7 - Hematolymphoid Pathology Flashcards
(60 cards)
Describe normal hematopoiesis and lymphopoiesis
Hematopoiesis: synthesis of blood cells, different cell lines each undergo differentiation into committed cells
Lymphopoiesis: synthesis of lymphoid cells. B cells mature in BM, T cells in thymus
What are the main components of peripheral blood? What are some important components of each layer?
Plasma (55%)
- albumin
- immunoglobulins
- clotting factors
Buffy coat (<1%)
- leukocytes
- platelets
Erythrocytes (45%)
- RBC
- serum
Describe the structure of Hb
- consists of 4 globin chains
- each chain has a heme mlc that contains iron
- in most adults, chain is 2 alpha 2 beta
What are the two main types of bleeding in the “increased loss” cause of anemia?
Acute bleeding = trauma
Chronic bleeding = GI bleeding
Describe the inherited (3) and acquired (1) diseases related to destruction of abnormal blood cells
Inherited:
- membranopathy (hereditary spherocytosis)
- enzymopathy (G6PD deficiency)
- abnormal Hb (sickle cell disease)
Acquired:
- PNH (paroxysmal nocturnal hemoglobinuria)
What are the 4 causes of destruction of NORMAL RBC?
- immune hemolytic anemia
- repetitive trauma
- infections (malaria)
- chemical/toxic injury (lead poisoning)
What are three categories of decreased RBC production and name the type of anemia associated with each
- Nutritional deficiencies
- iron deficiency anemia
- Megaloblastic anemia (B12/folic acid def) - Bone Marrow Failure
- Aplastic anemia - Inherited genetic defects
- Thalassemia
What are the 4 signs and 6 symtpoms of anemia?
Signs:
1. pale skin
2. pale mucosa
3. spoon nails, brittle nails
4. tachycardia (heart rate >100 bpm)
Symptoms:
1. fatigue
2. Weakness, exercise intolerance
3. Shortness of breath
4. drowsiness
5. chest pain
6. Unusual cravings (pica, ice)
Where is iron absorbed? How is it stored?
Absorbed in small intestine
Stored in ferritin, which aggregates into brown granules called hemosiderin
4 causes of iron def anemia?
- decreased intake
- decreased absorption
- increased loss
- increased requirements
3 lab results/diagnosis techniques of iron def anemia?
- blood smear
- Hb and low hematocrit
- serum iron and low ferritin
Treatment of iron def anemia?
iron replacement
What is aplastic anemia?
Loss of multipotent stem cells resulting in pancytopenia
Primary and secondary causes of aplastic anemia?
Primary = idiopathic
Secondary = related to BM suppression (chemicals, radiation, viral infection, inheritance)
2 lab results of aplastic anemia?
- CBC -> pancytopenia
- BM biopsy -> decrease in blood forming cells
2 causes of megaloblastic anemia?
- Vit B12 or folic acid deficiency
- Pernicious anemia, Crohn’s diseaese, gastric resection
2 lab results of megaloblastic anemia?
- blood smear -> oval macrocytes, large hyper-segmented neutrophils
- BM biopsy -> hypercellular with megaloblasts
3 pathogenesis of megaloblastic anemia?
- deficiencies delay normal maturation of RBC
- RBC precursors don’t mature but instead transform into megaloblasts
- Megaloblasts destroyed in BM/spleen
Treatment of megaloblastic anemia?
Give patients B12 intravenously or folic acid orally
Is thalassemia a quantitative or qualitiative defect in Hb? What about Sickle Cell Disease?
Thalassemia = quantity
Sickle Cell = quality
For α-thalassemia, what is defective? Describe the differences btwn 1 gene mutation up to 4 gene mutations.
Defect in synthesis of α chain
1 gene defect = asymptomatic
2 gene defect = mild anemia
3 gene defect = moderate to severe
4 gene defect = hydrops fetalis, intrauterine death
For β-thalassemia, what is defective? Describe the difference btwn thalassemia major and minor
Defective synthesis of β chain
Thalassemia minor (heterozygous) = mild, nonspecific symptoms
Thalassemia major (homozygous) = severe, serious disease
Why is it bad to have too many alpha globin chains? Too many beta globin chains?
Alpha = too many alpha chains results in α-globin aggregates (intravascular hemolysis)
Beta = not good for oxygen delivery
What is sickle cell disease caused by? What two things does it normally result into?
Defective β globin chain caused by point mutation (substitution of glutamic acid by valine)
Chronic hemolytic anemia & small vessel occlusion