SM Flashcards
Correcting sample turbidity for determining falser high Hb
Replace plasma with saline
Red cell agglutination results in
Falsely decrease RBC count
Falsely high MCV
MCV
Volume of packed RBCs/Red cell count
Roeleaux formation (stacked coins) means
High protein level
inflammation or malignancy
Plasmapheresis
Gets rid of IgM in serum to decrease viscosity
Which antibody causes cold agglutination
IgM against RBC
Causes of cold agglutination
Mycoplasma, EBV, lymphoma, non-lymphoid malignancy
Central pallor of RBC should be
<1/3 the diameter
Microcytic, hypochromic RBC
Iron deficiency
Microangiopathic hemolytic anemia
DIC, TTP, HUS, HELLP syndrome
Haptoglobin
Sign of hemolysis
Binds to free Hb
Autoimmune hemolytic anemia is secondary to what and causes what on blood smear
CLL and spherocytes
When shouldn’t you give rasburicase (recombinant urate oxidase used to prevent tumor lysis in CLL tx)
If patient has G6PD deficiency
Results in bite cells
Immature erythroid blood cells can artificially elevate
WBC count
Decrease Hgb and Hct but increase RBC count
Thalassemia
CBC parameters that don’t change between the sexes
MCV and RDW
Fick equation
Blood flow x Hgb x (A SaO2 - V SaO2)
Typical P50 for O2
27 mmHg
Shift O2 dissociation curve to the right
Decreased pH
Increased [CO2], 2,3 BPG, temperature
Mentzer index
MCV/RBC count
If <13, thalassemia is more likely than iron deficiency
Burr cell (Echinocytes)
Liver disease and chronic kidney disease
Mutation in uroporphyrinogen 3 cosynthase
Congenital eryhtopoietic porphyria (CEP)
Clinical manifestations of CEP
Photosensitivity Anemia Splenomegaly Hypertrichosis Decreased RBC lifespan and anemia
Autosomal dominant mutation in RBC membrane proteins
Hereditary Spherocytosis
Acanthocytes (spur cells)
Anorexia
Severe nutritional deficiency
Target cells (codocyte)
Macro - liver disease
Micro - Thalassemia, hemoglobin E, C disease
Results in pancytopenia and macrocytois
B12/folate deficiency
Beta locus for Hb located on
chromosome 11
Alpha locus for Hb located on
chromosome 16
Genetics of SCD
glutamic acid replaced by valine at the 6th codon of the beta gene
Gardos channel on RBC
Ca2+ in; K+ and water out
Causes sickling in SCD
KCl co-transporter
Activated by decreased pH (acidosis)
K+, Cl- and water leave the cell
Causes sickling in SCD
Cell fee Hb is a sink for what and causes what
NO
Vasomotor dysregulation
Most common location of vaso-occlusions in SCD
Post-capillary venules due to lowest O2 tension
Most common cause of death in children with SCD worldwide
Infection
Encapsulated - S pneumoniae, H influenzae, S aureus, Salmonella
Viral infection that causes aplastic crisis in SCD
parvovirus B19 (5th disease, slapped cheeks)
Infection leading to acute chest syndrome in SCD
Mycoplasma, chylamydia, S pneumoniae
SCD tx
Penicillin prophylaxis Hydroxyurea -> HbF Transfusions Stem cell transplantation Pain management
Most important determinant of intact RBC membrane
Cell surface/volume ratio
Non-spherocytic hemolytic anemia (CNSHA)
RBC enzymopathies
Drug that triggers acute hemolytic anemia in G6PD deficiency
Sulfa drugs
PKLR mutations
Pyruvate kinase deficiency
Leads to increase 2,3 BPG as compensation
Drugs that cause warm antibody hemolytic anemia
methyldopa, penicillin, quinidine
Hapten induced drug absorption
High dose penicillin
Cephalosporins, tetracycline
Drug binding to RBC is a critical step
Immune complex drug anemia
Quinidine, quinine, sulfonamides, isoniazid
Neoantigen - Coomb’s test would be negative
Autoimmune drug anemia
methyldopa, levodopa, procainamide
Drug stimulates production of autoantibody
So doesn’t matter if you stop the drug
Acute cold-antibody hemolytic anemia
Mycoplasma and EBV
Anti-I
mycoplasma
Anti-i
EBV, lymphoma
Transfusion can make hemolysis worse in
Also corticosteroids aren’t effective in
Cold agglutinins
Direct Coomb’s test positive
Warm agglutinins
Rh hemolytic disease
Indirect Coomb’s test positive
Cold agglutinins
ABO hemolytic disease
Mutation in PIG-A responsible for GPI-anchored protein deficiencies in
PNH
PNH
Cells deficiency in membrane inhibitor of lysis, CD59, leading to complement -mediated lysis of RBC.
Causes pancytopenia
Can evolve - aplastic anemia, myelodysplasia, leukemia
Results in thrombosis in portal vein, cerebral vessels and cutaneous veins
PNH
Erythropoiesis production time
5 days
EPO interacts with
Epo-R on MEP
EPO is useful when
Renal insufficiency
Post chemo
MDS
Early aplastic anemia
EPO not useful when
Pernicious anemia Aplastic anemia (late)
Interacts with c-mpl receptor on MEP
Thrombopoietin
Not useful clinically
Granulopoiesis production time
5-7 days
Other names for M-CSF
CSF-1, c-fms
Primes granulocytes for activation
GM-CSF
Used to shorten post chemo neutropenia
GM-CSF and G-CSF
SE of GM-CSF
Fever, eosinophilia
Example of class 1 cytokine receptors
IL3-R, IL5-R, GM-CSF-R
EPO-R, G-CSF-R
Example of class 3 cytokine receptors
VEGF-R
DNA repair defect of cross-link repairs
Fanconi anemia
Telomere defect
Dyskeratosis congenita
Mutation on SDBS gene
Shwachman-Diamond syndrome
Accumulation of mutations in HSC genome
MDS
Source of HSC in clinical use
Bone marrow
Cord blood
Cytokine mobilized
Committed progenitor cells, BFU-E and CFU-E, are
EPO dependent
Single amino acid substitution caused by point mutation activating cryptic mRNA splice site
Hemoglobin E disease
Acute hemolysis is more prominent in
Alpha thalassemia and HbH disease compared to beta-thalassemia
What to balance in thalassemia tx
Appropriate transfusions and adequate iron chelation
HbH clinical features
Iron overload
Hepatosplenomegaly
Cholelothiasis
Anemia during pregnancy
Agents available for iron chelation
DFO, Deferiprone, Deferasirox
Inhibitors of platelet coagulation generated by endothelium
Prostacyclin, NO
Antithrombotic mechanisms
Antithromin 3
Protein C and S
TFPI
Fibrinolytic system
Primary hemostasis
Vasoconstriction and aggregated platelets
Secondary hemostasis
Fibrin formation for more permanent clot
Burst of thrombin generation
Thrombin activates 5, 8, 11
Factors inhibited by warfarin
2, 7, 9, 10
These are all vitamin K dependent
Inhibitors of thrombin
Antithrombin and thrombomodulin
Inhibitors of Va and VIIIa
Protein C and Protein S
TFPI inhibits
Xa and TF-VIIa
Protease next 2 inactivates
Free factor 11a
Plasmin leads to fragments of cross-linked fibrin
D-dimers
Can be elevated even with clot present
PAI-1
Inhibitor of tPA (plasminogen activator)
Hepzyme
Neutralizes heparin which is present when patient has a central venous catheter
HHT is also known. as
Osler-Weber-Rendu syndrome
Mutation in Endogeni or ALK1 gene leading to dysregulated TGF-beta
HHT
Cryoprecipitate
Used to replace factor 8 and fibrinogen and vWF
1 Bethesda unit
Amount of antibody that neutralizes 50% of factor 8 or 9 in normal plasma after 2 hrs of incubation
Competitively inhibits binding of plasminogen and t-PA (used post-surgically)
Amicar/transexamic acid
Factor deficiency that doesn’t affect PT or PTT
Factor 13
Crosslinks fibrins
Riastap
Plasma-derived fibrinogen concentrate
Why should you transfuse carefully in long-standing anemia?
TACO
Transfusion-associated circulatory overload
Indications for giving EPO
Renal disease
Chemotherapy
Random donor platelets that require 5 units for adult dose
Whole-blood platelet unit
The way most platelet donation is done in the USA
Single-donor platelets
Plateletpheresis
Prevents anti-Rho antibodies from form when given D+ RBC
Rh immune globulin
Plasma has less — than FFP
Factor 8
Factor 7 1/2 life
4-6 hrs
Shortest
Factor 8 1/2 life
12 hrs