Intro to Hematopathology + anemia

Question 1

MCV

Answer 1

Mean Corpuscular Volume

Question 2

RDW

Answer 2

Red cell Distribution Width:

variance in cell size

Question 3

MCH

Answer 3

weight of Hgb

in red cell

Question 4

MCHC

Answer 4

concentration of Hgb

in red cell

Question 5

MPV

Answer 5

Mean platelet volume

Question 6

10 Things to look at on a blood smear

Answer 6

1. Red cell number
2. Red cell size
3. Red cell shape
4. Red cell chromasia
5. Reticulocytes
6. Weird stuff
7. White cell number
8. White cell differential
9. Platelet count
10. Platelet morphology

Question 7

Iron-Deficiency Anemia

Answer 7

Most important cause: GI bleeding
Microcytic, hypochromic anemia
Increased anisocytosis and poikilocytosis
Abnormal iron studies

Bottom line:
Premenopausal women: 
think MENORRHAGIA
Everyone else: 
think GI BLOOD LOSS

Symptoms:
asymptomatic
…or fatigue, dizziness
Signs:
pale
spoon nails
smooth tongue
Pica
craving for dirt, ice, Windex
cause or symptom?

Question 8

Iron storage

Answer 8

ferritin: quick in, quick out
hemosiderin: more stable

Question 9

Morphology of Iron-Deficiency Anemia

Answer 9

Blood
hypochromic, microcytic anemia
anisocytosis (RBCs of unequal size)
poikilocytosis (abnormally shaped RBCs)
decreased reticulocytes
increased platelets

Bone marrow
erythroid hypoplasia
dyserythropoiesis (defective RBC development)
decreased iron stores

Question 10

Labs in Iron-Deficiency Anemia

Answer 10

decreased serum iron
increased total iron-binding capacity
decreased ferritin

Question 11

Megaloblastic Anemia

Answer 11

Defective DNA synthesis
Nuclear/cytoplasmic asynchrony
decreased B12/folate
Macrocytic anemia with oval macrocytes and hypersegmented neutrophils

retarded DNA synthesis  and
unimpaired RNA synthesis
lead to...
BIG cells! 
immature nucleus
mature cytoplasm

In a patient with macrocytosis…
ALWAYS check for B12 deficiency.
(Even if folate is low!)

Question 12

B12

Answer 12

B12 sources
Meat, dairy, cereal
Not veggies!

B12 absorption, transport
Binds to IF (from parietal cells)
Absorbed in distal ileum
Carried in blood by transcobalamin II

converts homocysteine to methothionine

Question 13

Causes of B12 Deficiency

Answer 13

Diet (rare)
Lack of IF
Pancreatic damage
Ileal damage
Tapeworm

Question 14

Folate

Answer 14

Folate sources
Lots!
Green leafy veggies

Folate absorption, transport
Absorbed in jejunum
Converted to methyl-FH4
Transported freely to liver, red cells

Question 15

Causes of Folate Deficiency

Answer 15

Diet (small reserve)
Alcohol abuse
Jejunal damage
Drugs

Question 16

Morphology of Megaloblastic Anemia

Answer 16

Blood:
Macrocytic anemia
Oval macrocytes
Hypersegmented neutrophils

Bone marrow:
Megaloblastic erythroblasts
Megaloblastic neutrophils

Question 17

Megaloblastic Anemia: Diagnosis

Answer 17

MCV>100

smear:

megaloblastic
changes:
Serum B12: if decreased do schilling, pernicious anemia
Serum folate: if decreased, due to diet
RBC folate
if folate and B12 normal, its drugs or congenital

or no megaloblastic
changes:
alcoholism
myelodysplasia

Question 18

Types of Hemolytic Anemia

Answer 18

Chronic (usually congenital)
Well-compensated
Sometimes have crises

Acute (usually acquired)
Back, abdominal, limb pain
Headache, malaise, fever
Jaundice, pallor, tachycardia

Inherited
Membrane defects
Enzyme deficiencies
Globin defects

Acquired
Autoimmune hemolytic anemia 
Microangiopathic hemolytic anemia
Infection-related
Drug-related

Question 19

Signs of Destruction and Production

Answer 19

increased RBC destruction:
increased serum bilirubin
increased LDH
decreased haptoglobin
Hemoglobinemia/-uria 

increased RBC production:
Reticulocytosis
Nucleated red cells in blood

Question 20

Osmotic fragility test

Answer 20

Measures fragility of red cells

Positive result means spherocytes present

Question 21

Morphology of Hemolytic Anemia

Answer 21

Normochromic, normocytic anemia
Spherocytes
Other poikilocytes:
targets
sickles
fragmented red cells

Question 22

How to diagnose a Hemolytic Anemia

Answer 22

Look for signs of hemolysis:
Signs of destruction
Signs of production

Determine cause:
DAT + means immune cause
DAT - means non-immune cause

Question 23

Treatment of Hemolytic Anemia

Answer 23

Treatment depends on cause
If acute:
treat shock
use transfusions with caution

Splenectomy may help

Question 24

Hereditary Spherocytosis

Answer 24

Tons of spherocytes
Spectrin defect
Splenectomy is curative

Triad: anemia, jaundice, splenomegaly
“Common” (1 in 5000)
Variable age of onset, severity
Crises (often: parvovirus)

treatment:
Splenectomy
Or RBC transfusions as needed