Last minute revision of Blood Disorders

Important topics in hematology( blood disorders).

Immune thrombocytopenic purpura ITP

microhemorrhage : mucous membrane bleeding , epistaxis , hemoptysis , GI bleeding , hematuria , and menorrhagia , petechiae , purpura , intracranial bleeding occurs with severe thrombocytopenia ,↑ bleeding time .

Microangiopathic hemolytic anemia

1. Thrombotic thrombocytopenic purpura TTP : same as ITP .

 

2. Hemolytic uremic syndrome HUS : Skin and mucosal bleeding , microangiopathic hemolytic anemia , fever , renal insufficiency , CNS abnormalities.

Bernard soulier syn.

microhemorrhage : mucous membrane bleeding , epistaxis , hemoptysis , GI bleeding , hematuria , and menorrhagia , petechiae , purpura , intracranial bleeding occurs with severe thrombocytopenia ,↑ bleeding time .

Hemophilia A , B , C

deep tissue , joint , and postsurgical bleeding

Von willebrand disease

mild mucosal and skin bleeding

Vit k deficiency

bruising, petechiae, hematomas, oozing of blood at surgical or puncture sites, stomach pains; risk of massive uncontrolled bleeding; cartilage calcification; and severe malformation of developing bone or deposition of insoluble calcium salts in the walls of arteries

Disseminated intravascular coagulation (DIC)

widespread activation of clotting → difficiency of clotting factors → bleeding state .

Thrombosis

1. Disrubtion in normal blood flow : Immobilization , cardiac wall dysfunction , aneurism

 

2. endothelial cell damage : Atherosclerosis , vasculitis , CBS deficiency and increased homocysteine.

 

3. hypercoagulable state : decreased anticoagulant and increased procoagulant : Protein C or S deficiency : ↑ risk of thrombotic skin necrosis with hemorrgae following administration of warfarin .

Factor V leiden

Prothrombin 20210A

Antithrombin III deficiency

Oral contraceptives

embolism

Thromboembolus

Atherosclerotic embolus

 

Fat embolus : associated with bone fracture , characterized by dyspnea and petechia on the skin overlying the chest .

 

Gas embolus : joints and musle pain and respiratory symptoms .

 

Amniotic fluid embolus : shortness of breath , neurologic symptoms , and DIC .

 

Pulmonary embolism : shortness of breath , hemoptysis , pleuritic chest pain , and pleural effusion .

 

Systemic embolism

Anemia presents with signs and symptoms of hypoxia

weakness , fatigue , dyspnea , pale conjunctiva and skin , headache and lightheadedness , angina

Iron deficiency anemia

anemia , fatigue , conjunctival pallor , pica (consumption of nonfood substances) , spoon nails (koilonychia). May manifest as glossitis , cheilosis

Anemia of chronic disease

Associated with conditions such as rheumatoid arthritis, SLE, neoplastic disorders, and chronic kidney disease

Sideroblastic anemia

skin paleness, fatigue, dizziness, and enlarged spleen and liver. Heart disease, liver damage , and kidney failure can result from iron buildup in these organs.

α thalassemia

4 allele deletion: Incompatible with life (causes hydrops fetalis). 3 allele deletion: inheritance of chromosome with cis deletion + a chromosome with 1 allele deleted →HbH disease. Very little α-globin. Excess β-globin forms β4 (HbH).

2 allele deletion: less clinically severe anemia.

1 allele deletion: no anemia (clinically silent).

β thalassemia

β-thalassemia minor (heterozygote):Usually asymptomatic. Diagnosis confirmed by ↑ HbA2 (> 3.5%) on electrophoresis.

 

β-thalassemia major (homozygote): β chain is absent → severe microcytic, hypochromic anemia with target cells and increased anisopoikilocytosis requiring blood transfusion (2° hemochromatosis).

 

Marrow expansion (“crew cut” on skull x-ray) → skeletal deformities.

 

“Chipmunk” facies. Extramedullary hematopoiesis → hepatosplenomegaly. ↑ risk of parvovirus B19–induced aplastic crisis. ↑ HbF(α2γ2). HbF isprotective in the infant and disease becomes symptomatic only after 6 months, when fetal hemoglobin declines.

 

HbS/β-thalassemia heterozygote: mild to moderate sickle cell disease depending on amount of β-globin production

Lead poisoning

Lead Lines on gingivae (Burton lines) and on metaphyses of long bones D on x-ray. Encephalopathy and Erythrocyte basophilic stippling. Abdominal colic and sideroblastic Anemia. wrist and foot drop

Non megaloblastic macrocytic anemia

Caused by alcoholism, liver disease.

Folate deficiency

Loss of appetite and weight loss can occur. weakness, sore tongue , headaches ,heart palpitations , irritability, and behavioral disorders. In adults, anemia (macrocytic, megaloblastic anemia) can be a sign of advanced folate deficiency.

In infants and children, folate deficiency can slow growth rate. Women with folate deficiency who become pregnant are more likely to give birth to low birth weight premature infants, and infants with neural tube defects.

Vit B12 deficiency

Neurologic symptoms: reversible dementia, subacute combined degeneration (due to involvement of B12 in fatty acid pathways and myelin synthesis): spinocerebellar tract, lateral corticospinal tract, dorsal column dysfunction.

Orotic aciduria

Presents in children as failure to thrive, developmental delay, and megaloblastic anemia refractory to folate and B12. No hyperammonemia (vs ornithine transcarbamylase deficiency—↑ orotic acid with hyperammonemia).

Diamond blackfan anemia

Short stature, craniofacial abnormalities, and upper extremity malformations (triphalangeal thumbs) in up to 50% of cases

Hereditary spherocytosis

Splenomegaly, aplastic crisis (parvovirus B19 infection).

Sickle cell anemia

Complications in sickle cell disease: Aplastic crisis (due to parvovirus B19). Autosplenectomy (Howell-Jolly bodies) ↑ risk of infection by encapsulated organisms (eg, S pneumoniae). Splenic infarct /sequestration crisis. 

Painful crises (vaso-occlusive): dactylitis (painful swelling of hands/feet), priapism, acute chest syndrome, avascular necrosis, stroke. Renal papillary necrosis (↓ Po2 in papilla) and microhematuria (medullary infarcts).

Paroxysmal nocturnal hemolytic anemia

Intravascular hemolysis occurs episodically, often at night during sleep.

 

1.Mild respiratory acidosis develops with shallow breathing during sleep and activates complement.

 

2.RBCs, WBCs, and platelets are lysed.

 

3.Intravascular hemolysis leads to hemoglobinemia and hemoglobinuria (especially in the morning); hemosiderinuria is seen

days after hemolysis.

 

Triad: Coombs hemolytic anemia, pancytopenia, and venous thrombosis.

G6PD

Back pain, hemoglobinuria a few days after oxidant stress.

Autoimmune hemolytic anemia

a: warm agglutinin : Associated with SLE (most common cause), CLL, and certain drugs (classically, penicillin and cephalosporins)

 

b: cold agglutinin : acute anemia triggered by cold; seen in CLL, Mycoplasma pneumoniae infections, and infectious Mononucleosis (“cold weather MMMiserable”). RBC agglutinates A may cause painful, blue fingers and toes with cold exposure.

Microangiobathic hemolytic anemia

 RBCs are damaged when passing through obstructed or narrowed vessel lumina.

 

Seen in DIC, TTP/HUS, SLE, HELLP syndrome, and malignant hypertension

Macroangiobathic hemolytic anemia

Prosthetic heart valves and aortic stenosis may also cause hemolytic anemia 2° to mechanical destruction of RBCs.

Aplastic anemia

Symptoms: fatigue, malaise, pallor, purpura, mucosal bleeding, petechiae, infection.

Myelophthisic process : pancytopenia .

Last minute revision of Blood Disorders
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