Page 1 of 3: med---protein c deficiency?

akanksha · Credits: 41247 My Scrapbook My Reading List 14 Books

a 17 yr old nonsmoking guy presents with deep vein thrombosis and pulmonary embolism.this is his second hospital admission for a similar presentation 1yr ago.The pt has a family h/o recurrent pulmonary emboli.The PTT remains normal after initiation of heparin therapy.another dose of heparin produces similar results.the patient most likely has-
a)von Willibrand's disease
b)AntithrombinIII deficiency
c)Antibodies against heparin
d)Protein C defect

i think the ans shd be protien C defect.the sympotomatology is all going along the line.even the family history.but the prob is protien C def pts usually die in infancy!am i wrong?whers ur torch?throw sum light!pls!

doctorgirl78 · Credits: 5386 My Scrapbook

now i am not a hematologist.........if there's one out there reading this please correct me if i am wrong.

from what i know (from ganong ,CMDTand harri)
the clinical picture of anybody less than 30,w/o risk factors or predisposing conditions,positive family history presenting with recurrent thrombosis and embolic episodes be investigated for
1.antithrombin III deficiency
2.protein C and S deficiency
3.factor V leiden

vWF is obviously out----its a bleeding disorder NOT a coagulation ds.

antibodies to heparin isnot a choice becoz they develop after 5 days of administration and family history of embolism is not explained.and here thrombosis is coz of thrombocytopenia.

Now out of these....Factor V Leiden is most common and presents in adulthood.definitely more common than the upper two.but not one of your choices.

Protein C def---rare homozygous states present in nenatal period in sever form.there are various severity levels becuse of heterozygosity.can be a choice.

antithrombin III had same presentation.same incidence and spectrum of presentations because of heterozygosity.

from what these books say---factor V would be the choice if given.

I AM NOT ABLE to pick out between antithrombin III and protein C

Now you say PTT remains normal even after heparin-------what was PTT before?

well,i know not much help.........but i tried.

May be could help with the reference of the question---where did you pick it from?

doctorgirl78 · Credits: 5386 My Scrapbook

and ya...........protein C deficency homozygous state fatal in infancy is called
NEONATAL PURPURA FULMINANS.

akanksha · Credits: 41247 My Scrapbook My Reading List 14 Books

dear doc girl,
this Q was asked in NIMHANS 2002.even i thought dat factor V shd hav been in the choice.....but then!
i dunno exactly how to diff b/w antithrombin III and protein C def.even de gruchy isnt of much help.of course it does mention dat antithrombinIII def does present in 2nd-3rd decade.Now,is this pointing towards antithrombin III?
i give up!u say!

Bruno · Credits: 44715 My Scrapbook My Reading List 50 Books

Heparin is one of the few drugs that ACTIVATE an Enzyme. Remember that most of the drugs are enzyme inhibitors

. I will give you 48 hours to come with another common drug that activates an enzyme

Mechanism of action/Effect of Heparin:

Heparin
acts indirectly

at multiple sites

in both

the intrinsic and extrinsic blood clotting systems
to potentiate the inhibitory action of antithrombin III (heparin cofactor)
on several

activated coagulation factors,
including thrombin (factor IIa) and
factors IXa,
Xa,
XIa, and
XIIa,

by forming a complex with
and inducing a conformational change

in the antithrombin III molecule.

Inhibition of activated factor Xa
interferes with thrombin generation and thereby
inhibits the various actions of thrombin in coagulation.

Heparin also
accelerates the formation of an antithrombin III-thrombin complex, thereby
inactivating thrombin and
preventing the conversion of fibrinogen to fibrin;

these actions
prevent extension of existing thrombi.

Larger doses of heparin are required to inactivate thrombin than are required to inhibit thrombin formation.

Heparin also
prevents formation of a stable fibrin clot

by inhibiting the activation of the fibrin stabilizing factor

by thrombin.

Heparin has no fibrinolytic activity. 8)

Full-dose heparin prolongs partial thromboplastin time, thrombin time, whole blood clotting time, and activated clotting time (ACT).

Now come to the question

a 17 yr old nonsmoking guy presents with deep vein thrombosis and pulmonary embolism.this is his second hospital admission for a similar presentation 1yr ago.The pt has a family h/o recurrent pulmonary emboli. The PTT remains normal after initiation of heparin therapy.another dose of heparin produces similar results.the patient most likely has-
a)von Willibrand's disease
b)AntithrombinIII deficiency
c)Antibodies against heparin
d)Protein C defect

If there is a normal Anti thrombin III, the aPTT should be prolonged after administration of heparin

doctorgirl78 · Credits: 5386 My Scrapbook

thanks bruno...............how my ddddduffer brain ignored such a magnanimous fact.!!

well,
for enzyme inducers/activaters(i hope you mean the ones from general pharma?)

phenytoin
phenobarbitone
carbamazepine
rifampin
griseofulvin
chronic alcolohol intake

do let me know if i am right ,bruno.And of course,additions to the little list.

SO i guess,akansha ,i'll go for protein C defect.

Bruno · Credits: 44715 My Scrapbook My Reading List 50 Books

doctorgirl78 · Credits: 5386 My Scrapbook

yup,you are right,i just reconciled and confess the liner was an absent minded mistake...............GOD dont lemme make such in the finale test!!

so if aPTT stays normal......it was antithrombin deficiency.coz otherwise,aPTT should be prolonged.

akanksha · Credits: 41247 My Scrapbook My Reading List 14 Books

thanks bruno n doc girl.amazing dat we were ignoring the most imp point given in the question.
which is the other enzyme activating drug ure talking about?wait haa....i'll try n get the ans by tommorrow.till then happy studying!

doctorgirl78 · Credits: 5386 My Scrapbook

well,if we could master this art,we would be in AIIMS presenting cases in medicine as residents!!!!

well,bruno,i came up with an unlikely answer----
FORSKOLIN, inducer of adenylate cyclase,kind of herbal medicine.........

i didnt make it up.......came across it in chapter one of ganong.

all the best akansha........hope you manage a more sane sounding list...

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