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Old 04-20-2014
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Question Coagulation question

Given only the following coagulation lab results, which is possible? And what test should you do next?

7 year old girl fell off her bicycle and is bleeding profusely from a knee laceration.

Lab results:
Platelet count: 210 x 10^9/L
PT: 14.5 seconds (control: 12.2s)
APTT: 68s (control: 31s)
Bleeding time: 7 mins

Which of the following is likely?
a. Haemophilia A
b. Factor XII deficiency
c. Factor XI deficiency

Which test should be done next?
a. Mixing studies
b. Thrombin time
c. Fibrinogen assay
d. Assay all intrinsic pathway factors

Thanks to anyone who can help!!
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Old 04-21-2014
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Normal :
bleeding time - 2-7 min
platelet count - 150-400

Answer is A
Hemophilia A(8) which is a genetic factor 8 deficiency in which u have increased partial thromboplastin time as factor 8 comes under intrinsic pathway but normal bleeding time and platelet count
Note :- In case there would have been increase in bleeding time it would have been von willebrand dz which also is a genetic deficiency
Cause von willebrand factor stabilizes factor 8

WHere as for the rest options there would be increase in PTT time as well as bleeding time

Answer is A or D
Mixing studies - Cause in case of hemophilia A when normal plasma is mixed PTT wouldnt change
This test is also used to differentiate bw hemophilia S(9) and A cause both are genetic def and presents with same conditions and in case of Hemo S there would be correction of PTT
TT - NO because it would be indicative of extrinsic pathway not intrinsic
Fibrinogen - NO cause it belongs to extrinsic
Assay of all intrinsic pathway - Its help u to find out the problem is in this pathway but u wouldnt know which factor is it and moreover when u already know the dz u would look into specific test (cause i dunno how to explain this)

I would go with A

Hope this helps you
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Old 04-21-2014
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Quote:
Originally Posted by synaptobrevin View Post
Normal :
bleeding time - 2-7 min
platelet count - 150-400

Answer is A
Hemophilia A(8) which is a genetic factor 8 deficiency in which u have increased partial thromboplastin time as factor 8 comes under intrinsic pathway but normal bleeding time and platelet count
Note :- In case there would have been increase in bleeding time it would have been von willebrand dz which also is a genetic deficiency
Cause von willebrand factor stabilizes factor 8

WHere as for the rest options there would be increase in PTT time as well as bleeding time

Answer is A or D
Mixing studies - Cause in case of hemophilia A when normal plasma is mixed PTT wouldnt change
This test is also used to differentiate bw hemophilia S(9) and A cause both are genetic def and presents with same conditions and in case of Hemo S there would be correction of PTT
TT - NO because it would be indicative of extrinsic pathway not intrinsic
Fibrinogen - NO cause it belongs to extrinsic
Assay of all intrinsic pathway - Its help u to find out the problem is in this pathway but u wouldnt know which factor is it and moreover when u already know the dz u would look into specific test (cause i dunno how to explain this)

I would go with A

Hope this helps you
Yes, definitely helps, thank you!
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Old 04-21-2014
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as explained in pathoma:

mixing study: used to differ btw hemoph A & anti-FVIII: PTT does correct in hemoph A, PTT doesnt correct with antiF8.
--> its mixing the pt plasma with normal plasma.
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Quote:
Originally Posted by excellence View Post
as explained in pathoma:

mixing study: used to differ btw hemoph A & anti-FVIII: PTT does correct in hemoph A, PTT doesnt correct with antiF8.
--> its mixing the pt plasma with normal plasma.
& I too go with answers: A & A
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Quote:
Originally Posted by excellence View Post
as explained in pathoma:

mixing study: used to differ btw hemoph A & anti-FVIII: PTT does correct in hemoph A, PTT doesnt correct with antiF8.
--> its mixing the pt plasma with normal plasma.
This makes sense, but my I just read that the anti-VIII antibodies form as a result of exposure to infused VIII (Essential Haematology), and since there is no mention of previous illness in the question, I would assume she's never had an infusion.
So my question is - would the antibodies still be a possibility without exposure to infused VIII?
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