Page 523 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

CHAPTER 26 ■ Disorders of Primary Hemostasis and Thrombosis Vasculature and Platelets 507

scurvy, steroi -in uce ur ura, an so ar ur ura (seni e

ur ura)

EDS are a grou o rare connective tissue isor ers cause

by abnor a ities o co agen synthesis or rocessing. EDS

is ue to quantitative or qua itative e ects in ty e 3 co a-

gen, which is articu ar y abun ant in the arteria wa an

intestine.

Most atients re ort a history o excessive bruising an

b ee ing. Risk o ajor b ee ing is the greatest or EDS

(ty e IV). Patients with this isor er are rone to arteria

aneurys s an issections, signi cant b ee ing ro s on-

taneous ru ture o e iu -size ab o ina arteries, an

intestina ru ture. Arteria /intestina /uterine ragi ity or ru -
FIGURE 26.4 Disse inate intravascu ar coagu ation Histo ogy

showing icrothro bi ing the u ens o the a veo ar ca i ar- ture co on y arise in this ty e o EDS.

ies. (Fro Cag e P . Color Atlas and ext o Pulmonary Pathology. S ontaneous arteria ru ture has a eak inci ence in

Phi a e hia, PA: Li incott Wi ia s & Wi kins, 2005.) the thir or ourth eca e o i e but ay occur ear ier.
Li e ex ectancy is shortene with a ajority o in ivi u-

a s iving on y into their 40s. Pregnancies ay be co -
Dissem inated Intravascular Coagulation (DIC) icate by intra artu uterine ru ture an re- an

Initiation o isse inate intravascu ar coagu ation (DIC) ost artu arteria b ee ing. reat ents are avai ab e,

(see Cha ter 28 or a u iscussion o this isor er) which ay he exten i e, an surgica interventions are

(Fig. 26.4) can be cause by a nu ber o actors. I vascu ar i roving.

en othe ia a age resu ts in the ex osure o co agen an Screening tests show no he ostatic abnor a ities.

base ent e brane, co agen can activate coagu ation ac- B ee ing is thought to resu t ro abnor a ities in the eri-

tor XII. Factor XII has u ti e ro es in the irect or in irect vascu ar co agen ea ing to ragi ity o the subcutaneous

activation o coagu ation. vesse s. So e atients o have abnor a b ee ing ti es an

Regar ess o the initiating event, DIC is characterize ate et unction as we as b oo coagu ation actor e cien-

by excess thro bin or ation, conversion o brinogen cies. A skin bio sy can iagnose EDS IV.

to brin, an ate et consu tion an e osition. DIC is Tere are six ajor ty es o EDS. Each ty e has associ-

characterize by both thro bosis an he o ysis. ate genetic e ects. T e vascu ar ty e o EDS IV is cause

by structura e ects in the roa1(III) chain o co agen ty e

Cryo brinogenem ia III enco e by COL3A1. T is ty e o EDS is inherite in an

Cryo brinogene ia is a cause o vascu ar obstruction. In autoso a o inant attern.

this situation, cryo brinogens, co reci itab e as a

roteins that isso ve as as a are rewar e , are invo ve . Pseudoxanthom a Elasticum (PXE)

T is is a istinct rocess ro cryog obu ins that reci itate Pseu oxantho a e asticu is a so known as Gröenb a -

on coo ing o seru a er the as a roteins have been Stran berg syn ro e, Grönb a -Stran berg syn ro e,

re ove . T e esions in associate cryo brinogen isor- or PXE. his is an inherite connective tissue isor er

ers, such as Raynau ’s heno enon, eve o as the resu t that resu ts in ca ci ication an inera ization o e astic

o brin thro bi obstructing the s a - an e iu -size ibers, es ecia y in the interna e astic a ina o e iu -

er a b oo vesse s. size arteries with subsequent ru ture o the b oo ves-
se s. E astic ibers, a co onent o connective tissue,

Septic Em boli rovi e strength an exibi ity to structures throughout

Se tic e bo i resu ts ro the eve o ent o tissue isch- the bo y.

e ia, necrosis o the skin an subcutaneous ate, an PXE is inherite in an autoso a recessive attern, which

occasiona y ee er tissues. T is con ition is c assica y asso- eans that both co ies o the gene in each ce have uta-

ciate with atients who have en -stage rena ai ure an are tions. Most o en, the arents o an in ivi ua with an auto-

un ergoing he o ia ysis, but it can be associate with other so a recessive con ition each carry one co y o the utate

con itions as we . gene but oes not exhibit the signs an sy to s o PXE.
T ere are ve c inica ty es o PXE.

Bleeding because of Disorders of Mutations in the ABC-C6 gene cause PXE. T e ABC-

Perivascular Tissue C6 gene rovi es instructions or aking a trans e -
brane trans orter rotein, MRP6 rotein, a so known

Various isor ers be ong to this category o b ee ing is- as ABC-C6 rotein. MRP6 rotein is oun ri ari y

or ers. Re resentative isor ers are Eh ers-Dan os syn- in ce s o the iver an ki neys, with s a a ounts in

ro es (EDS), Mar an’s syn ro e, Loeys-Dietz syn ro e, other tissues, inc u ing the skin, sto ach, b oo vesse s,

osteogenesis i er ecta, seu oxantho a e asticu , an eyes.