CBC Flashcards
In a study, the patient’s diagnosis was made by the internist from:
- patient history: __%
- physical examination: __%
- laboratory diagnosis: __%
what should this tell you?
- 76%
- 12%
- 11%
you should not rely solely on lab tests; there are gray areas on lab interpretations; false-positives and false-negatives; interpreter or machine error exists
Greek root for white?
leuk
What occurs when you have insufficient or malformed red blood cells?
anemia
What do RBCs carry?
hemoglobin
What does hemoglobin transport?
iron
Any disorder that decreases RBCs can result in (…)
iron-deficiency (anemia)
What is one of the main tests used to diagnose anemia?
CBC
- Where might you lose you erythrocytes?
- what conditions might destroy your RBC?
- How do anemic people feel?
- menstruation, nose bleeds
- sickle cell, toxins, strong infections
- fatigue, SOB, pale under the eyes
What is another name for RBC?
erythrocytes
- What is the lifespan of RBC?
- How many RBCs are replaced daily?
- 120 days
- approximately 1%
What is a regulatory hormone that works on feed back loop and increases or decreases production upon demand for RBCs?
Erythropoietin (EPO)
Where is erythropoietin produced?
in the kidneys
When might we need to increase production of RBCs?
- at high altitude
- if you are bleeding a lot
For RBC production to work correctly, what factors are needed?
- iron
- vitamin B12 and folic acid
- vitamin C
If a patient is deficient in vitamin B12 or folic acid, what can occur and what is the result?
- impaired RBC maturation/differentiation due to impaired DNA synthesis
- result is large, undifferentiated RBC that is easily destroyed (megaloblast)
What is a very large, undifferentiated RBC that is easily destroyed?
megaloblast
What helps mobilize iron from its various forms to useful form for erythrocyte?
vitamin C
Vitamin B12 and folate deficiency leads to (…) which results in what type of erythrocytes?
- inhibition of DNA synthesis (cell multiplication)
- very few, large hemoglobin-rich erythrocytes (will be red and large)
Iron deficiency leads to (…) which results in what type of erythrocytes?
- inhibition of hemoglobin synthesis
- a few, small hemoglobin-poor erythrocytes (will be pale and small)
Vitamin B12 and folate are integral for erythrocyte DNA synthesis and differentiation, so in there absence, nuclear development is (…) than cytoplasmic development, so there will be (…) cytoplasm when folate or B12 deficient
- nuclear development is less than cytoplasmic development
- larger cytoplasm
What are the different common types of anemia?
- iron-deficiency anemia
- vitamin-deficiency anemia
- aplastic anemia
- hemolytic anemia
What is the most common form of anemia?
iron-deficiency anemia
What type of amenia results from low levels of vitamin B12 or folate?
vitamin-deficiency anemia
What is a more rare anemia that results when the body stops erythropoiesis?
aplastic anemia
What is the type of anemia that results from the destruction of RBCs?
hemolytic anemia
What type of anemia do these lead to:
- blood loss- loss of iron
- poor dietary intake in malnutrition or eating disorder
- pregnancy- increased demand
- gastric bypass- poor absorption (cutting of a lot of absorption sites)
iron-deficiency anemia
What type of anemia do these lead to:
- poor dietary intake in malnutrition or eating disorder
- alcoholism: reduces absorption of vitamins from GI tract
vitamin-deficiency anemia
What type of anemia do these lead to:
- toxin exposure, such as chemical exposure (benzene)
- some medications used to treat autoimmune disease
- some viruses (Epstein-Barr)
aplastic anemia
What type of anemia do these lead to:
- many causes including infection, genetics, autoimmune disease
hemolytic anemia
What type of anemia occurs in the presence of multiple chronic conditions?
anemia of chronic disease (ACD)
What type of anemia results from decreased RBC production by bone marrow?
anemia of chronic disease (ACD)
What type of anemia results from chronic inflammatory processes and poor production of erythropoietin in the kidneys?
anemia of chronic disease (ACD)
Anemia of chronic disease is common to see in patients with what?
- kidney disease
- cancer
- autoimmune disease
What type of anemia results when the bone marrow produces abnormal RBCs which prevent iron not incorporated in hemoglobin?
sideroblastic anemia
What type of anemia can be alpha or beta?
thalassemia
What may be one of the most important laboratory tests used in clinical medicine? When is it often ordered during?
CBC
- routine medical examination
- evaluation of infection
- evaluation of any type of inflammation
- evaluation of a possible neoplastic process (cancer)
What are some positives of CBC tests?
- provides high yield of information
- low-cost test
What in included (measured) in the CBC?
- white blood cells
- red blood cells
- platelets
What are the different types of white blood cells (there are 5)?
- monocytes
- lymphocytes
- eosinophils
- basophils
- neutrophils
What WBCs are collectively referred to as:
- granulocytes
- “the three phils”
- eosinophils
- basophils
- neutrophils
What are neutrophils referred to as?
- polymorphonuclear leukocytes
- “PMNs”
- “Polys”
What WBCs are the most important?
neutrophils
What number of the CBC may be considered the most important?
WBCs
What is the normal range of total WBC?
4.5-11.0 x 10^3/uL
What type of cells are responsible for fighting off infections?
WBC
Fluctuations in WBC can occur with what?
- stress
- exercise
- pain
- during pregnancy
- Elevated WBC count is described as (…)
- Decreased WBC count is described as (…)
- leukocytosis
- leukopenia
What causes leukocytosis?
- bacterial infections (less commonly, viral infections)
- widespread inflammation (autoimmune diseases)
- trauma and pain
- leukemia
Oral corticosteroids, such as prednisone, can cause (…)
- can occur within hours to days and typically resolves after finished
leukocytosis
In what patient(s) might you expect to see leukocytosis?
- patient with bacterial meningitis and septicemia
- patient given oral steroids for poison ivy
What does leukopenia typically result from?
- decreased production of RBC OR
- increased destruction of RBC
What causes leukopenia?
- viral infections
- benign ethnic leukopenia
- cancer or toxin-related
- malabsorption
Most (…) cause no decrease in total WBC count
viral infections
What are some viral infections that often cause leukopenia?
- measles
- influenza
Benign ethnic leukopenia in common in individuals of (…) descent and can confer (…) protection
- African descent
- malaria protection
Cancer or toxin-related leukopenia can be caused by treatment with (…) or (…) due to bone marrow failure
- radiation or chemotherapy
- aplastic anemia
Malabsorption causing leukopenia can be caused by what?
- alcohol use/abuse
- poor nutrition
- gastric bypass
- The majority of WBCs are (…)
- Any increase or decrease in total WBC count is usually a reflection of a change in (…)
neutrophils
- Neutrophilia is used interchangeably with (…) and (…)
- Neutropenia is used interchangeably with (…)
- leukocytosis and granulocytosis
- leukopenia
Causes of leukocytosis and leukopenia are causes of (…) and (…)
- neutrophilia
- neutropenia
Neutrophils come in two forms, (…) and (…)
- band neutrophils
- segmented neutrophils
- Which neutrophils have an immature nucleus?
- Which neutrophils have mature nucleus?
- band neutrophils
- segmented neutrophils
What refers to the level of maturation of the neutrophil in the blood sample?
the left shift
A left shift is caused by a higher predominance of (…) neutrophils present on a particular CBC
immature neutrophils
A left shift is often seen in (…) or (…) response
- infection (or)
- inflammatory response
There is usually not a left shift in (…) use, which may help make a diagnosis
corticosteroid use
You will not always see a left shift on WBC in infection, so it is only helpful to rule out what?
corticosteroid use as cause of leukocytosis
left shift is not steroid related
- Severe neutropenia puts individuals at a high risk for (…)
- Moderate neutropenia puts individuals at (…)
- Mild neutropenia puts individuals at (…)
- overwhelming and life threatening bacterial infection
- moderate risk for infection
- mild risk for infection
What are the three types of lymphocytes?
- T cells
- B cells
- Natural Killer cells (NK)
What’s function is to form immunity against foreign proteins and pathogens?
lymphocytes
Binding sites on which lymphocytes bind to specific antigens and play a role in their destruction?
T cells and B cells
What lymphocytes are involved in the destruction of tumors and virally infected cells?
NK (natural killer) cells
What are immature lymphocytes called?
blasts
What do these cause:
- infection (viral infections)
- mononucleosis virus
- cytomegalovirus (CMV)
- primary HIV infection
- viral pneumonia
- measles, mumps, rubella viruses
- varicella-zoster virus
- a few bacterial infections
- stress, drug reactions, and tobacco/alcohol abuse
Lymphocytosis (↑ lymphocytes)
The mononucleosis virus usually demonstrates 50% (…) and 10% or more (…)
- lymphocytes
- atypical lymphs
Which bacteria can cause lymphocytosis?
- Bordatella pertussis: “whooping cough”
- Bartonella henselae: “cat scratch disease*
What is the normal percentage of lymphocytes in WBCs?
20-40%
What do these cause:
- bacterial or fungal sepsis
- after surgery
- chemotherapy or radiation
- malignancy
- corticosteroids and other immunosuppressant medications
lymphocytopenia (↓ lymphocytes)
What is usually seen in patients in “comprised states” such as very ill patients?
lymphocytopenia
- An increase in neutrophils may be caused by (…) infections
- An increase in lymphocytes may be caused by (…) infections
- bacterial
- viral
What is the precursor of the macrophage?
monocyte
What helps remove dead or damaged tissue by evolving into macrophages and removes cellular debris?
monocytes
Macrophages secrete over 100 proteins that contribute to what?
host defense and immunity
What is monocytosis caused by?
- bacterial, viral, or parasitic infections
- multiple forms of leukemia and lymphoma
- chronic inflammatory diseases such as lupus and inflammatory bowel disease (crohn’s and ulcerative colitis)
Monocytopenia is (…)
rare
What is the name for increased eosinophils?
eosinophilia
What WBC is highly associated with allergies and allergic reactions?
eosinophils
What causes eosinophilia?
- parasites
- allergic disorders
- drug reactions
What causes eosinopenia?
many bacterial infections
What are similar to eosinophils as they are elevated in cases of parasitic infections and allergy-related illnesses?
basophils
What is probably the least used component of the CBC and is named the “boring and sad old phil”?
basophil
What are the smallest, but most numerous of the three main blood cell types?
platelets
What makes up only a small fraction of blood volume and has a main purpose to keep people from bleeding to death?
platelets
What is responsible for hemostasis and thrombosis through activation due to injury, adherence to endothelial wall of vessel, aggregation and interaction with coagulation factors?
platelets
What is the normal value of platelet count?
150-450 x 10^3/uL
Platelet counts are important in determining if a patient has what?
aa coagulation disorder, such as unexplained bruising
What should your first thought be when you see unexplained bleeding or bruising?
platelet function or underlying pathways of platelet function – if platelets are functioning, we can look at the factors of coagulation cascade
What is reactive thrombocytosis?
an increase in platelet count
What is reactive thrombocytosis typically driven by?
cytokines
What are inflammatory mediators produced in response to stress, infection, and injury?
cytokines
When cytokines are released, (…) can occur, driving up platelet count?
reactive thrombocytosis
What are some causes of thrombocytosis?
- infections
- post-surgery
- malignancy
- acute blood loss
- iron-deficiency anemia
What can cause thrombocytopenia?
- lab error
- medications
- viral, bacteria, and parasitic infections
- alcohol use
- pregnancy
- nutritional deficiencies
- malignancies
Why is lab error a reason why thrombocytopenia can occur?
platelets can be clumped by preservatives in blood collection tube or by error in automated cell counter at lab
What is the normal value of RBCs?
- males: 4.6-6.0 x 10^6/uL
- females: 3.9-5.5 x 10^6/uL
What is the most useful in the diagnosis of anemia?
RBC count
What other information can you get in a CBC about RBCs?
RBC indices
- volume of RBC
- concentration of hemoglobin in RBC
- weight of hemoglobin in RBC
What is erythrocytosis?
increase in RBC count
What is erythrocytopenia?
decrease in RBC count (anemia)
What describes an abnormally high RBC count and corresponding high hemoglobin count?
erythrocytosis
What does hypoxia stimulate?
increase in production of erythropoietin (EPO) by the kidneys
What are associated conditions with erythrocytosis?
- high altitude
- pulmonary diseases (emphysema)
- cancer
- renal disease
- EPO abuse (lance Armstrong)
What can cause erythrocytopenia?
- bleeding (GI or GYN primarily)
- bone marrow failure (radiation, toxins, or tumors)
- poor nutrition (B6, B12, folate, iron)
- drug induced (antibiotics, anti-inflammatories)
- pregnancy
- overhydration
What value(s) are increased in newborns?
- hemoglobin
- hematocrit
It is important to think of (1) and (2) as very close friends, they are often inseparable and tend to follow the same direction and are “attached” to each other?
- hemoglobin
- RBC
The same conditions that cause increased or decreased RBC production will also cause and increased or decreased (…) production
hemoglobin
If a patient pulls down on their bottom eyelid and it is pale, what is most likely affected?
decreased hemoglobin
What describes the percentage of whole blood that is made up of RBCs and is also called the packed cell volume (PCV)?
hematocrit
An increase or decrease in hematocrit values are the same causes as (…)
increased or decreased RBC
What blood levels trend with RBCs in many cases?
- hemoglobin
- hematocrit
What are the RBC indices (4 tests)?
- MCV
- MCH
- MCHC
- RDW
RBC indices give helpful information about what?
the types and causes of anemia
MCV, MCHC, and MCH are calculated mathematically using what?
- RBC count
- hemoglobin
- hematocrit
the fourth test (RDW) is not part of any calculations
What does RDW mean?
RBC distribution width
What describes the variation of the RBC volume (not diameter) of the erythrocyte from the standard deviation (as a percentage)?
- RDW
What does a higher RDW value mean?
larger variation in RBC volume
What may indicate many immature cells and production that is trying to compensate for loss or destruction?
a higher RDW
What appears to be the earliest manifestation of iron-deficiency anemia and is frequently increased in nutritional-linked anemias?
the RDW (higher)
What is considered to be less diagnostic than other RBC indices?
RDW
- A normal RDW has RBCs that are (…)
- An increased RDW has RBCs that are (…)
- the same size
- varying in size
What is the word describing cells of varying sizes?
anisocytosis
What does MCV stand for?
mean corpuscular volume
What measures the average volume of the RBC by dividing the Hct/Hgb and is used in the classification of type of anemia?
MCV
MCV categorizes the size of RBCs and divides them into 3 categories, what are they?
- microcytic: small, low volume RBCs
- normocytic
- macrocytic: larger than normal RBCs
- Microcytic leads to (…) MCV
- Macrocytic leads to (…) MCV
- a decreased MCV
- an increased MCV
In some forms of anemia, especially iron-deficiency anemia, RBCs become (…)
microcytic (small and puny)
What measures the mean amount of hemoglobin in each red blood cell in picograms/cells?
MCH
What does MCH stand for?
mean corpuscular hemoglobin
What measures the mean concentration of hemoglobin per volume of red cells in grams/deciliter (hemoglobin density) and takes the volume/size of the RBC into account?
MCHC
What does MCHC stand for?
mean corpuscular hemoglobin concentration
MCHC is also used in determination of what?
type of anemia
Iron is responsible for giving blood its (…)
- increased hemoglobin = increased iron = increased (…)
- characteristic red color
- increased red color of RBC
- What is a decreased concentration of hemoglobin called? How is MCH/MCHC affected?
- What is a normal concentration of hemoglobin called? How is MCH/MCHC affected?
- What is an increased concentration of hemoglobin called? How is MCH/MCHC affected?
- hypochromic RBCs, decreased MCH/MCHC
- normochromic RBCs, normal MCH/MCHC
- hyperchromic RBCs, increased MCH/MCHC
Microcrytic hypochromic anemia will have what type of RBCs?
smaller, paler RBCs
Macrocrytic normochromic anemia will have what type of RBCs?
larger, deeper red RBCs
spaghetti on a plate analogy
- RBC count = (1)
- hemoglobin = (2)
- hematocrit = (3)
- RDW = (4)
- MCV = (5)
- MCH = (6)
- MCHC = (7)
- total number of red plates present
- total amt of spaghetti present on all plates combined
- if you take all red plates & spaghetti, throw it in trash can, and fill trash can with water, what percentage of trash can filled by plates with spaghetti on them?
- if using different size plates, how much variation is there between volume of the plates
- average volume of all the red plates
- mean amount of spaghetti on our plates
- how much spaghetti fills the plate based on average volume of the plate
What type of anemia does this describe:
- acute blood loss
- anemia of chronic disease (75%)
- hemolytic anemia
- normocytic anemia
- low H&H
- MCV normal
75% of anemia of chronic disease is what?
normocytic
What type of anemia does this describe:
- iron-deficiency anemia (and hypochromic)
- alpha/beta thalassemia
- anemia of chronic disease (25%)
- lead poisoning
- microcytic anemia
- low H&H
- MCV low
25% of anemia of chronic disease is what?
microcytic
What type of anemia does this describe:
- alcoholism
- liver disease
- B12 or folate deficiency
- macrocytic anemia
- low H&H
- MCV high
iron-deficiency anemia causes what type of RBCs?
hypochromic microcytic anemia
What is used to look at RBCs and what they look like?
peripheral blood smears
What is not part of the CBC blood test and is primarily ordered to:
- follow up to abnormal CBC results
- investigate for bone marrow disorders?
reticulocyte count
What are immature red blood cells are are visible due to the presence of ribosomal RNA that turns blue when stained?
reticulocytes
What makes up approximately 1% of RBCs, circulate for 1-2 days, and then mature?
reticulocytes
In cases of severe anemia, (…) are prematurely released into circulation, so their count goes up?
reticulocytes
- What represents a recent or ongoing RBC production and activity?
- What represents decreases in RBC production
- elevated “retic count”
- decreased “retic count”
What are causes of an elevated retic count?
- hemolysis or hemolytic anemia
- acute blood loss
- bone marrow disorders (immature RBCs escape into circulation)
What are causes of a decreased retic count?
- vitamin deficiency anemia
- iron deficiency anemia
- bone marrow failure
- decreased EPO production due to renal disease/failure
- Hemoglobin A is composed of what?
- Hemoglobin A2 is composed of what?
- Hemoglobin F is composed of what?
- 2 alpha and 2 beta chains
- 2 alpha and 2 delta chains
- 2 alpha and 2 gamma chains
What type of hemoglobin results in higher oxygen affinity in utero?
hemoglobin F
What are some other common forms of hemoglobin types that result from variations in the beta hemoglobin chain?
S, C, E, & D
What are the many variations of Hgb and hemoglobinopathies?
- alpha thalassemia
- beta thalassemia
- hemoglobin S
- hemoglobin C
- hemoglobin E
- What results from impaired production of alpha chains?
- What results from impaired or very reduced beta hemoglobin chains?
- What causes sickle cell trait or disease?
- What causes mild anemia?
- What causes mild anemia, but is common in Asian descent?
- alpha thalassemia
- beta thalassemia
- hemoglobin S
- hemoglobin C
- hemoglobin E
Beta thalassemia is common what (…) descent
- Mediterranean
- Asian
- African
What are indications for hemoglobin electrophoresis?
- evaluation for suspected hemoglobinopathies
- following an abnormal CBC or finding of anemia (especially in pts where underlying/obvious cause is not found OR pts of Mediterranean, Asian, or African descent with anemia)
- family studies (family history of thalassemia trait or disease, sickle cell trait or disease)
Most thalassemias follow (…) inheritance pattern, but few are (…)
- autosomal recessive inheritance
- autosomal dominant
Iron supplements help anemic patients, but do not help patients with (…), why?
- thalassemia
it is a dysfunction in the chain, not with their iron
