Author Question: What is used to activate protein C in the chromogenic assay used to determine its concentration? ... (Read 36 times)

ericka1 · **on:** Jun 25, 2018

What is used to activate protein C in the chromogenic assay used to determine its concentration?

a. Partial thromboplastin
b. A specific snake venom
c. Kaolin
d. Heparin

Question 2

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?

a. Hemophilia A
b. Factor VIII inhibitor
c. Intrinsic factor deficiency
d. Lupus anticoagulant

bubulittle310@msn.cn · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

ANS: B
A specific snake venom is used to activate protein C in its chromogenic assay.

Answer to Question 2

ANS: D
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.