Hematology: Vascular Disorders & Coag Cascade Abnormalities

missing elastic fibers in the vascular walls; veins are very thin

Hereditary Hemorrhagic Telangiectasia (aka Rendu-Osler-Weber syndrome)

What are the clinical S/S of Hereditary Hemorrhagic Telangiectasia?

epistaxis, pinpoint, nodular or spider-like lesions on the skin and mucous membranes

What are the lab features of Hereditary Hemorrhagic Telangiectasia?

abnormal Rumple-Leede test

What is the treatment of Hereditary Hemorrhagic Telangiectasia?

obliteration of bleeding lesions

vascular defect of increased vascular fragility

Ehler's Danlos syndrome

What are the clinical S/S of Ehler's Danlos syndrome?

hyperelastic skin and joints, subcutaneous hemorrhages

What are the lab features of Ehler's Danlos syndrome?

abnormal Rumple-Leede, abnormal bleeding time

What is the treatment for Ehler's Danlos syndrome?

treat symptoms, no cure

decreased synthesis of hyaluronic acid

Vitamin C deficiency

What are the clinical S/S of Vitamin C deficiency?

purpura, subcutaneous ecchymoses, scurvy--poor wound healing, swollen and bleeding gums

What are the lab features of Vitamin C deficiency?

abnormal Rumple-Leede, decreased plasma ascorbic acid levels

What is the treatment for Vitamin C deficiency?

take vitamin C

What is the test of choice for assessing vascular function?

Rumple-Leede (tourniquet test)

What specific testing should be done with patients who have a vitamin C deficiency?

plasma ascorbic acid

What factors are in aged serum?

VII, IX, X, XI, XII, Fletcher, Fitzgerald

What factors are in adsorbed plasma?

I, V, VIII, XI, XII, Fletcher, Fitzgerald

If a patient has a factor VII deficiency, what would the PT, APTT and Stypven time be?

normal APTT

increased PT

normal Stypven

What factor is deficient in hemophilia A, B, and C?

A: VIII

B: IX (christmas disease)

C: XI

What is the bleeding time of the hemophilias?

normal (plts are fine)

Which factor is an acute phase reactant?

VIII (hemophilia A)

Which hemophilia is autosomal recessive?

C (A and B are sex-linked)

Why do patients with Factor XII and Prekallikrein deficiency have thrombotic problems?

both are plasminogen activators-- plasminogen cannot be activated to plasmin so clots cannot be broken down

What is the test of choice to differentiate between Factor XII and Prekallikrein?

APTT differential (incubate for 10 mins instead of 4)

Factor XII will be increased

Prekallikrein will be normal

What factors may be abnormal if the problem is the common pathway?

X, V, II, I

Where is Factor V stored?

alpha granules of plts

What organ is usually affiliated with Factor V deficiency?

acquired defect due to *liver* disease

factor deficiency often acquired due to liver disease or a vitamin K deficiency

Factor II deficiency

What is the treatment of choice for factor deficiencies?

recombinant factor

What factors are found in FFP?

all factors

What factors are found in cryoprecipitates?

I, VIII, vWF, XIII

What problem can arise if the patient is given concentrates for a factor deficiency?

may form antibodies overtime

Why might some fibrinogen disorders have a normal PT, APTT, and bleeding time?

lab tests may be normal if the fibrinogen level is close to normal

Heparin complexes with _______________ to inhibit factors primarily in the _______________ pathway.

antithrombin; intrinsic

(also inactivates plasmin)

What test is used to monitor heparin therapy? Coumadin therapy?

heparin therapy: APTT

coumadin therapy: PT

What component does heparin enhance the activity of?

antithrombin

A patient on heparin therapy should be expected to have an increased APTT. What might cause the APTT to be normal?

the patient may have an antithrombin deficiency

Coumadin is a derivative of rat poison. What factors does it inhibit?

vitamin K dependent factors: II, VII, IX, X

What test can be performed when suspecting a Factor XIII deficiency? What is the expected result?

5M urea solubility test

normal= clot remains after 24 hours

abnormal= clot dissolves

What are the vitamin K dependent factors?

II, VII, IX, X

(2+7=9, 10, or 1972. Same as prothrombin family)

What disorders are related to the vitamin K factors? (4)

hemorrhagic disease of the newborn

liver disease

antibiotic therapy

coumadin therapy

What are the factor specific inhibitors? (2)

Factor VIII inhibitor

Lupus inhibitor

What does the lupus inhibitor do?

inhibits Pf3

When PT/APTT results are elevated, what testing should be done first?

Mixing study with Patient Normal Plasma (PNP)

add PNP to patient plasma, 50/50 mix and repeat PT/PTT

When elevated PT/APTT results are pooled with normal plasma, what does it mean when:

result corrects?

result does not correct?

corrects: factor deficiency

does not correct: circulating inhibitor