Hemorrhagic diseases. Lesions of the blood vessels Lesions of the blood vessels Abnormal platelets Abnormal platelets Abnormalities in the coagulation.

Hemorrhagic diseases

• Lesions of the blood vesselsLesions of the blood vessels• Abnormal plateletsAbnormal platelets• Abnormalities in the coagulation cascadeAbnormalities in the coagulation cascade• Combinations of abnormalitiesCombinations of abnormalities

Lesions of the blood vesselsLesions of the blood vessels

• Senile purpuraSenile purpura*hemorrhage in *hemorrhage in

the back of hands and the back of hands and forearms or older forearms or older personspersons

*atrophy of the *atrophy of the vesselsvessels

SCURVY• Vitamin C deficiency

gingival bleeding( ANY mucous membrane)bleeding into musclesbleeding into subcutaneous tissuesbleeding around hair follicles; corkscrew-like hair

• Normal collagen synthesis depends upon the hydroxylation of proline and lysine

• enzymes that catalyze the hydroxylation require ascorbic acid

Hemorrhage in the hair follicles; corkscrew hair in scurvy

Thrombocytopenia (low platelets count)

• Petechiae in the skin• Oozing from mucosal membranes• Bleeding within the brain

• Low platelet count• Prolonged bleeding time

Causes of thrombocytopenia

• Drugs, chemicals• Irradiation• Leukemia• Myelophthisis (tumor cells replace normal

bone marrow cells)• Splenic sequestration• Multiple blood transfusions• DIC

Idiopathic thrombocytopenic purpura

• ITP• Antibodies against platelets• Damaged platelets are removes by

macrophages in the spleen• Low platelets• Normal/increased megakaryocytes

Thrombotic thrombocytopenic purpura

• TTP• Hyaline aggregates in small blood vessels• Low platelets• Anemia (abnormal blood vessels trap the RBC)• Renal, CNS abnormalities, fever• Cause: von Willebrand disease, enzyme

deficiency

• Von WIllebrand disease: abnormal platelet adhesion

• Aspirin intake: low TxA2; abnormal platelet aggregation

Abnormalities in the Coagulation cascade

• Bleeding from larger vesselshemarthroses (joints)large hematomas/ ecchymosesextensive bleeding with trauma

Abnormalities in the Coagulation cascade

• Classic hemophilia• Christmas disease• Vitamin K deficiency

Classic hemophilia

• Hemophilia A• Factor VIII deficiency• X-linked • Occurs worldwide• Bleeding into the :

musclesSubcutaneous tissuesJoints

• “royal disease”

Christmas disease

• Factor IX deficiency• Less common than Hemophilia A• Same presentation

Vitamin K deficiency

• Adults: fat malabsorption in diseases of the pancreas or small intestines

• Infants: Hemorrhagic disease of the newborn- intestines have small amounts of bacteria-decrease factors II, VII, IX, X

Combination of abnormalities

• Von Willebrand disease• DIC• Coagulopathy of liver disease

Von Willebrand disease

• MOST COMMON HEREDITARY BLEEDING DISORDER

• Autosomal dominant• Decreased in vWF: Decrease platelet adhesion

to the injured blood vessel (prolonged bleeding time)

DIC

• Consumption of platelets and coagulation factors II, V, VIII

• Low fibrinogen• Hemorrhage and thrombosis• Anemia• Cause: release of thromboplastin, triggers the

intrinsic pathway of coagulation; increased fibrinolysis

DIC• Obstetric complications

ToxemiaAmniotic fluid embolismretained dead fetusplacental accidents

• Cancer – lung, pancreas, prostate, stomach• Infection – bacteria• Trauma• Immune diseases

Coagulopathy of liver disease

• All coagulation factors are produced in the liver EXCEPT vWF

• Treatment: Vitamin K