Real-life experience of edoxaban treatment for venous thromboembolism (VTE)/pulmonary embolism (PE) in patients with isolated positive Lupus Anticoagulant (LAC) during the COVID-19 pandemic lockdown in Italy.

OBJECTIVE: Direct-acting oral anticoagulants (DOACs) have established indications, according to recent guidelines for the treatment and prevention of venous thromboembolism (VTE), including pulmonary embolism (PE), with a safer profile compared to vitamin K antagonist (VKA) in terms of a lower risk for major bleeding and no need of blood coagulation tests. However, DOACs are not indicated in the treatment of patients with triple-positive antiphospholipid syndrome (APS). This limitation is often extended in clinical practice to patients with isolated positivity. The COVID-19 pandemic has sometimes made it difficult to maintain a safe VKA treatment, due to the practical difficulties of performing INR. PATIENTS AND METHODS: We evaluated 39 patients with a previous unprovoked VTE/PE, who were no longer eligible for VKA treatment due to the difficulty of performing INR during the COVID-19 pandemic lockdown, in Italy. All patients had a positive LAC and refused a long-term anticoagulation with low molecular weight heparin. They were shifted to edoxaban. RESULTS: Any recurrence of VTE/PE occurred during the observation period (up to eight months of treatment), while only one minor bleeding event was recorded (Hazard ratio=0.06, 95% confidence interval 0.03-0.11, p=0.094). No arterial events occurred during the observation period. Hemoglobin, platelets, and creatinine were unchanged during the observation period. CONCLUSIONS: Edoxaban treatment may be safe and effective in preventing the recurrence of VTE/PE in patients with isolated LAC positivity, without the occurrence of arterial events.

The detection of anti-beta2-glycoprotein I antibodies is associated with increased risk of pregnancy loss in women with threatened abortion in the first trimester.

OBJECTIVE: This study was designed to evaluate whether the detection of serum antiphospholipid autoantibodies may be useful in predicting pregnancy outcome in women with threatened abortion in the first trimester. STUDY DESIGN: A group of 77 pregnant women of between 8 and 12 weeks' gestation with vaginal bleeding was tested for serum antiphospholipid, lupus anticoagulants, anticardiolipin, antinuclear antibodies, and anti-beta2-glycoprotein I antibodies, and was followed up until the spontaneous end of pregnancy. A control group composed of 15 healthy women with uncomplicated gestation was tested contemporarily for the same antibody panel. RESULTS: Of the 77 patients with threatened abortion, 32 (41.5%) progressed to deliver at term and 45 (58.5%) experienced early pregnancy loss. Among the antibodies evaluated, only anti-beta2-glycoprotein I was significantly more frequent in those women whose pregnancy resulted in spontaneous abortion (22/45, 49%) than in those who progressed to term (6/32, 19%) or in the control group (2/15, 13%; p=0.004). This difference was specific to the IgM isotype (p=0.001). After adjustment by multivariate analysis, the odds ratio for pregnancy loss associated with a positive beta2-glycoprotein I antibody test was 5.18 (p=0.001). CONCLUSION: The detection of anti-beta2-glycoprotein I antibodies is associated with an increased risk of pregnancy loss in women with threatened abortion in the first trimester.

Correlation between left atrial size, prothrombotic state and markers of endothelial dysfunction in patients with lone chronic nonrheumatic atrial fibrillation.

Atrial fibrillation is associated with a prothrombotic state and endothelial dysfunction. To understand whether the prothrombotic state was correlated with endothelial dysfunction and whether the latter was related to atrial dimension (endocardial damage), we studied systemic hemocoagulative activity and markers of endothelial dysfunction in 45 patients with chronic nonrheumatic atrial fibrillation and in 35 controls. We assessed fibrinogen, antithrombin III, protein C, markers of platelet activation (platelet factor 4 and beta-thromboglobulin) as markers of fibrinolysis, and D-dimer, tissue plasminogen activator, plasminogen activator inhibitor, von Willebrand's factor and soluble thrombomodulin as endothelial dysfunction. Plasma fibrinogen (P<0. 005), platelet factor 4 (P<0.001), thromboglobulin (P<0.001), D-dimer (P<0.03), tissue plasminogen activator (P<0.006), plasminogen activator inhibitor (P<0.04) and both von Willebrand's factor (P<0.0001) and soluble thrombomodulin (P<0.03) were significantly higher in the patients than in the controls. Positive significant linear correlations were found between fibrinogen and markers of endothelial dysfunction and left atrial volume and fibrinogen or markers of endothelial dysfunction. These findings confirm that chronic nonrheumatic atrial fibrillation is associated with a prothrombotic state but also suggest that there is a correlation between endothelial dysfunction, coagulation factors and left atrial dimension.

Different glycoforms of the human GPI-anchored antigen CD52 associate differently with lipid microdomains in leukocytes and sperm membranes.

CD52 is a human GPI-anchored antigen, expressed exclusively in the immune system and part of the reproductive system (epididymal cells). Sperm cells acquire the antigen from the epididymal secretions when transiting in the epididymal corpus and cauda. The peptide backbone of CD52, consisting of only 12 aminoacids, is generally considered no more than a scaffold for post-translational modifications, such as GPI-anchor and especially N-glycosylation which occur at the third asparagine. The latter modification is highly heterogeneous, especially in the reproductive system, giving rise to many different glycoforms, some of which are tissue specific. A peculiar O-glycan-containing glycoform is also found in reproductive and immune systems. We determined to locate CD52 in microdomains of leukocytes and sperm membranes using two antibodies: (1) CAMPATH-1G, the epitope of which includes the last three aminoacids and part of the GPI-anchor of glycoforms present in leukocytes and sperm cells; (2) anti-gp20, the epitope of which belongs to the unique O-glycan-bearing glycoform also present in both cell types. Using a Brij 98 solubilization protocol and sucrose gradient partition we demonstrated that the CD52 glycoforms recognized by both antibodies are markers of typical raft microdomains in leukocytes, whereas in capacitated sperm the O-glycoform is included in GM3-rich microdomains different from the cholesterol and GM1-rich lipid rafts with which CAMPATH antigen is stably associated. The importance of the association between GM3 and O-glycans for formation of specialized microdomains was confirmed by heterologous CD52 insertion experiments. When prostasomes from human seminal fluid were incubated with rat sperm from different epididymal regions, the CD52 glycoform recognized by anti-gp20 decorated rat epididymal corpus and cauda sperm, associated with the same low-cholesterol GM3-rich sperm membrane fractions as in human sperm. The glycoforms recognized by CAMPATH-1G were not found in rat sperm. The relationship between this differential insertion and differences in glycosylation of rat and human CD52 is discussed.