Anemia Flashcards
1
Q
Etiology of Anemia
A
- Blood loss
- Acute
- Loss of blood volume
- Chronic
- Only when regenerative capacity exceeded by blood loss or iron reserves depleted
- Acute
- Deficiency of Hb building blocks
- Fe ⇒ iron deficiency
- Porphyrin ⇒ sideroblastic
- Globin ⇒ Thalassemias
- Deficiency of DNA buidling blocks
- Vit B12/Folate
- Marrow failure
- Primary failure
- Aplasia, neoplasia, toxic suppression, infiltration
- Secondary failure
- Renal, endocrine, chronic inflammation, hepatic, drugs and poisons, infections, cancer
- Excess destruction ⇒ hemolytic anemia
- Congenital ⇒ mutation in RBC membrane, Hb, or RBC enzymes
- Acquired
- Primary failure
2
Q
Hypochromic Microcytic Anemias
A
- Anemia with low MCV
- Failure of marrow precursors to make Hb
- Fe, porphyrin, globin
- Differential dx
- Iron deficiency
- Thalassemias
- Sideroblastic anemia
3
Q
Iron Deficiency Anemia
Pathogenesis
A
- Dec. Fe ⇒ marrow can’t make Hb ⇒ anemia
- Causes ⇒ blood loss > nutritional lack
- Who
- Infants ⇒ Fe deficient diet
- Adolescent girls/Premenopausal women ⇒ Menses/pregnancy
- Post-menopausal women and all men ⇒ GI blood loss
4
Q
Iron Deficiency Anemia
Dx
A
- CBC
- Blood smear ⇒ paler/smaller, central clearing larger, anisocytosis
- Iron studies ⇒ Fe low, TIBC high, Ferritin low, RDW high
5
Q
Thalassemias
A
- Hypochromic, microcytic anemia
- Dec or absent synthesis of alpha or beta globin chains
- Alpha ⇒ Africa and SE Asia
- Beta ⇒ Mediterranean region
- Thalassemia trait ⇒ mild anemia w/ hypochromic microcytic RBC
- Thalassemia major ⇒ severe anemia in childhood, hepatosplenomegaly, jaundice, marked bone changes
6
Q
Beta-Thalassemia Minor
Dx
A
- Hb 10-13
- RBC slightly elevated
- MCV 60-70
- Smear ⇒ microcytosis, hypochromia, target cells, RBC with basophilic stippling
- Hb electrophoresis ⇒ slight dec Heb A, Inc. Hgb A2, Hgb F normal or slightly elevated
7
Q
Beta-Thalassemia Major
Dx
A
- Severe anemia in childhood ⇒ Hb 3
- Smear
- Markedly hypochromic with marked anisocytosis
- Poikilocytosis
- Stippled cells
- Target cells
- Ellipitcal cells
- Tear drop calls
- Hypochromic cells with polychormatophilic rims
- Nucleated RBCs
- Hb electrophoresis
- Absent or small amount of Hgb A
- Slighrly increased Hgb A2
- Rest Hgb F
8
Q
β-Thalassemia Major
Pathogenesis
A
- Dec. B-globin ⇒ excess A-globin ⇒ insoluble aggregates in erythroblasts
- Anemia d/t ineffective erythropoiesis & extravascular hemolysis
- Systemic iron overload
- Skeletal deformities ⇒ inc. EPO and bone marrow expansion
9
Q
Alpha Thalassemia
A
- Results from alpha gene deletion
- Single ⇒ silent
- 2 ⇒ trait
- 3 ⇒ Hb H disease
- All 4 ⇒ Hydrops fetalis
- Hb electrophoresis only Hgb Barts
- Mild microcytic anemia w/ normal to elevated RBC
- MCV 60-70
10
Q
Sideroblastic Anemia
A
- Porphyrin impairment ⇒ abnormal RBC iron metabolism
- Causes
- Hereditary
- Acquired ⇒ lead poisoning, ETOH, drugs
- Neoplasia ⇒ refractory sideroblastic anemia, sign of myelodysplastic syndromes
- Clinical findings
- Inc. Fe, Normal TIBC, Inc. ferritin
- Ringed sideroblasts in bone marrow
- Treatment ⇒ remove offending agent if possible, treat myelodysplasias
11
Q
Macrocytic Anemias
A
Anemia w/ high MCV
Pathophysiology ⇒ megaloblastic vs nonmegaloblastic
12
Q
Megalobastic Anemia
A
- Failure of DNA synthesis ⇒ async. maturation of nucleus and cytoplasm
- Caused by Vit B12 or folate deficiency
- See macrocytosis w/ low retic count
- Severe
- Neutropenia
- Thrombocytopenia
- Hypersegmented neutrophils
13
Q
Vit B12 Deficiency
Pathogenesis
A
- Cofactor for homocysteine ⇒ met
- Liver stores lasts 3+ years
- From fish and meat
- Absorbed bound to IF in terminal ileum
- Clinical Features
- Macrocytic megaloblastic anemia
- Glossitis
- Neuropathy
- Loss of position/vibratory sensation in LE, ataxia, UMN signs
- Urinary/fecal incontinence
- Impotence
- Dementia
- Neutropenia/thrombocytopenia
14
Q
Vit B12 Deficiency
Etiology
A
- Pernicious anemia
- Total gastrectomy
- Malabsorption disease
- Terminal ileum disease or removal
- Pancreatic insufficiency
- Drug induced malabsorption
- Food malabsorption
15
Q
Vit B12 Deficiency
Dx
A
- Peripheral smear
- Macrocytic RBC w/ MCV > 100
- Hypersegmented polys
- Serum B12 levels low
- Serum MMA high
- Serum homocysteine high
- Schillings test