Hematology

Question 1

Why use irradiated blood

Answer 1

Prevent graft vs. host disease

Question 2

TACO vs. TRALI

(a) Main clinical distinguishing factor

Answer 2

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

Question 3

Describe role of hepcidin in anemia of chronic disease

Answer 3

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

Question 4

What two types of hemolytic anemia does Coomb’s test help to distinguish?

Answer 4

Coomb’s test sees if antibody is directly bound to RBC surface

So positive in autoimmune hemolytic anemia, but negative in microangiopathic hemolytic anemia

Question 5

Diagnostic use of platelet-function assay

Answer 5

Platelet function assay to measure platelet adhesion and aggregation, specifically used to test for von Willebrands disease

Question 6

What bleeding abnormality should be tested for in a pt w/ severe aortic stenosis who develops mucocutaneous bleeding?

Answer 6

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)

Question 7

Lab test to distinguish iron deficiency anemia from thalassemia

Answer 7

RDW- high in IDA and normal in thalssemia

Question 8

Typical presentation of pt w/ lupus anticoagulant

Answer 8

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

Question 9

AIDS pt with CMV esophagitis started on IV ganciclovir- what needs to be monitored?

Answer 9

CBC for neutropenia

Ganciclovir frequently causes neutropenia, hepatotoxicity (all 3 cell lines can be affected) is actually a box warning for ganciclovir

Question 10

First line tx for pt over 60 yoa w/ essential thrombocytopenia and plts over 1000K

Answer 10

Hydroxyurea (platelet lowering agent) and low-dose aspirin (reduce risk of clot)

-older age and higher plt count carry higher risk for thrombosis

Question 11

Reversal agent for dabigatran

Answer 11

Idarucizumab (praxbind) = monoclonal Ab that binds directly to dabigatran, neutralizing its anticoagulant (direct anti-thrombin) effect in minutes

Question 12

Which NOAC has reversal agent?

Answer 12

Only one FDA approved is idarucizumab for pradaxa (dabigatran) reversal

Question 13

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?

Answer 13

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

Question 14

Triad of findings in Paroxysmal Nocturnal Hemoglobinuria

(a) Pathogenesis

Answer 14

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

Question 15

Name causes of non-immue mediated hemolytic anemia

Answer 15

1. TTP-HUS
2. PNH
3. Cardiac- sheer stress across valve
4. Hereditary spherocytosis

Question 16

2 lab tests distinguishing beta-thalassemia trait from iron-deficiency anemia

Answer 16

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

Question 17

What is a cryoglobulin?

Answer 17

Cryoglobulins = Antigen-antibody complexes (immunoglobulins) that precipitate at cold temps (below body temp)

Question 18

Distinguish cryoglobulinemia associated w/ multiple myeloma vs. hepatitis C

Answer 18

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

Question 19

What skin finding is typical for cryoglobulinemia vasculitis

Answer 19

Palpable purpura

2/2 cryoglobulin (Ag-Ab complexes) depositing in small vessels

Question 20

Amyloid A vs Amyloid light chain amyloidosis

(a) Cause

Answer 20

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

Question 21

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

Answer 21

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)

Question 22

FFP vs. cryo

Answer 22

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)

Question 23

Main indications for cryo

Answer 23

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

Question 24

Why may a pt w/ ITP have Howell-Jolly bodies?

Answer 24

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

Question 25

What is acute porphyria?

(a) What causes the defect?
(b) Most common clinical features

Answer 25

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