Anemias Flashcards
What is the cause of hereditary spherocytosis?
Genetic defect that causes abnormal proteins in RBC membrane -> RBC are round -> stuck in spleen red pulp fenestrations
What is the presentation of hereditary spherocytosis?
mild to severe anemia
Jaundice and enlarged spleen
Sometimes gallstones
Sometimes post acute infection
What are the lab findings for hereditary spherocytosis?
Increased Reticulocytes
High MCHC (big indicator)
Low or normal MCV
What is the treatment for hereditary spherocytosis?
Give Folic Acid to all
Transfusions/EPO for severe
Eventually splenectomy after age 5
Give antipneumococcal vaccination
What chromosome is the Alpha Hemoglobin on and how many copies does each person have?
Chromosome 16
4 total copies
What chromosome is the Beta Hemoglobin on and how many copies does each person have?
Chromosome 11
2 total copies
What is haptogen and what does it tell you?
A protein in the blood that binds to free hemoglobin. Low haptogen levels means that there is a lot of free hemoglobin, indicating lysis (esp intracellular)
What smear findings are c/w intravascular hemolytic anemias?
Schistocyte
What smear findings are c/w extravascular hemolytic anemias?
Spherocyte
Which type of hemolytic anemia (intra or extravascular) is associated with loss of iron stores?
Intravascular
What is the pathology of Alpha thalassemia?
Many small pale RBCs. Also excess beta chains that precipitate and damage RBC membranes causing hemolysis in bone marrow and spleen
Who is alpha thalassemia most common for?
Southeast and Chinese descent
How will a person with 1 abnormal alpha globulin gene will present?
Normal (silent carrier). Must do genetic testing
How will a person with 2 abnormal alpha globulin genes present?
Alpha thalassemia minor. HCT is 28-40% and MCV is 60-75 (both a hair low).
How will a person with 3 abnormal alpha globulin genes present?
Hemoglobin H disease. Have HgH (beta 4 tetramers) that have a high affinity for oxygen, and are highly unstable, precipitating as toxic Heinz bodies which predominate in mature red blood cells, leading to premature hemolysis
HCT 22-32
MCV 60-70
How will a person with 4 abnormal alpha globulin genes present?
Die in utero in either 2nd or 3rd trimester, called hydrops fetalis
How would you best describe the RBC of a patient with alpha thalassemia?
Hypochromic microcytic
What is the treatment for alpha thalassemia minima?
None
What is the treatment for alpha thalassemia minor?
Might require transfusions in gross blood loss, surgery, etc
Monitor iron, chelation if necessary
What is the treatment for HbH disease?
Folic acid, 1 mg QD
Avoid iron, oxidative drugs
Transfusion
Splenectomy
Iron monitoring
What is the treatment for hydrops fetalis?
Lethal in utero, termination recommended
What is the cause of beta thalassemias?
Gene point mutations of the beta chain causing reduced synthesis
What is beta+?
Reduced but not absent beta chain synthesis
What is beta0?
absent beta chain synthesis