CBC And Related Patho Flashcards
Do you have to request a differential for a CBC
Yes
Is fasting required for a CBC
No
*collection of blood should be fresh <3 hours old
Where are RBC, WBC, and platelets formed
In the bone marrow
“The factory”
What are the functions of RBC, WBC, Hgb, Hematocrit, and platelets
RBC: carry oxygen
WBC: fight infection
Hgb: O2 carrying protein in RBC
Hematocrit: proportion of red blood cells to plasma
Platelets: cells which help with blood clotting
What does a differential include?
- WBC types
*lymphocytes
*monocytes
*neutrophils
*eosinophils
What are granulocytes
- Neutrophils
- Basophils
- Eosinophils
What is leukocytosis and leukopenia?
Leukocytosis: WBC elevation (think inflammation, infection)
Leukopenia: Low WBC (think autoimmune issues, chemo, bone marrow problems)
What is the critical values of WBC
<2 or >40,000
What should you do if the WBC are high on the CBC
Look at the differential
What should you think of if the neutrophils, lymphocytes, monocytes, and eosinophils are elevated?
N (immature bands/mature segs): bacterial/progenitor infection
*bands are bad
L: viral, TB
M: viral, TB
E: allergy, parasite, fungal infection
What is another term for RBC count?
Erythrocyte count
*represent the # of RBC in the system
What are the trends of RBC relating to gender
W: lower RBC values
M: higher RBC values
What is anemia
When the value of RBC is decreased below the expected normal range
What are some causes of low RBC
- Hemorrhage
- Hemolysis (G6PD deficiency)
- Dietary deficiency
- Genetic aberrations
- Normal pregnancy
- Drug ingestion
- Marrow failure
- Chronic illness
- Organ failure
What are some causes of high RBC
- High altitudes
- Congenital heart disease
- Severe COPD
- Polycythemia Vera
- Drugs
*1,2,3 have low O2 levels therefore RBCs are stimulated to increase O2
What is polycythemia Vera
Neoplastic condition causing uncontrolled RBC production by bone marrow (will increase RBC)
What causes alteration of RBC count
- Dehydration
*total blood volume is contracted thus RBC is more conc - Over-hydration
*conc is diluted RBC is falsely low
What does Hbg measure
- The total amount of Hgb in peripheral blood
*should be repeated serially in patients with ongoing bleeding
*apart of anemia eval
What are the trends with hbg and gender?
W: lower
M:higher
*levels decrease with age
*abnl values indicate pathological state same as abnl RBC r
What can interfere with Hbg
- Heavy smoking
- High altitudes
- Drugs
- Dehydration and over hydration
What are the critical values of Hgb
<7 or >21g/dL
What makes the decision for a blood transfusion
Based on Hgb and Hct
*<7.5g/dL or Hct <24%
*if the patient is unstable dont wait to reach below 8
What are the consequence of too little Hgb
- Strain cardiopulmonary system to compensate
*angina, MI, CHF, stroke
What are the consequence of too high Hgb
Sludging from increased numbers of RBCs *Stroke, organ infarction
What is the Hct
% of blood volume that is RBC’s
*how conc is the blood with RBC
-Ratio of packed red blood cells to total sample size
What do Hct levels reflect
The Hgb and RBC values
*repeat serially in patients with ongoing bleeding
*used to help eval anemia
What is the relation between Hct and Hgb
Hct is approx 3x the Hgb under normal conditions
*EX: if Hgb is 14, Hct should be around 42%
What are the critical values of Hct
<21% or >65%
What info does the indices provide
Provide information about the size, weight, and hemoglobin concentration of RBCs
*helps to classify the anemias
*RBC, Hct, Hgb are needed to calculate RBC indices
What are the main the RBC indices
- Mean corpuscular volume (MCV)
- Mean corpuscular Hemoglobin concentration (MCHC)
What does Mean corpuscular volume (MCV) measure
- The volume, or size of a single RBC
What does a low, high, or normal MCV mean
Low: <80 (microcytic)
High: >100 (macrocytic)
Normal: 80-100 (normocytic)
With an increased macrocytic MVC what types of anemias will be present?
Megaloblastic anemias
1. Vitamin B12 (pernicious anemia)
2. Folate (MC cause)
Non-megaloblastic
1. Alcoholism
2. Chronic liver disease
With an decreased microcytic MVC what types of anemias will be present?
- Iron deficiency
- Thalassemia
- Anemia of chronic disease/inflammation
- Sideroblastic anemia (MC cause Lead Poisoning)
What does Mean corpuscular hemoglobin measure? (MCHC)
Measures average concentration or percentage of Hgb within a single RBC
*measure color
*how saturated the RBC is with Hgb
With a hypochromic MCHC what types of anemias will be present?
1.Iron deficiency
2.Thalassemia
3. Anemia of chronic disease/inflammation
4. Sideroblastic anemia (MC cause Lead Poisoning)
What does a low, normal MCHC mean
Low: hypochromic
*there are low values of hemoglobin
Normal: normochromic
*hemolytic anemia
What does Red blood cell distribution width measure? (RDW)
- Indication of variation in RBC size or degree of anisocytosis
What is anisocytosis?
Blood condition where RBC are varying in size/volume
What is polikilocytosis
Variation in shape
What are the critical values of platelet counts
<20,000 (spontaneous hemorrhage) or >1,000,000
What is thrombocytopenia and thrombocytosis
Penia: platelet count <100,000
*easy bruising, petechiae, expistaxis, hematuria
Cytosis: platelet count >400,000
*vascular thrombosis with tissue or organ infarction
How is anemia classified?
- Decreased in RBC number or function
- Decreased in the O2 capacity of blood
*condition not a disease
What are some signs of acute anemia
More symptomatic
1. Tachycardia
2. orthostatic changes
3. heart murmur
4. obvious blood loss
What are some signs of chronic anemia
Condition can be asymptomatic
1. Pallor
2. fatigue
3. jaundice/splenomegaly
4. exertional dyspnea
*Pica: appetite for non food substances like chalk and clay
*Pagophagia: ice craving
What will be present on the CBC for normocytic, normochromic anemia
- Decreased RBC count
- Decreased Hgb, Hct
*normal indices MCV MCHC
What are the different types of normocytic, normochromic anemias
- Anemia of chronic disease
*microcytic about 30% of the time - Aplastic anemia
*meds - Renal disease
What are the causes for microcytic Anemias?
T: thalassemia
I: iron deficiency
C: chronic disease
S: siderblastic anemia
*Low MCV
What will be present on the CBC for microcytic, hypochromic anemia
- Decreased RBC count
- Decreased Hgb, Hct
*abnormal indices <MCV <MCHC
What is the function of cooper
For gut absorption of iron
*may be a deficiency in bariatric patients
What will be present on the CBC for Microcytic, normochromic anemia
- Decreased RBC
- Decreased Hgb, HCT
*<MCV, normal MCHC
What is a common cause of microcytic, normochromic anemia
Chronic disease
*nomrocytic more common over 70% of the time
What will be present on the CBC for macroocytic, normochromic anemia
High MCV
Normal MCHC
What will cause macrocytic, normochromic anemia?
Vitamin B12 or folic acid deficiency
What are some causes of decreased bone marrow production of RBC
- Infiltration process
*myeloma, leukemia, bone marrow metastases - Aplastic anemia
- Decreased materials for RBC production
*iron, folate, b12
What is aplastic anemia
- Loss of hematopoietic cells leading to pancytopenia
*decrease in ALL blood cell types
*hematopoietic failure
Infiltration process and aplastic anemia causes low levels of what
- WBC and platelets, RBC
What is the cause of aplastic anemia
- Drugs
*chemo, RA, radiation - Viruses
- Autoimmune
For normocytic anemia what is normal, elevated, or decreased
Decreased: RBC
Normal: indices
What is the confirmatory test for aplastic anemia
Bone marrow biopsy
*will report hypoactive bone marrow
*myeloid cells are decreased (pancytopenia)
What is the treatment for aplastic anemia
- Removing the offending drug
*MC cause of death is from bleeding and infection
*bc there are no WBC or platelets
What represents iron stores
Ferritin
*if ferritin is normal or elevated with microcytic anemia iron deficiency is not the problem
What are the different categories of Anemia of chronic disease (ACD)
- Anemia of inflammation
- Anemia of organ failure
- Anemia of older adults
How is anemia of inflammation mediated
Through hepcidin
What is hepcidin
Acute phase protein that is (triggered with stress, inflammation, infection) a key regulator of iron metabolism
What will happen if there is an increase in hepcidin levels
Will block the iron absorption from the gut and release iron from marrow
*will be unable to use iron stores as a result of inflammation
*ferritin is normal to elevated
*low serum iron
What are the serum levels in anemia of organ failure?
Serum iron normal
*erythropoietin is reduced
Why is erythropoiesis impaired (organ failure)
Due to decrease in both EPO production from diseased kidneys and marrow responsiveness to EPO from inflammatory aspect
Why is iron needed
Hemoglobin production and function
What happens when there is little iron
Pale (hypochromic)
Small (microcytic)
Why does IDA happen in children and adults
C: poor diet
A: blood loss
What is thalessmias
- Microcytic anemia
*due to decreased amounts of Hgb
*will be normal or increased iron levels
*wont respond to iron treatment
What causes a thalassemias
- Reduction in production of alpha (major) or beta chain (minor)
*the more deletion the more serious the disease
*normal Hgb has 4 alpha and 4 beta
What are target cells?
RBC look like a target sign with a dark spot in their pale centers
*thalassemias
What is the key test for diagnosis of thalassemias
Hgb electrophoresis
What are trait thalassemias
Laboratory feature without significant clinical impact
*little or no anemias with strongly low MVC
What are intermedia thalassemias
There is an occasional RBC transfusion requirement
What are major thalassemias
The disorder is life-threatening and the patient is transfusion dependent
*many die from an overload of RBC transfusion
How to calculate the mentzer index
Mean corpuscular volume (MCV) / total RBC
*>13 IDA
*<13 thalassemia
What is the cause of siderolastic anemia
Acquired or congenital/inherited
*myelodysplasia
chronic alcoholism
****lead poisoning Mc causes
What is the pathology behind sideroblastic anemia
Condition will reduce the Hgb synthesis causing iron accumulation in the mitochondria
*x-linked condition
How can lack of raw material lead to decreased bone marrow production
- Inadequate levels of folate and B12 result in improper formation and early release of prematurely large RBC (macrocytic)
- There will also be an alteration of DNA synthesis in WBCs
*will be PMN white cells
*will be hypersegmented neutrophils with 5-6 lobes
What are the lab findings of sideroblastic anemia?
- Basophilic stippling on smear (lead poisoning)
- Bone marrow will have “ringed” sideroblastic seen with Prussian blue stain
- Resembles anemia of chronic disease except iron levels elevated
What causes megaloblastic anemias
- Abnormalities in DNA synthesis (hypersegmented neutrophils occur)
*vitamin b 12 deficiency
*folate deficiency
*antimtabolite drugs
What are the causes of nonmegaloblastic anemias?
There will be no hypersegmented neutrophils
1. Alcohol abuse
2. Liver disease
3. Hyperthyroidism
4. Myelodysplastic syndrome
Why is vitamin B12 needed
For the conversion of inactive form of folate to active
*will help with the formation and function of RBC
What would happen to the RBC if there is a B12 or folate deficiency
RBC become large (megaloblastic cells)
What is needed that is in the stomach that helps with vitamin B12 absorption
Parietal cells will secrete a protein called intrinsic factor (IF)
*IF binds to B12 which allow it to be absorbed in the terminal ileum
What can a vitamin B12 deficiency also cause
- Neurological symptoms
*folate will not have neurological symptoms
How will a B12 deficiency present
- Tingling/paresthesia or burning feelings on the skin
- A tongue that is red, shiny, and sore = glossitis
- Feeling tired and weak
- Problems with memory
What are produced against parietal cells
Autoantibodies
What leads to a reduction of B12 absorption (pernicious anemia)
Loss of intrinsic factor
*automimmune gastritis
What is the most common cause of B12 deficiency
Pernicious anemia
*associated with gastric cancer
How can pernicious anemia be diagnosed
Labs
*showing IF antibody and anti parietal cell antibody
**Schilling test is rarely performed, antibody testing and rapid radioimmunoassys have replaced schilling
Why is folic acid needed?
- To help with normal function of RBC and WBCs
What is the most common cause of Macrocytic anemia?
Folic acid deficiency
How to determine if there is a folate or a vitamin B12 def
Order methymalonic acid (MMA) *test of choice
*elevated MMA indicated B12 def
*folate will be normal
What are elevated Homocysteine levels associated with? (HCY)
Vitamin B12 of folate def
What are the different types of things that can result in anemia? (Loss of RBC)
- Bleeding
- Destruction (hemolysis)
*external (extracorpuscular) factors: acquired defect
*Internal (intracorpuscular) factors : problems with RBC itself, hereditary defect
A cause of hemolytic anemia would lead to increased production of what?
Bilirubin
*when RBC break down unconjugated (indirect) bilirubin forms in the circulation
*indirect bilirubin is elevated in hemolysis
What are the causes of extracorpuscular hemolysis
- Hyperactive spleen
*inappropriately destroys and removes RBC - Immune hemolytic anemia
- Infection
- Toxins
- Hemolytic syndrome
How will a patient present with hemolysis
- Rapid onset of pallor
- Normocytic/normochromic anemia
- Jaundice
- May have a history of pigmented (bilirubin) gallstones
- Splenomegaly
What are some findings of hemolysis or hemolytic anemia
- Indirect bilirubin levels will be elevated
- Jaundice will occur
- Elevated lactic acid dehydrogenase (LDH)
- Increased retic count (reticulocytosis)
*bone morrow factory starts pumping out immature RBC
What are the special tests to detect hemolytic anemia
- Erythrocyte fragility
*detects hereditary spehrocytosis - Hemoglobin electrophoresis
*SCA, thalassemia
What underlying problem can cause the production of defective RBC
- Membrane of RBC (Spherocytosis)
- Hemoglobin (sickle, cell)
- Metabolic enzyme
***function is altered, leads to anemia and inadequate oxygen delivery
What is sickle cell disorder
Autosomal recessive disorder
*mutation in beta chain of hemoglobin
*deoxygenation will cause a sickle shape
*Hgbs instead of Hgb A
What is sickle cell trait
Heterozygous Hgb AS
*asymptomatic MC
What is the most severe form of sickle cell
Homozygous Hgb SS
*both beta chains are affected
*inherit two copies of the sickle cell gene one from each parent
What is sickle cell presentation in a patient
- Healthy infant until around 6 months
*fever
*dactylitis
*splenomegaly then regresses around 4 and no palpable
Why does the spleen regress in size around 4 (sickle cell)
Bc of organ occlusion, the spleen is not getting proper blood supply
What is acute chest syndrome (sickle cell)
- Sickling in blood vessels deprive lungs of oxygen
*lung tissue is damaged and cannot exchange
*chest pain and tachycardia
What is aplastic crisis (sickle cell)
- Causes bone marrow to stop producing new RBC for a while
*from parvovirus B19
*will have slapped check syndrome
Main sickle cell management
Vaccinations SHIN
S: strep pneumonia
HI: Haemophilus influenza
N: neisseria meningitis
*stem cell transplant is only cure for SCD
What is hereditary spherocytosis
- Autosomal dominant
*there is an issue with the RBC membrane not as malleable which causes them to get stuck in the spleen and destroyed
*splenomegaly is common
What is the hallmark of hereditary spherocytosis
- Microspherocytes or spherocytes
*round RBC lacking central clearing
*increase MCHC (hyperchromic, microcytic anemia)
What tests will be + or - (hereditary spherocytosis)
- Osmotic fragility test +
*indicated cells easily lyse - High RDW
- Coombs test -
*indicates not an autoimmune process
What is the treatment of hereditary spherocytosis
Splenectomy
*folate replacement
What is pyruvate kinase and the def
- An enzyme that helps cells turn sugar into energy
*RBC lack mitochondria so the rely on glycolysis for energy - Deficiency can lead to a deficiency in energy and to premature RBC destruction
Absence of pyruvate kinase can lead to what?
Damage and death to RBC causing anemia
What is Glucose-6-phosphate dehydrogenase deficiency(G6PD Deficiency)
Genetic disorder X-linked recessive (males)
*defect in enzyme glucose 6 phosphate dehydrogenase causes RBC to break down prematurely
What is G6PD involved with
Protecting the RBC against oxidative stress
*oxidative stress is when there is an imbalance of production of free radicals and the ability of the body to counteract or detoxify their harmful effects
What does oxidative stress oxidize hemoglobin into
Methomeglobin (does not carry oxygen well)
*causes RBC membrane damage (so anemia)
Why dos hemolysis occur (G6PD def)
In response to infection, drugs, or fava beans
What is the presentation of G6PD def
- Asymptomatic until oxidative stress
- Will be self limiting
*lasts 8-14 days due to compensatory response to produce new RBC with high levels of G6PD
People with G6PD def have protection against what
Malaria
*more difficult for parasite to invade RBC
