A 37-year-old female patient has a PTT of 76 seconds (reference range,25 to 37 seconds).Her plasma is mixed 1:1 with normal plasma.An immediate PTT performed on the mix is 74 seconds.Which of the following is the most likely diagnosis?

Question

Quizplus · Accepted Answer

A prolonged PTT that remains prolonged after an immediate repeat of the PTT on the 1:1 mix is seen in patients (either male or female subject)with the lupus anticoagulant.A patient with hemophilia A would most likely be a male subject (female hemophilia A is rare).In addition,the immediate 1:1 mix should correct,as it also would with an intrinsic factor deficiency.The PTT on an immediate 1:1 mix in the presence of a factor VIII inhibitor would also essentially correct.

A 37-Year-Old Female Patient Has a PTT of 76 Seconds