Heme/Onc/Bili Flashcards by Gina Fong

What is first site of hematopoiesis? Second? Third?

Secondary yolk sac (until 6 weeks)
Fetal liver (6-22 weeks)
Bone marrow (primary 22+, starts 8-19)

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How do RBC indices change as GA increases? Hct? MCV? RBC number? Retic? nRBC?

Increases: hct, RBC number
Decreases: MCV, nRBC
*Retic peaks at 26-27 wks then declines

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How much fetal hemoglobin do term infants have? At 6 months of age?

Term - 80%

6 months - 5%

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What chromosomes are alpha and beta globin genes on?

Alpha - chr 16

Beta - chr 11

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What makes up HgbF?

2 alpha and 2 gamma

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What makes up Hgb A? A2?

A = 2 alpha, 2 beta (inc quickly after birth)
A2 = 2 alpha, 2 delta (inc tiny bit steadily after birth)

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What are signs of various alpha thal?

1 missing - silent carrier (all normal)
2 missing - trait, normal to inc Hb Barts (4-6%), may be asymptomatic or mild microcytosis
3 missing - Hb H (4 beta chains), infant has 20-30% Barts, child with 4-20% Hb H, moderate severe anemia, Heinz bodies. May need splenectomy
4 missing - no Hb A or F, almost all Bart’s. Hydrops, rare, very severe

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What is Hb Gower and when is it expressed?

2 zeta (or alpha) chains and 2 epsilon chains
Embryonic from the yolk sac

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Where is Hb F made?

Fetal liver

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What is inheritance of HbSS? What is mutation?

Autosomal recessive

Valine (instead of glutamic acid) in beta globin gene

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What will sickle cell patients be missing?

HbA (no beta chains)

Presents ~6 months

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What is Hemoglobin E?

Most common worldwide hemoglobinopathy
Decreased transcription beta gene
Mild chronic microcytic anemia

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How many pregnancies have fetal maternal hemorrhage?

50-75% (most very small amount)
1/400: >30 ml
1/2000: >100 ml

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What is Kleihauer Betke calc ?

% Hb F = fetal cells/ maternal cells x 100

1% = 50 ml fetal blood

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What are signs of Diamond-Blackfan anemia?

Pure red cell aplasia
Macrocytic anemia, low retic. High epo. Bone marrow with absent erythroid precursor
Also w abnormal face, 3 joint thumbs, short, heart/renal anomalies
Need chronic transfusion, BMT

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What is Fanconi’s anemia?

Constitutional aplastic anemia
Autosomal recessive
Chromosome instability (test w mitomycin C -> lots of breaks)
Pancytopenia after 5 years
Also short, abnl thumbs, small head, hyperpigmented

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What are signs of vit B12 and folate deficiency?

Hypersegmented neutrophils

Macrocytic anemia, low retic

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What causes microcytic anemia?

Thalassemia
Iron deficiency
Lead poisoning
Infection

What causes Macrocytic anemia?

Methylmalonic aciduria 
Folate/B12 deficiency
Acquired aplastic anemia
Fanconi anemia
Diamond Blackfan anemia
Drugs
Hypothyroid

When is physiologic nadir in term infants? Preterm?

Term - 10-12 wks (Hb 9)

Preterm - 8 weeks or earlier (Hb 7-8)

What is difference between direct Coombs and indirect Coombs?

Direct: detects antibodies on surface of RBCs
Indirect: detects antibodies in serum (mixes serum with RBCs having known antigen to see if antibodies stick)

How is hereditary spherocytosis inherited? Diagnoses?

Most autosomal dominant

Test: osmotic fragility test (expose RBCs to hypo-osmolar solutions) -> will lyse

What is inheritance of G6PD? Findings?

X linked recessive

Heinz bodies, shorter RBC lifespan, anemia

How to diagnose G6PD?

Test for enzyme activity (but young RBCs have higher levels so don’t test during crisis bc most will be young RBCs)

How is pyruvate kinase deficiency inherited?

Autosomal recessive (2nd most common inherited RBC enzyme defect, 2nd to G6PD) Disruptions of Embden-Myerhoff pathway and pentose phosphate shunt Signs: chronic anemia (normocytic) high 2,3 DPG

What is the formula for partial volume exchange?

Blood vol exchanged = [(obs hct - desired hct)/obs hct ] x infants blood vol

What is normal level of met hemoglobin?

What are signs of methemoglobinemia?

Normal paO2 but low sat Brown blood when exposed to air Hb is oxidized in ferric state so can’t bind O2

What makes platelets? When does production start?

Megakaryocytes | 8 weeks GA

What is most common antigen in NAIT?

HPA-1a (80-90% of cases)

What do you expect of plts in Thrombocytopenia absent radii syndrome (TAR)?

Severe low plts at birth, with absent or reduced megakaryocytes If survive past 4 months, gradual resolution of thrombocytopenia by school age

What is amegakaryocyte thrombocytopenia?

``` Rare, x linked condition Severe isolated thrombocytopenia No other abnormalities 50% develop aplastic anemia High mortality, risk of leukemia ```

Do maternal clotting factors cross placenta?

No, all clotting factors are from fetus

When do clotting factors reach adult levels?

6 months of age

What is hemophilia A?

``` Factor VIII deficiency X linked recessive 70% of all hemophilia Severe (<1% factor level) Mod (1-5%) Mild (>5%) ```

What is hemophilia B?

Factor IX deficiency X linked recessive 30% of all hemophilia

What is hemophilia C?

``` Factor XI deficiency Autosomal recessive Associated w Noonan Doesn’t matter how much factor, no correlation with severity Treat with FFP ```

What is factor XIII deficiency?

Autosomal recessive Normal clotting studies but bleeding from umbilical stump or several days after circ Treat with cryo or factor XIII concentrate

What is von Willebrand disease?

Autosomal dominant or recessive Component of factor VIII that attaches platelet to vessel Rarely presents in newborns Abnl bleeding time, usually normal PT and plts. Dx: check ristocetin factor

What are neonatal risks for vitamin K deficiency?

``` Maternal anticonvulsant meds Liver disease Malabsorption Antibiotics Coumadin Breastfeeding ```

How do you diagnoses vit K?

Isolated prolonged PT! (Only have prolonged PTT if deficient for extended time)

What is most common solid tumor in neonatal period? Second most common?

1. Teratoma | 2. Neuroblastoma

How much blood volume is replaced in a double volume exchange?

87%

What is primary way phototherapy reduces bilirubin?

Structural isomerization to lumirubin which can be excreted in bile or urine