Hematolgy I - DONE Flashcards
What is hematocrit?
Percentage of whole blood that is comprised of red blood cells
- HCT (%) = MCV(fL) x RBC(mln/µL) / 10
- Reference ranges: 26-50%
What is hematocrit used for?
- Identify and evaluate the severity of anemia (low RBCs, low hemoglobin, low hematocrit) or polycythemia (high RBCs, high hemoglobin, high hematocrit)
- Monitor the response to treatment of anemia or polycythemia and other disorders that affect RBC production or lifespan
- Help make decisions about blood transfusions or other treatments if anemia is severe
- Evaluate dehydration
MCV =
Mean Corpuscular Volume
What is Mean Corpuscular Volume (MCV)?
A measurement of the average size of a single red blood cell
- MCV (fL) = HCT (%) x 10 / RBC (mln/µL)
- Reference ranges: 80-96 fL (depends on age)
What is the factor 3 rule?
Physiologically RBC count, hemoglobin and hematocrit are related to one another by a factor 3
- RBC (x10^6/ul)x3=Hemoglobin (g/dL)
- Hemoglobin (g/dL)x3= Hematocrit (%)
MCH =
mean corpuscular hemoglobin weight
What is Mean Corpuscular Hemoglobin weight (MCH)?
A calculation of the average amount of hemoglobin inside a single red blood cell
- Reference ranges: 26-38 pg
- MCH = HGB (g/dL) x10 / RBC (mln/µL)
MCHC =
Mean Corpuscular Hemoglobin Concentration
What is Mean Corpuscular Hemoglobin Concentration (MCHC)?
A calculation of the average concentration of hemoglobin inside a single red blood cell
- Reference ranges: 31-37 g/dL
- MCHC = HGB(g/dl) x100 / HCT(%)
What does high MCHC indicate?
High MCHC is indicative for hereditary spherocytosis
What is indicative for hereditary spherocytosis?
High MCHC is indicative for hereditary spherocytosis
What is the maximal value of MCHC? And what does higher values than that indicate?
Maximal value 38 g/dL
- higher values are indicative for autoimmune hemolytic diseases
- a CBC should be measured in warm (37C) sample
RDW =
red blood cells distribution width
What is red blood cells distribution width (RDW)?
a calculation of the variation in the size of RBCs
- RDW CV (%) = SD x 100% / MCV
- RDW SD (fL) = MCVmax – MCVmin
What is anisocytosis?
Variable size of red blood cells is called
What are reticulocytes?
Immature red blood cel with network of ribosomes and endoplasmic reticulum
- Reference ranges: 0.5-1.5%
ESR =
Erythrocytes sedimentation rate
What is Erythrocytes sedimentation rate (ESR)?
the rate at which red blood cells sediment in a period of one hour
What results in elevated Erythrocytes sedimentation rate (ESR)?
If the ESR is elevated, it is typically a result of two types of proteins, globulins or fibrinogen
What can can increase Erythrocytes sedimentation rate (ESR)?
- dextran
- methyldopa
- oral contraceptives
- penicillamine procainamide
- theophylline
- vitamin A
What can can decrease Erythrocytes sedimentation rate (ESR)?
- aspirin
- cortisone
- quinine
What is anemia?
Decrease of hemoglobin concentration below reference ranges for age and gender
What does anemia do?
It stimulates several compensatory mechanisms:
- tachypnoe
- tachycardia
- EPO
How is anemia classified?
- Classification based on pathophysiology
- Classification based on MCV
(SE TABLE page 4/11)
What are the markers of hemolysis?
- ↑ LDH
- ↑ Bilirubin (unconjugated)
- ↓ haptoglobin
- ↑ plasma hemoglobin
- Hemoglobin in urine
- Hemosiderin in urine
What are the symptoms of hemolytic anemia?
- Jaundince
- fatigue
- tachycardia
- pallor
- pigmented gallstones
- back pain
- dark urine
- splenomegaly
Intravascular hemolysis:
- Schistocytes
- ↑LDH
- ↓haptoglobin
- ↑ free hemoglobin, urine hemoglobin
- hemosideruria
Extravascular hemolysis:
- Microspherocytes
- ↑LDH
- N or ↓haptoglobin
- ↑indirect bilirubin
- ↑urine and fecal urobilinogen
Autoimmune hemolytic anemia:
- Antibody attaches to red blood cell
- Opsonins cause RBCs destruction in spleen
- Others activate complement Warm autoimmune hemolytic anemia IgG antibodies that bind RBC in 37°C
Opsonins (google def:)
it is any molecule that enhances phagocytosis by marking an antigen for an immune response or marking dead cells for recycling
Cold autoimmune hemolytic anemia
- IgM antibodies that bind RBC in 0-22°C
- Diagnosis: positive DAT
Post-transfusion autoimmune hemolytic anemia:
Transfusion of red blood cells bearing an antigen foreign for recipient
Hemolytic disease of newborns diagnosis:
blood group typing of mother, father and neonate, DAT, indirect AT during pregnancy, fetal RBC in maternal blood enumeration
Hereditary spherocytosis:
- genetic defects of spectrin, ankiryn, band 3 protein, protein 4.2 and/or others erythrocytes plasma membrane proteins.
- Deficiency of cytoskeleton proteins results in characteristic red blood cell’s shape