UWorld Heme/Onc Flashcards
This is a lymphoplasmocytic malignancy characterized by the excessive production of monoclonal IgM antibody
Waldesnstrom macroglobulinemia
Bone marrow biopsy in Waldenstrom macroglobulinemia
->10% clonal B cells
What are common consequences of elevated serum IgM in patients with Waldenstrom macroglobulinemia?
- Hyperviscosity syndrome
- neuropathy
- cryoglobulinemia
Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder driven by the abnormal fusion of what genes on what chromosomes?
-This gene causes leukomogenesis due to what constitutively enzyme?
- BCR-ABL (translocation between chromosomes 9 and 22)
- Tyrosine kinase (first line treatment tyrosine kinase inhibitors such as imatinib)
main lab finding in CML
dramatic leukocytosis (often > 100,000)
Mutation in Polycythemia vera?
JAK2
Treatment of Polycythemia vera?
- Phlebotomy
- Hydroxyurea (If increased risk of thrombus)
For patients with a DVT/PE and on warfarin, the warfarin dose is typically adjusted to achieve a therapeutic INR values of what?
between 2 and 3
Clinical features of Thrombotic thrombocytopenia purpura (TTP)
- Hemolytic anemia (Increased LDH, decreased haptoglobin) with schistocytes
- Thrombocytopenia (high Bleeding time, normal PT/PTT)
- Sometimes: renal failure, neurologic, fever
Pathophys of TTP
low ADAMTS13 –> uncleaved vWF multimers –> platelet trapping and activation
Management of TTP
- Plasma exchange
- Glucocorticoids
- Rituximab
- Thrombocytopenia
- microangiopathic hemolytic anemia
- renal insufficiency
- neurologic changes
- fever
- Classic pentad of what
TTP
what lab values are due to microangiopathic hemolytic anemia
-high indirect bilirubin, AST/ALT, LDH
Evidence of thrombocytopenia and microangiopathic hemolytic anemia should always raise suspicion for TTP . . what is a crucial test in the diagnostic workup?
What would it show?
- Peripheral blood smear
- signs of intravascular hemolysis (e.g. schistocytes, helmet cells, triangle cells)
how to diagnose Chronic lymphocytic leukemia?
- Severe lymphocytosis and smudge cells
- flow cytometry
- lymph node and bone marrow biopsy NOT generally needed
This is caused by autoantibodies to platelet factor 4 (PF4) complexed with heparin and is characterized by thrombocytopenia, arterial or venous thrombosis, and necrotic skin lesions at heparin injection sites within 5-10 days of therapy
Heparin-induced thrombocytopenia (HIT)
Most patients with Factor V leiden have an autosomal dominant point mutation in the gene for factor V that makes it unable to respond to what?
activated protein C, an innate anticoagulant
PT and activated PTT times in Factor V leiden
-Can be normal as the major procoagulant effects are due to continued thrombin formation
Lab findings in Acute myeloid leukemia
- Cytopenias (leukocytes may be up, normal, or down)
- Elevated LDH
- Peripheral smear - usually myeloblasts with Auer rods
One unique type of AML is APML, which is characterized by life threatening coagulopathy due to what?
-DIC (prolonged PT/active PTT, HYPOfibrinogenemia)
Anaphylactive reactions to transfused blood products are characterized by rapid onset (within seconds to minutes) of respiratory distress and hypotension, which quickly progress to respiratory failure and shock. Individuals with what are at increased risk and why?
-IgA deficiency due to the presence of anti-IgA antibodies
- Bone marrow transplant in HLA-matched siblings
- Skin (maculopapular rash involving palms, soles, and face)
- intestine (blood-positive diarrhea)
- Abnormal liver function tests and jaundice
- What is the disease and pathophysiology?
- Graft-versus-host disease
- Activation of DONOR T lymphocytes
What are the clinical signs of type 2 heparin induced thrombocytopenia
Suspected with heparin exposre > 5 days and any of the following:
- Platelet count reduction >50% from baseline
- Arterial or venous thrombosis
- Necrotic skin lesions at heparin injection sites
- Acute systemic anaphylactoid reactions after heparin
What is the diagnostic evaluation in type 2 heparin-induced thrombocytopenia?
- Serotonin release assay: Gold standard confirmatory test
- Start treatment in suspected cases prior to confirmatory tests
Therapy in type 2 heparin induced thrombocytopenia
- Stop ALL heparin products
- Start a direct thrombin inhibitor (e.g. argatroban) or fondaparinux (synthetic pentasaccharide)
Describe the use of warfarin in HIT
- Warfarin is used for anticoagulation maintenance in patients with HIT but only after the patient has received another anticoagulant and the platelet count is >150k.
- Initial treatment with warfarin is contraindicated in patients with HIT as it rapidly lowers protein C levels, which may transiently increase the risk of thrombus