In this in vitro study, the type of reference standard had a major impact on the measurement of BAX 855 activity. Evaluation was more accurate and precise when using a product-specific reference standard.

SummaryLittle is known on the haemostatic profiles of human microvascular endothelial cells (MVEC) from different tissues. In addition it is not known whether MVEC from patients display the same haemostatic pattern as MVEC coming from healthy controls. To address these questions MVEC from human lung and brain were isolated and stimulated with tumour necrosis factor α (TNF) and E. coli lipopolysaccharide (LPS) for 24 h. The level and the kinetics of procoagulant activity (PCA) and thrombomodulin (TM) expression were found to be different depending on the tissue of origin and on the agonist used. In particular, the inducible PCA was higher in lung than in brain MVEC, an observation that may be related to the frequency of lung involvement in septic shock. Differences were also observed for tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) with MVEC supernatants or cell lysates. These variables were then measured in lung MVEC purified from patients with acute respiratory distress syndrome (ARDS) and compared to controls. Cells from ARDS patients constitutively expressed more PCA and PAI-1 than controls. The fibrinolytic potential, expressed as t-PA/PAI-1 ratio, was lower in ARDS than in lung MVEC. It is concluded that MVEC display different haemostatic features depending on the tissue they come from and that lung MVEC from ARDS patients present a procoagulant profile when compared with those from controls.

Cases of passive alloimmune thrombocytopenia have been reported due to transfusions of blood products with antiplatelet antibodies. The aim of our study was to search for antiplatelet antibodies in HPA-homozygous blood donor women once pregnant and also to perform, in case of positivity, a retrospective analysis of platelet counts of the recipients of their blood products. HPA-1, -2, -3 and -5 genotyping were performed on 500 platelet donors (42% women). Circulating antiplatelet antibodies were screened for by MAIPA assay in 122 women who experienced at least one pregnancy and who were homozygous for either HPA-1a, -1b, -3a, -3b, -5a or -5b. None of the women homozygous for HPA-1 or -3 had circulating antiplatelet antibodies. In contrast, two of the 98 women homozygous for HPA-5a and one of the two women homozygous for HPA-5b had circulating antibodies. A retrospective analysis of the medical charts of the 37 recipients of 55 blood components from these three women showed no case of passive alloimmune thrombocytopenia. Our study indicates the presence of platelet-specific antibodies in 2.5% of HPA-homozygous female platelet donors who were previously pregnant. Although none of the recipients developed passive alloimmune thrombocytopenia, this aspect of blood transfusion safety should be addressed by a large prospective trial.

No abstract

No abstract