Hemolytic Anemia 1 Flashcards
lifespan of RBC
120d
sites of extra medullary hematopoiesis
spleen
liver
lymph nodes
hemoglobinopathy
genetic mutation for abnormal globins
thalssemia
mutation decreasing globin synthesis
hemolysis
RBC destruction resulting in release of Hb
signs of hemolytic anemia
elevated erythropoietin
increased erythropoiesis
increased Hb catabolites (bilirubin)
intravascular hemolysis
mechanical injury or toxic injury resulting in complement fixation from antibody/antigen reactions
consequences of intravascular hemolysis
anemia hemoglo binemia hemoglobinuria hemosiderinuria jaundice
anemia
reception in total RBC cells leading to tissue hypoxia and reduced oxygen caring capacity
hemoglobinemia
free Hb in blood
hemoglobinuria
free Hb in urine
hemosiderinuria
hemosiderin binds iron from hemoglobin in urine and is excreted in urine
best marker for intravascular hemolysis
hemosiderinuria
jaundice
yellowing of skin from elevated bilirubin
extravascular hemolysis
less severe, more common
less deformable RBCs that can’t get through spleen and get stuck
consequences of extravascular hemolysis
anemia
splenomegaly
jaundice
cell counts/ indices that indicate hemolysis
increased reticulocyte count reduced MCV elevated MCHC increased free Hb decreased haptoglobin increased LDH increased free Hb
haptoglobin
binds free Hb
reduced in hemolysis
osmotic fragility test
expose abc to decreasing salt/increasing water concentration and watch when lysis occurs
osmotic fragility test in hemolysis
decreased in membrane defects
conditions with membrane defects
hereditary spherocytosis
hereditary elliptocytosis
protein electrophoresis
separating RBC membrane proteins by size with predictable migration pattern
protein electrophoresis in hemolysis
different band patterns in membrane defects
sickling test
used for sickle cell disease
mix blood with oxygen consuming agent and watch for sickling
Hemoglobin electrophoresis
different band pattern from Hb with a change in the protein (sickle cell)
hereditary spherocytosis genetics
autosomal dominant
heterogeneous
northern europeans
same mutations within familiese
etiology of hereditary spherocytosis
membrane defect from reading frame shifts of stop codons resulting in mutated ankyrin, spectrum, band 4.2
pathophysiology of hereditary spherocytosis
fragile less deformable RBC
little pieces of membrane are lost –> forms a sphere
diagnostic findings associated with membrane defects
low/normal MCV
elevated MCHC
more sensitive to osmotic lysis
missing bands in protein electrophoresis
complications of membrane defect
abc get trapped in the spleen
10-20d life
treatment for membrane defects
splectomy
hereditary elliptocytosis genetics
autosomal dominant equatorial africa (resistance to malaria)
etiology of hereditary elliptocytosis
alpha spectrin mutation
G6PD deficiency genetics
x linked recessive
G6PDa- blacks
G6PD mediterranean- middle east
pathophysiology of G6PD deficiency
increased susceptibility to oxidative injury
missing G6PD needed to convert NADP to NADPH which reduces glutathione so it can remove H2O2
diagnostics for G6PD deficiency
Heinz bodies
bite cells
heinz bodies
denatured Hg clumps inside RBC
bite cells
RBC with bites taken out by splenic macrophages
attempted removal of heinz bodies
consequences of G6PD deficiency
acute hemolysis when exposed to oxidative compounds
oxidative compounds
certain drugs (antimalarials, sulfonamides, nitrofurantoin)
fava beans
viral/bacterial infections
treatment for g6PD deficiency
avoid oxidative stressses
sickle cell disease genetics
8% of blacks
homozygous
sickle cell disease etiology
point mutation in beta global gene that switches glutamate for valine
sickle cell disease pathogenesis
deoxygenation triggers polymerization reaction that forms rigid polymers that damage the membrane
may be reversible with oxygenation
sickle cell disease diagnosis
clinical presentation family history blood smear- drepanocytes, anisocytosis, poikilocytosis sickling test hemoglobin electrophoresis dna testing
sickle cell disease acute complications
acute microvascular occlusion and tissue damage
bone, lung, spleen- infarction, sequestration, brain, penis
susceptibility to encapsulated organisms
sickle cell disease chronic complications
anemia
cholelithiasis
aplastic crisis
sickle cell treatment
reduce HbS blood transfusion dehydration increase HbF reduce inflammation maintain intracellular pH
complications of hemolytic disorders
bone marrow expansion
iron overload with chronic transfusion
gallstones
aplastic crisis
aplastic crisis
parvovirus infects erythroid precursor cells
low Hb and Hct
giant pronormoblasts in bone marrow
infectious causes of hemolysis
parvovirus b19
babes microti
falciparum malaria
clostridium welchii
