Anemia II Flashcards
anemia of chronic disease/inflammation
normochronic, normocytic, hypoproliferative
can also by hypo chromic and microcytic
pathogenesis of anemia of chronic disease
autoimmune dysreg –> downstream effects
- increased hepcidin –> less iron absorption
- iron gets trapped in macrophages
- direct inhibition of erythropoiesis
–> functional iron deficiency
labs in anemia of chronic disease
ferritin normal-high transferrin low to normal T sat low-normal iron low marrow iron stores high sed rate high
tx of ACD
transfusion if severe anemia
erythropoietin if nec
aplastic anemia
diminished or absent hematopoietic precursors due to injury to HSC –> pancytopenia and empty bone marrow
causes of aplastic anemia
primary: idiopathic, fanconi anemia (genetic)
secondary: radiation, chemo, other drugs, viruses (EBV)
anemia of chronic kidney disease
decreased erythropoietin production due to decreased renal cortical cells,
+ freq phlebotomy, shortened RBC life span –> normocytic anemia
other causes of hypoproliferative normocytic anemias
drugs (chemo)
infiltration of bone marrow (malignancy or infection)
endocrine: hypothyroidism, panhypopituitarism, low testosterone
intravascular hemolysis of RBCs
haptoglobin binds Hgb
HgB-haptoglobin removed by RES – prevents iron-utilizing bacteria from benefitting from hemolysis
extravascular hemolysis of RBCs
occurs in spleen and liver
lab findings in hemolysis (both intra- and extra-vascular)
anemia w/ increased reticulocytes
increased LDH
indirect bilirubin
decreased haptoglobin
lab findings specific to intravascular hemolysis
schistocytes
hemoglobinemia
hemoglobinuria
clinical findings differentiating extravascular hemolysis from intravascular
intravascular –> hemoglobinemia and -uria
extravascular –> NO hemoglobinemia or-uria
Immune hemolytic anemia
antibodies against RBCs
positive DAT or direct coombs
Direct coombs test
are RBCs in here already bound by antibodies?
tx for autoimmune hemolytic anemias
address cause steroids immunosuppression anti-CD20 therapy (rituximab) splenectomy
IHA due to warm antibodies
IgG - spleen destroys antibody coated RBCS
IHA due to cold antibodies
IgM - bind in cold areas (extremities, face), pick up complement on way to body center –> RBCs lyse in circulation or in the liver
caused by virus and mycoplasma
drug induced hemolytic anemia - 3 mech
- hapten (ex penicillin)
- innocent bystander (ex quinine)
- antigenic - drug incorporated into RBC membrane (ex methyldopa)
microangiopathic hemolytic anemia
non-immune hemolytic process w/ prominent red cell fragmentation (schistocytes)
causes of microangiopathic hemolytic anemia
- TTP-HUS
- DIC
- malfunctioning heart valves
TTP - HUS
thrombocytopenia and RBC fragmentation
assoc w/ ADAMSTS mutations, HIV, shiga-toxin E coli
tx plasmapheresis
membranopathies causing normocytic anemia
- hereditary sperocytosis
2. Paroxysmal nocturnal hemoglobinuria
hereditary spherocytosis
autosomal dom inheritance, common in northern europeans
spectrin mutation –> decreasesd membrane mechanical stability –> RBCs can’t pass through splenic microcirculation, RBCs die prematurely
tx splenectomy
paroxysmal nocturnal hemoglobinuria
acquired defect in cell membrane
missing GPI due to PIG-A gene defect –> RBCs vulnerable to complement –> intravascular hemolysis
PNH s/sx
patient wakes up in morning w/ dark urine
significant risk of thrombosis
PNH dx
flow cytometry - missing CD59 and CD55
PNH tx
transfusions
fe and folate supplementation
eculizumab (anti-complement)
stem cell transplant
G6PD deficiency
problems w/ maintaining Hgb in face of oxidative stress
dx: measure G6PD activity
path: Heinz bodies and best cells
x-linked
what two infections cause hemolytic anemia?
- malaria
- babeosis
sickle cell mutation
single amino acid substitution in beta chain of chrome 16: valine for glutamic acid –> Hemoglobin S
how long do sickle cells live?
10-20 days (most removed by spleen)
clinical manifestations of sickle cell disease
hemolysis delayed growth infection vaso-occlusive cerebrovascular events retinopathy aplastic episodes (parvovirus)
tx for sickle cell
supportive tx for pain crises
hydroxyurea - increases Hgb F, decreases Hgb S
Hematopoietic stem cell transplant
