Microvesicles in haemoglobinopathies offer insights into mechanisms of hypercoagulability, haemolysis and the effects of therapy.

Levels of circulating red blood cell (RBC)-derived vesicles are increased in sickle cell anaemia (SCA) and thalassaemia intermedia (TI) but the mechanisms, effects and controlling factors may differ. This study found that levels of vesicles and intravascular haemolysis were linked as shown by the correlation between levels of vesicles and plasma Hb. Vesicle levels were 6-fold greater in SCA and 4-fold greater in TI than in controls.

The clinical utility of ADAMTS13 activity, antigen and autoantibody assays in thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) has been linked to a severe deficiency in ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 motif, member 13) activity. Since the identification of ADAMTS13, and its target cleavage sequence in von Willebrand factor (VWF), several novel ADAMTS13 activity, antigen and autoantibody assays have been developed. Our aim was to evaluate the potential use of these novel assays.

Assessment of the antiplatelet effects of low to medium dose aspirin in the early and late phases after ischaemic stroke and TIA.

Vascular events commonly recur in stroke patients on aspirin, and may reflect incomplete inhibition of platelet function with aspirin therapy. The platelet function analyser (PFA-100) activates platelets by aspirating a blood sample at a moderately high shear rate through a capillary to a biologically active membrane with a central aperture. The membrane is coated with collagen, and either ADP (C-ADP) or epinephrine (C-EPI).

Platelet degranulation and monocyte-platelet complex formation are increased in the acute and convalescent phases after ischaemic stroke or transient ischaemic attack.

Flow cytometric studies suggest that platelets are activated in ischaemic stroke or transient ischaemic attack (TIA). However, few studies have measured circulating leucocyte-platelet complexes in this patient population. Whole blood flow cytometry was used to quantify the expression of CD62P-, CD63-, and PAC1-binding, and the percentages of leucocyte-platelet complexes in acute (1-27 d, n = 79) and convalescent (79-725 d, n = 70) ischaemic cerebrovascular disease (CVD) patients compared with controls without CVD (n = 27).

A multicentre assessment of the endogenous thrombin potential using a continuous monitoring amidolytic technique.

This study assessed the inter-laboratory imprecision associated with the measurement of the endogenous thrombin potential (ETP). The initial studies used techniques that had evolved in each of the participating laboratories. Samples from normal healthy subjects (n = 10), two patients receiving coumarin therapy [International Normalized Ratio approximately 2.

Tissue factor pathway inhibitor antigen and activity in 96 patients receiving heparin for cardiopulmonary bypass.

Objective: To identify patients with poor tissue factor pathway inhibitor (TFPI) response to heparin and observe any association with increased risk of excessive coagulation activation, morbidity, or mortality.

Design: Prospective, observational cohort study.

Setting: University hospital.