Deficiency in mouse hyaluronidase 2: a new mechanism of chronic thrombotic microangiopathy.
; ; et al
in Haematologica (2015)
Hyaluronan is a major component of the extracellular matrix and glycocalyx. Its main somatic degrading enzymes are the hyaluronidases 1 and 2, none of which is active in the bloodstream. We generated ... [more ▼]
Hyaluronan is a major component of the extracellular matrix and glycocalyx. Its main somatic degrading enzymes are the hyaluronidases 1 and 2, none of which is active in the bloodstream. We generated hyaluronidase 2 deficient mice. They suffer from mild chronic anemia and thrombocytopenia, in parallel with a 10-fold increase in plasma hyaluronan concentration. The current study explores the mechanism of these hematological anomalies. The decreased erythrocyte and platelet counts were assigned to peripheral consumption. The erythrocyte half-life was reduced from 25 to 8 days without signs of premature aging. Hyaluronidase 2 deficient platelets were functional. Major intrinsic defects in erythrocyte membrane or stability, as well as detrimental effects of high hyaluronan levels on erythrocytes, were ruled out in vitro. Normal erythrocytes transfused into hyaluronidase 2 deficient mice were quickly destroyed but neither splenectomy nor anti-C5 administration prevented from chronic hemolysis. Schistocytes were present in hyaluronidase 2 deficient smears at a level of 1 to 6%, while virtually absent in control mice. Hyaluronidase 2 deficient mice had increased markers of endothelial damage and microvascular fibrin deposition, without renal failure, accumulation of ultra-large multimers of von Willebrand factor, deficiency of A Disintegrin And Metalloproteinase with ThromboSpondin type 1 motifs, member 13 (ADAMTS13), or hypertension. There was no sign of structural damage in hepatic or splenic sinusoids, or in any other microvessels. We conclude that hyaluronidase 2 deficiency induces chronic thrombotic microangiopathy with hemolytic anemia in mice. The link between this uncommon condition and hyaluronidase 2 remains to be explored in man. [less ▲]Detailed reference viewed: 25 (8 ULg)
Dabigatran Etexilate and Risk of Myocardial Infarction, Other Cardiovascular Events, Major Bleeding, and All-Cause Mortality: A Systematic Review and Meta-analysis of Randomized Controlled Trials.
; Buckinx, Fanny ; et al
in Journal of the American Heart Association (2014), 3(3), 000515
BACKGROUND: Signals of an increased risk of myocardial infarction (MI) have been identified with dabigatran etexilate in randomized controlled trials (RCTs). METHODS AND RESULES: We conducted searches of ... [more ▼]
BACKGROUND: Signals of an increased risk of myocardial infarction (MI) have been identified with dabigatran etexilate in randomized controlled trials (RCTs). METHODS AND RESULES: We conducted searches of the published literature and a clinical trials registry maintained by the drug manufacturer. Criteria for inclusion in our meta-analysis included all RCTs and the availability of outcome data for MI, other cardiovascular events, major bleeding, and all-cause mortality. Among the 501 unique references identified, 14 RCTs fulfilled the inclusion criteria. Stratification analyses by comparators and doses of dabigatran etexilate were conducted. Peto odds ratio (ORPETO) values using the fixed-effect model (FEM) for MI, other cardiovascular events, major bleeding, and all-cause mortality were 1.34 (95% CI 1.08 to 1.65, P=0.007), 0.93 (95%CI 0.83 to 1.06, P=0.270), 0.88 (95% CI 0.79 to 0.99, P=0.029), and 0.89 (95% CI 0.80 to 1.00, P=0.041). When compared with warfarin, ORPETO values using FEM were 1.41 (95% CI 1.11 to 1.80, P=0.005), 0.94 (95%CI 0.83 to 1.06, P=0.293), 0.85 (95% CI 0.76 to 0.96, P=0.007), and 0.90 (95% CI 0.81 to 1.01, P=0.061), respectively. In RCTs using the 150-mg BID dosage, the ORPETO values using FEM were 1.45 (95% CI 1.11 to 1.91, P=0.007), 0.95 (95% CI 0.82 to 1.09, P=0.423), 0.92 (95% CI 0.81 to 1.05, P=0.228), and 0.88 (95% CI 0.78 to 1.00, P=0.045), respectively. The results of the 110-mg BID dosage were mainly driven by the RE-LY trial. CONCLUSIONS: This meta-analysis provides evidence that dabigatran etexilate is associated with a significantly increased risk of MI. This increased risk should be considered taking into account the overall benefit in terms of major bleeding and all-cause mortality. [less ▲]Detailed reference viewed: 63 (33 ULg)
Morphology, cytogenetics, and survival in myelodysplasia with del(20q) or ider(20q): a multicenter study.
; ; et al
in Annals of Hematology (2012), 91(2), 203-13
Isochromosome of the long arm of chromosome 20 with interstitial loss of material [ider(20q)] is a rare cytogenetic abnormality reported in myelodysplastic syndrome (MDS), with neither specific ... [more ▼]
Isochromosome of the long arm of chromosome 20 with interstitial loss of material [ider(20q)] is a rare cytogenetic abnormality reported in myelodysplastic syndrome (MDS), with neither specific morphological pattern nor clear prognostic significance. The aim of this retrospective multicentric study is to compare the peripheral blood and bone marrow morphology of MDS patients with ider(20q) (n = 13) and del(20q) (n = 21) and controls (n = 47) in order to investigate whether the ider(20q) harbors specific morphological features. The secondary objective is to compare the outcome of patients from both groups. This study performed on the largest cohort of MDS patients with ider(20q) is the first that identifies specific morphological features (hypogranulated and vacuolized neutrophils and neutrophil erythrophagocytosis) allowing the identification of this cytogenetic abnormality with high sensitivity (70%) and specificity (85.7%). Suspected ider(20q) by morphology should therefore support targeted FISH tests in case of non informative karyotype. This combined approach will allow a better estimation of the prevalence of this underdiagnozed entity. The overall survival and progression-free survival did not statistically differ in both groups. However, hypogranulated and vacuolized neutrophils were significantly associated with survival. [less ▲]Detailed reference viewed: 24 (4 ULg)
BM-573 INHIBITS THE EARLY ATHEROSCLEROTIC LESIONS IN APO-E DEFICIENT MICE BY BLOCKING TP RECEPTORS AND THROMBOXANE SYNTHASE
Cherdon, Céline ; ; Hanson, Julien et al
in Congress of the International Society of Thrombosis and Hemostasis- 57th Annual SSC Meeting (2011, July)
Atherosclerosis is the principal cause of mortality in industrialized countries. Its development is influenced by several mediators of which thromboxane A(2) (TXA(2)) and 8-iso-PGF(2() have recently ... [more ▼]
Atherosclerosis is the principal cause of mortality in industrialized countries. Its development is influenced by several mediators of which thromboxane A(2) (TXA(2)) and 8-iso-PGF(2() have recently received a lot of attention. This study aimed to investigate the effect of a dual thromboxane synthase inhibitor and thromboxane receptor antagonist (BM-573) and ASA on lesion formation in apolipoprotein E-deficient mice. The combination of ASA and BM-573 was also studied. Plasma measurements demonstrated that the treatments did not affect body weight or plasma cholesterol levels. BM-573, but not ASA, significantly decreased atherogenic lesions as demonstrated by macroscopic analysis. Both treatments alone inhibited TXB(2) synthesis but only BM-573 and the combination therapy were able to decrease firstly, plasma levels of soluble intracellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) and secondly, the expression of these proteins in the aortic root of Apo E. These results were confirmed in endothelial cell cultures derived from human saphenous vein endothelial cells (HSVECs). In these cells, BM-573 also prevented the increased mRNA expression of ICAM-1 and VCAM-1 induced by U-46619 and 8-iso-PGF(2(). Our results show that a molecule combining receptor antagonism and thromboxane synthase inhibition is more efficient in delaying atherosclerosis in Apo E(-/-) mice than sole inhibition of TXA(2) formation. [less ▲]Detailed reference viewed: 79 (14 ULg)