Lecture 4: Anemia II Flashcards
What is aplastic anemia?
Failure of hematopoietic bone marrow due to suppression of or injury to stem cells.
What is the MC of aplastic anemia?
Idiopathic autoimmune suppression of hematopoiesis.
What kind of diseases result in aplastic anemia?
PNH
SLE
Transfusion GVHD
What toxins can cause aplastic anemia?
BENZENE
toluene
insecticides
mercury
What medications can cause aplastic anemia?
CHEMO
anticonvulsants
chloramphenicol
cimetidine
sulfa
What infections can cause aplastic anemia?
HEPATITIS
EBV
Parvovirus B19
CMV
What other things can cause aplastic anemia?
Radiation exposure
Pregnancy
Congenital
Describe the pathology of aplastic anemia.
Hypoplasia of hematopoietic bone marrow leads to decrease in ALL hematopoietic cell lines.
Note:
This means platelets and WBC production are affected as well.
What does hypoplastic bone marrow look like?
Very white due to increased fat deposits and reduced hematopoeisis.
How does aplastic anemia present clinically?
Decreased WBCs leads to increased infections.
Decreased RBCs leads to pallor, fatigue, dyspnea, and palps.
Decreased platelets leads to bruising, bleeding from mucosa and skin.
Exam findings:
Pallor, purpura, petechiae.
Lack of hepatomegaly or splenomegaly.
How do I differentiate rashes from petechiae/purpura?
Rashes will blanch when pressure is applied.
How does aplastic anemia present on lab findings?
WBC: decreased
Platelets: decreased
Retic: Little to none
MCV: normal or increased
MCH: normal
Bone marrow biopsy would show hypocellular aspirate with little to no hematopoietic precursors.
What kind of anemia is aplastic anemia usually? (Morphologically)
Normocytic normochromic anemia.
What kind of supportive treatment can be given with aplastic anemia?
RBC transfusion
Platelet Transfusion
Antimicrobials
Note:
Do not transfuse WBCs, since risk of fever or autoimmune reaction is high.
What kind of growth factors can be given for aplastic anemia? Why?
Multilineage: Eltrombopag/Promacta. Helps boost RBC and WBC production.
Erythropoietic: Epoetin, Darbepoetin
Myeloid: Filgrastim, Sargramostim
What are the two major treatments for aplastic anemia?
Bone marrow transplants for pts under 40 yo with full HLA-matched sibling donors.
Immunosuppression for ineligible transplant candidates.
Equine ATG + cyclosporine + steroids +/- eltrombopag + bone marrow stimulating drug
Why are corticosteroids given with horse/equine ATG?
Preventing anaphylaxis.
What are epoetin and darbepoetin?
Human EPO made via recombinant DNA.
Darbepoetin alfa has 3x the halflife of epoetin alfa
They are also cytokines and growth factors.
What is the purpose of human EPO?
It stimulates division and differentiation of the erythroid precursors.
What are the other indications of human EPO?
Anemia due to CKD, chemotherapy, and myelodysplasia
What are the CIs for human EPO?
Allergy
Uncontrolled HTN
Pure red cell aplasia post tx
What is pure red cell aplasia?
RBC production suddenly stops, meaning the bone marrow is too dependent on EPO.
What are the main SE associated with human EPO?
HTN and thrombosis.
Most increased risks of death are due to an infarct or thrombosis.
What should be monitored in someone being given human EPO?
CBC
Iron
BP
Hb (weekly)