα shedding was dependent on rheological conditions, with a 2.8-fold increase at high- versus low-flow rates. Platelets perfused at high-flow rates before being transfused to immunodeficient mice were eliminated faster in vivo with an accelerated clearance of GP Ibα-negative versus GP Ibα-positive platelets.
CONCLUSIONS
ECMO-associated shear forces induce GP Ibα shedding and thrombocytopenia due to faster clearance of GP Ibα-negative platelets. Inhibiting GP Ibα shedding could represent an approach to reduce thrombocytopenia during ECMO.
Topics: Humans; Animals; Mice; von Willebrand Factor; Prospective Studies; Mice, Inbred NOD; Mice, SCID; Blood Platelets; Thrombocytopenia
PubMed: 37883587
DOI: 10.1161/CIRCRESAHA.123.322752 -
Hamostaseologie Feb 2024Trauma-induced coagulopathy (TIC) is a complex hemostatic disturbance that can develop early after a major injury. There is no universally accepted definition of TIC....
Trauma-induced coagulopathy (TIC) is a complex hemostatic disturbance that can develop early after a major injury. There is no universally accepted definition of TIC. However, TIC primarily refers to the inability to achieve sufficient hemostasis in severely injured trauma patients, resulting in diffuse microvascular and life-threatening bleeding. Endogenous TIC is driven by the combination of hypovolemic shock and substantial tissue injury, resulting in endothelial damage, glycocalyx shedding, upregulated fibrinolysis, fibrinogen depletion, altered thrombin generation, and platelet dysfunction. Exogenous factors such as hypothermia, acidosis, hypokalemia, and dilution due to crystalloid and colloid fluid administration can further exacerbate TIC. Established TIC upon emergency room admission is a prognostic indicator and is strongly associated with poor outcomes. It has been shown that patients with TIC are prone to higher bleeding tendencies, increased requirements for allogeneic blood transfusion, higher complication rates such as multi-organ failure, and an almost fourfold increase in mortality. Thus, early recognition and individualized treatment of TIC is a cornerstone of initial trauma care. However, patients who survive the initial insult switch from hypocoagulability to hypercoagulability, also termed "late TIC," with a high risk of developing thromboembolic complications.
Topics: Humans; Blood Coagulation Disorders; Hemostasis; Hemorrhage; Fibrinolysis; Blood Platelet Disorders; Hemostatics; Wounds and Injuries
PubMed: 38417803
DOI: 10.1055/a-2215-8936 -
Frontiers in Immunology 2023Chimeric antigen receptor (CAR) T cell therapy for solid tumors shows promise, but several hurdles remain. Strategies to overcome barriers such as CAR T therapy-related... (Review)
Review
Chimeric antigen receptor (CAR) T cell therapy for solid tumors shows promise, but several hurdles remain. Strategies to overcome barriers such as CAR T therapy-related toxicities (CTT), immunosuppression, and immune checkpoints through research and technology are needed to put the last nail to the coffin and offer hope for previously incurable malignancies. Herein we review current literature and infer novel strategies for the mitigation of CTT while impeding immune suppression, stromal barriers, tumor heterogeneity, on-target/off-tumor toxicities, and better transfection strategies with an emphasis on clinical research and prospects.
Topics: Humans; Receptors, Chimeric Antigen; Receptors, Antigen, T-Cell; T-Lymphocytes; Tumor Microenvironment; Neoplasms; Thrombocytopenia
PubMed: 37520522
DOI: 10.3389/fimmu.2023.1203230 -
The Turkish Journal of Pediatrics 2024Classical clinical triad of hemolytic uremic syndrome (HUS) is microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury associated with endothelial... (Review)
Review
Classical clinical triad of hemolytic uremic syndrome (HUS) is microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury associated with endothelial cell injury. Several situations, including infections, medications, malignancies, and transplantation can trigger endothelial damage. On the HUS spectrum, atypical hemolytic uremic syndrome (aHUS) deserves special attention in pediatric patients, as it can cause endstage kidney disease and mortality. A dysfunction in the alternative complement pathway, either acquired or genetic, has been shown to be the main underlying cause. In the last decades, breathtaking advances have been made in understanding the pathophysiology of this rare disease, which has led to more efficient treatment. Recent studies have implicated genes in pathways beyond the alternative complement system, such as DGKE, TSEN2, and INF2 highlighting the importance of personalized management. Eculizumab has brought about dramatic improvements in the treatment of aHUS. Beyond eculizumab, there are many alternative therapeutics in the pipeline that target the complement system. Because of the rarity of aHUS, data from multiple patient registries are very important. The present report aimed to summarize the most important aspects of diagnosing and treating aHUS based on the Turkish national registry and the literature so as to improve clinical practice.
Topics: Humans; Child; Atypical Hemolytic Uremic Syndrome; Purpura, Thrombotic Thrombocytopenic; Anemia, Hemolytic; Acute Kidney Injury; Kidney Failure, Chronic
PubMed: 38523374
DOI: 10.24953/turkjped.2023.596 -
Cancer Jun 2023Patients with cytopenic myelofibrosis (MF) have more limited therapeutic options and poorer prognoses compared with patients with the myeloproliferative phenotype.
BACKGROUND
Patients with cytopenic myelofibrosis (MF) have more limited therapeutic options and poorer prognoses compared with patients with the myeloproliferative phenotype.
AIMS AND METHODS
Prognostic correlates of cytopenic phenotype were explored in 886 ruxolitinib-treated patients with primary/secondary MF (PMF/SMF) included in the RUX-MF retrospective study. Cytopenia was defined as: leukocyte count <4 × 10 /L and/or hemoglobin <11/<10 g/dL (males/females) and/or platelets <100 × 10 /L.
RESULTS
Overall, 407 (45.9%) patients had a cytopenic MF, including 249 (52.4%) with PMF. In multivariable analysis, high molecular risk mutations (p = .04), intermediate 2/high Dynamic International Prognostic Score System (p < .001) and intermediate 2/high Myelofibrosis Secondary to Polycythemia Vera and Essential Thrombocythemia Prognostic Model (p < .001) remained associated with cytopenic MF in the overall cohort, PMF, and SMF, respectively. Patients with cytopenia received lower average ruxolitinib at the starting (25.2 mg/day vs. 30.2 mg/day, p < .001) and overall doses (23.6 mg/day vs. 26.8 mg/day, p < .001) and achieved lower rates of spleen (26.5% vs. 34.1%, p = .04) and symptom (59.8% vs. 68.8%, p = .008) responses at 6 months compared with patients with the proliferative phenotype. Patients with cytopenia also had higher rates of thrombocytopenia at 3 months (31.1% vs. 18.8%, p < .001) but lower rates of anemia (65.6% vs. 57.7%, p = .02 at 3 months and 56.6% vs. 23.9% at 6 months, p < .001). After competing risk analysis, the cumulative incidence of ruxolitinib discontinuation at 5 years was 57% and 38% in patients with cytopenia and the proliferative phenotype (p < .001), whereas cumulative incidence of leukemic transformation was similar (p = .06). In Cox regression analysis adjusted for Dynamic International Prognostic Score System score, survival was significantly shorter in patients with cytopenia (p < .001).
CONCLUSIONS
Cytopenic MF has a lower probability of therapeutic success with ruxolitinib as monotherapy and worse outcome. These patients should be considered for alternative therapeutic strategies.
Topics: Male; Female; Humans; Retrospective Studies; Primary Myelofibrosis; Thrombocytopenia; Anemia; Drug-Related Side Effects and Adverse Reactions
PubMed: 36932983
DOI: 10.1002/cncr.34722 -
Blood Cancer Journal Jan 2024We describe 1000 patients with essential thrombocythemia seen at the Mayo Clinic between 1967 and 2023: median age 58 years (18-90), females 63%, JAK2/CALR/MPL-mutated...
We describe 1000 patients with essential thrombocythemia seen at the Mayo Clinic between 1967 and 2023: median age 58 years (18-90), females 63%, JAK2/CALR/MPL-mutated 62%/27%/3%, triple-negative (TN) 8%, extreme thrombocytosis (ExT; platelets ≥1000 × 10/L) 26%, leukocytosis (leukocyte count >11 × 10/L) 20%, and abnormal karyotype 6%. JAK2-mutated patients were older (median 71 years), and CALR mutated (52 years), and TN (50 years) younger (p < 0.01). Female gender clustered with TN (73%) and JAK2 (69%) vs. CALR/MPL (49%/47%) mutations (p < 0.01). ExT clustered with CALR (type-2 more than type-1) and TN and leukocytosis with JAK2 mutation (p < 0.01). In multivariable analysis, risk factors for overall survival were older age (p < 0.01), male gender (HR 1.8), absolute neutrophil count (ANC) ≥ 8 × 10/L (HR 1.6), absolute lymphocyte count (ALC) < 1.7 × 10/L (HR 1.5), hypertension (HR 1.7), and arterial thrombosis history (HR 1.7); for leukemia-free survival, ExT (HR 2.3) and abnormal karyotype (HR 3.1); for myelofibrosis-free survival, ANC ≥ 8 × 10/L (HR 2.3) and MPL mutation (HR 3.9); for arterial thrombosis-free survival, age ≥60 years (HR 1.9), male gender (HR 1.6), arterial thrombosis history (HR 1.7), hypertension (HR 1.7), and JAK2 mutation (HR 1.8); for venous thrombosis-free survival, male gender (HR 1.8) and venous thrombosis history (HR 3.0). Associations between ExT and leukemic transformation and between ANC and fibrotic progression were limited to JAK2-mutated cases. Aspirin therapy appeared to mitigate both arterial (HR 0.4) and venous (HR 0.4) thrombosis risk. HR-based risk models delineated patients with median survivals ranging from 10 years to not reached and 20-year leukemia/myelofibrosis incidences from 3%/21% to 12.8%/49%. The current study provides both novel and confirmatory observations of essential thrombocythemia.
Topics: Humans; Male; Female; Middle Aged; Thrombocythemia, Essential; Leukocytosis; Thrombosis; Mutation; Primary Myelofibrosis; Abnormal Karyotype; Hypertension; Janus Kinase 2; Calreticulin
PubMed: 38238303
DOI: 10.1038/s41408-023-00972-x -
The Journal of Rheumatology Jun 2023The complement system is a tightly regulated, cascading protein network representing a key component linking the innate and humoral immune systems. However, if... (Review)
Review
The complement system is a tightly regulated, cascading protein network representing a key component linking the innate and humoral immune systems. However, if misdirected or dysregulated, it can be similarly damaging to host-tissue. The role of complement dysregulation on vascular endothelial cells has been well established in atypical hemolytic uremic syndrome (aHUS), a thrombotic microangiopathy (TMA) characterized by microangiopathic hemolytic anemia, thrombocytopenia, and target organ injury. Yet, a great deal of complexity exists around the role of complement in TMA associated with other diseases. A further complicating factor is the cross-talk between complement, neutrophils, and coagulation pathways in the pathophysiology of TMA. Advancements in the understanding of the etiopathogenesis of aHUS paved the way for the successful development of anticomplement therapies (complement C5 inhibitors), which have revolutionized the treatment of aHUS. Therefore, a clearer understanding of the role of the complement system in TMA associated with other conditions will help to identify patients who would benefit from these therapies. This review aims to provide an assessment of the nature and extent of complement involvement in TMA associated with autoimmune diseases such as systemic lupus erythematosus, antiphospholipid syndrome, and scleroderma renal crisis. Defining the role of complement in TMA in these conditions will help to guide timely diagnosis and management.
Topics: Humans; Endothelial Cells; Thrombotic Microangiopathies; Complement System Proteins; Lupus Erythematosus, Systemic; Atypical Hemolytic Uremic Syndrome; Complement C5
PubMed: 36642429
DOI: 10.3899/jrheum.220752