Normocytic Anemia Flashcards
What is anemia
Anemia is a decrease in the RBC measurements: RBC count (part of CBC), hemoglobin (concentration in g/dL) and hematocrit (volume % of RBC in the body)
What is the rule of 3
Hgb = 3 * RBC count
Hct = 3 * Hgb
What are the clinical features of anemia
Vary based on degree of anemia and onset (rapid/slow)
Can be asymptomatic
Weakness
Fatigue
Dyspnoea
Pallor - unhealthy pale appearance (skin of palms and face, also nails and conjunctivae)
Mention the RBC indices
Mean corpuscular volume (femolitres)
Mean corpuscular hemoglobin (pg/cell)
Mean corpuscular Hgb concentration (g/dL)
What is the normal MCHC
34g
What is the normal MCH
27.5 to 33.2 pg/cell
What is the normal MCV
80 to 100 fL
What are the blood cell indices
Describe mean characteristics of RBCs
Measured by automated blood counters
Used in the evaluation of anemias
What is MCV
The average volume of a red cell
What is MCH
Average weight of hemoglobin inside of each red cell
What are the classifications of anemia based on MCV
Microcytic
Normocytic
Macrocytic
What type of anemia is MCV < 80
Microcytic
What is macrocytic anemia
MCV > 100
What is normocytic anemia
MCV 80-100
Give some examples of microcytic anemias
Iron deficiency
Thalassemia
Anemia chronic disease
Sideroblastic anemia
Lead poisoning
Give some examples of normocytic anemia
Anemia chronic disease
Hemolysis
Aplastic anemia
Chronic kidney disease
Give some examples of macrocytic anemia
Folate/B12 deficiency
Liver disease
Alcohol use
Reticulocytosis
What are retuculocytes
Immature red blood cells
Usually about 1-2% of RBC in peripheral blood
In anemia, the bone marrow produces more reticulocytes so the percentage of cells that are reticulocytes should increase in the setting of anemia
When there’s anemia, the kidney produces more EPO. The EPO drives the bone marrow to produce more reticulocytes
Used in anemia to determine if bone marrow response is adequate
Should ride if bone marrow responds normally
Must be corrected for degree of anemia
If < 2% -> Inadequate bone marrow response
What might this be
Reticulocyte count
Correct the reticulocyte count for an Hct of 11 and Retic of 8%
Corrected RC = 8% * (11/45) = 2%
45 is the normal Hct level
What’s the equation for reticulocyte production index
Corrected retic% / Maturation time (varies - increases with decreasing Hb levels)
What RPI level is seen in patients with bone marrow failure
RPI < 2%
Which RPI percentage is a normal marrow response to anemia
> 3%
Hypochromia in blood smear is characteristic of what condition
Iron deficiency
Spherocytes in blood smear is characteristic of what condition
Spherocytosis
Target cells in blood smear is characteristic of what condition
Thalassemia
Dacrocytes (tear drop cells) in blood smear is characteristic of what condition
Marrow fibrosis
Acanthocytes in blood smear is characteristic of what condition
Liver disease (spiked RBCs)
Schistocytes in blood smear is characteristic of what condition
Hemolysis
What are the two causes of normocytic anemia
Decreased red cell production
Increased red cell destruction/loss
What feature is characteristic of a decrease red cell production
A low reticulocyte count
What feature is characteristic of an increased red cell production in normocytic anemias
A high reticulocyte count
What are some causes of normocytic anemias
Anemia or chronic disease
Chronic kidney disease (low EPO)
Hypothyroidism
Bone marrow failure
Aplastic anemia
What are some causes of increased red cell destruction leading to a normocytic anemia
Acute blood loss
Hemolysis
What is the most common cause of normocytic anemia
Anemia of chronic disease
Which anemia is common in rheumatoid arthritis
Anemia of chronic disease
Anemia in association with inflammation
Common in rheumatoid arthritis, lymphoma, other chronic conditions
Usually a mild anemia (Hgb > 10g/dL)
Symptoms of anemia rare
Often incidental finding in blood testing
Microcytic in about 25% of cases
Most common normocytic anemia
What condition could this be
Anemia of chronic disease
Acute blood loss causes ……….. anemia
Normocytic
Chronic blood loss causes …….. anemia
Microcytic
Loss of iron in hemoglobin
Leads to iron deficiency
Common with occult GI bleeding
What kind of blood loss could this be
Chronic blood loss
Loss of red cells
Remaining red cells have a normal MCV
What type of blood loss could this be
Acute blood loss
Which agents are used to treat chronic kidney disease causing a normocytic anemia
EPO stimulating agents
Epoetin or darbepoetin (longer-acting)
Used when Hgb < 10g/dL
Goal Hgb: 10 to 11.5g/dL (any higher Hg greater than this increases mortality and myocardial infarction because these drugs can cause or worsen HTN)
Good response to this drug requires iron (iron deficiency -> poor response)
What drug may this be
EPO stimulating agents
Specific type of bone marrow failure where there are defective stem cells which leads to an acellular or hypo-cellular bone marrow
Pancytopenia
Low WBC, low platelets, low RBC
Low reticular count
Hypo-cellular bone marrow
Absence of infiltrate or fibrosis
What condition may this be
Aplastic anemia
How is aplastic anemia diagnosed
Pancytopenia
Bone marrow biopsy
Acellular or hypocellular bone marrow
Absence of cells/replacement with fat
What are some causes of aplastic anemia
Most commonly idiopathic
Radiation exposure
Drugs
Toxins (benzene)
Viruses
Inherited (Fanconi anemia which develops in children)
What is the mechanism of aplastic anemia
Most cases involve autoimmune damage to stem cells even when underlying cause is present
Drugs, chemicals or viruses alter stem cells
Leads to autoimmune destruction
Immunosuppression improves aplastic anemia
What are some drugs which could cause aplastic anemia
Chemotherapy (anticipated effect)
Antibiotics (chloramphenicol and sulfonamides)
NSAIDs (phenylbutazone and indomethacin)
Anti-seizure drugs (carbamazepine and phenytoin)
Anti-thyroid drugs (methimazole and propylthiouracil)
Infects proerythroblasts
Usually causes a decrease in RBCs
Pancytopenia can occur (high risk in immunocompromised patients)
What virus could this be
Parvovirus B19
What are some viruses which could cause aplastic anemia
Parvovirus
Acute viral hepatitis (develops weeks to months after acute hepatitis)
Others: HIV, EBV, CMV
Inherited aplastic anemia
Autosomal recessive or x-linked
Usually presents in children less than 16 years old
More than half of patients have physical deformities (short stature, malformed thumbs, hypo or hyperpigmentation, café-au-lair spots
More than 13 genetic abnormalities identified
May involve DNA repair enzymes
What condition might this be
Fanconi anemia
What is the treatment for aplastic anemia
Stop offending agent
Blood and platelet transfusions
Bone marrow stimulation (GM-CSF)
Immunosuppression (antithymocyte globulin - a collection of T cell antibodies, cyclosporine)
Bone marrow transplant
