Background Thrombotic thrombocytopenic purpura is a potentially fatal disease characterized by widespread platelet thrombi in the microcirculation.
In the normal circulation, von Willebrand factor is cleaved by a plasma protease.
We explored the hypothesis that a deficiency of this protease predisposes patients with thrombotic thrombocytopenic purpura to platelet thrombosis.
Methods We studied the activity of von Willebrand factor-cleaving protease and sought inhibitors of this protease in plasma from patients with acute thrombotic thrombocytopenic purpura, patients with other diseases, and normal control subjects.
We also investigated the effect of shear stress on the ristocetin cofactor activity of purified von Willebrand factor in the cryosupernatant fraction of the plasma samples.
Results Thirty-nine samples of plasma from 37 patients with acute thrombotic thrombocytopenic purpura had severe deficiency of von Willebrand factor-cleaving protease.
No deficiency was detected in 16 samples of plasma from patients with thrombotic thrombocytopenic purpura in remission or in 74 plasma samples from normal subjects, randomly selected hospitalized patients or outpatients, or patients with hemolysis, thrombocytopenia, or thrombosis from other causes.
Inhibitory activity against the protease was detected in 26 of the 39 plasma samples (67 percent) obtained during the acute phase of the disease.
The inhibitors were IgG antibodies. (...)
Mots-clés Pascal : Purpura thrombocytopénique thrombotique, Déficit, Inhibiteur enzyme, Facteur Willebrand, Clivage, Peptidases, Hydrolases, Enzyme, Thrombose, Aigu, Immunoglobuline, Anticorps, Immunoélectrophorèse, Traitement, Etude statistique, Etude comparative, Enfant, Homme, Adulte, Thrombocyte, Hémopathie, Anémie hémolytique, Système nerveux pathologie, Appareil urinaire pathologie, Capillaire sanguin pathologie, Peau pathologie, Vaisseau sanguin peau pathologie, Appareil circulatoire pathologie, Vaisseau sanguin pathologie, Etiopathogénie, Immunopathologie, Biologie clinique
Mots-clés Pascal anglais : Thrombotic thrombocytopenic purpura, Deficiency, Enzyme inhibitor, Willebrand factor, Cleavage, Peptidases, Hydrolases, Enzyme, Thrombosis, Acute, Immunoglobulins, Antibody, Immunoelectrophoresis, Treatment, Statistical study, Comparative study, Child, Human, Adult, Platelet, Hemopathy, Hemolytic anemia, Nervous system diseases, Urinary system disease, Capillary vessel disease, Skin disease, Vascular disorders of the skin, Cardiovascular disease, Vascular disease, Etiopathogenesis, Immunopathology, Clinical biology
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0071891
Code Inist : 002B19C. Création : 31/05/1999.