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Military Medical Research Dec 2023The essential roles of platelets in thrombosis have been well recognized. Unexpectedly, thrombosis is prevalent during thrombocytopenia induced by cytotoxicity of...
BACKGROUND
The essential roles of platelets in thrombosis have been well recognized. Unexpectedly, thrombosis is prevalent during thrombocytopenia induced by cytotoxicity of biological, physical and chemical origins, which could be suffered by military personnel and civilians during chemical, biological, radioactive, and nuclear events. Especially, thrombosis is considered a major cause of mortality from radiation injury-induced thrombocytopenia, while the underlying pathogenic mechanism remains elusive.
METHODS
A mouse model of radiation injury-induced thrombocytopenia was built by exposing mice to a sublethal dose of ionizing radiation (IR). The phenotypic and functional changes of platelets and megakaryocytes (MKs) were determined by a comprehensive set of in vitro and in vivo assays, including flow cytometry, flow chamber, histopathology, Western blotting, and chromatin immunoprecipitation, in combination with transcriptomic analysis. The molecular mechanism was investigated both in vitro and in vivo, and was consolidated using MK-specific knockout mice. The translational potential was evaluated using a human MK cell line and several pharmacological inhibitors.
RESULTS
In contrast to primitive MKs, mature MKs (mMKs) are intrinsically programmed to be apoptosis-resistant through reprogramming the Bcl-xL-BAX/BAK axis. Interestingly, mMKs undergo minority mitochondrial outer membrane permeabilization (MOMP) post IR, resulting in the activation of the cyclic GMP-AMP synthase-stimulator of IFN genes (cGAS-STING) pathway via the release of mitochondrial DNA. The subsequent interferon-β (IFN-β) response in mMKs upregulates a GTPase guanylate-binding protein 2 (GBP2) to produce large and hyperreactive platelets that favor thrombosis. Further, we unmask that autophagy restrains minority MOMP in mMKs post IR.
CONCLUSIONS
Our study identifies that megakaryocytic mitochondria-cGAS/STING-IFN-β-GBP2 axis serves as a fundamental checkpoint that instructs the size and function of platelets upon radiation injury and can be harnessed to treat platelet pathologies.
Topics: Humans; Animals; Mice; Megakaryocytes; Thrombocytopenia; Radiation Injuries; Apoptosis; Nucleotidyltransferases; Thrombosis
PubMed: 38111039
DOI: 10.1186/s40779-023-00499-z -
Intensive Care Medicine Nov 2023Thrombocytopenia (platelet count < 150 × 10/L) is common in intensive care unit (ICU) patients and is likely associated with worse outcomes. In this study we...
PURPOSE
Thrombocytopenia (platelet count < 150 × 10/L) is common in intensive care unit (ICU) patients and is likely associated with worse outcomes. In this study we present international contemporary data on thrombocytopenia in ICU patients.
METHODS
We conducted a prospective cohort study in adult ICU patients in 52 ICUs across 10 countries. We assessed frequencies of thrombocytopenia, use of platelet transfusions and clinical outcomes including mortality. We evaluated pre-selected potential risk factors for the development of thrombocytopenia during ICU stay and associations between thrombocytopenia at ICU admission and 90-day mortality using pre-specified logistic regression analyses.
RESULTS
We analysed 1166 ICU patients; the median age was 63 years and 39.5% were female. Overall, 43.2% (95% confidence interval (CI) 40.4-46.1) had thrombocytopenia; 23.4% (20-26) had thrombocytopenia at ICU admission, and 19.8% (17.6-22.2) developed thrombocytopenia during their ICU stay. Absence of acquired immune deficiency syndrome (AIDS), non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay. Among patients with thrombocytopenia, 22.6% received platelet transfusion(s), and 64.3% of in-ICU transfusions were prophylactic. Patients with thrombocytopenia had higher occurrences of bleeding and death, fewer days alive without the use of life-support, and fewer days alive and out of hospital. Thrombocytopenia at ICU admission was associated with 90-day mortality (adjusted odds ratio 1.7; 95% CI 1.19-2.42).
CONCLUSION
Thrombocytopenia occurred in 43% of critically ill patients and was associated with worse outcomes including increased mortality. Platelet transfusions were given to 23% of patients with thrombocytopenia and most were prophylactic.
Topics: Adult; Humans; Male; Female; Middle Aged; Platelet Transfusion; Cohort Studies; Prospective Studies; Thrombocytopenia; Intensive Care Units; Hemorrhage; Retrospective Studies
PubMed: 37812225
DOI: 10.1007/s00134-023-07225-2 -
Journal For Immunotherapy of Cancer Jun 2023Hematologic toxicities, including coagulopathy, endothelial activation, and cytopenias, with CD19-targeted chimeric antigen receptor (CAR) T-cell therapies correlate...
BACKGROUND
Hematologic toxicities, including coagulopathy, endothelial activation, and cytopenias, with CD19-targeted chimeric antigen receptor (CAR) T-cell therapies correlate with cytokine release syndrome (CRS) and neurotoxicity severity, but little is known about the extended toxicity profiles of CAR T-cells targeting alternative antigens. This report characterizes hematologic toxicities seen following CD22 CAR T-cells and their relationship to CRS and neurotoxicity.
METHODS
We retrospectively characterized hematologic toxicities associated with CRS seen on a phase 1 study of anti-CD22 CAR T-cells for children and young adults with relapsed/refractory CD22+ hematologic malignancies. Additional analyses included correlation of hematologic toxicities with neurotoxicity and exploring effects of hemophagocytic lymphohistiocytosis-like toxicities (HLH) on bone marrow recovery and cytopenias. Coagulopathy was defined as evidence of bleeding or abnormal coagulation parameters. Hematologic toxicities were graded by Common Terminology Criteria for Adverse Events V.4.0.
RESULTS
Across 53 patients receiving CD22 CAR T-cells who experienced CRS, 43 (81.1%) patients achieved complete remission. Eighteen (34.0%) patients experienced coagulopathy, of whom 16 had clinical manifestations of mild bleeding (typically mucosal bleeding) which generally subsided following CRS resolution. Three had manifestations of thrombotic microangiopathy. Patients with coagulopathy had higher peak ferritin, D-dimer, prothrombin time, international normalized ratio (INR), lactate dehydrogenase (LDH), tissue factor, prothrombin fragment F1+2 and soluble vascular cell adhesion molecule-1 (s-VCAM-1). Despite a relatively higher incidence of HLH-like toxicities and endothelial activation, overall neurotoxicity was generally less severe than reported with CD19 CAR T-cells, prompting additional analysis to explore CD22 expression in the central nervous system (CNS). Single-cell analysis revealed that in contrast to CD19 expression, CD22 is not on oligodendrocyte precursor cells or on neurovascular cells but is seen on mature oligodendrocytes. Lastly, among those attaining CR, grade 3-4 neutropenia and thrombocytopenia were seen in 65% of patients at D28.
CONCLUSION
With rising incidence of CD19 negative relapse, CD22 CAR T-cells are increasingly important for the treatment of B-cell malignancies. In characterizing hematologic toxicities on CD22 CAR T-cells, we demonstrate that despite endothelial activation, coagulopathy, and cytopenias, neurotoxicity was relatively mild and that CD22 and CD19 expression in the CNS differed, providing one potential hypothesis for divergent neurotoxicity profiles. Systematic characterization of on-target off-tumor toxicities of novel CAR T-cell constructs will be vital as new antigens are targeted.
TRIAL REGISTRATION NUMBER
NCT02315612.
Topics: Humans; T-Lymphocytes; Retrospective Studies; Neoplasm Recurrence, Local; Immunotherapy, Adoptive; Hematologic Neoplasms; Cytokine Release Syndrome; Thrombocytopenia
PubMed: 37295816
DOI: 10.1136/jitc-2022-005898 -
Journal of Thrombosis and Haemostasis :... Jun 2023Severe deficiency in ADAMTS-13 (<10%) and the loss of von Willebrand factor-cleaving function can precipitate microvascular thrombosis associated with thrombotic...
BACKGROUND
Severe deficiency in ADAMTS-13 (<10%) and the loss of von Willebrand factor-cleaving function can precipitate microvascular thrombosis associated with thrombotic thrombocytopenic purpura (TTP). Patients with immune-mediated TTP (iTTP) have anti-ADAMTS-13 immunoglobulin G antibodies that inhibit ADAMTS-13 function and/or increase ADAMTS-13 clearance. Patients with iTTP are treated primarily by plasma exchange (PEX), often in combination with adjunct therapies that target either the von Willebrand factor-dependent microvascular thrombotic processes (caplacizumab) or the autoimmune components (steroids or rituximab) of the disease.
OBJECTIVES
To investigate the contributions of autoantibody-mediated ADAMTS-13 clearance and inhibition in patients with iTTP at presentation and through the course of the PEX therapy.
PATIENTS/METHODS
Anti-ADAMTS-13 immunoglobulin G antibodies, ADAMTS-13 antigen, and activity were measured before and after each PEX in 17 patients with iTTP and 20 acute TTP episodes.
RESULTS
At presentation, 14 out of 15 patients with iTTP had ADAMTS-13 antigen levels of <10%, suggesting a major contribution of ADAMTS-13 clearance to the deficiency state. After the first PEX, both ADAMTS-13 antigen and activity levels increased similarly, and the anti-ADAMTS-13 autoantibody titer decreased in all patients, revealing ADAMTS-13 inhibition to be a modest modifier of the ADAMTS-13 function in iTTP. Analysis of ADAMTS-13 antigen levels between consecutive PEX treatments revealed that the rate of ADAMTS-13 clearance in 9 out of 14 patients analyzed was 4- to 10-fold faster than the estimated normal rate of clearance.
CONCLUSION
These data reveal, both at presentation and during PEX treatment, that antibody-mediated clearance of ADAMTS-13 is the major pathogenic mechanism that causes ADAMTS-13 deficiency in iTTP. Understanding the kinetics of ADAMTS-13 clearance in iTTP may now enable further optimization of treatment of patients with iTTP.
Topics: Humans; Autoantibodies; Purpura, Thrombotic Thrombocytopenic; von Willebrand Factor; Purpura, Thrombocytopenic, Idiopathic; Thrombosis; ADAMTS13 Protein; Immunoglobulin G
PubMed: 36813118
DOI: 10.1016/j.jtha.2023.02.011 -
International Journal of Molecular... Sep 2023Atypical hemolytic uremic syndrome (aHUS) is a rare disease caused by a genetic dysregulation of the alternative complement pathway, characterized by thrombocytopenia,... (Review)
Review
Atypical hemolytic uremic syndrome (aHUS) is a rare disease caused by a genetic dysregulation of the alternative complement pathway, characterized by thrombocytopenia, hemolytic anemia, and acute kidney injury, and included in the group of thrombotic microangiopathies. With the introduction of humanized monoclonal antibodies that inhibit C5 activation, the natural history of aHUS completely changed, with a better prognosis, a quick recovery of renal function, and a significant reduction of end-stage renal disease incidence. Nowadays, there is an increasing interest in the molecular and genetic bases of this severe disease. The aim of this narrative review is to provide readers with a practical guide about different possible involved genes, elucidating the specific role of each transcribed protein in the pathogenesis of aHUS. Moreover, we analyzed the main current evidence about the relationship among genetic mutations, outcomes, and the risk of recurrence of this manifold disease.
Topics: Humans; Atypical Hemolytic Uremic Syndrome; Thrombotic Microangiopathies; Kidney Failure, Chronic; Acute Kidney Injury; Mutation
PubMed: 37833944
DOI: 10.3390/ijms241914496 -
Blood Cancer Journal Jan 2024We describe 1000 patients with essential thrombocythemia seen at the Center Research and Innovation of Myeloproliferative Neoplasms (CRIMM), Florence, Italy, between...
We describe 1000 patients with essential thrombocythemia seen at the Center Research and Innovation of Myeloproliferative Neoplasms (CRIMM), Florence, Italy, between 1980 and 2023: median age 59 years (18-95), females 65%, JAK2/CALR/MPL-mutated 66%/19%/4%, triple-negative (TN) 11%. Extreme thrombocytosis (ExT, platelets ≥1000 × 10/L) in 16%, leukocytosis (leukocytes >11 × 10/L) in 16%, and at least one cardiovascular risk factor in 52% of cases. JAK2-mutated patients were older (median 62 years) and CALR-mutated and TN (53 years for both) younger (p < 0.001). Female gender clustered with TN (76%) and JAK2 (67%) vs CALR (46%) mutations (p < 0.001). ExT clustered with CALR (type-2 more than type-1), TN and MPL, and leukocytosis with JAK2 mutation (p < 0.001). In multivariable analysis, risk factors for arterial thrombosis-free survival were age ≥60 years (HR 2.0; p < 0.001) and JAK2 mutation (HR 1.3; p = 0.02) with borderline significance for male gender (p = 0.08) and cardiovascular risk factors (p = 0.08); for venous thrombosis-free survival, JAK2 mutation (HR 1.9; p = 0.03) with borderline significance for venous thrombosis history (p = 0.07); for overall survival, older age (p < 0.001), male gender (HR 1.9; p < 0.001), absolute neutrophil count (ANC) ≥ 8 × 10/L (HR 1.8; p = 0.01), absolute lymphocyte count (ALC) < 1.7 × 10/L (HR 1.2; p = 0.03); for myelofibrosis-free survival, CALR mutation (HR 2.7; p < 0.001, particularly for CALR type 1/1-like, HR 3.3) and MPL mutation (HR 3.9; p = 0.001); for leukemia-free survival, older age (p = 0.03). Cytoreductive therapy appeared to mitigate both venous (HR 0.3; p = 0.01) and arterial thrombosis (HR 4; p = 0.04); there was a trend for aspirin in preventing arterial thrombosis recurrence. The current study provides real-world observations in essential thrombocythemia, representing a valid source document for interpreting current literature and planning future studies.
Topics: Humans; Male; Female; Middle Aged; Thrombocythemia, Essential; Leukocytosis; Myeloproliferative Disorders; Thrombocytosis; Thrombosis; Mutation; Janus Kinase 2; Calreticulin
PubMed: 38238287
DOI: 10.1038/s41408-023-00968-7 -
British Journal of Haematology Sep 2023Gallo et al. assessed the impact of implementing a clinical decision support tool in a multi-hospital setting. This is one of three important points to unlock the...
Gallo et al. assessed the impact of implementing a clinical decision support tool in a multi-hospital setting. This is one of three important points to unlock the capabilities of the next-generation of diagnostic instruments: (a) integrating diagnostic information from various sources, (b) ensuring accurate development and validation in well-designed clinical studies and (c) seamlessly integrating them into clinical practice. Commentary on: Gallo et al. Clinical decision support to reduce unnecessary diagnostic testing for heparin-induced thrombocytopenia. Br J Haematol 2023;202:1011-1017.
Topics: Humans; Thrombocytopenia; Hematology
PubMed: 37357435
DOI: 10.1111/bjh.18949 -
Blood Advances Oct 2023Complement activation in the diseases paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS) results in cytolysis and fatal thrombotic...
Complement activation in the diseases paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS) results in cytolysis and fatal thrombotic events, which are largely refractory to anticoagulation and/or antiplatelet therapy. Anticomplement therapy, however, efficiently prevents thrombotic events in PNH and aHUS, but the underlying mechanisms remain unresolved. We show that complement-mediated hemolysis in whole blood induces platelet activation similarly to activation by adenosine 5'-diphosphate (ADP). Blockage of C3 or C5 abolished platelet activation. We found that human platelets failed to respond functionally to the anaphylatoxins C3a and C5a. Instead, complement activation did lead to prothrombotic cell activation in the whole blood when membrane attack complex (MAC)-mediated cytolysis occurred. Consequently, we demonstrate that ADP receptor antagonists efficiently inhibited platelet activation, although full complement activation, which causes hemolysis, occurred. By using an established model of mismatched erythrocyte transfusions in rats, we crossvalidated these findings in vivo using the complement inhibitor OmCI and cobra venom factor. Consumptive complement activation in this animal model only led to a thrombotic phenotype when MAC-mediated cytolysis occurred. In conclusion, complement activation only induces substantial prothrombotic cell activation if terminal pathway activation culminates in MAC-mediated release of intracellular ADP. These results explain why anticomplement therapy efficiently prevents thromboembolisms without interfering negatively with hemostasis.
Topics: Humans; Rats; Animals; Complement Membrane Attack Complex; Hemolysis; Erythrocytes; Complement Activation; Blood Platelets; Hemoglobinuria, Paroxysmal; Atypical Hemolytic Uremic Syndrome
PubMed: 37428869
DOI: 10.1182/bloodadvances.2023010817 -
Journal of Feline Medicine and Surgery Jul 2023Thrombocytosis is an uncommon hematologic abnormality that is associated with various physiologic, metabolic, inflammatory and neoplastic conditions in people and dogs....
OBJECTIVES
Thrombocytosis is an uncommon hematologic abnormality that is associated with various physiologic, metabolic, inflammatory and neoplastic conditions in people and dogs. Thrombocytosis is not a well-described abnormality in cats. The objective of this study was to classify thrombocytosis in cats based on underlying disease processes and severity, and to compare this with a control population of cats.
METHODS
A retrospective study was conducted by reviewing the medical records of cats with increased (600 × 10/µl; thrombocytosis group) and normal (200-600 × 10/µl; 2:1 age-matched control group) platelet counts between 2011 and 2018. Platelet counts were estimated based on blood smear assessment in all cats. Cats were classified by the severity (mild, moderate or marked) of thrombocytosis. Diagnoses were recorded for all cases, and were classified broadly into either neoplasia, endocrine or inflammatory disease.
RESULTS
In total, 158 cats were identified with thrombocytosis, with 315 cats in the control group. Non-neoplastic inflammatory disease was the most common diagnosis in both groups (54.4% in cats with thrombocytosis and 56.2% in controls; = 0.77); however, gastrointestinal diseases were more common in cats with thrombocytosis (75.6%) when compared with controls (34.5%; <0.0001). Neoplasia was diagnosed more frequently in cats with thrombocytosis (44.3%) compared with the control group (25.4%; <0.0001). Round cell tumor was the most common neoplasia diagnosis in both groups, but gastrointestinal and multicentric lymphoma were diagnosed more frequently in cats with thrombocytosis compared with control cats. No association between the severity of thrombocytosis and etiology was identified.
CONCLUSIONS AND RELEVANCE
Thrombocytosis in cats is more commonly associated with gastrointestinal, hepatobiliary or immune-mediated diseases when compared with a control population. Neoplasia, especially multicentric and gastrointestinal lymphoma, was more commonly diagnosed in cats with thrombocytosis when compared with control cats.
Topics: Cats; Animals; Dogs; Retrospective Studies; Thrombocytosis; Platelet Count; Sarcoma; Cat Diseases; Dog Diseases
PubMed: 37470518
DOI: 10.1177/1098612X231185680 -
Nature Communications Jun 2023Loss of NBEAL2 function leads to grey platelet syndrome (GPS), a bleeding disorder characterized by macro-thrombocytopenia and α-granule-deficient platelets. A...
Loss of NBEAL2 function leads to grey platelet syndrome (GPS), a bleeding disorder characterized by macro-thrombocytopenia and α-granule-deficient platelets. A proportion of patients with GPS develop autoimmunity through an unknown mechanism, which might be related to the proteins NBEAL2 interacts with, specifically in immune cells. Here we show a comprehensive interactome of NBEAL2 in primary T cells, based on mass spectrometry identification of altogether 74 protein association partners. These include LRBA, a member of the same BEACH domain family as NBEAL2, recessive mutations of which cause autoimmunity and lymphocytic infiltration through defective CTLA-4 trafficking. Investigating the potential association between NBEAL2 and CTLA-4 signalling suggested by the mass spectrometry results, we confirm by co-immunoprecipitation that CTLA-4 and NBEAL2 interact with each other. Interestingly, NBEAL2 deficiency leads to low CTLA-4 expression in patient-derived effector T cells, while their regulatory T cells appear unaffected. Knocking-down NBEAL2 in healthy primary T cells recapitulates the low CTLA-4 expression observed in the T cells of GPS patients. Our results thus show that NBEAL2 is involved in the regulation of CTLA-4 expression in conventional T cells and provide a rationale for considering CTLA-4-immunoglobulin therapy in patients with GPS and autoimmune disease.
Topics: Humans; Adaptor Proteins, Signal Transducing; Blood Platelets; Blood Proteins; CTLA-4 Antigen; Gray Platelet Syndrome
PubMed: 37349339
DOI: 10.1038/s41467-023-39295-7