aPTT
mixing studies - 2
Must first have a prolonged aPTT
Procedure:
If aPTT is corrected
(time shortened):
Normal plasma added with patient
plasma and aPTT repeated using normal 3 minute incubation
Factor deficiency ?
If aPTT is not
corrected (time same):
High-phospholipid reagent + pt
plasma
aPTT repeated with 3 min incubation
aPTT normal = lupus anticoagulant
Normal plasma + pt plasma
aPTT with 1-2 hr incubation
aPTT normal = anti-factor (VIII?)
aPTT abnormal = lupus
anticoagulant ?
Bethesda titer done
confirmation
confirmation