Hematology Flashcards
NEJM John's Hopkins
Why use irradiated blood
Prevent graft vs. host disease
TACO vs. TRALI
(a) Main clinical distinguishing factor
TACO = transfusion-associated circulatory overload
(ex: HF pt who gets fluid overloaded w/ rapid transfusion)
(a) Distended neck veins, hypertensive
TRALI = transfusion related acute lung injury
(a) More associated w/ hypotension and no signs of fluid overload
Describe role of hepcidin in anemia of chronic disease
Increased hepcidin (made in liver as reactant to inflammation) in AOCD which decreases reutilization of Fe
Hepcidin reduces iron absorption in gut and reduces iron release from macrophages
What two types of hemolytic anemia does Coomb’s test help to distinguish?
Coomb’s test sees if antibody is directly bound to RBC surface
So positive in autoimmune hemolytic anemia, but negative in microangiopathic hemolytic anemia
Diagnostic use of platelet-function assay
Platelet function assay to measure platelet adhesion and aggregation, specifically used to test for von Willebrands disease
What bleeding abnormality should be tested for in a pt w/ severe aortic stenosis who develops mucocutaneous bleeding?
Acquired von Willebrand disease- sheer stress across AV breaks down multimers of vWF causing vWF degradation by ADAMTS13 => reduced vWF activity => increase bleeding risk similar to vWB disease
Test for this by von Willebrand factor assay (not factor activity b/c that should be normal)
Lab test to distinguish iron deficiency anemia from thalassemia
RDW- high in IDA and normal in thalssemia
Typical presentation of pt w/ lupus anticoagulant
PE or DVT- lupus anticoagulant = antibody leading to prolonged PTT causing increased risk of clotting (not increased bleeding risk)
Can have mild/moderate thrombocytopenia 2/2 platelet consumption
AIDS pt with CMV esophagitis started on IV ganciclovir- what needs to be monitored?
CBC for neutropenia
Ganciclovir frequently causes neutropenia, hepatotoxicity (all 3 cell lines can be affected) is actually a box warning for ganciclovir
First line tx for pt over 60 yoa w/ essential thrombocytopenia and plts over 1000K
Hydroxyurea (platelet lowering agent) and low-dose aspirin (reduce risk of clot)
-older age and higher plt count carry higher risk for thrombosis
Reversal agent for dabigatran
Idarucizumab (praxbind) = monoclonal Ab that binds directly to dabigatran, neutralizing its anticoagulant (direct anti-thrombin) effect in minutes
Which NOAC has reversal agent?
Only one FDA approved is idarucizumab for pradaxa (dabigatran) reversal
42 y/oM w/ worsening lethargy and intermittent confusion x1 week
Lab work:
Coombs negative hemolytic anemia
Plts 15
6 months ago- exposure to SQH
Meds: HCTZ, metformin
Most likely diagnosis?
TTP = thrombotic throimbocytopenic purpura
Classic pentad: fever, neurologic abnormalities (AMS), renal failure, thrombocytopenia, microangiopathic hemolytic anemia (so hemolyzing not b/c of autoimmune aka coombs negative)
TTP 2/2 ADAMST13 deficiency (protease that cleaves vWF multimers) => vWF multimers build up and form microthrombi and platelet activation
-erythrocytes shear as they pass through platelet-rich thrombi
Triad of findings in Paroxysmal Nocturnal Hemoglobinuria
(a) Pathogenesis
PNH = anemia, thrombosis, pancytopenia
(a) Acquired bone marrow defect, acquired mutation causing CD55/59 on RBC surface that makes them more susceptible to complement-mediated lysis
=> intravascular hemolysis
Name causes of non-immue mediated hemolytic anemia
- TTP-HUS
- PNH
- Cardiac- sheer stress across valve
- Hereditary spherocytosis
2 lab tests distinguishing beta-thalassemia trait from iron-deficiency anemia
Beta-thal: lower MCV (like in 60s) with near normal Hb (11s) and high erythrocyte count
IDA: once MCV got as low as 60s the Hb would be very low, typically see MCV in 70s
low erythrocyte count
What is a cryoglobulin?
Cryoglobulins = Antigen-antibody complexes (immunoglobulins) that precipitate at cold temps (below body temp)
Distinguish cryoglobulinemia associated w/ multiple myeloma vs. hepatitis C
Cryoglobulins = proteins (mostly immunoglobulins) that precipitate at cold temps
Monoclonal IgG cryoglobulins occur in cases of multiple myeloma
While it’s a mix of monoclonal and polyclonal IgM/G/A along w/ complement proteins (C4) seen in mixed cryoglobulinemia 2/2 chronic infections such as hepatitis C, HIV, hep B, EBV
What skin finding is typical for cryoglobulinemia vasculitis
Palpable purpura
2/2 cryoglobulin (Ag-Ab complexes) depositing in small vessels
Amyloid A vs Amyloid light chain amyloidosis
(a) Cause
Amyloid A- associated w/ underlying chronic disease: chronic infection (Tb, osteo) chronic inflammation (IBD, RA)
Amyloid light chain- plasma cell dyscrasia related to myeloma
due to monoclonal plasma cell production of light chains that deposit in tissues
Most likely diagnosis for pt who presents w/ vision changes due to hyperviscosity
Found to have WBC 13k, elevated serum IgM, bone marrow biopsy w/ plasmocytoid lymphocytes
Waldestroms macroglobulinemia = specific B cell cancer causing high levels of circulating IgM
IgM are stick => hyperviscosity causing impaired blood flow to CNS => vision changes
Plasmocytoid lymphocytes = diagnostic finding in bone marrow biopsy to distinguish from other plasma cell dyscrasias (MM, MGUS)
FFP vs. cryo
FFP has all soluble factors- use for pt w/ multiple factor deficiencies who is bleeding
Cryo is a concentrated subset of FFP, has fibriogen, vWF, factors VIII and XIII
Use in hypofibrinogen states (cirrhosis, would have to give way too much volume of FFP to replace all that fibriogen), vonWillebrand disease (if DDAVP not working or unavailable)
Main indications for cryo
Cryoprecipitate = fibrinogen, vonWillebrand factor, factors VIII and XIII
- low fibrinogen and bleeding (ex: cirrhosis)
- vonWillebrand disease and bleeding refractory to DDAVP
- hemophilia A (factor VIII deficiency) and factor VIII concentrate unavailable
Why may a pt w/ ITP have Howell-Jolly bodies?
Howell-Jolly bodies = RBC inclusions (nuclear remnants) removed in the spleen, so if present it indicates either surgical or functional asplenia
2nd line tx (after steroids) for ITP includes splenectomy and rituxan
What is acute porphyria?
(a) What causes the defect?
(b) Most common clinical features
Acute porphyria = defect in heme synthesis due to some trigger (Ex: meds) that causes protein buildup that causes neurovisceral side effects
(a) Defect in heme biosynthesis => build up of porpyrins
(b) Neuro and visceral- abdominal pain, N/V, neuropathy => weakness, numbness
