Flashcards in Hematology - General Deck (55):
What are three tests for HIT?
1. Serotonin-release assay (gold standard)
2. Heparin-induced aggregation
3. HIT antibody
Name three indications for Erythropoietin
1. CKD especially Hgb < 10, not more than 12
2. HIV especially Epo < 500
3. Autologous blood donation
What treatment (3) is used for Autoimmune Aplastic Anemia, and why is it effective?
1. Antithymocyte globulin - horse- or rabbit-derived antibodies against T cells
2. Cyclosporine - interferes with T cell activity
3. BMT for < 50 years with HLA-matched siblings
***These target interferon-activated T lymphocytes and prevents transfusion requirements in 70-80% of patients
What type of platelets should be used in patients with aplastic anemia and why?
Single-donor apheresis platelets (rather than pooled multiple-donor platelets)
What is the genetic rearrangement in CML?
t(9;22) or the Philadelphia chromosome
What is the alternative treatment (3) to Imatinib in treating CML?
3. +/- Cytarabine
Name three most common causes of SECONDARY Erythrocytosis
1. Arterial Hypoxemia
a. High altitude
b. Chronic lung disease
c. Cyanotic heart disease
2. Impaired O2 delivery
3. Tumors (renal, adrenal, bronchial, hepatic...)
1. What diagnostic test can be performed for Polycythemia Vera? Describe the pathophysiology.
2. What other pathology does it suggest (2)?
3. What serologic lab is low with Polycythemia Vera?
1. JAK2 - heightened sensitivity to erythropoietin
2. a. Essential Thrombocythemia
b. Primary Myelofibrosis
What type of bone imaging is not helpful in Multiple Myeloma, and why?
Bone Scans - lytic lesions are primarily osteoclast rather than osteoblast
What are treatment options for Multiple Myeloma (5)?
1. AUTO-logous Stem Cell Transplant < 65
2. Bortezomib - PI, pre-HSCT
3. Melphalan - alkylators
5. Corticosteroids adjunct
**No treatment if asymptomatic
If an aPTT or PT is abnormally long, what is the next test that should be performed?
1. Mixing study - patient plasma with normal plasma --> clotting times
*if normal, then factor deficiency
*if still abnormal, then clotting inhibitor
What are the three Antiphospholipid antibodies?
1. Lupus anticoagulant
1. What is the pathophysiology behind Factor V Leiden deficiency?
2. What is the increased frequency of VTE with OCP?
1. Resistance to activated Protein C
What is the pathophysiology behind the Prothrombin mutation
Increased activity of Prothrombin by 30%
In addition to PT/PTT, what should be tested in patients under 50yo who have their first venous thromboembolic event (3)?
2. Protein C
3. Protein S
Which anticoagulation alternative is metabolized in the kidneys? In the liver?
Renal = Lepirudin
Hepatic = Argatroban
How does Fondaparinux work?
What is the pathogenesis for von Willebrand disease? Give examples of clinical manifestations (5).
Deficiency of vWF causes failure of platelets to adhere to sites of vascular damage and leads to accelerated platelet clearance and:
- easy bruising
- bleeding gums
- heavy menses
What are treatment options for Idiopathic Thrombocytopenic Purpura (5)?
1. Prednisone 1 mg/kg/d
2. anti-D immunoglobulin
3. Immunoglobulin infusion
Describe the two variants of HUS
1. Post-enteric infection
- mostly children
- bloody diarrhea after Verotoxin-producing E. Coli (O157:H7)
- mostly adults, usually postpartum
- no diarrhea
What is seen on blood smears for uremic patients?
Ecchinocytes = burr cells
What is a integumental physical exam finding in iron deficiency anemia?
Koilonychia - spoon nails
What is the pathophysiology of Pernicious Anemia?
Deficiency of Intrinsic Factor due to anti-parietal cell and anti-IF antibodies, thus poor B12 (cobalamin) absorption
What are the irreversible neurologic features of B12 deficiency (3)?
1. Loss of vibratory sense
2. Spastic ataxia
1. What labs are high with isolated B12 deficiency?
2. What labs are high with isolated folate deficiency?
1. Methylmalonic acid -and- Homocysteine
2. ONLY homocysteine
What labs are characteristic of hemolytic anemia (5)?
1. Elevated unconjugated bilirubin
2. Elevated LDH
3. Elevated uric acid
4. Elevated reticulocyte count
5. Decreased haptoglobin
1. Describe the pathogenesis of WARM-antibody mediated Autoimmune Hemolytic Anemia.
2. How is it tested?
3. How is it treated?
1. a. IgG binds Rh-antigens on RBC >37C
b. Destruction by splenic macrophages
2. Direct antiglobulin (Coombs' test)
3. Steroids or splenectomy
1. Describe the pathogenesis of COLD-antibody mediated Autoimmune Hemolytic Anemia.
2. How is it tested?
3. How is it treated?
1. a. IgM binds to RBC below 37C
b. Complement fixation
c. Destruction by intravascular hemolysis (clumping and agglutination seen in peripheral smear)
2. Peripheral smear
3. a. Warm environment
b. Alkalating agents or Rituximab
****NOT steroids or splenectomy
What chronic diseases are associated with Hemochromatosis (3)?
3. Liver failure/cirrhosis
What diagnostic tests are used for Hemochromatosis (3)?
1. Transferrin saturation >60% men >50% women
2. Ferritin > 1000
3. Liver biopsy
What is the goal for phlebotomy in treatment of Hemochromatosis?
Ferritin < 50 micrograms/L
1. What is missing in Hemophilia A?
2. What is missing in Hemophilia B?
3. Which coagulation test is abnormal?
1. Factor VIII
2. Factor IX
3. aPTT because INTRINSIC pathway
1. What labs are abnormal with DIC (4)?
2. How is it treated (2 options)?
1. Elevated d-dimer
2. Prolonged PT
3. Decreased Fibrinogen
4. Decreased Factor VI and VIII
**Fresh Frozen Plasma for factors
***Cryoprecipitate for Fibrinogen
Which monoclonal antibody is used for Paroxysmal Nocturnal Hemoglobinuria?
What lab distinguishes Iron Deficiency Anemia from Chronic Inflamation?
Iron Deficiency Anemia has
* Iron very low, especially < 25
* Ferritin < 100, especially < 10
Which drug used to treat Sickle Cell Disease is contraindicated in pregnancy?
1. Which hematologic disorder is DDAVP used to treat?
2. How does it work?
1. VonWillebrand Factor Deficiency (and Factor VIII Deficiency or mild Hemophilia A)
2. Induces release of intrinsic vWF
In addition to Aspirin, what treatment decreases the risk for stroke in patients with Sickle Cell Anemia?
What is the differential for microspherocytes (3)?
1. Hereditary Spherocytosis
2. Microangiopathic Autoimmune Hemolytic Anemia (HUS/TTP)
What is the differential for target cells (5)?
1. Iron Deficiency
2. HbC Disease
4. Liver Disease
***Mnemonic = I-HALT
How do the smears of Intravascular Hemolysis differ from Extravascular Hemolysis?
Intravascular - fragmented RBC
Extravascular - spherocytes
What are smudge cells indicative for?
B-Cell Chronic Lymphocytic Leukemia
With a moderately high risk of DVT (via Well's Criteria for DVT) what should be done after negative duplex ultrasound?
Repeat duplex in 5-7 days
What are two populations that should not receive Low Molecular Weight Heparin?
1. Obese patients
2. Renal insufficiency
What is the duration of treatment for:
1. First VTE
2. Recurrent VTE
3. Antiphospholipid Ab or 2 mutations
1. First VTE:
*reversible risk factor = 3 months
*idiopathic or nonreversible >=3 months
2. Recurrent VTE = lifelong
3. Antiphospholipid Ab or 2 mutations = lifelong
1. What are the two Microangiopathic Hemolytic Anemias?
2. How are they similar?
3. How are they distinct?
1. Thrombotic Thrombocytopenic Purpura
More CNS involvement
Deficiency of ADAMTS13 - decreased vWF
2. Hemolytic Uremic Syndrome
More renal impairment
***Both are MAHA and thrombocytopenias
1. What is the genetic inheritability of vWF?
2. What is also carried by vWF?
3. What are two abnormal coags in vWF?
1. Autosomal dominant
2. Factor VIIIc
3. Prolonged aPTT (because decreased Factor VIII)
1. What is the difference between ITP and TTP?
2. How are ITP and TTP treated differently?
1. a. ITP = failure of the blood to clot
b. TTP = platelets excessively aggregate and hemolyze/fragment RBC leading to MAHA
2. a. ITP = IVIG and steroids
b. TTP = plasma exchange removes inhibitors of ADAMTS13 +/- steroids
1. What are the features of TTP?
2. What is the pathophysiology of TTP?
3. How is it treated and why?
4. What should not be used and why?
b. Anemia from MAHA
d. Renal Impairment
e. Nervous System Abnl: HA, AMS, seizures
2. Antibodies againts ADAMTS13 causes excessive platelet aggregation, leading to hemolysis (fragmentation) of RBC
3. Plasma exchange to remove antibodies to ADAMTS13 and large vWF multimers
4. Platelet transfusion because can worsen thrombosis
What does the CBC with differential compare between Thalassemia and Iron Deficiency?
1. MCV less 75
2. MCV/RBC-count less than 13
3. RDW variable
Iron Deficiency with:
1. MCV NO-LESS than 80
2. MCV/RBC-count more than 13
3. RDW elevated
1. What are risk factors for Acquired Hemophilia (3)?
2. What two serologic tests help confirm this?
3. What is treatment, and how does it work?
1. a. Postpartum (pregnancy)
c. Autoimmune disorders
2. a. Isolated aPTT prolongation
b. Mixing study without full correction, suggests inhibitor
3. Factor VIII concentrate which activates Factor X independent of the intrinsic pathway
What special serologic tests is diagnostic for Beta-Thalassemia?
Hemoglobin electrophoresis with HbA2
What are the two diagnostic criteria of Essential Thrombocytosis?
1. Plt greater 600,000 x 2 (separated by 1m)
2. BM with hypercellular marrow with abnormal megakaryocytic hyperplasia
1. In general, what is Paroxysmal Nocturnal Hemoglobinuria?
2. What are key features (3)?
3. How is it diagnosed?
1. Acquired stem cell disorder
2. a. Unprovoked VTE at unusual location
b. Hemolytic anemia
3. Flow-cytometry for CD55 and CD59