heme II Flashcards
where is erythropoisesis in PT vs T?
in pt it’s in liver. less responsive to anemia and hypoxia (maybe to avoid polycythemia in the relatively hypoxic fetal environment). in T it’s in kidney.
overally fetal erythro-progenitors are more sensitive to epo than adults - need less epo to get the same job done
which factors are part of intrinsic and which are extrinisic?
Intrinsic (PTT - normally prolonged in neonates): XII, XI, XI, VIII (all hemophilias)
Extrinsic (PT - vit K): II, V, VII, X
what is Ddimer a product of
breakdown product of fibrin
how is factor V leiden deficiency inherited, tested, and how does it present?
AD. Genetic screen. Presents with abnormal thrombus including renal artery thrombus, stroke
Presents in 5% of NA whites
Factor V is both intrinsic and extrinsic - cofactor to FX to convert prothrombin to thrombin. Normally Protein C binds and inactivates FV. In FVL: resistant to Protein C –> prothrombotic
How do protein C and protein S deficiency work?
Protein C and S are vit K dependent factors. Thrombin activates protein C –> pC inactivates FV and VIII with the help of pS to prevent clotting.
How does a prothrombin mutation work?
Actually cause hypercoagulability. Causes there to be elevated amounts of thrombin. Rare.
is unconjugated bilirubin hydrophilic or hydrophobic?
hydrophobic –> binds to albumin to go into liver. Since it is hydrophobic/lipophilic, can freely cross BBB
what is ligandin in hyperbilirubinemia?
ligandin transfers bilirubin from plasma to ER. low levels at birth causing slow uptake.
when do UGDPT levels reach adult levels?
around 1 m of life. Low at birth. Catalyzes bilirubin to glucoronic acid making it hydrophilic.
how does phototherapy impact bilirubin?
converts bilirubin in three ways: #1: configurational isomerization to E, reversible, 20% elimination #2: structural isomerization to lumirubin, 6% elimination, light dose dependent. Still lipophilic but can be excreted in urine/bile #3: photo-oxidation --> bleaching, doesn't do much
what are the different forms of hemorrhagic disease of the newborn?
early: 0-2d (mom meds (warfarin, seizure meds))
classic: 2-7d (poor intake, poor stores - breastfeeding, no vit K injection)
late: 7d - 6m (liver disease, poor intake (breastfeeding))
severe ICH in 60% of these cases
Other than anti-D, which other RBC antigens cause hemolysis?
Kell (K1): (Kell kills) causes hemolysis and erythropoiesis suppression
Rhc: also results in moderate disease (C, e and E not so much) - c for common
Duffy: Fy a and b - moderate to severe disease from hemolysis
Lewis: hemolysis rare b/c on IgM
which factors are elevated in the neonate, at or above adult levels?
factor v, viii and xiii
how are fetal megakaryocytes different than adult ones?
smaller but more in number
what is the etiology of thrombocytopenia in TAR?
block differentiation of megakaryocytic precursors
what are the embryologic hemoglobin?
z2e2 (Gower 1), z2g2 (Gower 2), a2e2 (poland)
when does fetal hemoglobin premonimate
a2g2 (z –> a; e –> g) predominates after 8 weeks
when does HbA start revving up
around 30 weeks, at birth it is 60-90% of all hgb
What is Cooley’s anemia? How does it present?
homozygous B thal. Presents with chronic hemolytic anemia, bilirubinemia, cholelthiasis, HSM, skeletomegaly, growth delay
what is Hb Constant Spring
- two types of HbH disease (-a, –) and HbH CS (-aCS, -a)
- long unstable Hb chain, assc with a thal
- more severe than just HbH
- clinically similar to B thal major, infants may need transfusions.
What is the use of direct and indirect Coombs in hemolysis?
Direct: look at baby rbc and add anti-Ab reagent. If agglutinate, then Ab present against RBC (abo or Rh)
Indirect: look at moms blood and add reagent with Rh ag. If agglutination, mom has Anti Rh Ab (Rh)
what is the purpose of irradiation, washing and leukocyte reduced RBDs?
irradiation: prevent GVHD, donor T cells attack host HLA Ag. Usually after large volume transfusions. Rare by 95% mortality. Presents ~1m after transfusion.
washing: washing with NS reduces plasma by 95%, for patients at risk for severe hyperK
leukocyte reduced: decreased WBC, reduces febrile nonhemolytic transfusion reactions by 60%, viral (cytomegalovirus) transmission, and HLA alloimmunization
what are good and bad prognosticators for neuroblastoma
usually presents in adrenal
bad: uniform –> more likely to grow; MYCN amplification; elevated LDH
good: cystic –> more likely to regress; 4S, Ms stage; younger than 18m a diagnosis
what are types of renal tumors?
1 congenital mesoblastic nephroma (75%)
WM is very rare in nenonates, 25% assc with syndrome
rhabdoid tumor is very aggressive
clear cell carcinoma, rare but better prognosis if in neonate
what are sites of erythropoiesis?
yok sac: makes embryonic hgb
liver: makes fetal hgb
bm: by 22 weeks, all in bm
how much fetal hgb is present during different stages of the baby?
22w: 100%
term: 75%
6m: 5%
when do you need cmv neg, leukoreduced and irradiated rbc?
cmv neg or leukoreduced always, either is fine
irradiated (to prevent gvhd) in <1500g or immunocompromised
which gene does TMD orginate from
GATA gene on X chromosome, mutation for megakarycocyte transcription factor
what components of which part of the brain can be stained by kernicterus?
globus pallidus, subthalamic nuclei and substantia nigra of basal ganglia
what is the difference between howell jowel bodies vs heinz bodies
HJ bodies: small round nuclear remnants that can be seen in RBC with asplenia
heinz: denatured hgb seen in g6pd
are babies more predisposed to thrombosis or hemmorhage?
slightly more predisposed to thrombosis
what is the treatment for symptomatic hemmorrhagic disease of the newborn (vit K def)
first FFP then vit K, b/c vit K will take 4 hours to work. treat the bleed.
what is the cause and presentation of purpura fulminans
causes include dic (gbs, neisseria meningitis) and congenital protein c or s deficiency.
presents as microvascular thrombosis in dermis followed by perivascular emmorhage
what should you think of what portal vein thrombosis and what is follow up for
omphalitis and uvc
follow up for 10 years to evaluate for portal hypertension and liver lobe atrophy
how are direct and indirect bili measured?
react with diazo reagent to create colored derivatives. indirect is catalyzed by caffeine or dmso
when does bilirubin peak?
4-5 days
