Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0409974 (lupus)
 22,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Platelet activation has been suggested to play a crucial role in the pathogenesis of haemostatic disorders in antiphospholipid syndrome (APS). In 16 patients with primary APS (PAPS) we investigated by flow cytometry the presence of circulating activated platelets as defined by the surface expression of activation-dependent glycoproteins CD62 and CD63. In addition, the relationships among activated platelets, thrombocytopenia, antiphospholipid antibodies (aPL) and platelet associated IgG (PalgG) were evaluated. Compared to normal subjects CD62, but not CD63 expression, was found significantly increased in patients. All thrombocytopenic subjects showed a percentage of CD62 expressing platelets above the cut off. In thrombocytopenics a significantly increased percentage of CD62 and higher levels of aCL IgG were found compared to PAPS patients with normal platelet count. No correlation was found between activated platelets and both lupus anticoagulant antibodies and PalgG. Our data demonstrate that circulating activated platelets are detectable by flow cytometry in the majority of PAPS patients and suggest the existence of a relationship among activated platelets, thrombocytopenia and aPL levels.
Lupus 1997
PMID:Flow cytometric detection of circulating activated platelets in primary antiphospholipid syndrome. Correlation with thrombocytopenia and anticardiolipin antibodies. 910 34

Thromboembolism is a common occurrence in patients with the antiphospholipid syndrome (APS). The mechanism responsible for this phenomenon is unclear; there are several theories. One possibility is that a pathogenic interaction exists between antiphospholipid antibodies and platelets, leading to their activation. This study examined the expression of the platelet activation markers CD62 and CD63 by flow cytometry in 20 patients with the primary antiphospholipid syndrome (PAPS). Levels of soluble P-selectin were also assayed. Reticulated platelets were measured as an indicator of increased platelet production and/or turnover. Median CD63 expression was significantly increased in patients (14.3%) compared to a group of healthy controls (10.1%, P = 0.0008). There was no significant difference in median CD62 expression or percent reticulated platelets between the two groups. The median level of soluble P-selectin was significantly higher in PAPS patients (35.5 ng/ml) compared to controls (18.8 ng/ml, P = 0.0028). Patients receiving aspirin had lower median CD63 values (13.1%) when compared to those patients who were not (18.0%, P = 0.023). However, aspirin therapy did not prevent significant platelet activation occurring in some individual patients. Our data suggest that although not excessive, there is a degree of increased platelet activation in some PAPS patients, which is not always suppressed by antiplatelet therapy with aspirin.
Lupus 1998
PMID:Platelet activation and turnover in the primary antiphospholipid syndrome. 969 37

Platelets play an important part in normal haemostasis, and are likely to be involved in the thromboembolism seen in the primary antiphospholipid syndrome (PAPS). Evidence exists for platelet activation in this disorder, and new flow cytometric techniques have made it possible to detect low levels of activation. We have previously studied the expression of the platelet activation markers CD62p and CD63, percentage of reticulated platelets, and levels of soluble P-selectin in a group of PAPS patients. Median platelet CD63 expression and plasma soluble P-selectin levels were significantly increased in PAPS patients compared to a group of controls; there was no difference in reticulated platelet percentages between the two groups. Additional assays of platelet activation (PAC-1 expression, Annexin V binding, platelet microparticles and complexes) are being developed and assessed with respect to disease activity, thrombosis risk and effects of antithrombotic therapy.
Lupus 1998
PMID:Platelet activation markers and the primary antiphospholipid syndrome (PAPS). 981 73