Anemias

Question 1

3 main types of anemias

Answer 1

Microcytic (MCV below 80fL)
normocytic (MCV 80-100 fL)
Macrocytic (MCV over 100 fL)

Question 2

causes of microcytic anemia

Answer 2

Fe deficiency (late), anemia of chronic disease, Thalassemias, Lead poisoning, sideroblastic anemia

Question 3

types of normocytic anemia

Answer 3

Honhemolytic (reticulocyte count nl or low) vs hemolytic (reticulocyte count increased)
- Hemolytic normocytic anemias divided into intrinsic vs extrinsic hemolysis

Question 4

types of Normocytic anemia with extrinsic hemolysis

Answer 4

autoimmune conditions, microangiopathic, macroangiopathic, infections

Question 5

types of normocytic anemia with intrinsic hemolysis

Answer 5

RBC membrane defect:mhereditary spherocytosis, RBC enzyme deficiency (G6PD, pyruvate kinase), HbC defect, paroxysmal nocturnal hemaglobinuria, sickle cell anemia

Question 6

causes of normocytic nonhemolytic anemias

Answer 6

anemia of chronic disease, aplastic anemia, chronic kidney disease, early Fe deficiency

Question 7

Fe deficiency

Answer 7

cause of microcytic, hypochromic anemia

• low Fe from chronic bleeding, lamnutrition/absorption disorders, or increased demand (prego)
• this causes less functional final step of heme synthesis

Question 8

Findings of Fe deficiency

Answer 8

low Fe/ferritin, increased TIBC

• Fatigue, conjunctival pallor, spoon nails (koilonychia)
• Microcytosis and hypochromia.= (central pallor)
• May manifest as Plummer-Vinson syndrome (triad of Fe deficiency anemia, esophageal webs, and atrophic glossitis)

Question 9

Plummer Vinson syndrome

Answer 9

triad of Fe deficiency anemia, esophageal webs, and atrophic glossitis

Question 10

alpha thalassemia

Answer 10

alpha globin gene deletions causing decreased alpha globin synthesis

• cis deletion prevalent in Asian populations
• Trans deletion prevalent in African populations

Question 11

types of alpha thalassemia

Answer 11

• 4 allele deletion = no alpha globin. Excess gamma globin forms (Hb Barts). Incompatible with life –Hydrops fetalis
• 3-allele deletion: HbH disease. Very little alpha globin. Excess beta globin forms beta4(HbH)
• 1-2 allele deletion: less clinically severe anemia

Question 12

beta thalassemia

Answer 12

point mutation in splice sites and promotor sequences leading to decreased beta globin synthesis
- prevalent in Mediterranean populations

Question 13

Types of beta thalassemia

Answer 13

minor (heterozygote): Beta chain underproduced; usually asymptomatic; diagnosis confirmed by increased HbA2 ( above 3.5%) on electrophoresis

Major: homozygote with absent beta chain causing severe anemia requiring blood transfusion (secondary hemochromatosis)

• Marrow expansion – skeletal deformities. “Chipmunk” facies
• extramedullary hematopoiesis (leads to hepatosplenomegaly). increased risk of parovirus B19 induced aplastic crisis
• increased HbF (alpha2gamma2). Protective as infant and disease symptomatic only after 6 months

Question 14

HbS/beta thalassemia heterozygote

Answer 14

mild to moderate sickle cell disease depending on amount of beta-globin production

Question 15

types of macrocytic anemia

Answer 15

megaloblastic vs nonmegaloblastic

Question 16

megaloblastic, macrocytic anemia causes

Answer 16

folate deficiency, B12 deficiency, orotic aciduria

Question 17

non-megaloblastic, macrocytic anemia causes

Answer 17

liver disease, alcoholism, reticulocytosis

Question 18

sideroblastic anemia

Answer 18

defect in heme synthesis

• Hereditary: X-linked defect in delta-ALA synthase gene
• Causes: genetic, acquired (myelodysplastic syndromes), and reversible (EtOH most common); also lead, vit B6 deficiency, copper deficiency, isoniazid

Question 19

Lead poisoning

Answer 19

Lead inhibits ferrochelatase and ALA dehydratase, so you’ll have decreased heme synthesis and increased RBC protoporphyrin

• inhibits rRNA degradation, causing aggregates of rRNA (see basophilic stippling)
• high risk in old houses with chipped paint

Question 20

LEAD poisoning pneumonic

Answer 20

LEAD:

• Lead Lines on gingivae (burton lines) and metaphyses of long bones on xray
• Encephalopathy and Erythrocyte basophilic stippling
• Abdomoinal coli cand sideroblastic Anemia
• Drops - wrist and foot drop. Dimercaprol and EDTA are 1st line treatment
• SUCcimer for chelation in kids (It “SUCks: to be a kid who eats lead)

Question 21

sideroblastic anemia treatment

Answer 21

B6 pyridoxine(cofactor for delta-ALA synthase)

Question 22

sideroblastic anemia findings

Answer 22

ringed sideroblasts (with iron-laden Prussian blue-stained mitochondria) seen in bone marrow

• increased Fe, nl/low TIBC, increased ferritin