Heme Flashcards
Baby with severe thrombocytopenia with normal maternal platelets. Next step?
Get HUS, Plt transfusion (ideally HPS-1B) and IVIG
Neonatal Alloimmune Thrombocytopenia
Production and transfer of maternal alloantibodies against paternally inherited antigens on fetal platelets
Intracranial hemorrhage in 10 to 15% of cases
› Normal coagulation testing
› Most common cause: Incompatibility in HPA-1 (PLA-1)
• Mother HPA-1b (PLA-1)
• Father HPA-1a (PLA1+)
• Fetus HPA-1a (PLA1+)
Baby and mother with thrombocytopenia. Which is the most common disease in mother?
ITP
Think autoimmune.
Milder neonatal thrombocytopenia
Tx IVIG
Only give platelets random donor if bleeding (avoid if possible)
Neonates have _____ clotting time as compared to adults
Shorter clotting time
Male with prolonged PTT and bleeding. Dx?
Hemophilia A, Deficiency factor VIII
Bleeding in a noonan infant. Which dx?
AR, Factor XI
Bleeding in a neonate, umbilical stump. Clotting studies are normal. Dx?
Factor XIII
Reason for anemia of prematurity
Low epo production
Insufficient placental transfer of iron
Short survival of fetal and neonatal RBC
Phlebotomy losses
What is the role of hepcidin in iron storage?
High hepcidin blocks release of iron from enterocytes into the circulation.
Hepcidin expression is decreased in response to iron deficiency or increased erythropoeisis leading to increased iron absorption in interstine and increase circulating iron.
Which type of platelet transfusion should be ordered for pt with suspected NAIT?
Random donor plts
Enzyme responsible for enterohepatic bilirubin circulation
Β glucuronidase
- deconconjugates bilirubin which allows for its réabsorption in the intestine
What enzyme catabolizes biliverdin to unconjugated bilirubin in the RES of spleen, liver and bone marrow?
Biliverdin reductase
Thrombocytopenia is inversely correlated with gestational age.
T or F
True
Irradiation of prbcs is done to prevent _______?
Graft vs host disease
Side effect: hyperkalemia
How does hbg F differ from maternal hgb in KB test?
Resistance to acid elution
What is the critical threshold for oxygen delivery in adults for which we develop tissue hypoxia?
7.3ml/kg/min
What is the clinical presentation of TMD (Transient Myeloproliferative Disorder)
10% of T21 patients
Hepatomegaly - MC presenting sign (50%)
Asymptomatic —->fulminant with hydrops —-> respiratory or ♥️ failure
Rash on face
Fetal megakaryocytes are smaller than adult megakaryocytes, but there are a larger number circulating in fetuses compared with adults
T or F
TRUE
Stem cells originate from ______
Mesoderm
Where does early activé hematopoiesis occur?
Secondary yolk sac
(2-6 weeks)
Déclines after 8 weeks
When does fetal liver hematopoiesis begin?
When does the liver become the primary site for hematopoiesis?
Begins: 5-6 weeks gestation
Primary site: 6-22 weeks’ gestation
Which red blood cell indices INCREASE with increasing gestational age?
RBC Number
Hématocrit
Reticulocytes (peaks at 26-27 weeks) then declines
Which red blood cell induces DECREASE with increasing gestational age?
MCV
Nucleated RBC
Complications of hemangiomas
Hypothyroidism- if involves thyroid (2/2 ⬆️ in type 3 iodothyronine deiodinase) or liver
High output ❤️ failure - if involves liver
Describe the triad in Kasaback-Merritt Syndrome
High output heart failure, DIC and thrombocytopenia in a pt that has multiple or single large hemangioma-like lesions
What does leukocyte reduced RBC blood prevent?
Irradiated RBC?
CMV
Graft vs host reaction
Delayed cord clamping decreases _______
Need for transfusion
Risk for IVH and NEC
What percent of iron stores are accrued in 3rd trimester
80%
Iron content in term baby 75mg/kg body weight
How can a neonate have a normal G6PD enzyme levels yet be deficient later in life?
Significant Hemolysis leads to increased reticulocytes that have normal enzyme levels.
2d 32 weeks Neonate with PLT 100k
Monitor and repeat
Min risk for bleeding plt count 20k-100k
Mod risk for bleeding plt count <20k
Severe risk for plt count <5k
Mild thrombocytopenia 100-150k
Mod 50-100k
Severe <50k
Whst is the differential for late onset thrombocytopenia
Sepsis (bacterial, viral, fungal)
NEC
IEM (propionoc acidemia, methylmalonic acidemia, Gauchers)
What is the role of hepcidin in fetal iron transfer?
Hepcidin is a key regulator of maternal - fetal iron metabolism
Maternal hepcidin exerts negative effect on iron absorption and placental transfer
Fetal hepcidin can downregulate placental iron delivery once its needs are met
Hepcidin levels will decrease throughout pregnancy to allow more iron absorption
Which conditions are associated with low iron stores?
Fetal overgrowth
Male sex
Preterm birth
Multiple gestation
Low fetal iron stores occur with what maternal conditions ?
Placental insufficiency Diabetes Severe stressors Obesity Chronic illness
*increased maternal hepcidin levels —> decreased placental iron transfer (endowment)
What is the MOA and concerning side effects of tin mesoporphrin
Photosensitization induced cytoxicity
Which metalloporphrin can be orally administered for treatment of severe hemolytic disease?
Chromium mesoporphyrin
zinc bis glycol
TRansient myeloproliferative disorder affects which cell lines?
Disease of megakaryocytes precursors, mutagenesis of immature myeloblast or megakaryoblast lineages
What metabolic derrangement is associated with polycythemia?
Hypoglycemia
What are the features of hepatoblastoma?
Abdominal mass - MC in RIGHT lobe Thrombocytosis Elevated AFP (>90%) - low levels can indicate poor prognosis
How to interpret KB test?
1%HbF=50ml
%HbF=#fetal cells/maternal cells x100
Remember vial of rhogam needed is determined by mL of fetal blood loss/15 where 1 vial=300mcg
Baby with macrocytic anemia, reticulocytopenia, increased RBC adenosine deaminase, increased RBC Hb F and I antigen, triphalangeal thumb, hypoplastic radi. Dx?
Fanconi Anemia
Test chromosomes with mitomycin C with increased chromosomal breaks
Can predispose to AML
What is the bilirubin:albumin molar ratio?
Measure of bili binding capacity of albumin
Surrogate to estimate free bili
Increases with increasing GA
<0.8 in healty term neonates
How to test for G6PD?
Spectrophotometric quantitative enzyme assay based on NADPH (nicotinsmide adenine dinucleotide phosphate)
Enzyme active <30% of normal is confirmatory
Whai is neonatal auto immune thrombocytopenia?
Mother + baby with decreased platelet
Caused by maternal auto antibodies (MC in Mommy’s with ITP or lupus)
MC tumor of the kidney
Congenital mesoblastic nephroma
What explains low plasma concentration of epo
In preemies,
Increased metabolic clearance of epo
Ehat is the cause of hemolysis and anemia in an jnfant with NEC?
T antigen activation
Cause bt neuramidase in bacteria such as clostridia and Streptococcus pneumonia or from a virus
In a non activated state N acetyl neuraminic acid is attached to galactose on T antigen on surface of RBC. When neuraminidase cleaves NeuAc exposing galactose residues l, T antigen is activated and naturally occuring anti-T antibodies in humans attach to activated T antigen resulting in hemolysis and anemia.
It also cause platelet destruction and thrombocytopenia
Washed packed RBCs are indicated if T antigen activation is confirmed
5 or more cutaneous hemangiomanas. Next best step?
Hepatic US for hepatic hemangioma As AV shunting of blood through large hepatic hemangioma can lead to CHF
Rarely seen is a consumptive form of hypothyroidism with HH. Excessive production of type 3 iodothyronine deiodinasr leading to inactivation of thyroid hormones
Serum bilirubin/albumin ratio in which exchange should be performed?
> 6.8 if preterm w risk factors
> 8 if term w risk factors
What affects albumin binding ability to albumin ?
Sepsis Acidosis Hypoxia Free fatty acid Albumin binding drugs (ceftriaxone, sulfonamides, indomethacin)
The ratio of B/A (bilirubin to albumin) can be used as a surrogate for unbound bilirubin
T or F
True
As part of multi factorial analysis
What are the 3 types of hemorrhagic disease of the newborn ?
Classic (DOL 2-7)
Bleeding from umbilical stump or after invasive procedure
Vit K stores < Vit K intake
*Exclusively breastfed at ⬆️ risk
Early (within 24 h)
Placentally transferred drugs that inhibit Vit K production (anticonvulsants, cephalosporin, warfarin)
Late Onset (2w - 6mo) ⬆️ boys, in summer Poor enteral intake Vit K or liver disease
