Pediatric Heme Flashcards
Severe Congenital Neutropenia
AKA Kostmann Syndrome
- Auto recessive mutation in ELA-2 –> apoptosis of myeloid precursors
- Severe neutropenia in neonatal period, ANC < 200
- Monocytosis and eosinophilia in blood
- Myeloid hypoplasia (bone marrow biopsy) w/ arrest in promyelocyte/myelocyte stage
- Recurrent Staph aureus, E coli, Pseudomonas
- At risk for MDS/AML
- Tx - aggressive abx when infection, GCSF, bone marrow transplant if poor response
Cyclic Neutropenia
- Stem cell disorder in which all marrow elements cycle; apoptosis of precursors –> cyclic hematopoiesis
- Also ELA-2 mutation; usually auto dominant
- Recurrent fever, pharyngitis, peridontitis, ulcerations when ANC low
- Usually 21 day cycle w/ ANC < 200 for 3-6 days
- Myeloid hypoplasia (bone marrow biopsy) w/ arrest in myelocyte stage
- May have cyclic variation in platelets and retic too
- Tx - aggressive abx when infection, GCSF
Shwachman Diamond Syndrome
- Apoptosis of myeloid precursors, dec CD34+ cells, stromal defects
- Auto rec; usually SBDS gene
- Multi-system - neutropenia, pancreatic insufficiency, metaphyseal chondro dysplasia, facial defects
- Recurrent infections (often gingivitis –> alveolar bone)
- 25% marrow dysplasia and 25% develop MDS/AML
- Tx - GCSF, pancreatic enzyme replacement, aggressive abx when infected, bone marrow transplant if severe complications
Chediak- Higashi
- Abnormal intracellular transport protein
- Auto rec - LYST or CHS1 mutation
- Multi-system - hypopigmentation of skin/eyes/hair, recurrent infections, abnormal NK cell function, prolonged bleeding, easy bruising, peripheral neuropathy
- Tx - aggressive abx and bone marrow transplant (curative)
What is the most common cause of acquired dec bone marrow production in kids?
Infection
- Esp viral, acute (resolves in days to months)
- Inc utilization of neutrophils, complement or cytokine-mediated margination, direct marrow suppression, antibody production
- Want to trend counts over time to see resolution
4 Types of Pediatric Peripheral Neutrophil Destruction
1- Alloimmune - maternal alloimmunization to paternal neutrophil antigens in baby –> cross placenta and bind
2 - Chronic Benign Neutropenia of Childhood - development of anti-neutrophil auto-antibodies by host
3- Autoimmune
- Antibody-mediated destruction of neutrophils; inc neutrophil turnover; can be associated w/ other immune disorders and heme antibodies (treat underlying disease or antibodies)
4- Drug-induced
Alloimmune Neutropenia
- Neutropenia for 2-4 wks or 3-4 months –> asymptomatic OR skin infection, pneumonia, sepsis, meningitis
- Biopsy - marrow hyperplasia w/ arrest at mature precursor level
- Tx - aggressive abx w/ infection, if severe maybe use GCSF
Chronic Benign Neutropenia of Childhood
- development of anti-neutrophil auto-antibodies by host
- Dx around 8-11 mo (median length is 20 mo)
- Usually no predisposition to infection
- ANC < 500 then spontaneous remission
- Dx - may have pos antibody
- Biopsy - would show normal or inc myeloid w/ dec levels of bands or mature neutrophils
- Tx - abx and support w/ infections, get blood cx if fever, GCSF used if profound infection
What are the normal Hb/MCV levels in kids? (2 rules)
- Dec in Hgb in first 2-3 mo of life then start to inc
- 11 + .1 rule to calc normal Hgb; 11 + age(.1) = lower limit of normal of Hgb (2 std dev below mean)
- 70 + 1 rule for MCV; 70 + age(1) = lower limit of normal for MVC (2 std dev below mean)
Iron Def Anemia in Toddler v. Older Kids
Infant - Dietary hx (cow milk has minimal iron and poorly absorbed and more cow milk intake leads to dec other iron foods and can upset stomach –> GI bleed)
Older kids - concerned for blood loss (GI - Chrons, UC, hook worm, esophageal varices if portal HTN, Meckel’s, polyp, ulceration) OR epistaxis
Adol - consider menses (heaviness, timing, duration), rapid growth phases, gross hematuria in athlete (esp long runs - “march hematuria”)
Transient Erythroblastopenia of Childhood (TEC)
- Normocytic anemia w/ low reticulocyte count
- Slowly developing, median age 18-26 mo
- Immunological etiology w/o direct link to specific viruses
- Can be accompanied by neutropenia or neuro manifestations
- Ultimately recover w/o meds
Transient Autoimmune Defiencies of Childhood (3)
ITP > AIN and AIHA in prevalence
Immune thrombocytopenia purpura (dec platelets)
Autoimmune neutropenia (dec neutrophils)
Autoimmune hemolytic anemia (dec RBCs)
ITP in Kids (2 diff presentations)
- ITP = sudden ecchymoses or petechiae w/ low platelet count but other CBC normal; may be antecedent infection
- High Risk ITP presentation - adol (esp black female) w/ family hx autoimmune disease and platelets 50,000 (more likely to become chronic)
- Dx - usually clinical; if atypical may have to r/o leukemia and get bone marrow biopsy
- Tx- Ig products, corticosteroids, rare splenectomy
Rh Hemolytic Disease
- Rh negative mom attack Rh pos infant blood
- Can be life-threatening
- In Utero - hydrops fetalis (heart defect from severe anemia) –> death
- Infant - kernicterus (from high bilirubin from breakdown of RBCs)
- Blood smear - nucleated RBCs from early release
- Tx - exchange transfusion
- Prophylaxis w/ anti-D globulin if Rh negative mother at delivery or w/ invasive amniocentesis (when blood mixes); so now dec incidence
Aplastic Anemia
- Pancytopenia (low RBC and low neutrophils and low platelets) + low reticulocyte count (production is slowly down)
- Bone Marrow Biopsy - hypocellular w/ all elements dec; mostly fat and stroma, residual HSCs are normal in morphology (no malignancy, fibrosis or megaoblastic cells)
- Severity = Mild, moderate, severe, very severe (ANC<200)
- Tx - platelet transfusion, iron chelation if overloaded from transfusions, no Epo, blood transfusions
- May use immunosuppression/steroids but NOT curative; combo is best (cyclosporine A + anti-thymocyte globulin)
- HSC transplant is curative (esp in those < 45yo)
