Thromb Haemost 1992; 68(05): 495-499
DOI: 10.1055/s-0038-1646306
Original Article
Schattauer GmbH Stuttgart

Prolonged Bleeding Time in Patients with Lupus Anticoagulant

E Orlando
The Department of Hematology, Ospedali Riuniti di Bergamo, Bergamo, Italy
,
S Cortelazzo
The Department of Hematology, Ospedali Riuniti di Bergamo, Bergamo, Italy
,
M Marchetti
The Department of Hematology, Ospedali Riuniti di Bergamo, Bergamo, Italy
,
R Sanfratello
The Department of Hematology, Ospedali Riuniti di Bergamo, Bergamo, Italy
,
T Barbui
The Department of Hematology, Ospedali Riuniti di Bergamo, Bergamo, Italy
› Author Affiliations
Further Information

Publication History

Received 23 January 1992

Accepted after revision 10 June 1992

Publication Date:
04 July 2018 (online)

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Summary

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.