Intro to Hematopathology + anemia Flashcards
MCV
Mean Corpuscular Volume
RDW
Red cell Distribution Width:
variance in cell size
MCH
weight of Hgb
in red cell
MCHC
concentration of Hgb
in red cell
MPV
Mean platelet volume
10 Things to look at on a blood smear
- Red cell number
- Red cell size
- Red cell shape
- Red cell chromasia
- Reticulocytes
- Weird stuff
- White cell number
- White cell differential
- Platelet count
- Platelet morphology
Iron-Deficiency Anemia
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?
Iron storage
ferritin: quick in, quick out
hemosiderin: more stable
Morphology of Iron-Deficiency Anemia
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
Labs in Iron-Deficiency Anemia
decreased serum iron
increased total iron-binding capacity
decreased ferritin
Megaloblastic Anemia
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!)
B12
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
Causes of B12 Deficiency
Diet (rare) Lack of IF Pancreatic damage Ileal damage Tapeworm
Folate
Folate sources
Lots!
Green leafy veggies
Folate absorption, transport
Absorbed in jejunum
Converted to methyl-FH4
Transported freely to liver, red cells
Causes of Folate Deficiency
Diet (small reserve)
Alcohol abuse
Jejunal damage
Drugs
Morphology of Megaloblastic Anemia
Blood:
Macrocytic anemia
Oval macrocytes
Hypersegmented neutrophils
Bone marrow:
Megaloblastic erythroblasts
Megaloblastic neutrophils
Megaloblastic Anemia: Diagnosis
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
Types of Hemolytic Anemia
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
Signs of Destruction and Production
increased RBC destruction: increased serum bilirubin increased LDH decreased haptoglobin Hemoglobinemia/-uria
increased RBC production:
Reticulocytosis
Nucleated red cells in blood
Osmotic fragility test
Measures fragility of red cells
Positive result means spherocytes present
Morphology of Hemolytic Anemia
Normochromic, normocytic anemia Spherocytes Other poikilocytes: targets sickles fragmented red cells
How to diagnose a Hemolytic Anemia
Look for signs of hemolysis:
Signs of destruction
Signs of production
Determine cause:
DAT + means immune cause
DAT - means non-immune cause
Treatment of Hemolytic Anemia
Treatment depends on cause
If acute:
treat shock
use transfusions with caution
Splenectomy may help
Hereditary Spherocytosis
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
