title: Prolonged bleeding time in patients with lupus anticoagulant.
abstract: Platelet adhesion to collagen under flow conditions was studied in 18 patients with lupus anticoagulant, seven of which showed a prolonged bleeding time in the presence of a normal platelet count. The effect of patient plasma, IgG and purified anticardiolipin antibodies on platelet adhesion was also examined. We found a significant reduction of platelet adhesion in patients with lupus anticoagulant, which was more evident in patients with prolonged bleeding time. This platelet adhesion defect could be attributed to a plasma factor. In fact, patients' platelets regained normal adhesion when mixed with normal plasma, whereas controls' platelets showed abnormal adhesion in the presence of patient plasma. A causative role of antiphospholipid antibodies was demonstrated in experiments using purified immunoglobulins and anticardiolipin antibodies.
authors.affiliation: Department of Hematology, Ospedali Riuniti di Bergamo, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Orlando
authors.forename: S
authors.initials: S
authors.lastname: Cortelazzo
authors.forename: M
authors.initials: M
authors.lastname: Marchetti
authors.forename: R
authors.initials: R
authors.lastname: Sanfratello
authors.forename: T
authors.initials: T
authors.lastname: Barbui
mesh_terms: D000328:Adult; D000368:Aged; D017153:Antibodies, Anticardiolipin / Q000097:blood; D001760:Bleeding Time; D005260:Female; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D066298:In Vitro Techniques; D016682:Lupus Coagulation Inhibitor / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010973:Platelet Adhesiveness
chemical_list: D017153:Antibodies, Anticardiolipin; D007074:Immunoglobulin G; D016682:Lupus Coagulation Inhibitor