Hematology Flashcards
Normal retic count
0.5-2%
When does physiologic anemia of infancy occur
2-3 months
Lab findings in aplastic anemia
Hypocellular or acellular bone marrow
Platelets < 20, ANC < 0.5, retics < 20
What is the osmotic fragility test for?
Hereditary spherocytosis
Cause of
1. Febrile non-hemolytic reactions
2. Allergic reactions
3. Acute hemolytic reactions
4. GVHD
from blood transfusions
- Cytokines or Abs to WBC antigens
- Foreign plasma proteins
- ABO incompatibility
- Donor WBCs (why we irradiate)
Why do we
1. Irradiate
2. Leukoreduce
blood products
- Prevent GVHD
- Reduce febrile reactions, reduce CMV transmission
Metzner index
MCV/RBC
13+ = IDA
< 13 = thalassemia
Most common complication of hereditary spherocytosis
Gallstones
Is ABO vs Rh incompatibility
Rh more severe
ABO can occur with initial pregnancy (sensitized through diet)
What is in
1. Crypoprecipitate
2. FFP
- Fibrinogen, factor 8, factor 13, VWF
- All factors (but less VWF)
Lab findings in DIC
Increased PT and PTT
Thrombocytopenia
Decreased fibrinogen
Elevated D dimer
Increased thrombin time
RBC fragments
5 causes of isolated PTT elevation
Hemophilia
Factor 11 or 12 deficiency
Lupus anticoagulant
vWD
Heparin
4 causes of isolated INR elevation
Factor 7 deficiency
Early vitamin K deficiency
Early liver disease
Early/chronic DIC
7 causes of prolonged INR and PTT
Factor 10 deficiency
Factor 5 deficiency
Factor 2 deficiency
Low fibrinogen
Xa inhibitors
DIC
Severe liver disease
Risk factors for IDA
Prematurity
LBW
Maternal anemia or obesity
Early cord clamping
Exclusive BF > 6 mo
Infection
Lead exposure
Diet
Low SES
Empiric abx in acute chest syndrome
3rd gen cephalosporin + macrolide
Red flags in ITP
History: constitutional sx, bone pain, recurrent thrombocytopenia, poor response to tx
Physical: HSM, lymphadenopathy, unwell, signs of chronic disease
Labs: more than mild Hb, high MCV, abnormal WBC/neutrophil count, abnormal morphology
NAIT treatment
Gold standard: washed maternal platelets
Can also do antigen compatible donors, IVIG and random donor
Threshold usually 30
Treatment for stroke in SCD
Sats 95+
IV hydration not exceeding maintenance
Exchange transfusion with goal HbSS < 30%
Screening for stroke in SCD
Screen annually from 2-16 years with a transcranial Doppler US
If at risk, begin chronic transfusions to maintain HbS < 30% to reduce risk of first stroke
When does ITP typically resolve
75-80% within 6 months
Most resolved by 1 year
Treatment for neonatal autoimmune thrombocytopenia
Limited to severe and clinically significant bleeding
IVIG, steroids, platelet transfusions if ++ serious
How long to wait after IVIG before giving live vaccines
11 months
Hereditary spherocytosis
Autosomal dominant
Northern Europeans
Low MCV, high MCHC
Neonatal anemia, hyper bili
Splenomegaly common after infancy, gallstones around 4-5
Can get aplastic crisis from parvo
Splenectomy is curative
Kasabach-Merritt syndrome
Giant hemangiomas can have localized DIC causing thrombocytopenia and hypofibrinogenemia
More in kaposiform or tufted hemangiomas
Blood smear shows microangiopathic changes
Normal INR/PTT
Transient erythroblastopenia of childhood
Acquired red cell aplasia
Children 1-3 years old
Often follows a viral illness
NO organomegaly or petechiae
Normocytic anemia, reticulocytopenia
Supportive care, resolves in 1-2 mo
Diamond-Blackfan anemia
Autosomal dominant congenital red cell aplasia
Presents in infancy
Congenital anomalies often present
Macrocytic anemia, reticulocytopenia, increased fetal hemoglobin
Tx: RBC transfusions, steroids
TEC vs Diamond blackfan
Both affect RBCs
TEC: Normocytic, reticulopenic, no increased fetal Hb
DBA: Macrocytic, reticulopenic, increased HbF
Type 1 VWD
Decreased AMOUNT of vWF
Most common
Normal PT and aPTT
AD inheritance
Type 2 VWD
PT is normal
aPTT is prolonged
Type 2A = decreased binding to platelets
Type 2B = increased binding to platelets, but bound to early so not helpful
Type 2M = mix
Type 2N = decreased binding to factor 8 (PT and aPTT are normal)
AD except 2N which is AR
Type 3 VWD
Undetectable vWF levels and low factor 8
Rare, autosomal recessive
More severe symptoms (like hemophilia)
Prolonged aPTT, PT
Treatment for VWD
Type 1: DDAVP
Type 2/3, unknown, severe bleeding: vWF/factor concentrates
Could also use cryoprecipitate
Factor 5 leiden
Factor 5a becomes resistant to inactivation by protein C (causes excessive clotting)
Causes strokes and hemiplegic CP in neonates
Hemophilia
A = factor 8, B = factor 9 deficiency
X linked recessive inheritance
PTT is increased, PT is normal
Muscle and joint hemorrhages
Treat with factor concentrates
Hemophilia C
Factor 11 deficiency
AR inheritance
Less severe than A or B
Bleeding risk does not correlate with factor levels
TXA for mucosal bleeding, FFP if severe
Fanconi anemia
AR inheritance
Congenital pancytopenia
Hyper/hypo pigmentation, cafe au lait, absent or abnormal thumbs, other congenital stuff
Increased risk of hepatic and squamous cancerns
HSCT will cure aplasia
What chains are involved in:
1. HbA
2. HbF
3. HbA2
4. HbSS
- 2 alpha, 2 beta
- 2 alpha, 2 gamma
- 2 alpha, 2 delta
- 2 alpha, 2 S
Beta thalassemia
Autosomal recessive, chromosome 16 (2 alleles)
B0 = no beta = no HbA
B+ = reduced beta globin = some HbA
Minor: AB0 or AB+, elevated HbA2> 3.5% = diagnostic for B thal minor
Intermedia: B+/B+ or B+B0, elevated HbA2 and HbF
Major: B0/B0, HbF predominant
Alpha thalassemia
Autosomal recessive, chromosome 16 (4 alleles)
Absent or decreased alpha chains
A thal trait = 1 loci, asymptomatic
A thal minor = 2 loci, mild anemia
HbH disease = 3 loci (4 beta chains), mod to severe
Hb Bart = 4 loci (4 gamma), death in utero
Hb electophoresis not sensitive enough for diagnosis
4 naturally occurring anticoagulants and where they work
Antithrombin - factor 10, thrombin
Protein C - factor 5, 8
Protein S - cofactor for C
Tissue factor pathway inhibitor - limits activation of factor 10
Heparin MOA
Binds to antithrombin
Causes inactivation of thrombin and factor 5
UFH monitoring = PTT
LMWH monitoring = anti-Xa
Reversal = protamine
Contact factors
Factor 7, high molecular weight kininogen, prekallikrein
Reduced levels of contact factors = prolonged aPTT but NOT increased risk for hemorrhage
Schwachman-Diamond
Severe congenital neutropenia and pancreatic exocrine insufficiency
Autosomal recessive
Like CF, but normal sweat test
How to manage severe bleeding from ITP
Ex: prolonged epistaxis, GI bleeding, or ICH
IV steroids and IVIG
TXA can be used
Platelet tx only for acute, life threatening bleeds or children needing immediate surgery
Where is
1. folate
2. B12
absorbed
- Jejunum
- Terminal ileum
