Silica clotting time (SCT) as a screening and confirmatory test for detection of the lupus anticoagulants.
We have developed a Silica Clotting Time (SCT) test suitable to screen patients with lupus anticoagulants (LA) and compatible with photo-optical instruments. The SCT results were considered to be positive for LA whenever the clotting times were longer than the upper normal limit at low phospholipid concentration and to be confirmed when the prolonged clotting times were corrected to normal by high phospholipid concentration. We studied plasmas from healthy subjects, patients with known diagnoses of LA, patients with acquired deficiencies of blood coagulation and hemophiliacs with anti-factor VIII antibodies. The test was positive for all LA patients, and negative for all non-LA patients except 7 hemophiliacs with anti-factor VIII antibodies. Our data indicate that the SCT is a sensitive test, suitable for screening patients suspected of having LA. Its compatibility with photo-optical instruments makes it a suitable candidate to replace the kaolin clotting time. The contemporaneous performance of SCT at low and high phospholipid concentrations provides screening and confirmation in a single procedure.
Chantarangkul
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A. Bianchi Bonomi Hemophilia and Thrombosis Center, University, Milano, Italy.
Tripodi
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Arbini
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Mannucci
P M
PM
D000925:Anticoagulants / Q000494:pharmacology; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001778:Blood Coagulation Disorders / Q000097:blood; D001780:Blood Coagulation Tests / Q000295:instrumentation / Q000379:methods*; D005169:Factor VIII / Q000276:immunology; D006467:Hemophilia A / Q000097:blood; D006801:Humans; D007616:Kaolin; D008103:Liver Cirrhosis / Q000097:blood; D016682:Lupus Coagulation Inhibitor / Q000032:analysis*; D008403:Mass Screening / Q000379:methods*; D010743:Phospholipids / Q000097:blood; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide
D000925:Anticoagulants; D001323:Autoantibodies; D016682:Lupus Coagulation Inhibitor; D010743:Phospholipids; D007616:Kaolin; D012822:Silicon Dioxide; D005169:Factor VIII