فرفرية نقص الصفيحات المناعية المزمنة Chronic Immune Thrombocytopenic Purpura

Thrombocytopenia absent Radius syndrome (TAR)
(rare,episodic throbmcytopeia, extermities deformities, organs anomalies:cardiac,facial.... )

Wiskott-Aldrich syndrome/X-linked Thrombocytopenia:

(eczema, thrombocytopenia, immune deficiency, and bloody diarrhea....and a propensity for autoimmune disorders and malignancies)

Kassbach-Merritt Syndrome:

(rare, hemangioendothelioma and other vascular tumors, consumptive thrombocytopenia may lead to DIC)

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Thou probably meant TTp not tpp.......
first of All,— Thrombocytopenia during pregnancy has been ascribed to TTP-HUS, preeclampsia (including the HELLP syndrome), and idiopathic thrombocytopenic purpura.....

ttp is what we want right now......the problem in ttp is with Von Willebrand factor ,whose clearance is inhibited.......ergo ,there is an extra VWf in blood which leads to ttp....
now we have two things to talk about :
1-pregnancy and TTp
2-estrogen and ttp

about the second one ,we can simply say that:
VWF production in endothelial cells is increased by both estrogen and thyroid hormone ......

and about the first one we can say briefly:
Vwf-clearing protease is decreased in pregnancy,ergo,more Vwf,and ttp.........

to talk more about that clearing-factor and the production of Vwf...u can read this which's been taken feom uptodate:

ADAMTS13 deficiency:
. Von Willebrand factor (VWf) is synthesized in endothelial cells and assembled in larger multimers that are present in normal plasma. The larger multimers, called unusually large von Willebrand factor (ULVWf), are rapidly degraded in the circulation into the normal size range of VWf multimers by a specific von Willebrand factor-cleaving protease (or cleaving metalloproteinase, now called ADAMTS13:
ADAMTS13 deficiency could lead sequentially to the accumulation of ULVWf multimers, platelet aggregation, and the platelet clumping that is characteristic of the disease [31] . ULVWf multimers (including unique forms arising from proteolytic digestion [32] ) accumulate in patients with TTP, being found in the platelet thrombi and serum [3,33,34] . These ULVWf multimers can attach to activated platelets, thereby promoting platelet aggregation.
ULVWf multimer accumulation in TTP has been associated with absent or markedly diminished ADAMTS13 activity due to an inherited or acquired deficiency.
An intriguing observation is that protease levels appear to decrease during the last two trimesters of pregnancy, being lowest at 36 to 40 weeks of gestation and the early puerperium [57,63] . This observation may be relevant to the increased frequency of TTP-HUS during pregnancy, especially at the time of delivery

an important thing to tell:
House series is actually a very amazing medical series ,but not all things mentioned are evidenced-based,... and also sometimes the writer makes mistakes on purpose just to make the medical case cool with some drama he wanna show......
u can read a very good review of every episode of house in this link,they discuss every episodes medically and dramatically:
http://www.politedissent.com/house_pd.html

sorry Fouad that I mentioned sth not related to ur thread

oh, ur right, it was ttp not tpp. it was my mistake.

thanks alot mbs, important and useful points indeed.

thank u both