module 7 hemolytic anemia Flashcards
signs increased RBC production:
RPI >2, inceased IRF, leukocytosis, nucleated RBCs, polychromasia of RBCs, normoblastic erythroid hyperplasia.
signs increased RBC destruction
Anemia, schistocytes, spherocytes, positive DAT, decreased haptoglobin andhemopoexin, increased billirubin and urobillinogen, increased serum LD, increased CO.
Signs increased IV hemolysis
hemoglobinemia and uria, hemosiderinuria, methemoglobinemia
clinical findings HA
jaundice, gallstones, dark or red urine in IV hemolysis, anemia, thinning cortical bone, Extramedullary hematopoeisis, splenomegaly.
loss of vertical interactions
cause microvessicles and spherocytes (ankyrin, band 4 protein 4.2)
loss of horizontal interactions leads to
poikilocytes (spectrin, actin, protein 4.1, GPC)
acanthocyte
spiked membrane, excess in outer layer
stomatocyte
looks like kissing lips or coffee bean,
lipid composition defects characterized by
acanthocytes
Hereditary spherocytosis
deficient in membrane proteins, permeable monovalent cations. Often combined spectrin ankyrin deficiency. Membrane loss causes decreased SA to volume ratio and spherocyte. More permeable to Na, causing pumps to work harder expend more glucose. Can be well compensated. Can have aplastic crisis after viral infection.
HS LAB RESULTS
Reticulocyte count > 8%. MCHC increased. MCV decreased. increased billirubin, increased LD.
Osmotic fragility test
incubate in varying NaCl solutions. HS hemolyze at higher salt concentrations than normal. Little water can be absorbed before lysis. If < 2% spherocytes, incubate overnight at 37C before addition to NaCl. Increases SA loss and spherocyte formation.
Target cells and thalassemia in osmotic fragility test
target cells such as those in thalassemia shift to right because lysis occurs at lower NaCl concentration due to increased SA to volume ratio.
Autohemolysis test
incubate cells at 37C. Increased hemolyisis due to membrane chages. corrected by addition of glucose. Autohemolyisis increases in immunue hemoluytic anemia, but glucose does not correct.
HS and HE shape acquired
in the circulation, not created with misshape.
HE defect
horizontal interactions, such as: defective spetrin chains decrease dimer : tetramer ratio, band 4.1 defect, , abnormal GPC/ band 3.
HE clinical findings
hemolysis mild and well compensated. Membrane more rigid, may provide malaria defense.
HE lab findings
> 25 % elliptocytes. Osmotic fragility positive but not necessary as picture is obvious. Responds well to splenectomy.
HPP defect
disintegrate at 45-46C unlike normal at 50C. or >37C for 6 hours. Due to inheritance of both a mutant spectrin and a decreased expression spectrin gene. Disruption membrane, fragmentation, poikilocytosis.
HPP clinical and lab finding
exchange transfuion needed. bizarre shapes. Extreme microcytosis 25-55 fL MCV. Osmotic fragility abnormal after incubation and heat. Autohemolysis not corrected by glucose. SPlenectomy.
Overhydragted hereitary stomatocytosis
Gain of Na+ which exceeds K+ loss. Water enters cell, causes formation of stomatocyte.
dehydrated hereditary spherocytosis
Loss of K+ which exceeds Na gain. water leaves cell, becomes targeted.
HSS clinical and lab findings
abnormal cation permeability. mild to moderate anemia, 10-50% stomatocytes. osmotic fragility and autohemolysis increased, partially corrected by glucose.
acanthocytosis
increased sphingomyelin secondary to plasma changes. expansion of outer leaflet, decreased deformability. Not due to proteins. Abetalipoproteinemia, spur cell anemia,
glucose corrects for autohemolysis test in
HS not IHA.
SPUR CELL ANEMIA
type acanthocytosis associated with liver disease.
G6PD
first step in Hexose monophosphate shunt for GSH. Therefore responsible for preventing cellular oxidation.
Oxidation causes
iron oxidation and sulfahydryl groups of globin. Cannot bind oxygen, heinz bodies. Ion proetins and lipids also need to stay reduced.
Bite and Blister cells
G6PD deficiency. Splenic macrophages take bite out of cell. MCV goes down, MCHC goes up. Can cause spherocytes.