RBC Disorders - Diagnostic studies Flashcards
Contains EDTA as anticoagulant
“Purple top” or “Lavender top”
vacutainer tubes are used for CBC
A CBC with diff includes
_____, in addition to normal CBC
information:
WBC differentiation
When is CBC with diff indicated?
Generally costs a little more and is really only indicated when infectious processes are in question or in the case of leukemia/lymphoma
On a CBC, “Hgb” gives us the ____
total hemoglobin concentration
Hemoglobin & hematocrit are increased in
hemoconcentration (vomiting,
dehydration, burns), polycythemia, etc.
Hemoglobin & hematocrit are decreased in
hemodilution and macrocytic,
normocytic, and microcytic anemias
Critical low for hemoglobin
Critical low: Less than 7 g/dL
How is HgB measured?
It is measured by spectrophotometry on automated instruments after lysis of RBCs as part of the process
Hct
The percentage of whole blood
volume composed of erythrocytes.
How is Hct measured?
Nowadays, measured by automated
instruments with calculation of RBC
count X the MCV.
○ Normal for males: About 39-49%
○ Normal for females: About 35-45%
Anemia diagnosis with CBC
“Anemia” can be diagnosed based on
the H & H, but then further evaluation of the CBC (and possibly other tests) is needed to determine the type and cause of the anemia
Red Blood Cell Count
The actual number of red blood cells in a microliter of blood
RBC’s counting process and range
RBCs are counted by automated instruments using electrical impedance or light scattering.
○ Normal for males: About 4.3-6.0 x 10 6 /mcL
○ Normal for females: About 3.5-5.5 x 10 6 /mcL
RBCs increased in
Polycythemia vera, secondary
polycythemia, hemoconcentration (such as dehydration), etc.
RBCs are decreased in
most macrocytic, normocytic,
and microcytic anemias.
White Blood Cell Count measurement
Typically measured by an automated lab hematology analyzer in today’s day in age. Manual differentiation can be done.
○ Normal: About 4.5-11.0 x 10 3 /mcL. Critical: Less than 1.5
WBC count is increased in
acute infections, inflammatory disorders, leukemias, myeloproliferative
disorders, steroid use, allergies,
hypersensitivity reactions, stress, etc
WBC count is decreased in
infections, myeloid hypoplasia,
myelosuppression, hypersplenism, alcoholism, etc
Absolute counts of WBCs can be calculated from a combination of the
_____
WBC count and the percentage of each WBC type
Platelet count measurement
It is typically obtained by an automated CBC analyzer.
○ Normal: About 150-450,000 per mcL
○ Many labs are now reporting 100-500,000 as normal
Critical low platelets
Less than 25,000 per mcL
Critical low WBCs
Less than 1.5
WBC normal ranges
○ Neutrophils: 50-70%
○ Lymphocytes: 20-40%
○ Monocytes: 2-6%
○ Eosinophils: 1-4%
○ Basophils: 0-1%
Platelets can be increased in
some myeloproliferative conditions, some myelodysplastic disorders, acute blood loss, postsplenectomy,
reactive thrombocytosis, infection, some malignancies, etc
Platelets can be decreased in
bone marrow suppression, chemotherapy, HIV, hypersplenism, disseminated intravascular coagulopathy, TTP, ITP, some drugs, etc
RBC Indices
Red Blood Cell indices are a group of blood tests
included in the CBC that provide information about the
hemoglobin content and size of red blood cells
What is included in the RBC indices
○ Mean Corpuscular Volume (MCV)
○ Mean Corpuscular Hemoglobin (MCH)
○ Mean Corpuscular Hemoglobin Concentration (MCHC)
○ Red Cell Distribution Width (RDW)
Abnormal values in RBC indices areas can indicate the presence of
_____
certain types of anemia
The _____ is the average volume of the
red blood cells.
Mean Corpuscular Volume
Helps us determine if an anemia is categorized as a
macrocytic, normocytic, or microcytic anemia
MCV
Normal MCV
80-100 fl
Common microcytic anemias based on MCV
● Iron Deficiency
○ Chronic blood loss
○ Dietary
● Thalassemias
● Anemia of Chronic Disease (some)
● Lead toxicity
Common normocytic anemias based on MCV
● Anemia of Chronic Renal Disease
● Anemia of Chronic Disease (some)
● Aplastic Anemia
● Acute Blood Loss
● Hemolytic Anemia
Common macrocytic anemias based on MCV
● Vitamin B12 Deficiency
● Folate Deficiency
● Myelodysplasia
● Alcoholism related
● Aplastic Anemia (sometimes)
The Mean Corpuscular Hemoglobin indicates the amount of
hemoglobin per RBC in absolute units
Mean corpuscular hemoglobin
MCH increased in
macrocytosis and hemochromatosis
Normal MCH =
26-34 pg
MCH decreased in
iron deficiency, thalassemia, lead poisoning, and anemia of chronic disease
The ____ represents the average hemoglobin concentration in RBCs
Mean Corpuscular Hemoglobin Concentration - MCHC
Normal MCHC
31-36 g/dL
MCHC increased in
autoimmune hemolytic anemia, as well as other forms of hemolytic anemia
MCHC decreased in
iron deficiency anemia, thalassemia, lead poisoning, anemia of chronic disease, etc.
The ____ is a measurement of the variability of RBC size
RDW - Red Cell Distribution Width
_____ means variability in the size of RBCs
Anisocytosis
Normal rance RDW
11.5-14.5
The higher it is, the more variation in size describes what
RDW
Normal RDW And elevated MCV =
Aplastic anemia
Normal RDW And normal MCV:
Normal (obviously), or it could be anemia of chronic disease, acute blood loss, hemolysis, thalassemia, etc
Elevated RDW and elevated MCV:
Vitamin B12 deficiency, folate deficiency,
autoimmune hemolytic anemia, liver disease, etc
Elevated RDW and normal MCV:
EARLY iron deficiency anemia, folate
deficiency anemia, or vitamin B12 deficiency anemia
elevated RDW and decreased MCV:
Iron deficiency anemia, certain forms of
Thalassemia (uncommon).
Serum Vitamin B12 Level is increased in
Leukemia, marked leukocytosis, and
polycythemia vera (not diagnostically useful, however).
Serum Vitamin B12 Level is decreased in
Pernicious anemia, gastrectomy, gastric
carcinoma, malabsorptive conditions (such as Celiac Disease), pregnancy, dietary deficiency, and some drugs
(such as omeprazole, metformin, carbamazepine).
Folate can either be measured as a _____ or _____
plasma level or from the
red blood cells (both automated processes)
Folic acid is decreased in
folic acid deficiency (inadequate intake,
malabsorption), alcoholism, some drugs, vitamin B12 deficiency (50-60%, since cellular uptake of folate depends on Vitamin B12).
_____ is very important for maintaining several functions in the body, especially the production of functional hemoglobin
Iron
Serum iron is increased in
excessive iron states, hemolytic anemia, pernicious anemia, thalassemia, hemochromatosis, etc.
Serum iron is decreased in
iron deficiency anemia,
nephrotic syndrome, chronic renal failure,
and active hematopoietic states
_____ is a measurement of the
maximum amount of iron the blood is able to bind/carry
Total Iron Binding Capacity - TIBC
an indirect measure of available Transferrin
TIBC
Each Transferrin is able to bind ____ Iron molecules
two
Normal TIBC
About 250-460 mcg/dL
TIBC is increased in
iron deficiency anemia, infancy, acute hepatitis, late pregnancy, and some oral contraceptives
Decreased in _____
hypoproteinemic states (malnutrition,
nephrotic syndrome), hemochromatosis, thalassemia, etc.
Normal ferritin level
○ Normal for males: About 16-300 ng/mL
○ Normal for females: About 4-161 ng/mL
In the absence of liver disease and infection/inflammation,
_____ is a more sensitive test for iron deficiency than TIBC
and serum iron levels
Ferritin
Ferritin is decreased in
iron deficiency
Ferritin is increased in
Hemochromatosis, acute or chronic liver disease, alcoholism, inflammatory conditions, some malignancies, etc.
Similar to and based off the TIBC, the _____ is an estimate of the percentage of Transferrin that
is saturated with iron
percent of iron saturation
Percent iron saturation is increased in ____
hemochromatosis, excessive iron intake,
hemolytic anemia, recent transfusion, thalassemia, etc.
Percent iron saturation is decreased in ____
hypochromic anemias, such as iron deficiency anemia (usually saturation less than 16%).
Peripheral Blood Smear
Also sometimes called a Blood Film or Manual Differential, this test
involves examining a whole blood sample under a microscope
The peripheral blood smear should be
examined when the CBC _____
reveals abnormal
blood counts.
T/F No evaluation of anemia is complete without
inspection of the blood smear
T
Poikilocytosis
Variability in RBC shape
Spherocytes
Small, spherical RBCs
_____, a familial hemolytic disorder caused by hemolytic destruction of abnormally shaped RBCs (a form of
hemolytic anemia)
Hereditary spherocytosis
Target Cells are
RBCs with small amounts of Hgb
Seen sometimes with Hemoglobinopathies, such as Thalassemia, sickle cell disease, etc
_____: Fragmented RBCs, appearing in various “jagged” shapes
Schistocytes
____: Inclusions within RBCs composed of denatured Hgb
Heinz Bodies
____: Damaged RBCs, with chunks taken out.
Bite Cells (Degmacyte)
○ Fairly characteristic of hemolytic anemia secondary to G6PD deficiency
_____: Nuclear remnants (clusters of DNA) in RBCs
Howell-Jolly Body
_____: Stacks or linear aggregates of RBCs
Rouleaux Formation
Characteristic of Multiple Myeloma (or preparation artifact)
Rouleaux Formation:
_____: Small peripheral dots in the RBCs (ribosomes)
Basophilic Stippling
Several potential causes of basophilic stippling
Hemolytic anemia, lead poisoning, heavy metal poisoning, alcohol abuse, Myelodysplastic syndrome, etc
A reticulocyte count measures ____
how rapidly these are produced
by the bone marrow and released into circulation
○ Reflects the erythropoietic activity of the bone marrow
Reticulocyte count is increased in
hemolytic anemia, acute blood loss, and response to therapy from iron, vitamin B12, or folate
Reticulocyte is decreased in
iron deficiency anemia, aplastic anemia,
anemia of chronic disease, megaloblastic anemia, bone marrow suppression or infiltration, myelodysplastic syndrome, etc
Normal reticulocyte count
33-137K / mcL
Hemoglobin Electrophoresis
A blood test that can detect different forms of Hemoglobin found within a patient’s blood sample
Coomb’s Test two types:
Also known as Antiglobulin Test (AGT)
○ Direct Coomb’s Test (DCT) / Direct Antiglobulin Test (DAT)
○ Indirect Coomb’s Test (ICT) / Indirect Antiglobulin Test (IAT)
● The Direct Coomb’s Test is more sensitive and specific for diagnosing Autoimmune Hemolytic Anemia.
