Interpret the following results: PT: 11.8 sec (RR: 11.2-13.8 sec)
INR: 1.07
APTT: 57 sec (RR: 23-32 sec)
Closure time: increased
Ristocetin aggregation: decreased aggregation
Based on this information, what is the most likely disorder?
A) Hemophilia A
B) Bernard-Soulier syndrome
C) DIC
D) von Willebrand's disease

Question

Quizplus · Accepted Answer

- PT (prothrombin time) is within normal range, which rules out factors associated with hemophilia A or DIC.
- APTT (activated partial thromboplastin time) is significantly prolonged beyond the reference range, which suggests a clotting factor deficiency or inhibition. However, the INR (international normalized ratio) is normal, which rules out vitamin K deficiency or warfarin therapy.
- The closure time is prolonged, which indicates impaired platelet function.
- Ristocetin aggregation test is decreased, indicating a defect in von Willebrand factor. 
All of these findings are consistent with von Willebrand's disease.

Interpret the Following Results: PT: 11