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
What will an electrophoresis for beta thalassemia show?
HBA2 and HgF
What is HgF?
Fetal hemoglobin. Made with 2 alphas and 2 gamma chains. Primary until 6 months of age
What is HgA2?
Hemaglobin made with 2 alphas and 2 delta chains
Who is beta thalassemia most common in?
Mediterranean descent
What is the pathology for beta thalassemia?
Causes many small pale RBCs. Alpha chains precipitate and cause RBC membrane damage, hemolysis in the liver and spleen, and damage erythroid precursors therefor preventing production
What are the genotypes for thalassemia minor?
Beta/beta+ or beta/Beta0 (must have one normal copy)
What are the genotypes for thalassemia intermedia?
Beta+/Beta+
What are the genotypes for thalassemia major?
Beta0/beta0 or beta+/beta0
Which beta thalassemia patients require transfussions?
Major are dependent on transfusions. Intermedia need occasional transfusions. Minor should not require transfusions.
What does mod-severe beta thalassemia cause in the bone marrow?
Erythroid hyperplasia that leads to chipmunk facies, thin long bones, pathologic fx, and failure to thrive
What is the treatment for beta thalassemia minor?
None, monitor for iron overload
What is the treatment for beta thalassemia intermedia?
Monitor iron
Occasional transfusions
Maybe splenectomy
What is the treatment for beta thalassemia major?
Transfusion dependent
splenectomy
Luspatercept (Reblozyl) (promotes RBC production via TGF-B signaling)
Allogeneic bone marrow transplant is definitive txt
What is the mode of inheritance for sickle cell disease?
Autosomal recessive
What is the cause of sickle cell disease?
SNP in beta chain
Who is sickle cell disease most common in?
African Americans (8% are carriers)
1/400 black children have sickle cell anemia
What is the pathology of sickle cell disease?
Unstable HgS polymerizes causing sickled shaped RBC, RBC cause vasoocclusive episodes
What destroys RBCs in sickle cell disease?
Spleen sequesters and destroys sickled cells
What are triggers for sickle cell disease?
Hypoxemia, acidosis, infection, excessive exercise, abrupt temperature change, anxiety/stress, dehydration
What will the electrophoresis look like for a carrier of sickle cell disease?
HbA and HbS bands
What will the electrophoresis look like for a patient with sickle cell disease?
HbS band and a little bit of HbF
What are Howell-Jolly inclusion bodies?
These are usually single peripheral bodies within red cells representing DNA material. These bodies may be seen in post-splenectomy, megaloblastic anemia, severe hemolysis, and myelophthisic anemia.
How will a patient with sickle cell trait present?
Asymptomatic but might have s/s during physical stress
How will a patient with sickle cell anemia present?
Chronically Ill
Jaundice, pallor, ulcers
Pain, swelling, dactylitis
VC, retinopathy, retinal detachment (cotton wool spots)
Splenomegaly, hepatomegaly, gallstones
Cardiomegaly, hyperdynamic precordium
What is the typical age of onset of sickle cell anemia?
6 months old
What is the definition of a sickle cell crisis?
Ischemic injury to 1+ organs. Sx of pain, fever, tachycardia, tenderness, and anxiety
What is sickle cell treatment?
1 mg folic acid per day
All vaccines
ACEI to prevent kidney damage
Omega 3 fatty acids
Transfusions
Pain management
Antibiotics to prevent infection
Monitor iron
Hydroxyurea (increases HbF levels, causes bone marrow supression)
Crizanlizumab (Adakveo) (MAB agains P-selectin proteins, reduces stickiness)
L-glutamine (Endari) (Reduces oxidative stress)
Allogenic stem cell transplant
What is HOP for sickle cell anemia?
Hydration, Oxygenation, Pain Control
What is a splenic sequestration crisis?
Sickle cell anemia complication where too much blood is sequestered in the spleen, causing rapid splenomegaly and a Hgb drop of >2 g/dL below bsl. Very dangerous and indication for splenectomy.
What is the cause of G6PD deficiency?
X linked recessive mutation in the glucose-6-phosphate dehydrogenase enzyme
Who is G6PD most common in?
African american males
What is the pathology of G6PD?
RBCs are prone to oxidative stress -> Hb denatures and forms Heins bodies-> RBC membrane ruptured -> spleen destroys
Is G6PD inter or extravascular hemolysis?
Both!
Does G6PD have splenomegaly?
No! Spleen only destroys, is not hurt by clots so does not grow
What are the triggers for G6PD?
Antibiotics: sulfa, quinolones, Macrobid
Azo, asprin
Food: fava beans, soy, red wine, beans, blueberries
What are the sx of G6PD?
malaise, weakness, abdominal/lumbar pain, jaundice, dark urine
What is the treatment for G6PD?
Supportive care only
Folic acid
Rarely need transfusions