(F) L1: RBC Disorders (Part 1: Anemia and Polycythemia) Flashcards
- A condition characterized by an elevated number of red blood cells
- It signifies an excess of RBCs which can result in increased blood viscosity and related complications
Polycythemia
- A condition that is characterized by a lower than normal amount of red blood cells or reduced amount of hemoglobin in the blood
- Reflects as a deficiency of RBCs leading to oxygen carrying capacity problems
Anemia
TOF: Anemia and Polycythemia are related
True (both involved in the imbalance of RBC number but in OPPOSITE directions)
- The process by which the RBCs are produced in the body (in the bone marrow)
- It begins with hematopoietic stem cells which are considered multipotent (can differentiate into various cell types)
Erythropoiesis
Hematopoietic stem cells differentiate into proerythroblasts under the influence of what hormone which is produced where?
Erythropoietin (in the kidneys)
Note: This is in response to LOW oxygen levels
At what red cell stage does hemoglobin accumulation begin?
Note: Hgb enables RBCs to carry oxygen
Erythroblast
As erythroblasts mature, their nuclei (swell/shrink) and are eventually (expelled/binded to the cell)
- Shrink
- Expelled (it allows for more space for Hgb)
Red cells without a nucleus but contain residual organelles and ribosomes are called?
Reticulocytes
How many days do reticulocytes circulate in the bloodstream before they lose their remaining organelles and mature into fully functional RBCs?
1-2 days
Polycythemia or Anemia?
↑ Hgb, Hct, and RBC count
Polycythemia
Polycythemia or Anemia?
↓ Hgb, Hct, and RBC count
Anemia
Refers to the TRUE increase/decrease of Hgb and Hct
Absolute
Refers to the FALSE increase/decrease of Hgb and Hct
Relative
- The condition wherein the increase of RBC concentration is due to a false increase in the number of the red blood cells
- A result of decreased plasma volumes due to dehydration and other factors
- The actual RBC volume is not increased but Hct is, so it leads to the appearance of this condition
Relative Polycythemia
Relative polycythemia is aka “stress polycythemia” or what syndrome?
Gaisbock Syndrome
Causes of Relative Polycythemia
- This is one of the most common causes of relative polycythemia
- Refers to when the body loses excessive amounts of fluids through sweating or not consuming enough water leading to a reduced plasma volume
- It causes RBCs to become more concentrated
Dehydration
Causes of Relative Polycythemia
- This is caused by diarrhea, vomiting, or severe bleeding which contributes to decreased plasma volume leading to false increased RBC concentration
Fluid Loss
Causes of Relative Polycythemia
- These are medications that are frequently recommended to patients suffering from heart failure and hypertension
- It can increase urine output leading to dehydration and decreased plasma volume
Diuretics
Familiarize yourself with the 6 causes of relative polycythemia
- Dehydration
- Fluid loss
- Burns
- Diuretic use
- Alcohol and smoking
- Prolonged tourniquet application
Characterized by a true increase in the number of RBCs wherein the bone marrow produces too many RBCs leading to a higher hematocrit and hemoglobin level
Absolute Polycythemia
What is the other name for Primary Polycythemia?
Polycythemia Vera
- This is a rare, chronic myeloproliferative disorder in which the BM overproduces RBCs, WBCs, and platelets
- Often caused by a mutation of JAK2 gene (a JAK2 V617F mutation)
- These mutated cells are continuously produced even in the absence of the body’s normal regulatory signals
- It results in a true increase in RBC number
Polycythemia Vera/Primary Polycythemia
Polycythemia Vera/Primary Polycythemia
This is a gene that provides instruction for producing kinase
Janus Kinase (JAK2)
Polycythemia Vera/Primary Polycythemia
This mutation is characterized by a single point mutation in which valine is replaced by phenylalanine at position 617 of the JAK2
JAK2 V617F Mutation
Valine (V) at the 617th position replaced by Phenylalanine (F)
Polycythemia Vera/Primary Polycythemia (S&S)
Blood hyperviscosity can lead to conditions like deep vein thrombosis or pulmonary embolism which is caused by the formation of what?
Clot
Polycythemia Vera/Primary Polycythemia (S&S)
- This condition causes the blood flow to become impaired in the circulatory system, so the oxygen supply to the various tissues and organs becomes insufficient
- The patient may experience low fatigue and dizziness
Hyperviscosity of blood
Polycythemia Vera/Primary Polycythemia (S&S)
Blood hyperviscosity causes our spleen to (shrink/enlarge) which contributes to the sequestration or trapping of the blood cells
Enlarge
Polycythemia Vera/Primary Polycythemia (S&S)
This occurs after exposure to warm water
Itching (Pruritus)
Polycythemia Vera/Primary Polycythemia (S&S)
This condition is accompanied by reddish/bluish coloration of the hand
Burning pain in hand
Polycythemia Vera/Primary Polycythemia (Lab Findings)
- (High/Low) blood count
- (High/Low) ferritin
- (Increased/Decreased) ESR
- (High/Low) LDH
- (Hyper/Hypo)-uricemia
- (High/Low) Vit. B12
- (High/Low) EPO
- (Hyper/Hypo)-plastic bone marrow
- High blood count
- Low ferritin
- Decreased ESR
- High LDH
- Hyperuricemia
- High Vit. B12
- Low EPO
- Hyperplastic BM
- This occurs in response to external factors that stimulate the body to produce more RBCs
- The primary mechanism of this is the body’s attempt to increase the oxygen carrying capacity in response to low oxygen levels (hypoxia)
Secondary Polycythemia
Causes of Secondary Polycythemia
When oxygen is reduced at high locations, the body is triggered to produce more RBCs to compensate
High altitudes
Causes of Secondary Polycythemia
Conditions such as emphysema or COPD can result to inadequate oxygenation of the blood leading to secondary polycythemia
Chronic Lung Disease
Causes of Secondary Polycythemia
Conditions such as congenital heart defects can reduce oxygen delivery to the tissues stimulating the production of more RBCs
Heart Disease
Causes of Secondary Polycythemia
Due to exposure to carbon monoxide, it can lead to reduced oxygen carrying capacity of the blood leading to increased RBC production
Smoking
Causes of Secondary Polycythemia
There is production of tumors that can produce EPO leading to secondary polycythemia
Erythropoietin-producing tumors