Hematology Flashcards
1
Q
Most common laboratory abnormality during childhood
A
Anemia
2
Q
Microcytic, hypochromic anemias
A
- Iron deficiency
- Thalassemia
- Sideroblastic anemia
- Lead toxicity
- Chronic disease
3
Q
Macrocytic anemias
A
- Vitamin B12 deficiency
- Thiamine deficiency
- Folate deficiency
4
Q
Normocytic, normochromic anemias with high reticulocyte count
A
- Hemangioma
- DIC
- Hemolytic anemias
- Sickle cell disease
- Blood loss
5
Q
Normocytic, normochromic anemias with low reticulocyte count
A
- Red cell aplasia
- Malignancy
- Fanconi anemia
6
Q
Hemolytic anemias due to intrinsic RBC defects
A
- RBC membrane disorders: hereditary spherocytosis, hereditary elliptocytosis
- RBC enzyme disorders: G6PD deficiency, pyruvate kinase deficiency
7
Q
Hemolytic anemias due to extrinsic RBC defects
A
- HUS
- Autoimmune
- Alloimmune
8
Q
Red cell aplasias
A
- TEC
- Diamond-Blackfan syndrome
- Parvovirus B19 infection
9
Q
Occult blood loss with resultant iron deficiency may be secondary to
A
- Polyps
- Meckel’s diverticulum
- Inflammatory bowel disease
- Peptic ulcer disease
- Early ingestion of whole cow’s milk before 1 year of age
10
Q
Clinical features of beta thalassemia major
A
- Hemolytic anemia
- Hepatosplenomegaly
- Bone marrow hyperplasia in sites that results in a characteristic thalassemia facies (frontal bossing, maxillary hyperplasia with prominent cheekbones and skill deformities)
11
Q
What can beta thalassemia minor be easily misdiagnosed as
A
Iron deficiency anemia, however iron level is normal or elevated in these patients
12
Q
Sideroblastic anemia
A
- Ringed sideroblasts in the bone marrow
- Result from the accumulation of iron in the mitochondria of RBC precursors
- Acquired as a result of drugs or toxins (isoniazid, alcohol, lead poisoning, chloramphenicol)
13
Q
Clinical features of vitamin B12 deficiency
A
- Anorexia
- Smooth red tongue
- Neurologic manifestations (ataxia, hyporeflexia, positive Babinksi)
14
Q
Clinical features of hereditary spherocytosis
A
- Splenomegaly by 2-3 years of age
- Pallor
- Weakness
- Pigmentary gallstones
- Aplastic crises (most commonly associated with parvovirus B19)
15
Q
Clinical features of hereditary elliptocytosis
A
- Most patients asymptomatic
- 10% have jaundice at birth
- Splenomegaly
- Gallstones
16
Q
Inheritance pattern of hereditary spherocytosis and hereditary elliptocytosis
A
Autosomal dominant
17
Q
Pyruvate kinase deficiency
A
- Autosomal recessive
- Decreased production of PK isoenzyme leading to ATP depletion and decreased RBC survival
18
Q
Clinical features of pyruvate kinase deficiency
A
- Pallor
- Jaundice
- Splenomegaly
- Kernicterus in neonates
19
Q
Laboratory findings of pyruvate kinase deficiency
A
- Varying degrees of anemia
- Blood smear showing polychromatic RBCs
20
Q
Most common RBC enzymatic defect
A
Glucose-6-phosphate dehydrogenase deficiency
21
Q
Types of autoimmune hemolytic anemia
A
- Primary: generally idiopathic; viral infections and occasionally drugs
- Secondary: underlying disease process, such as lymphoma, SLE, immunodeficiency disease
22
Q
Fulminant acute type AIHA
A
- Infants and young children
- Preceeded by a respiratory infection
- Acute onset of pallor, jaundice, hemoglobinuria and splenomegaly
- Complete recovery is expected
23
Q
Prolonged type AIHA
A
- Protracted and high mortality
- Underlying disease is frequently present
24
Q
Types of alloimmune hemolytic anemias
A
- Rh hemolytic disease
- ABO hemolytic disease
25
Etiology of microangiopathic hemolytic anemia
- Severe hypertension
- Hemolytic uremic syndrome
- Artificial heart valves
- Giant hemangioma
- Disseminated intravascular coagulation
26
Leading cause of death in patients with sickle cell disease
Infection - up to 30% of patients develop sepsis or meningitis in the first 5 years of life
27
Preventative care in sickle cell disease
- Hydroxyurea - decreases incidence of vasoocclusive crises
- Daily oral penicillin prophylaxis is started in the first few months of life to decrease the risk of S pneumonia infection
- Daily folic acid is given to prevent deficiency
- Routine immunizations
- Serial transcranial Doppler ultrasound or magnetic resonance angiography is recommended beginning at 2 years to identify patients at risk for stroke
28
Long term complications of sickle cell disease
- Delayed growth and puberty
- Cardiomegaly
- Hemochromatosis
- Cor pulmonale
- Gallstones
- Poor wound healing
- Avascular necrosis of the femoral and humeral heads
- Diminished cognition and school performance
29
Pancytopenia
Bone marrow failure with decreased RBCs, leukocytes and platelets
30
Congenital aplastic anemia/ Fanconi anemia
- Autosomal recessive
- Onset of bone marrow failure occurs at mean age of 7 years
- Typical presentation is with ecchymosis and petechiae
- Skeletal abnormalities, which include short stature is almost all patients, and absence or hypoplasia or the thumb and radius
- Skin hyper pigmentation
- Renal abnormalities
31
Laboratory findings of Fanconi anemia
- Pancytopenia
- RBC macrocytosis
- Low reticulocyte count
- Elevated HbF
- Bone marrow hypocellularity
32
Etiologies of acquired aplastic anemia
- Drugs: sulfonamides, anticonvulsants, chloramphenicol
- Infections: HIV, EBV, CMV
- Chemicals
- Radiation
- Idiopathic
33
Appropriate polycythemia may be caused by chromic hypoxemia as a result of
- Cyanotic congenital heart disease (most common cause of polycythemia in childhood)
- Pulmonary disease
- Residence at high altitudes
34
Inappropriate polycythemia may be caused by
- Benign and malignant tumors of the kidney, cerebellum, ovary, liver and adrenal glands
- Excess hormone production (corticosteroids, growth hormone, androgens)
- Kidney abnormalities (hydronephrosis)
35
Clinical features of polycythemia
Ruddy facial complexion and normal sized liver and spleen
36
Phlebotomy is used to keep the hematocrit under what in polycythemia
60%
37
Relative polycythemia
Apparent increase in RBC mass caused by a decrease in plasma volume. Most commonly caused by dehydration.
38
Describe severe, moderate and mild forms of Hemophilia A
- SEVERE: spontaneous bleeding (<1% factor VIII protein activity)
- MODERATE: bleeding only with trauma (1-5% factor VIII protein activity)
- MILD: bleeding only after surgery or major trauma (>5% factor VIII protein activity)
39
Describe types of von Willebrand's disease
- Type I: classic type, mild quantitative deficiency of vWf and factor VIII protein; most common form
- Type II: qualitative abnormality in vWf
- Type III: absence of vWf; most severe type
40
Laboratory findings of von Willebrand's disease
- Prolonged BT and aPTT may be present, but not always (they are always present in type III disease)
- Quantitative assay for vWf antigen and activity (ristocetin cofactor assay) are diagnostic
41
Hemorrhagic disease of the newborn
Special type of vitamin K deficiency. It may occur EARLY (within 24 hours after birth), within the first week of life (CLASSIC form), or LATE (1-3 months after birth)
42
Laboratory findings of liver disease
- Same as those seen in DIC
- Prolonged PT and aPTT
- Increased fibrin degradation products
- Thrombocytopenia
43
Disorders of blood vessels
- These diseases affect the integrity of blood vessels and may present with bleeding
- Henoch-Schonlein purpura
- Hereditary hemorrhagic telangiectasia
- Scurvy
- Inherited disorders of collagen synthesis
- Malnutrition and corticosteroids
44
Henoch-Schonlein purpura
- IgA mediated vasculitis
- Presents with palpable purport on the lower extremities and buttocks, renal insufficiency, arthritis and abdominal pain
- Platelet count is normal
45
Hereditary hemorrhagic telangiectasia
- Autosomal dominant
| - Characterized by locally dilated and tortuous veins and capillaries of the skin and mucous membranes
46
Most common cause of bleeding
Thrombocytopenia
47
Quantitative platelet disorders that involve decreased platelet production
- Wiskott-Aldrich syndrome
| - Thrombocytopenia-absent radius syndrome
48
Quantitative platelet disorders that involve increased platelet destruction
- Immune thrombocytopenic purpura
- Neonatal immune-mediated thrombocytopenia
- Drugs, DIC and enlarged spleen
- Hemolytic uremic syndrome
- Large hemangioma
49
Qualitative platelet disorders
- Glanzmann's thrombasthenia
- Bernard-Soulier syndrome
- Drugs (aspirin, valproate), uremia, severe liver disease
50
Wiskott-Aldrich syndrome
- X linked
- Thrombocytopenia with unusually small platelets
- Eczema
- Defects in T and B cell immunity
51
Thrombocytopenia-absent radius syndrome
- Autosomal recessive
- Thrombocytopenia
- Limb abnormalities (absence of radius, but THUMB is present)
- Cardiac and renal disease
- Thrombocytopenia improves in second or third year of life
52
Most commonly acquired platelet abnormality in childhood
Immune thrombocytopenic purpura
53
Etiology of ITP
- Viral
- Drug induced
- Idiopathic
54
Pathophysiology of ITP
Because ITP often follows a viral infection, it is thought that the virus triggers antibodies that cross react with platelets, causing their destruction and removal by the spleen
55
Clinical features of ITP
Illness typically occurs 1-4 weeks after a viral infection. It begins abruptly with cutaneous bleeding (e.g. petechiae, bruising) or mucous membrane bleeding (e.g. epistaxis, gum bleeding). Internal bleeding into the brain (occurs in <1%), kidneys or GI tract may occur but is rare.
56
Laboratory findings of ITP
Studies reveal thrombocytopenia and a blood smear showing few large "sticky" platelets
57
Management of ITP
- Supportive care
- IVIG or corticosteroids for low platelets
- 2nd line: Anti-D immunoglobulin - binds to erythrocyte D antigen on RBCs and allows them to be preferentially cleared by the spleen, allowing platelets to escape destruction
- Platelet transfusions are generally avoided because transfused platelets are rapidly destroyed
58
Passive autoimmune thrombocytopenia vs isoimmune thrombocytopenia of the neonate
- PASSIVE - mother has ITP and antibodies against her own platelets cross the placenta and destroy the fetus's platelets; mom has thrombocytopenia
- ISOIMMUNE - occurs when mother produces antibodies against her fetus's platelets as a result of sensitization to an antigen that her own platelets lack; mom does not have thrombocytopenia
59
Kasabach-Merritt syndrome
Characterized by an enlarging hemangioma, microangiopathic hemolytic anemia, thrombocytopenia and consumptive coagulopathy
60
Inherited coagulation abnormalities leading to hypercoagulability
Deficiencies of proteins C or S or antithrombin III or mutations in factor V (factor V Leiden)
61
Protein C deficiency
A vitamin K dependent factor that is the most potent anticoagulant protein known. Inheritance may be either AR or AD.
62
Clinical features of protein C deficiency
- HOMOZYGOTES: no protein C activity and are detected soon afar birth; PURPURA FULMINANS (nonthrombocytopenic purport) is often the initial presentation; characterized by fever, shock and rapidly spreading skin bleeding and IV thrombosis
- HETEROZYGOTES: present later with deep venous or CNS thrombosis
63
Most common cause of neutropenia during childhood
Infections may all suppress the bone marrow, marginate neutrophils or exhaust marrow reserves resulting in neutropenia:
- Viruses (HIV, CMV, EBV, hepatitis A and B, influenza A, parvovirus B19)
- Bacteria (typhus, rocky mountain spotted fever)
- Protozoan (malaria)
64
Chronic benign neutropenia of childhood
Common cause of neutropenia in children younger than 4 years, refers to a group of acquired and inherited disorders with NONCYCLIC neutropenia as the only abnormality. In most, resolves spontaneously within months to years.
65
Clinical features of chronic benign neutropenia of childhood
- Variable course
- Most children have increased incidence of mild infections (otitis media, sinusitis, pharyngitis, and cellulitis)
- Severe infections may occur but are uncommon
- Children are otherwise healthy with normal appearance and growth
66
Laboratory findings of chronic benign neutropenia of childhood
- Low ANC
- Normal or slightly low WBC
- Bone marrow demonstrates immature neutrophil precursors (development of mature neutrophils is arrested)
67
Severe congenital agranulocytosis/ Kostmann syndrome
Autosomal recessive disorder with frequent and life threatening pyogenic bacterial infections beginning in infancy. ANC usually less than 300.
68
Chediak-Higashi syndrome
- Autosomal recessive
- Oculocutaneous albinism
- Large blue gray granules in the cytoplasm of neutrophils
- Neutropenia
- Blond or brown hair with silver streaks
- Patients are at high risk for serious infection
69
Cartilage-hair hypoplasia syndrome
- Autosomal recessive
- Short stature
- Immunodeficiency
- Fine hair
- Neutropenia
70
Schwachmann-Diamond syndrome
- Exocrine pancreatic insufficiency with malabsorption
- Short stature caused by metaphyseal chondrodysplasia
- Neutropenia
- Failure to thrive and recurrent infections (esp otitis media) are common
