Can anti-cardiolipin or anti-beta-2 glycoprotein antibodies cause prolonged PTT in the absence of a lupus anticoagulant?
Labs with normal PT, but prolonged PTT (47 sec; ULN 40 sec) that does not correct on immediate mix. Lupus anticoagulant negative (DRVVT and hexagonal phase), but anti-cardiolipin and anti-beta-2 glycoprotein IgM titers are extremely high, above quantitative levels. Factor VIII, IX, XI, and XII levels are normal, and the vWD panel is normal. No bleeding or clotting episodes.
1 Answer
Mednet MemberInvited Expert
Hematology · University of Wisconsin
Answered on
Lupus anticoagulants are a heterogeneous group of antibodies that do not have uniform activity in all assays. Furthermore, testing procedures are not well-standardized. Since relevant clotting factor deficiencies have been ruled out and the long PTT does not correct with mixing, and since there is o...
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