Hemostasis and platelet aggregation in purpuric pigmented angiodermatitis eruptions
1Department of Dermatology, Hospital de Clinicas Dr. Manuel Quintela, Montevideo, Uruguay.
Abstract:
Ten patients with chronic purpuric and pigmented angiodermatitis in the extremities and two patients with acute and disseminated eczematoid-like purpura angiodermatitis were studied with current hemostasis parameters: (1) platelet aggregation, (2) platelet circulating aggregates, (3) clotting factor measurements and high molecular weight kininogen (HMWK) in their coagulation fraction. The results showed: (1) reactional thrombocytosis with morphologic changes; (2) increased levels of platelet circulating aggregates; (3) increased response of platelet aggregation to different agonists, especially at very low doses, and also when we used washed platelets resuspended in normal plasma; (4) delayed activation of the contact system; (5) decrease of the activity of the fibrinolysis activators; and (6) diminished function activity of the HMWK coagulation fraction. As a physiopathogenic hypothesis in these patients, there is a cutaneous pathology that could be entailed to these hematologic alterations of the platelet-HMWK-endothelial cells-kinins-coagulation-fibrinolysis system.
More Related Videos
09:13Turbidimetry on Human Washed Platelets: The Effect of the Pannexin1-inhibitor Brilliant Blue FCF on Collagen-induced Aggregation
Published on: April 6, 2017
04:37Comprehensive Analysis of Procoagulant Platelets Exhibiting Features of Necrosis, Apoptosis and Platelet Activation
Published on: May 23, 2025
Related Concept Videos
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Introduction to Hemostasis
The three phases of hemostasis involve many clotting factors present in plasma and several substances released by platelets and injured tissue cells. It is a fast, localized, and...
Formation of the Platelet Plug
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
Extrinsic and Intrinsic Pathways of Hemostasis
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which forms a...
Clot Retraction and Fibrinolysis
Disorders of Hemostasis
Thromboembolic Disorders
Two factors primarily cause thromboembolic conditions.
