Heme Onc Flashcards
What does leukoreduction do to blood products
Decrease CMV, viruses
Reduces febrile non hemolytic rxns
Reduces allo-ummunization
Whta type of hemoglobin do most people have
and what subunits are these
HbA (αβ) = 97%
HbA1 (αδ) = 2%
Ddx Microcytic anemia
Thalasemisa ACD Iron def Lead poisoning Sideroblastic anemia
Ddx macrocytic anemia
Megaloblastic anemia
- B12
- Folate
Marrow failure
- Myelodysplasia, Diamond-Blackfan, Fanconi anemia, Aplastic anemia
Other
- Normal newborn, Hypothyroidism, Down syndrome, chronic liver disease, drugs (alcohol, AZT
DDx Normocytic anemia
ACD
Chronic renal failure
TEC
Malignancy/marrow infiltration
Blood loss
Hemolytic disorders
- problems intrinsic to the RBC
ddx
Problem Intrinsic to the Red Cell
• Membranopathy: hereditary spherocytosis, elliptocytosis
• Enzymopathy: G6PD deficiency, PK deficiency
• Hemoglobinopathy: HbSS, SC, S-βthal
Blood smear:
Howell-Jolly
asplenia, megaloblastic anemia, hemolysis
Blood smear:
• Basophilic stippling
lead poisoning or thalassemia
Blood smear:
Heinz bodies
G6PD
Why does excessive cow milk lead to iron deficiency?
Iron is absorbed at 50% efficiency from breast milk and 10% from cow’s milk. Excessive cow’s milk also interferes with balanced nutrition, and causes GI blood loss.
Who is at risk for iron deficiency anemia
- Premature infants,
- infants who are exclusively fed breast milk after 6 months,
- children drinking excessive amounts of cow’s milk,
- menstruating teenagers, and
- those with chronic inflammatory or renal disorders or other blood loss.
What is mentzers index and when to use
The Mentzer’s index (MCV/RBC) is >13 in IDA, and < 13 in thal trait.
Dose of iron supplementation
4-6 mg/kg/day of elemental iron for children
Preterm infants 2mg/kg/d
Term infants if BF - 1mg/kg/d at 4mo
What kind of defect is present in thalassemia
diminished or absent globin chain production
= quantitative defect
Alpha thalassemia
Absent alpha genes
Trait = 2-3 alpha chain Disease = 1 alpha chain
Beta Thalassemia
- minor
- major
Minor = one defective gene; either ββ0 or ββ+
Increased HbA2 ~5-7%
(90-95% HbA)
Intermedia = Usually two reduced function genes: β+β+, or β+β0
– 20-40% HbA
– 5%HbA2
– 60-80% HbF
Major = Either β0β+ or β0β0
– 95%HbF
– No HbA for β0β0 (or very low HbA for β+β0)
- Need transfusions and iron chelation
What is the number one cause of complications in beta thalassemia major
Iron overload
How to dx thalassemia
Hb electrophoresis
Congenital pancytopenia? (3)
Schwachmann Diamond (pancreatic insufficiency)
Fanconi anemia
Dyskeratosis Congenita
Diamond-Blackfan Anemia
- characteristics
- associated congenital anomalies
- risk
- tx
Congenital pure RBC aplasia
50% have congenital anomalies:
– Craniofacial malformations
– Thumb or upper limb abnormalities
– Cardiac defects, etc.
Leukemia, other malignancies
steroids
Transient Erythroblastipenia of Childhood
- age
- presentation
- prognosis
1-3 yo
Otherwise healthy
Often after viral trigger
Gradual onset, can become severe
Recovers in 1- 2 months
Goat’s milk - what to worry about
Folate deficiency - macrocytic anemia
Hereditary Spherocytosis
- type of anemia
- diagnosis
Hemolytic anemia
Osmotic fragility
What is the most common presentation of spherocytosis in the newborn
Jaundice
What is the most common complication of hereditory spherocytosis
- other complication?
gall stones
aplastic crisis
G6PD deficiency
- what is G6PD
- presentation
G6PD is an X-chromosome enzyme which protects RBCs from oxidative damage
Hemolysis from oxidative stress
Sx: jaundice, dark urine
Auto-immune Hemolytic Anemia
- labs
hemolysis and + DAT
What is the genetic cause of sickle cell disease and what does it lead to
How to Dx
Single nucleotide substitution (Val ->Glu) of beta globin gene on chromosome 11
Qualitative defect
Hb electrophoresis or DNA analysis
(sickledex does not work <3mo and does not distinguish trait from disease)
Triggers of acute vaso occlusive crisis in sickle cell
- mgmt
tissue ischemia related to vascular occlusion => PAIN
Triggers: infection, temp extremes, dehydration, stress, or no obvious cause
Pain management (PCA, opioids, NSAIDs) Hydration Physio Ancillary therapies Incentive spirometry helps prevent pain crisis from becoming chest crisis
NOT TRANSFUSION
Acute complications of Sickle Cell Disease
Acute vaso-occlusive crisis Infection Stroke Retinopathy Acute Chest Syndrome Pulmonary hypertension Lung disease of SCD Splenic Sequestration Cholelithiasis Priapism Renal insufficiency Bone: osteonecrosis, OM Kidney: Papillary necrosis, nephropathy
Fever in pt w sickle cell dz
Parenteral antibiotic coverage
If chest sx - do CXR
If bone pain - consider OM
Treatment of stroke in sickle cell disease?
Exchange transfusion
How to prevent second stroke in SCD
chronic transfusion
keep HbS < 30%
Risk factors for stroke in SCD
SS genotype, low baseline Hb, previous TIA, high blood pressure, rate of and recent episode of acute chest crisis
Most common cause of admission in sickle cell
VOC > ACS
Acute chest syndrome in SCD
- dx
- tx
dx = fever + infiltrate
mgmt:
- Antibiotics (including cephalosporin and macrolide(ex azithro)),
- oxygen,
- hydration,
- incentive spirometry,
- bronchodilators
if hypoxia or Hct<18%: simple transfusion
if hypoxia and multiple infarcts: exchange transfusion
Splenic sequestration in SCD
dx:
- sudden enlargement of spleen
- drop in Hb by 20 + reticulocytosis
Preventative care in sickle cell disease
- Penicillin prophylaxis should begin at 3months and continue until 5 years
- Appropriate pneumococcal vaccination
– Prevnar-13 at 2, 4 and 12mo
– Pneumovax-23 should be given at 2y and 5y - Transcranial doppler starting 2yo, yearly until 16yo if SS or SB0
- Routine Screening for end organ damage
- Hydroxyurea
SCD: indications for simple tranfusion
– Aplastic crisis – Splenic sequestration – Pre-op (high risk surgeries) – Stroke – if low Hb, awaiting exchange – ACS – if low Hb, awaiting exchange – Also used chronically to prevent stroke by keeping Hb S under 30%
Generally not for VOC
SCD: indications for exchange tranfusion
stroke, severe ACS, and pre-op some major surgeries
generally not VOC
Fanconi Anemia
Autosomal recessive
CAL
Short stature
Thumb/hip abnormalities
Malignancy risk
Shwachman-Diamond
– Short stature
– Skeletal abnormalities (metaphyseal widening)
– Pancreatic insufficiency
– Bone marrow dysfunction
• Risk of MDS, leukemia
Neonatal thrombocytopenia
1) Decreased production: congenital syndromes
• TAR (thrombocytopenia absent radii syndrome) in which megakaryocytes are absent in the bone marrow.
• Tx is with plt transfusions. Chidren usually recover production by 3 years of age.
2) Non-immune destruction:
• TORCH eg CMV
• NEC, RDS, and transiently after maternal pre-eclampsia. (In general, a sick neonate).
3) Immune destruction:
• Maternal ITP – check mom’s CBC
• NAIT - alloantibody directed against an antigen on the newborn’s platelets made by mother
NAIT - treatment
1st line
- mothers washed platelets
- HPA-negative platelets
2nd line
- IVIG
Maternal ITP - treatent
IVIG
IVIG - side effects
headache
nausea, vomiting
aseptic meningitis
allergic rxn
Indications for a bone marrow biopsy in setting of probable ITP
Low white cell count Low hemoglobin Blasts on the peripheral smear Lymphadenopathy Hepatosplenomegaly
which type of hemorrhagic disease of the newborn presents w ICH
Late onset
von Willebrand disease - types
Type 1 vWD: quantitative deficiency of normal vWF
= mild bleeding sx
Type 2 vWD: qualitative problems
Type 3: rare (1 in 250,000) autosomal recessive disorder characterized by complete absence of vWF and severe bleeding.
Treatment of vWD
1) DDAVP (type1)
2) Factor VIII-vWF concentrate
3) OCP
4) Avoidance of bleeding (sports, wear helmet, etc)
5) Antifibrinolytics (eg tranexamic acid)
Hemophilia A and B - inheritance
X linked
List 4 clinical presentations of hemophilia in the neonatal period
Intraventricular hemorrhage Circumcision bleeding IM hematoma after vit K injection Bleeding at the umbilical stumb Large caput or subgaleal bleed Excessive bleeding with phlebotomy (Hemarthrosis and deep muscle bleeding
