Clinical Correlations Flashcards
Hereditary spherocytosis
Deficiency in RBC structural proteins (usually spectrin)
1. Symptoms
A. Spherocytes w/ dec life span
B. Hemolytic anemia
C. Splenomegaly
2. Genetics
A. 1/5000 people of Northern European ancestry
Hereditary elleptocytosis
RBCs elliptical shape
1. Usually spectrin abnormality
Pyruvate kinase deficiency
Leads to hemolytic anemia (nonspherocytic) 1. Symptoms A. Fatigue B. Pallor C. SOB D. Jaundice E. Inc risk gallstones 2. Second most common single gene disorder after G6PD deficiency 3. No Heinz bodies (precipitated Hb)
G6PD deficiency
- Episodic hemolytic anemia induced by oxidative stress
- RBCs have Heinz bodies (precipitated Hb)
- One of most common single gene disorders
- Genetics
A. X-linked
B. Inc pop specific polymorphism
C. 400 distinct variants Id
D. 200 mutations (most point missense)
E. Alter enzyme kinetics- Stability (majority)
- Active site
- Allosteric site
- Classes I-IV
- Prevalence
A. 10% black men in US
B. Middle Mediterranean
C. Sardinians
D. Sephardic jews
G6PD deficiency type I
Very severe
1. Clinical symptoms
A. Chronic nonspherocytic hemolytic anemia
2. Residual enzyme activity: <10%
G6PD deficiency type II
Severe
1. Clinical symptoms
A. Acute hemolytic anemia
2. Residual enzyme activity: <10%
G6PD deficiency type III
Moderate
1. Residual enzyme activity: 10-60%
G6PD deficiency type IV
No symptoms
1. Residual enzyme activity: >60%
General anemia
Dec circulating RBCs 1. Causes hypoxia 2. Dx: dec hematocrit and Hb A. Hb normal 1. Men: 13.6-17.2 2. Women: 12.0-15.0 B. Hematocrit normal 1. Men: 39-49 2. Women: 33-43 3. Classification A. Blood loss B. Hemolytic C. Impaired RBC production 4. Clinical findings A. Pale B. Weakness, malaise, and easy fatigability C. Dec O2 sat -> dyspnea
Hemolytic anemia
Accelerated RBC destruction (hemolysis)
- Life span <120 days
- Inc EPO release from kidneys -> RBC production -> inc reticulocytes in marrow
- Hallmarks: erythropoietin hyperplasia and reticulocytes
- Extravascular hemolysis
- Intravascular hemolysis
Extravascular hemolysis
1.in phagocytes -> splenomegaly if persistent A. RBCs less deformable => get stack B. Features 1. Splenomegaly - often splenectomy 2. Anemia 3. Jaundice
Intravascular hemolysis
- RBCs burst in circulation
- Less common
- Cause:
A. Mechanical force - defective heart valve
B. Biochem agents damage membrane - Clinical findings
A. Hemoglobinemia
B. Hemoglobinuria
C. Hemosiderinuria
D. Dec serum haptoglobin
E. Iron loss
Hereditary spherocytosis (HS)
- Inherited RBC membrane defect -> spherocytes
- Sequestration and destruction in spleen
- Genetics: AD (75%)
- Prevalence: N. Europe 1/5000
- Pathogenesis:
A. Spectrin = major membrane protein affected- Self-associates one end
- Binds short actin filaments
- Connect other network proteins
A. Band 3
B. Glycophorin
C. Ankyrin
D. Band 4.2
E. Band 4.1
- Dx: osmotic fragility test = gold standard
- Tx:
A. No specific
B. Splenectomy improves anemia- Weigh pros and cons
Hereditary spherocytosis morphology
1. Smears A. Spherocytes B. Dark red C. No central pallor D. Dec MCV E. Inc MCHC 2. Marrow A. Hyperplasia RBC progenitors B. Reticulocytes 3. Splenomegaly from xs macrophages 4. Cholelithiasis (40-50%)
Hereditary spherocytosis clinical features
- Anemia
- Splenomegaly
- Jaundice
- Cells inc osmotic fragility in hypotonic soln
- Generally stable w/ aplastic crises occasionally
- Parvovirus B19 -> most severe crises
A. Targets erythroblasts -> apoptosis
B. No RBC progenitors in marrow until infection controlled
C. Anemia rapidly worsens
Hereditary spherocytosis in Peds
- Need for transfusion does not lead to more severe disease later
- Some transfusion dependent until 6-12 mo old
- Monitor growth
- Exercise tolerance and spleen size documented
- Keep vaccinations up to date
- Gallbladder screening begin ~4 y/o, then every 3-5 years
- Document
A. Parvovirus B19 susceptibility
B. HIV and hepatitis serology - Folic acid supplementation for moderate to severe
A. Inc demand of brisk erythopoiesis
G6PD pathogenesis
Episodic hemolysis w/ exposure to oxidative stress
1. Drugs
A. Anti-malarial
B. Sulfonamides
1. Bactrim: trimethoprim-sulfamethoxazole (TMP-SMX)
C. Nitrofurantin
D. Phenacetin
E. Aspirin (large doses)
F. Vit K derivatives
1. Fava beans (G6PD-B)
A. Divicine
B. Isouramil
C. Convincine
2. Infection (more common) -> phagocytes inc ROS
A. Oxidants attack globin chains
B. Oxidized Hb -> Heinz bodies
C. Heinz bodies -> intravascular hemolysis
D. Splenic phagocytes “pluck out” Heinz bodies -> bite cells
E. Bite cells trapped in spleen -> extravascular hemolysis
G6PD clinical features
- Hemolysis 2-3 days after drug exposure
- RBCs uniformly deficient and vulnerable to oxidant injury
- Marrow -> new RBCs w/ adequate G6PD => hemolysis ends even if drug exposure continues
- Transient jaundice
- Dark urine
- Back and/or abdominal pain
- Severe
A. Hemoglobinuria
B. Acute kidney failure - Hemolytic anemia (congenital)
Paroxysmal Nocturnal Hemoglobinuria (PNH)
- Acquired PIGA mutation
A. PIGA needed for glycosylphosphatidylinositol (GPI)
B. GPI = membrane anchor for proteins - Rare: 2-5/million in US
- PIGA X-linked => one mutated gene -> dec GPI
- Mutations in hematopoietic stem cells => all clinal progeny affected
- Thrombosis = leading COD
- 5-10% dev AML or myelodysplastic syndrome
- Dx: flow cytometry
- Tx: Eculizumab use to prove complement role
A. Prevents C5-C5a
B. Worked as tx
C. Dec hemolysis
D. Dec risk thrombsis 90%
E. Drawbacks- Very expensive
- Risk serious/fatal meningococcal infections
F. Hematopoietic stem cell transplant = only cure
Paroxysmal Nocturnal Hemoglobinuria (PNH) Pathogenesis
- Blood deficient 3 GPI-linked proteins that reg complement activity
A. Decay-accelerating factor (CD55)
B. Membrane inhibitor reactive lysis (CD59)- Most important
- C3 convertase inhibitor
C. C8 binding protein
- RBC inc susceptible lysis/injury by complement
- Intravascular hemolysis by C5b-C9 membrane attack complex
- Complement fixation inc by dec pH in sleep
- Present w/ anemia and iron deficiency
- Thrombosis = leading COD
7.
Immunohemolytic anemia (IHA)
- Antibodies (Ab) bind determinants on RBC membranes
A. Arise spontaneously or induced by exogenous agents - Uncommon
- Classified
A. Nature of AB
B. Presence predisposing conditions - Dx: detect Ab and/or complement on RBCs
A. Direct Coombs test
B. (+) = RBCs agglutinate w/ Abs - Warm Ab IHA
- Cold Ab IHA
Warm antibody immunohemolytic anemia (IHA)
AutoAb bind RBCs and phagocytosed (spleen)
1. Incomplete -> spherocytes -> extravascular hemolysis
2. IgG (rarely IgA) active at 37C
3. Etiology
A. 60% idiopathic (primary)
B. 25% secondary to immunologic disorder or drugs
4. Presentation
A. Chronic mild anemia
B. Moderate splenomegaly
5. Usually don’t require tx
Cold Ab IHA
Distal parts of body
1. Low-affinity IgM bind RBCs at temps <30C
A. Cross link RBCs -> agglutinate -> Raynaud phenomenon
2. Bind C3b in cold
3. Warmer: lose IgM, keep C3b coating
4. C3b coating -> extravascular hemolysis
5. Episodes
A. Recovery mycoplasma pneumonia and infectious mononucleosis
6. Chronic
A. B cell neoplasms
B. Idiopathic condition
Microangiopathic hemolytic anemia
Small vessels narrowed/obstructed -> RBC damage 1. Disseminated intravascular coagulation (DIC): vessels narrowed w/ fibrin A. Most common 2. Other causes A. Malignant HTN B. Thrombotic thrombocytopenia purpura (TTP) C. SLE D. Hemolytic uremic syndrome (HUS) E. Disseminated cancer 3. Peripheral smear A. Burr cells B. Helmet cells C. Triangle cells
Sickle cell anemia
Prototypic hemoglibinopathy
1. Mutation in beta-globin -> sickle Hb (HbS)
2. Most common familial hemolytic anemia
3. Prevalence
A. 30% in Africa- protects against malaria
B. U.S. - 8% blacks heterozygous (1/600 affected)
Sickle cell pathogenesis
- Single aa substitution in beta-globin -> deoxy HbS -> polymers -> sickle shape
A. Glu -> Val at position 6 - Sickling initially reversible w/ reoxygenation
- Over time -> irreversible -> rapid hemolysis
- Sickling consequences
A. Chronic moderate to severe hemolytic anemia- RBC life span ~20 days
- Severity proportional to irreversibility of sickled RBCs
B. Vascular obstructions -> ischemia and pain crises
Sickle cell morphology
1. Anatomic changes from A. Severe chronic HA B. Ischemia and infarction C. Inc breakdown heme -> bilirubin 2. Peripheral smear: sickled RBCs 3. Bone marrow: reticulocyte hyperplasia 4. Prominent cheekbones 5. “Crew cut” skull changes 6. Splenomegaly in kids -> nubbin fibrous tissue w/ time = autosplenectomy 7. Hemosiderosis and pigment gallstone common 8. Usually presents after 6 mo old when HbF -> HbS 9. Avg. hematocrit = 18-30%
Sickle cells clinical features
- Hyperbilirubinemia
- Reticulocytosis
- Vasoocclusive crises: pain and tissue damage
A. Hand-foot syndrome: most common in kids
B. Acute chest syndrome: slugging blood flow in inflamed lung
C. Stroke
D. Proliferation retinopathy -> blindness/vision damage - Aplastic crisis: sudden dec RBC production
A. Triggered by parvovirus B19
B. Self-limited - Prone to infection
A. Functionally asplenic
B. Encapsulated bacteria (pneumococci)
C. Salmonella osteomyelitis
Sickle cell dx and tx
- Dx: electrophoresis
- Clinical course highly variable
- Supportive care -> inc survival to adulthood
A. 50% live >50 yrs - Prophylactic tx w/ penicillin (usually <5 y/o)
- Tx: hydroxyurea - “gentle” DNA synthesis inhibitor
A. Allosteric bone marrow transplant
Thalassemia
Inherited mutation in globin -> dec synthesis of alpha or beta globin -> precipitates 1. Prevalence - prevents malaria A. Mediterranean B. African C. Asian
Beta-Thalassemia pathogenesis
- Genetics: Autosomal codominant
A. 2 alpha-globin genes on chromosome 16
B. One beta-globin gene on chromosome 11 - Types
A. Beta0: no beta-globin chains
B. Beta+: dec beta-globin chains - > 100 single-base mutations
A. Abnormal DNA splicing - Beta-thalassemia minor (trait): heterozygous
A. Asymptomatic/mildly symptomatic - Beta-thalassemia major: homozygous
- Beta-thalassemia intermedia: at least one beta+
A. Milder disease - Anemia mechanisms
A. Dec HbA formation -> Microcytic and hypochromic RBCs
B. Accumulation unpaired alpha-globin chains -> toxic precipitation damage precursors and RBC membranes- Ineffective erythropoiesis: precursors -> apoptosis
- RBCs produced dec life span
- Ineffective hematopoiesis-> inc absorption dietary Fe -> overload
A. Caused by dec hepcidic (- regulators)
Alpha-thalassemia pathogenesis
- Deletions 1< or = or 4 alpha-globin genes
- Severity depends on # deletions
A. Single = silent-carrier
B. All 4 = fatal in utero (hydros fetalis)
C. 3= xs beta globin-> HbH and Hb Bart -> dec damage => less ineffective erythropoiesis- Inc affinity O2 => dec delivery
Beta-minor and alpha-trait thalassemia morphology
Abnormalities only in peripheral blood
- Microcytic and hypochromic
- Target cells
Beta-thalassemia major morphology
1. Peripheral smear A. Microcytosis B. Hypochromia C. Poikilocytosis D. Anisocytosis E. Nucleated RBCs (normocytic) 2. Bone marrow A. Progenitor hyperplasia B. Shift toward early forms 3. Skeletal deformities from marrow filling intramedullary space 4. Splenomegaly 5. Hepatomegaly 6. Lymphadenopathy 7. Ineffective precursors -> growth retardation an cachexia 8. Iron overload -> severe hemosiderosis if not treated
Beta-minor and alpha-trait thalassemia clinical features
- Asymptomatic
- Mild Microcytic hypochromic anemia
- Normal life expectancy
Beta-thalassemia major clinical features
- Presents as HbF deficiency
- Growth retardation
- Sustained w/ blood transfusions
A. Life span 20s to 30s
B. Iron overload - Treated w/ iron chelators
A. Prevent cardiac dysfunction - Hematopoietic stem cell transplant young = best tx
HbH and beta-intermedia clinical features
- Moderate anemia - don’t usually need transfusions
2. Iron overload rare
HbC disease
Hb structural defect
- Homozygosity = rare
- Mild, chronic hemolytic anemia w/o infarction crisis
- No specific therapy
HbSC disease
Hb structural defect
- Hb = 1/2 HbC + 1/2 HbS
- Compound heterozygotes = double hetrozygotes
- Crises less frequent and severe than sickle cell
Methomoglobinemias
1. [O] result of A. Acquired: drugs/chem 1. Nitrates 2. Nitrites 3. Sulfone drugs 4. Sulfonamides 5. Lidocaine 6. ROS B. Congenital defects: mutations 1. NADH-cytochrome b5 reductase (NADH-methemoglobin reductase) 2. Alpha or beta-globin chain -> HbM = resistance to reductase 2. Babies more sensitive to oxidants 3. Presentation A. “Chocolate cyanosis” - blue skin and mucous membranes 1. Brown blood from HbM B. Symptoms related to degree tissue hypoxia 1. Anxiety 2. Headache 3. Dyspnea 4. Coma and death rare 4. Tx: methylene blue - [O] as reduces Fe3+ -> Fe2+ 5. Kentucky blue people
Adenoiditis
Chronic inflammation and hyperplasia of pharyngeal tonsils
1. Can lead to middle ear infections
MALT lymphomas
Usually in stomach
Lymphadenopathy
Swelling, enlargement
- Disrupt architecture
- Pain/tenderness varies
- Lymphoma = one cause
Lymphogenous spread (metastasis)
Metastasis via lymph nodes
- Sentinel lymph nodes: 1st set lymph nodes downstream of tumor
- Staging systems: evaluate progression and prognosis
IPEX syndrome
Immunodysregulatory polyendocrinopathy enteropathy X-linked 1. X-linked defect FoxP3 2. Severe autoimmunity 3. Presentation A. Early onset diarrhea B. Type I DM C. Failure to thrive D. Classic triad 1. Enteropathy 2. Endocrinopathy 3. Dermatitis 4. Tx: tried BMT w/ mixed results
Microcytic anemias
- Caused by disorders of Hb synthesis
- Normal production requires
A. Iron
B. Protoporphyrin (heme)
C. Globin - Iron deficiency anemia
- Anemia of chronic disease
Iron deficiency anemia
1. Most common nutritional deficiency in the world A. 10% people developed countries B. 25-50% developing countries 2. Causes A. Dietary lack B. Dec absorption C. Chronic blood loss 3. Etiology A. Maintain normal need 1 mg Fe absorbed B. Only 10-15% absorbed 1. 7-10 mg adult men 2. 7-10 mg adult female C. Western world 1. Men eat enough 2. Women marginal D. Animal sources better absorbed than plant E. Impaired absorption 1. Sprue 2. Chronic diarrhea and gastrectomy F. Inc requirements 1. Growing infants 2. Kids/adolescents 3. Premenopausal women 4. Pregnant G. Chronic blood loss 1. Most common in western world 2. External or GI bleed
Iron deficiency anemia pathogenesis
- Causes hypochromatic Microcytic anemia
- Initially ferritin and hemosiderin reserves maintain normal Hb and hematocrit
- Depletion -> dec serum Fe and transferrin saturation levels
A. Still no anemia - Anemia= complete depletion
A. Dec serum iron
B. Dec ferritin
C. Dec transferrin sat levels => inc free transferrin
Iron deficiency anemia morphology
- Disappearance stainable iron from macrophages in bone marrow
- Peripheral smear
A. Microcytic
B. Hypochromic
C. Pencil cells
Iron deficiency anemia clinical features
- Pale
- Weakness, malaise, fatigue
- Dyspnea w/ mild exertion
- Chronic
A. Koilonychia (finger nails)
B. Alopecia
C. Atropic change in tongue and gastric mucosa
D. Intestinal malabsorption - Dx criteria
A. Anemia
B. Hypochromic and Microcytic RBCs
C. Dec serum ferritin and Fe
D. Dec transferrin sat
E. Inc total iron-binding capacity
F. Respond to iron therapy - Inc platelet count common
Anemia of chronic disease
Microcytic anemia 1. Associated w/ chronic inflammation 2. Most common in hospitalized pts 3. Erythopoiesis suppressed by systemic inflammation 4. Causative disorders A. Chronic microbial infections B. Chronic immune disorders C. Neoplasms
Anemia of chronic disease pathogenesis
- Inc plasma hepcidin: blocks Fe transfer to precursors by downregulating ferroportin in macrophages
A. Caused by Il-6
Anemia of chronic disease clinical features
- Dec serum FE
- RBCs hypochromic and Microcytic
- Fe storage in marrow inc
- Inc serum ferritin
- Dec total iron binding capacity
- Other causes
A. Thalassemia
B. Sideroblastic anemias
C. Dec heme synthesis
Macrocytic anemias
- Stem cell abnormalities impair RBC maturation
- Main causes
A. Folate deficiency
B. Vit B12 deficiency - Pathogenesis
A. Dec thymidine biosynthesis -> abnormal rapidly dividing cells
B. RNA and cytoplasmic elements preceded normal rate -> hematopoietic precursors show nuclear-cytoplasmic asynchrony -> apoptosis (ineffective hematopoiesis)
C. Granulocytes and platelet precursors affected -> pancytopenia - Morphology
A. Marrow- Hypercellular w/ megablastic eerythroid progenitors
- Reticulocytes
- Nuclear-cytoplasmic asynchrony
B. Peripheral - Hypersegmented neutrophils = earliest stage
- RBCs large, egg shaped macroovalocytes
- MCV > 110 fL
Folate deficiency anemia
1. Causes A. Dec intake 1. Alcoholics 2. Elderly 3. Poor 4. Most destroyed by cooking in 10-15 min B. Impaired absorption 1. Phenytoin 2. Oral contraceptives 3. Acidic foods 4. Beans/legumes 5. Celiac 6. Tropical sprue C. Inc loss: hemodialysis D. Inc requirements 1. Pregnancy 2. Infancy 3. Inc hematopoiesis E. Drugs: methotrexate (antagonist)
Folate deficiency anemia pathogenesis
- Dihydrofolate -> tetrahydrofolate
A. Dihydrofolate reductase - Tetrahydrofolate needed dTMP synthesis
- Dec dTMP -> dec DNA synthesis -> megaloblastic anemia
Folate deficiency anemia clinical features
- Insidious onset
- Nonspecific symptoms
A. Weakness
B. Easy fatiguability - Can coexist w/ othe deficiencies
- GI tract problems (sore tongue)
- No neurologic defects
- Different from Vit B12 deficiency
A. Serum levels
B. RBC folate
C. Vit B12 levels
Vitamin B12 (cobalamin) deficiency
1. Causes A. Vegan diet B. Dec absorption 1. H+ pump inhibitors 2. GI tract probs 3. Gastrectomy 4. Ileal resection 5. Disorders fxn distal ileum 6. Gastric atrophy C. Inc requirement 1. Pregnancy 2. Hyperthyroidism 2. After absorption A. Stored in lever (sufficient supply 5-20 yrs)
Vitamin B12 (cobalamin) deficiency pathogenesis
- Pernicious anemia: autoimmune attack gastric mucosa -> dec intrinsic factor
A. Chronic strophic gastritis- Dec parietal cells
- Inc immune cells
- Megaloblastic change in mucosal cells
- Neurologic lesions = demyelination
Vitamin B12 (cobalamin) deficiency clinical features
- Nonspecific symptoms
A. Pallor
B. Easy fatiguability
C. Dyspnea - Megaloblastic change oropharyngeal epithelium -> beefy red tongue
- Neurologic symptoms
A. Don’t always resolve if deficiency corrected - Inc risk gastric cancer
- Dx:
A. Dec serum Vit B12
B. Normal/inc folate serum
C. Moderate to severe Macrocytic anemia
D. Leukopenia w/ hypersegmented granulocytes
E. Dramatic reticulocyte response to Vit B12 tx
Normocytic anemias
- Diverse etiologies
- RBC shape clue to Dx
- Categories
A. Hemolytic anemias: inc reticulocytes
B. Aplastic anemias: dec reticulocytes
Aplastic anemias
Normocytic anemia 1. Multipotent myeloid stem cells suppressed -> marrow failure and pancytopenia A. Marrow: no recognizable hematopoietic elements (mostly fat) 2. Etiology A. No initiating factor ID’d in most cases B. 65% idiopathic C. Most known = chem/drugs 1. Chemo 2. Benzene 3. Causes marrow suppression A. Dose related B. Reversible 4. Other not usually associated A. Chloramphinicol B. Gold salts D. Viral infections -> persistent marrow aplasia (hepatitis 5-10% cases) E. Specific inherited abnormalities 1. Fancoi anemia 2. Telomerase defects
Aplastic anemias pathogenesis
Not fully understood
1. 2 mechanisms
A. “Extrinsic” immune-mediated marrow progenitor suppression
1. Cells antigenically altered by drugs, infectious agents, environmental factors
2. Immune response
A. Th1 -> IFN-gamma and TNF -> suppress and kill progenitors
3. Supported by trials w/ immunosuppressants (effective 60-70% pts)
B. “Intrinsic” stem cell abnormality
1. Supported by 5-10% w/ telomerase defect -> shorter life span hematopoietic stem cells
3. Mechanisms not exclusive
A. Cells w/ telomerase defect could -> T cell attack
Aplastic anemias morphology
1. Marrow A. Hypocellular B. Mostly fat and fibrous stroma C. Scattered lymphocytes and plasma cells D. Aspirated often “dry tap”
Aplastic anemias clinical features
- Any age, either sex
- Insidious onset
- Pancytopenia
A. Anemia
B. Thrombocytopenia- Petichae and ecchymosis
C. Neutropenia - Persistent infection
- Sudden onset chills and fever
- Petichae and ecchymosis
- Dx: bone marrow biopsy
- Prognosis: variable
- Tx
A. BMT: 5 yr survival 75%
B. Immunosuppression if can’t do BMT
Pure red cell aplasia
Only RBC progenitors suppressed
1. Completely absent in marrow = severe
2. Associated w/ neoplasms
A. Thymoma
B. Large granular lymphocytic leukemia
3. Drug exposure
4. Autoimmune disorders
5. Parvovirus B19: only one w/o autoimmune basis
A. Usually cleared 1-2 wks
B. Hemolytic anemias -> aplastic crisis
C. Severe immunosuppression -> chronic aplasia and anemia
Myelophthistic anemia
Space occupying lesions replace marrow
- Metastatic cancer = #1 cause
- Inflitrative processes
- Spent phase of myeloproliferative disorders
- Immature granulocytes and nucleated RBCs in peripheral smears
- Tear drop cells
Chronic renal failure
Associated w/ anemia 1. Severity proportional to uremia severity 2. Dec EPO synthesis 3. Tx: recombinant EPO A. +/- iron replacement
Congenital hypoplastic anemia
“Diamond black fan anemia” (DBA) 1. Rare 2. Congenital bone marrow failure 3. Symptomatic early infancy 4. 7/million live births 5. Genetics: AD A. Phenotype diversity 5. Morphology A. Nomochromic B. Macrocytic C. Reticulocytopenia
Congenital hypoplastic anemia clinical features
- Anemia appears 2-6 mo (25% at birth)
- 92% dx by 1 yr old
- 40-50% pts congenital anomalies
A. Craniofacial (50%)- Snub nose
- High-arched palate
B. Skeletal (30%) - Upper limb and hand
- Thumb
A. Flat thenar eminence
B. Triphalangeal thumb
C. Absent radial pulse
D. Genitourinary (38%)
E. Cardiac (30%)
F. Ophthalmic
G. Musculoskeletal
H. Short stature common - Unsure if result of disease, therapies, or both
- Tx: limited response
A. Corticosteroids- 80% initially respond
- Dec growth
- Dec physical and cognitive dev
- Often delay use until after 1 yr
B. Transfusion
C. Hematopoietic stem cell transplant - potentially curative - Sibling donors: HLA-matched
- < or = 9 y/o to avoid iron overload
- Cancer predisposition: solid tumor/leukemia 20% by 46 y/o
Fanconi anemia (FA)
Rare multi system hereditary disorder 1. Bone marrow failure 2. Predisposition cancers A. MDS B. AML C. Epithelial cancer 3. Congenital malformations 4. 1/200,00 most populations A. Ashkenazi Jews (1/30,000) B. Afrikaners (1/22,000) 5. Carrier frequency: 1:200-300 most populations 6. Genetics: AR 7. All racial and ethnic groups
Fanconi anemia (FA) clinical features
1. Triad A. Bone marrow failure B. Congenital anomalies C. Inc chromosome fragility 2. Pancytopenia 3. Short stature 4. Microcephaly (25-37%) 5. Microphthalmia (41%) 6. Hearing loss 7. Endocrine abnormalities 8. Absent radii and thumbs 9. Dev disabilities (27%) 10. Hyperpigmentation 11. Dx: hypocellular marrow A. Check 1. Blood counts 2. Bone marrow fxn 3. Growth 4. Dev 5. Organ fxn 12. Tx: A. Primarily supportive B. Bone marrow transplant cures hematopoietic probs C. Multidisciplinary team
Di George syndrome
- Aka:
A. Velocardiofacial syndrome
B. Shprintzen syndrome
C. 22q11.2 microdeletion syndrome
Di George syndrome clinical features
1. Triad A. Conotruncal cardiac abnormalities B. Hypoblastic thymus -> dec T cells C. Hypocalcemia -> tetany or seizures w/in days after birth 2. Performance A. Normal dev/mild learning probs (62%) B. Moderate to severe learning probs (18%) C. IQ: 70-90 D. Psychiatric disorders (10%) E. Dec motor tone and axial instability (walking 16-24 mo) 3. Growth: short stature (36%) 4. Ears and hearing: conductive hearing loss 5. Craniofacial A. Cleft palate B. Velopharyngeal incompetence C. Small/absent adenoids D. Prominent, squared nose E. Narrow palpebral fissures F. Abundant scalp hair G. Deficient malar area H. Vertical maxillary xs w/ long face I. Returned mandible w/ dec chin J. Microcephaly (40-50%) 6. Limbs A. Slender and hypotonic B. Hyperextensible hands and fingers (63%) 7. Cardiac defects (85%) A. Ventricular septal defect (62%) B. Right aortic arch (52%) C. Tetralogy of fallot (21%) D. Aberrant left subclavian a.
Kawasaki disease
“Musocutanieus Lymph node syndrome” 1. Most common cause acquired heart disease in kids 2. Dr. Tomisaku Kawasaki 1967 3. More Asians 4. Cause unknown: possibly viral/bacterial pathogens 5. Coronary a. Vasculitis -> MI 6. <5 y/o (80-90%) 7. M>F (1.5:1) 8. All racial and ethnic groups 9. Winter/spring seasonal predominance 10. DDX A. Virus B. Bacteria C. Drug rxns 1. Serum sickness 2. Stevens-Johnson syndrome D. Rheumatologist disease E. Heavy metal toxicity: mercury
Kawasaki disease clinical findings
1. Dx criteria A. Fever > or = 5 days +4: 1. Polymorphous exanthem: red rash w/ several different looking parts 2. Conjunctival injection w/o exudate: sclera bright red 3. Oropharyngeal erythema, lips cracking, “strawberry tongue” 4. Extremity erythema, edema, and periungual desquamation (skin peeling) 5. Cervical lymphadenopathy > 1.5 cm (unilateral) 2. Associated findings A. Cardio (on echo) 1. Coronary a. Ectasia/aneurysms 2. Pericarditis 3. Myocarditis 4. Valvular regurgitation 5. Other aneurysms B. CNS 1. Aseptic meningitis 2. Extreme irritability C. GI 1. Hepatitis 2. Jaundice 3. Diarrhea 4. Gallbladder hydrops 5. Pancreatitis D. GU 1. Urethritis 2. Hydrocele E. MSK 1. Arthritis 2. Arthralgia F. Derm 1. Erythema at site BCG vaccination 2. Erythema w/ desquamation of groin G. Ocular: anterior uveitis H. Resp 1. Radio graphic pneumonia 2. Antecedent resp illness I. Labs 1. Anemia (normocytic, normochromatic) 2. Inc inflam markers 3. Leukocytosis w/ neutropenia and band form 4. Thrombocytosis (subacute phase) 5. Hypoalbuminemia 6. Inc serum transaminase 7. Hyperbilirubinemia J. Urine: sterile pyuria K. CSF: neutrophilic pleocytosis
Kawasaki disease tx
1. Acute A. IVIG = mainstay B. Inc dose aspirin 1-2 mo C. Tx in 1st 10 days of fever D. Delayed tx -> aneurysms E. Start after 4 days of fever 2. Long term care A. Cardiac care based on severity B. Aneurysms resolves 50% cases C. Persistent aneurysms -> stenosis -> occlusion and MI
Henoch-Schonlein Purpura (HSP)
- Unknown definitive cause
- Immune-mediated process induced by environmental factors
- Aberrant glycosylation of IgA1
A. Can’t clear immune complexes -> deposited on organs - C3 deposited w/ IgA1 -> inflammation rxn
- Risk factors
A. 90% <5 y/o
B. Peak incidence 6 y/o
C. 13-20/100,000 younger than 1 y/o
D. M > F (1.5:1) - Triggers
A. Infectious: usually URI- H. Influenzae
- Strep
- Staph
- Varicella zoster
- Epstein-Barr
- Parvovirus B19
B. Meds
C. Insect bites
D. Cold weather
E. Foods
F. Trauma
Henoch-Schonlein Purpura (HSP) clinical features
- Rash: first sign (75%)
- Joint involvement
- Glomerulonephritis
A. Hematuria
B. Proteinuria
C. Nephrotic syndrome
D. Acute nephrotic syndrome
E. HTN
F. Renal failure
G. Follow rash w/in 1-4 mo - Low grade fever
- Local angiodema
- Triad
A. Purpura
B. Arthralgia
C. Abdominal pain: w/in 1 wk cutaneous findings- Usually resolves in few days
- Intussusception: complication
Henoch-Schonlein Purpura (HSP) dx and tx
1. DDx: A. Child abuse B. Meningococcemia C. Rocky Mountain spotted fever D. Papular-purpuric gloves and socks syndrome E. SLE F. Systemic juvenile idiopathic arthritis G. Wegner granulomatosis 2. Dx: A. Mostly clinical B. Labs 1. CBC: platelet count and thrombocytopenia 2. Urinalysis: initial and follow up 3. Urine protein quantification 4. Serum creatinine: renal fxn 5. Serum albumin: hypoalbuminemia associated w/ nephrotic syndrome 3. Tx: A. Supportive care B. Fluid intake orally C. IV fluids if needed D. Rest E. Avoid strenuous exercise F. NSAIDs if no renal/GI probs G. Acetaminophen H. ACE inhibitors/angiotensin receptor blockers: persistent proteinuria I. Corticosteroids: acute phase severe joint, GI, renal involvement (consult nephrologist) 4. Monitoring A. Wks 1-4: weekly urinalysis and BP B. Wks 5-12: every other wk C. 6-12 mo: once/mo D. Stop after 1 yr if okay 5. Prognosis A. Recurrent disease: usually less bed subsequent times B. Recur w/in 4 mo 33% kids C. More common older kids and renal involvement
Intussuusception
Complication of HSP
- One segment bowel invaginates into another -> obstruction
- Bowel May “telescope”
- Abdominal ultrasound
- Mesentery compressed
- Bowel wall obstructs lumen
- Colicky abdominal pain and vomiting
- Lymphatic and venous obstruction -> ischemia
- Usually ileocecal in kids
Disorders due to vessel wall abnormalities
- Relatively common
- Mild bleeding problems
- Presentation
A. Petichiae and purpura skin and mucous membrane (gingival)
B. PT and PTT usually normal => dx of exclusion - Infections -> petichiae and purpura
A. Meningococcemia
B. Septicemia
C. Infective endocarditis
D. Risckettsioses
E. Mechanisms- Microbial vasculitis
- DIC
- Drug rxns -> cutaneous petechiae and purpura w/o thrombocytopenia
A. Deposited immune complexes in vessel walls -> hypersensitivity vasculitis - Scurvy and Ehlers-Danilo’s syndrome
A. Inc bleeding from collagen defects -> weak vessel walls
Hereditary Hemorrhagic telangiectasia
“Weber-Osler-Rendu syndrome”
1. Genetics: AD
A. Mutations 5 < or + genes modulate TGF-beta signaling
2. Presentation
A. Dilated, tortuous blood vessels w/ thin walls - bleed easily
B. Bleeding most common mucous membranes
1. Nose
2. Tongue
3. Mouth
4. Eyes
5. GI tracts
Thrombocytopenia
- Isolated thrombocytopenia: bleeding tendency w/ normal coag tests
A. If platelets 20,000-50,000 -> inc risk post-traumatic bleeding
B. <5000 plots/uL -> spont bleeding
C. CNS hemorrhage = major hazard for severe - Causes
A. Dec production
B. Inc destruction- Marrow shows inc megakaryocytes
- Immune thrombocytopenic purpura (ITP)
- Thrombotic microangiopathies
Immune thrombocytopenic purpura (ITP)
- Chronic = adults
2. Acute = kids
Chronic ITP
- Relatively common
- F>M
- 20-40 y/o
- AutoAb mediated platelet destruction
- Secondary: predisposing conditions and exposures
A. SLE
B. HIV
C. B cell neoplasms (CLL) - Primary (idiopathic): only dx after secondary excluded
Chronic ITP pathogenesis
- AutoAb directed at membrane glycoproteins IIb-IIIa of Ib
A. Most IgG - Spleen = major site opsonized platelet removal
- Antiplatelet Ab recognized by IgG Fc receptor on phagocytes -> inc destruction
Chronic ITP morphology
1. Non-specific A. Spleen normal size 1. Sinusoid congestion 2. Splenic follicle enlargement 3. Reactive germinal centers B. Bone marrow 1. Megakaryocytes 2. Used to rule out thrombocytopenia from marrow failure or other primary marrow disorders C. Peripheral smear 1. Megathrombocytes
Chronic ITP clinical features
- Insidious onset
- Petichiae
- Epitaxis
- Gum bleeding
- Hemorrhages from minor trauma
- Serious brain trauma
- Labs
A. Dec platelets
B. Normal or inc megakaryocytes in marrow
C. Large platelets in smear
D. PT and PTT normal - Dx of exclusion
- Tx: drugs
A. Dec Ab production- Splenectomy
- Corticosteroids
- Ritiximab
B. Dec platelet destruction - Splenectomy
- Corticosteroids
- IVIG
- Anti-D immune globin
C. Inc platelet production - Thrombopoietin receptor agonists (eltrombopag)
Acute ITP
Children 1. Most common thrombocytopenia in kids (1:20,000) 2. Peak age: 1-4 yrs 3. Preceding viral infection 50-65% cases 4. Classification A. No symptoms B. Mild symptoms 1. Bruising/petichiae 2. Occasional minor epitaxis 3. Little interference w/ ADL C. Moderate 1. More severe skin and mucosal lesions 2. Moderate epitaxis 3. Inc menorrhagia D. Severe 1. Bleeding episodes A. Menorrhagic B. Epitaxis C. Melena 2. Requires transfusion/hospitalization 3. Seriously interferes w/ ADL
Acute ITP pathogenesis
- AutoAb directed at membrane glycoproteins IIb-IIIa of Ib
A. Most IgG - Spleen = major site opsonized platelet removal
- Antiplatelet Ab recognized by IgG Fc receptor on phagocytes -> inc destruction
- Common viruses
- Epstein-Barr
- HIV
Acute ITP clinical features
- Sudden onset petichiae and purpura
A. “Fine yesterday” - Bleeding gums and mucous membranes (platelets <10x10^9)
- Other abnormal findings on physical exam rare
A. Should look for other disorders if found
Acute ITP tx
- Only education and counseling unless severe
A. Avoids therapeutic roller coster
B. Cheap
C. Min side effects - IVIG/corticosteroids if mucocutaneous bleeding
A. First line tx
B. Dec Fc-mediated phagocytosis
C. Expensive and time-consuming
D. ADRS- Headache
- Vomiting
- IVIG-induced aseptic meningitis
- Corticosteroids used many years
A. Prednisone : more rapid inc platelets
B. Short course until platelets >20 x 10^9
Thrombotic microangiopathies
- Widespread platelet -rich thrombi in microcirculation
- Platelet consumption -> thrombocytopenia
- Narrowing vessels -> microangiopathic hemolytic anemia
- Thrombotic thrombocytopenia purpura (TTP)
- Hemolytic uremic syndrome (HUS)
Thrombotic thrombocytopenia purpura (TTP)
- Deficiency ADAMTS13 (vWF metalloprotease)
A. Degrades high-MW multiverses of vWF
B. Dec => multiverses accumulate -> platelets activation and aggregation
C. Inherited or acquired
Hemolytic uremic syndrome (HUS)
- Normal ADAMTS13
- Associated w/ infectious gastroenteritis
A. E. Coli strain 0157: H7 - Toxin changes endothelial cell fxn -> platelet activation and aggregation
- Children and older adults highest risk
- Presentation
A. Bloody diarrhea first
B. HUS presents a few days later - Supportive care -> complete recovery
- Irreversible renal damage and death in severe cases
Bleedining disorders related to defective platelet fxns
- Several rare, inherited disorders
- Classification
A. Adhesion defects
B. Aggregation defects
C. Platelet secretion disorders- Defective release mediators platelet activation (thromboxane and granule-bound ADP)
- Bernard-Soulier syndrome
- Glanzmann thrombashenia
- Acquired defects
A. Aspirin/NSAIDs
B. Uremia
Bernard-Soulier syndrome
- Defective platelet adhesion to subendothelial matrix
- Genetics: AR
- Deficiency platelet membrane glycoprotein complex Ib (GpIb)
A. VWF receptor - Pts variable, often severe, bleeding tendency
Glanzmann thrombashenia
- Defective platelet aggregation
- Genetics: AR
- Platelets fail to aggregate in response to ADP, collagen, epinephrine, or thrombin
- Deficiency/dysfunction glycoproteins IIb-IIIa
A. Used in bridge-formation between platelets by binding fibrinogen - Bleeding other severe
Acquired coagulation disorders
- Most common
- Several factors
A. Vit K required for factors VII, IX, X, and prothrombin => deficiency -> coag defect
B. Hepatic parenchymal disease -> hemorrhagic diatheses - Disseminated intravascular coagulation (DIC)
Disseminated intravascular coagulation (DIC)
Acquired coagulation disorder
1. Complication of many disorders
2. Systemic coag activation -> thrombi throughout microcirculation
3. Platelets and coag factors consumed -> fibrinolysis activated
4. Can cause
A. Tissue hypoxia from thrombi
B. Bleeding disorder
C. Depends on
1. Fibrinolysis
2. Consumption coagulopathy: depletion elements required for homeostasis
Disseminated intravascular coagulation (DIC) pathogenesis
- Clotting
A. Intrinsic pathway: factor XII activation by surface contact, collagen, other (-) substances
B. Extrinsic: release tissue factor
C. Both -> thrombin
D. Normally limited by rapid clearance of clotting factors- Macrophages
- Liver
- Endogenous anti-coags (protein C)
- Activation fibrinolysis
- Triggered by
A. Release tissue factor or thromboplastic substances- Placenta
- Cancers (APL, adenocarcinomas)
- Gram +/- sepsis
B. Widespread endothelial damage -> release tissue factor - Expose subendothelial collagen and vWF
- Antigen-Ab complexes
- Temp extremes
- Infections
- Results
A. Inc thrombin
B. Dec inhibitory pathways that limit coag - Can result from acute intravascular hemolytic transfusion rxn
Disseminated intravascular coagulation (DIC) clinical features
- Acute = bleeding disorder
- Chronic = thrombosis
- Severity ranges
A. Minimal
B. Shock
C. Acute renal failure
D. Dyspnea
E. Cyanosis
F. Convulsions
G. Coma - Labs
A. Thrombocytopenia
B. Inc PT and PTT
C. Inc fibrin split products - Prognosis varies
- Tx: directed at underlying cause
Hereditary coagulation disorders
- Von Willebrand disease
- Hemophilia A
- Hemophilia B